Issuu

MAGAZINE NO. 3 – SPRING 2021

Mineral and vitamin

supplementation in reptile nutrition

About piranhas in aquarium (and not only there)

Herbs

in fish nutrition

Dear Readers, here’s the third issue of Tropical EDU Magazine. Our authors did their best to prepare interesting and informative articles, just in time for the still chilly spring evenings. You’ve probably noticed long ago that our hobbies – I’m talking about aquarium and terrarium hobby – make us involuntarily, and a little bit unintentionally, delve into very different fields of science. We learn not only the requirements of our pets, but also where they live in the wild, what they feed on and what their behaviors are. We arrange aquariums and terrariums for them. We explore technical issues: water filtration, heating, lighting, humidification, etc. And finally, sometimes out of necessity and sometimes prophylactically, we learn how to help them when they get sick. I hope that articles prepared by our team will be another spark igniting your passions. Enjoy the reading. I wasn’t prepared for the passion, I wasn’t looking for it. I didn’t notice as it approached and set a trap for me (...) Little did I know that true passion tolerates no concessions or compromises, no half-measures, no substitute solutions. It enters your life abruptly like an intruder and arranges the reality according to its very own rules... Wojciech Jagielski “Trębacz z Tembisy” (“Trumpeter from Trembisa. Road to Mandela”) Aleksandra Kwaśniak-Płacheta Chief editor

Chief editor: Aleksandra Kwaśniak-Płacheta, PhD Leading editor: Paweł Czapczyk, PhD DTP: Marek Kantor Publisher: Tropical Tadeusz Ogrodnik Cover photo: Shutterstock

CONTENTS – TROPICAL EDU MAGAZINE NO. 3 Herbs in fish nutrition – Aleksandra Kwaśniak-Płacheta, PhD

About piranhas in aquarium – and not only there (part 1) – Paweł Czapczyk, PhD 14 The Brazilian-Bolivian borderland closed in a glass (part 2) – Kamil Hazy 20 Marine fish for beginner aquarists (part 2) – Bartłomiej Stańczyk 28 Rules of proper supplementation in reptile nutrition – Dawid Krótki 40

HERBS

IN FISH NUTRITION

Aleksandra KWAŚNIAK-PŁACHETA, PhD Hydrobiologist, expert on feeding and breeding of ornamental fish, aquarium enthusiast. A highly recognized speaker of many aquarium training courses and symposiums. Author of articles published in domestic and foreign magazines including ”Nasze Akwarium”, ”Magazyn Akwarium”, ”Planeta Zwierząt”, ”Tanganika”, ”Fauna & Flora”, ”Pet Market”, ”Aquafeed Magazine”, ”Pet Worldwide” and various publications of Wrocław Aquarium Association.

Herbal medicine (or phytotherapy) is a type of treatment that uses plants. The first documented reports of human use of herbs to treat various ailments date back five thousand years. However, it can be assumed that people had used the beneficial properties of plants to help them with numerous conditions much earlier. People had been gathering this knowledge and passing it on to the next generations and with time they started to write it down. The Sumerians recorded their prescriptions and infor-

tha sp.), aloe (Aloe vera) and greater celandine (Cheli-

mation about medicinal plants in cuneiform script on

donium majus).

clay tablets. The oldest Chinese herbarium (Pent-Sao

The most prominent ancient physician and expert on

book) dates back to the XXVIII century BC. It contains

plant medicines was Hippocrates of Kos (460-377 BC).

descriptions of plant remedies (juices, infusions, de-

Another one was Dioskurides (1st century BC). Some

coctions, powders, ointments and wines). In Egypt,

of the herbs he described are still used today – e.g.

information about herbs has survived on temple walls

chamomile (Matricaria chamomilla), valerian (Vale-

and papyri. Ebers papyrus seems particularly interest-

riana officinalis), comfrey (Symphytum officinale) or

ing. This more than 20-metre-long scroll was written

lemon balm (Melissa officinalis). In the 2nd century AD,

down around 1550 BC. It contained almost 800 re-

Galen introduced various forms of medicines made

cipes for medicines, which were mainly based on plant

from fresh or dried herbs.

materials, including garlic (Allium sativum), mint (Men-

Alkaloids give the plant a bitter taste, which is probably to protect it from eating by animals. Some animals, by eating plants rich in alkaloids, acquire poisonous properties, which protects them from attack by predators. Many alkaloids are used in medicine. The most popular include: ephedrine (among other things, increases metabolism, stimulates the heart muscle and respiratory center), quinine (analgesic and antipyretic effects, and also deadly for malarial spores), codeine (cough suppressant), caffeine (reduces the feeling of sleepiness and fatigue, speeds up heart rate), theine (regulates intestinal movements and relieves pain). Phenols are strong antimicrobial agents, found in oak bark, fruit, Ketapang leaves, chicory, and elderberry, arnica, and others. Flavonoids are colourful compounds found in almost all plants. Their main groups are yellow flavones and colored anthocyanins (their color changes from orange, through purple, to violet – depending on the pH of the cell sap). They protect the plant from insects and fungi. They are strong antioxidants. Tannins are compounds of varying chemical composition, very common in plant tissues, but generally found in low concentrations. They protect plants against pests and pathogens (bacteria, fungi, viruses). The best known is a common tannin, which is found in very high amounts in Ketapang leaves and oak bark. We experience the tart taste of tannin every day when drinking our tea. The bactericidal effect of tannins is due to their ability to bind proteins. Tannins are a component of black waters. Thanks to their disinfectant properties, they are responsible for low concentrations of microorganisms in the water environment. Glycosides are a group of organic compounds with a very complicated chemical structure, in which sugar combines with alcohols, phenols, sulfur compounds, etc. The most important group of glycosides are flavonoids, cardiac glycosides and phenolic glycosides. They all play an important role in herbal medicine.

The fall of Roman civilization resulted in a decreased

the plant. The first active substances were isolated

interest in science. And while herbs have not been to-

from plants in the early 19th century. In 1815, Friedrich

tally forgotten, a lack of observation and research has

Wilhelm Adam Sertürner identified the active ingre-

stunted the development of herbal medicine. At that

dient in poppy and named it morphine. In 1818 Pierre

time alchemy had its golden age. In the dark ateliers,

Joseph Pelletier and Joseph Bienaimé Caventou iso-

the search was on for the Philosopher’s Stone, an ex-

lated strychnine from the seeds of the strychnine tree

traordinary substance that would change common

(Strychnos nux-vomica) and two years later chinin

metals into gold. Alchemists wanted to create a mi-

from the bark of the Cinchona tree (Cinchona suc-

raculous elixir to prolong youth, life and cure all dis-

cirubra). In 1820, Friedlieb Ferdinand Runge obtained

eases. They never managed to fulfill their dreams, but

caffeine from coffee (Coffea arabica) seeds.

they made outstanding contributions to chemistry.

The most important groups of active plant com-

The 16 century belonged to Paracelsus, who was the

pounds include: alkaloids, phenols, glycosides, flavo-

first to notice that some ”chemical bodies” in plants

noids, tannins, essential oils, mucilages and pectins.

were responsible for their healing properties. And it was this chemical body that had to be extracted from

HERBS IN FISH FOOD For the breeding and raising consumer fish, substances with immunostimulatory properties may be the alternative to drugs. The most popular include lipopolysaccharides (LPS), extracted from the cell walls of various Gram-negative bacteria pathogenic to fish, and beta-glucans, most commonly extracted from yeast cell walls. However, polysaccharides, vitamins and plant extracts can also affect non-specific immunity in fish. When used in aquaculture, herbs enhance weight gain and exhibit antimicrobial properties. Chinese medicine is rich in numerous species of herbs with immunostimulating properties. One of the most famous Chinese herbs is Mongolian milkvetch (Astragalus membranaceus). The main active substances in the root of this plant are polysaccharides, which support non-specific immunity. This was confirmed by studies conducted on carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus). The carp given the HERBAL MEDICINE TODAY

Mongolian milkvetch extract better fought infection

Currently, almost half of the medicines produced in

caused by Aeromonas hydrophila. Another interest-

the world contain active substances derived from

ing plant used in Chinese medicine is the Japanese

plants or synthesized on their basis. The medicinal

honeysuckle (Lonicera japonica), often grown also as

properties of many plant species have been scientif-

an ornamental plant. It is credited with having a ben-

ically confirmed, and the chemical structure of many

eficial effect on the immune system. In Nile tilapia, ad-

plant-derived active substances has been identified.

ministration of Japanese honeysuckle increased mac-

Interestingly, while doing this research, it turned out

rophage activity and reduced mortality in comparison

that many plants that have been used for centuries

to fish that did not receive it.

for specific ailments may have much broader uses. An

Using mixtures of different species of herbs gives very

example would be tannins. They have been known for

good effects in fish. In this case, the active substanc-

their anti-inflammatory and antibacterial properties.

es from them interact, so they work together more

However, in-depth studies have revealed their potent

strongly (synergy), as well as the body itself may re-

immunostimulatory effects.

act more strongly to treatment with several different herbs. Such a synergistic effect has been observed

HERBS IN ANIMALS NUTRITION

when fish were treated with a mixture of Chinese

Herbs have not only been used to treat humans, but

herbs, designated C-UPIII, consisting of Chinese rhu-

they are also commonly used as a nutritional supple-

barb (Rheum officinale), green chiretta (Andrographis

ment in foods for livestock and pets. Their flavor is

paniculata), woad (Isatis indigotica) and Japanese

tempting for many animals, so their presence in the

honeysuckle (Lonicera japonica). The mixture given

feed increases intake, which is eagerly used in live-

to guppies (Poecilia reticulata) increased their surviv-

stock farming, where rapid weight gain is important.

al rate during infection with Tetrahymena pyriformis.

Herbs increase the palatability of food and the appe-

This is just one of many examples of combinations of

tite of animals, improve digestion. They also have an

different herbs used in fish.

anti-inflammatory, diarrheal, bacteriostatic effect and

Numerous scientific studies have also investigat-

have a positive influence on general health.

ed the use of Indian herbs in fish health prevention.

that regulate metabolic processes, detoxify the body and positively affect the overall health of fish. COMMON NETTLE (Urtica dioica) Nettle contains minerals, amines, glycosides, pectins and tannins. It has anti-inflammatory and immunostimulating effect. In poultry studies, capsaicin (a compound we know from hot peppers, responsible for their pungent taste), antimicrobial cinnamaldehyde and antiseptic carvacrol were found to have positive effects on the poultry’s growth. This became the premise for experiments on fish. Scientists studied the effects of different doses of nettle in the diet of juvenile and adult Labeo victorianus, an endemic carp fish inhabiting the Lake Victoria catchment in Africa. The results confirmed the beneficial effect of nettle on the immune system of fish and its anti-infective properties. In addition, nettle components can One of the well-known plants from this culture is the

affect pathogenic and non-pathogenic bacterial spe-

emblic (Phyllanthus emblica), also known as myro-

cies in the digestive tract of fish. This leads to a better

balan. This plant shows strong antioxidant, antifungal,

utilization of the food, which accelerates growth and

anti-inflammatory and antibacterial properties. In ad-

facilitates immunity. Nettle also had beneficial effects

dition, the fruit of this plant is known for its very high

on the immunity of rainbow trout (Oncorhynchus my-

vitamin C content. The aqueous extract of myrobalan

kiss) and beluga sturgeon (Glycyrrhiza glabra).

fruit showed positive effects on the immune system

It is worth noting that non-specific immunity, which

of Nile tilapia (Oerochromis niloticus). Also, Indian lilac

is vertebrates’ first line of defense against pathogens,

(Azadirachta indica), known as neem, has shown sim-

plays more important role in fish than in mammals.

ilar effects in experiments with tilapia.

Hence, enhancing non-specific immunity of fish

Researchers also looked at species such as smooth li-

through various natural immune stimulators is a very

corice (Glycyrrhiza glabra), mistletoe (Viscum album),

important issue. Especially when it comes to reducing

nettle (Urtica dioica), and ginger (Zingiber officinale).

the use of synthetic drugs, including antibiotics.

Extracts from these plants were administered to rain-

Common nettle is added to Malawi Flakes (3.75%),

bow trout (Oncorhynchus mykiss) with positive out-

Malawi Chips (4%), Cichlid Color (2.5%). Its active sub-

comes.

stances regulate digestive processes, prevent inflammatory conditions of digestive tract and strengthen

HERBS IN AQUARIUMS

immunity of fish.

Herbs are also present in aquaristics. They play an important role in the preparation of water and make

GARLIC (Allium sativum)

an ingredient of both ready-made and home-made

Garlic is a flavorful spice and herb plant known to all

foods. In its aquarium fish foods Tropical uses: garlic,

and used in folk medicine for ages. Garlic cloves con-

nettle, aloe vera, oak bark and Ketapang (Terminalia

tain sulfur compounds, including allin, which breaks

catappa).

down after tissue damage to form allicin. It is to alli-

It is worth remembering that aquarium fish foods

cin that garlic owes its strong antibacterial action and

contain plants (spinach, peas, grasses) and algae (spi-

characteristic smell. Garlic also contains flavonoids,

rulina, chlorella, Kelp algae) rich in active substances

pectin, mucilage, a number of vitamins and trace el-

ements. It is very readily added to foods prepared at home, especially for discus and other South American cichlids that are often attacked by parasites and suffer from inflammatory disorders of digestive tract. Scientific research has confirmed the medicinal properties of garlic, including the bactericidal and bacteriostatic effects of sulfur compounds (allicin and diallyl trisulfide). In Tropical’s wide offer of foods there are several products containing garlic. The leading food with this ingredient is D-Allio Plus, available as flakes and granules. It can be fed to all aquarium fish. It contains 5% garlic concentrate. And what do the experiments conducted on fish say? Application of garlic in doses of 0; 0.05; 0.1; 0.5; 1.0 g per 100 grams of food to rainbow trout for 14 days resulted in a significant decrease in mortality of Aeromonas hydrophila-infected fish. Doses of 0.5 and 1.0 grams per 100 grams of food reduced fish die-off to 4% compared to 88% in the control group. In addition, an increased growth was observed due to better food utilization. Similar observations were made when feeding garlic to the African catfish Clarias gariepinus. Garlic, admittedly in smaller quantities, can also be found in foods: Gel Formula for Omnivorous Fish (3.5%), Soft Line America (4.5%), Soft Line Africa Carnivore (4.5%), Discus Gran D-50 Plus Baby (5%), Discus Gran Wild (5%). OAK BARK (Quercus sp.) Oak bark meal has been used in three Tropical products: Gel Formula for Herbivorous Fish (0.7%), Pleco’s Tablets (1%) and Hi-Algae Discs XXL (1%). They are all intended for feeding herbivorous fish, including Loricariidae and other species that use wood as a food source. Their specially adapted teeth and mouth equipped with a sucker allow them to rub off branches and other tree fragments submerged in water. The bacteria in the fish’s gut are involved in digesting this food. No doubt oak bark meal found its way into these foods as a source of fiber and an important component of the diet of wood-eating Loricariidae. It is also worth noting the health-promoting properties of this ingredient. Oak bark has been found to contain large amounts of tannins, polyphenols, flavonoids, fatty ac-

ids, vitamins, including an exceptionally large amount of vitamin E and sterols. In herbal medicine, oak bark has been used for digestive problems, skin inflammation and urinary tract infections. It is attributed with antibacterial, anti-inflammatory and anti-diarrheal properties. ALOE VERA It is one of the many species of aloe whose properties for humans and some domestic animal species have been so well investigated. It is used for injuries, skin inflammation, light burns, digestive disorders, constipation, decreased immunity and many other health problems. The properties of aloe vera can be attributed to a large amount of polysaccharides present in the gel obtained from the leaves of this plant. Aloe vera administered to carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) together with food resulted in better utilization of the food, which led to more intensive growth. At the same time an increase in immunity was observed when aloe vera was administered to Brycon amazonicus fish. Studies conducted on juveniles of pacu (Piaractus mesopotanicus) have shown the great potential of this plant. It was found that the addition of aloe extract (1% and 2%) activated the mechanisms responsible for non-specific immunity in fish. The study also included the catfish Clarias

gariepinus, in which the addition of aloe vera clearly intensified growth. In addition, catfish showed greater survival under adverse low pH conditions compared to the control group. Apart from 12% algae, 3-Algae also contains aloe vera extract (2%). This food is available in the form of flakes, granules, sinking tablets and adhesive tablets, which gives the possibility to feed many species of fish. Aloe extract has been also added to many water treatment products such as Esklarin with Aloe and Sanital with Aloe, where its soothing effect on abrasions and other skin injuries is used. PREPARATION OF WATER Herbaceous plants also prove useful for preparing water for ornamental fish. Commonly used Polish plant species include common oak (Quercus robur) and sessile oak (Quercus sessilis), as well as cones of black alder (Alnus glutinosa) or grey alder (Alnus incana), extremely rich in tannins, flavonoids, phenols,

SEA ALMOND (Terminalia catappa)

terpenes and phytoncides (substances with antibiotic

In nature sea almond can be mostly found in South-

effect). Tannins and organic acids released from oak

east Asia. The Ketapang leaves came to aquariums

leaves and alder cones cause a slight decrease in wa-

from Asian folk medicine, where they are used to

ter pH. Tannins give the water a golden brown color,

treat liver and skin diseases. The properties of this

and if we put too many leaves or cones the water

plant have been confirmed by scientific studies. Ex-

turns dark brown, while their bactericidal properties

tracts obtained from Terminalia catappa have an-

allow to get rid of excess bacteria from the aquarium

ti-inflammatory, antioxidant, anticancer effects and

environment. Similar properties are presented by sea

protect the liver from hepatotoxins. Although scien-

almond (Terminalia catappa) leaves.

tists managed to isolate many active substances from

Ketapang leaves and recognize their properties, not

released to the water slightly decrease the pH of the

all mechanisms of action have been fully researched.

water. Ketapang allows to create in a home aquar-

When placed in an aquarium, dry Ketapang leaves

ium conditions similar to natural ones, typical for soft,

release various substances into the water, including

slightly acidic and tannin-rich waters.

dyes that give the water a golden brown color. At this

Asian ornamental fish farmers use Ketapang to pro-

point, almost every aquarist knows that Ketapang is

tect eggs from mold. To do this, they apply the leaf

a source of humic compounds and extremely high

to a working filter or directly to the spawning tank.

amounts of tannins. In addition to these, alkaloids,

With this treatment, hatchability and hatchling sur-

terpenes and phenols etc. also enter the water. The

vival rates increase significantly. Due to the antiseptic

high concentration of these substances in Ketapang

(disinfectant) properties of Ketapang, it is also used

leaves is probably a defense mechanism of the tree,

in situations of increased risk of damaging the exter-

protecting its leaves and fruits from parasite attacks.

nal layers of fish, i.e. after water changes, after trans-

Substances released into the water greatly limit the

port and during the period of fish acclimatization in

growth and reduce the concentration of bacteria,

a new tank. Substances released from Ketapang

fungi and protozoa in the aquarium environment.

leaves accelerate wound healing, regeneration of mu-

However, unlike medicinal preparations, they do not

cous membranes and fish fins. Tannins and humic ac-

impair biological filtration. Humic acids and tannins

ids also inhibit the development of blue-green algae,

so undesirable in aquariums. Ketapang leaves used in experimental cultures of tilapia (Oerochromis niloticus) contributed to a large reduction in the concentration of Aeromonas bacteria and Trichodina protozoa, and also reduced egg mold. Tropical offers a product in the form of crushed Ketapang leaves in convenient sachets. It can be easily applied to the filter or put in any place of the tank. Furthermore, Ketapang has been used as an ingredient in the food for algae-eating Loricariidae – Green Algae Wafers – and in sticks for freshwater shrimps: Shrimp Sticks. To both products, 2% of the meal obtained from the leaves of the almond tree has been added. SUMMARY Numerous studies indicate that herbs can be used to increase the natural immunity of fish, which gives hope for reducing the use of synthetic drugs, including antibiotics, in commodity farms. Drawing on this knowledge, we can use herbs in ornamental fish nutrition and water treatment products for aquarium.

LITERATURE Burlacu E., Nisca A., Tanase C. (2020), A Comprehensive Review of Phytochemistry and Biological Activities of Quercus Species, Forests 11 (9), 904. Chansue N., Ponpornpisit A., Endo M., Sakai M., Yoshida S. (2000), Improved Immunity of Tilapia Oreochromis niloticus by C-UP III, a Herb Medicine, Fish Pathology, 35 (2), 89-90. Chitmanat C., Tongdonmuan K., Khanom P. et al. (2005), Antiparasitic, antibacterial, and antifungal activities derived from a Terminalia catappa solution against some tilapia (Oreochromis niloticus) pathogens, ISHS Acta Horticulturae 678. De Vico G., Guida V., Carella F. (2018), Urtica dioica (Stinging Nettle): A Neglected Plant with Emerging Growth Promoter/Immunostimulant Properties for Farmed Fish, Frontiers in Physiology 9, 285. Drozd J. (2012), Wczoraj i dziś ziołolecznictwa, Przegląd Medyczny Uniwersytetu Rzeszowskiego i Narodowego Instytutu Leków w Warszawie 2, 245-251. Gabriel N.N., Wilhelm M.R., Habte-Tsion H.M. et al. (2019), Effect of dietary Aloe vera polysaccharides supplementation on growth performance, feed utilization, hemato-biochemical parameters, and survival at low pH in African catfish (Clarias gariepinus) fingerlings, Int Aquat Res 11, 57-72. Galina J., Yin G., Ardó L., Jeney Z. (2009), The use of immunostimulating herbs in fish. An overview of research, Fish Physiol Biochem, Nov, 35(4), 669-676. Gilman E., Watson D. (1994), Terminalia catappa, Tropical-Almond, Fact Sheet ST-626, Forest Service US Departament of Agriculture. Hasik J. (2001), Usprawnienia dietetyczne procesów metabolicznych. Co to są fitaminy?, Postępy Fitoterapii nr 6 (2-3). Jamroz D., Podkówka W., Chachułowa J., Żywienie zwierząt i paszoznawstwo, t. III, Państwowe Wydawnictwo Naukowe, Warszawa 2001. Jing G., Xinhui T., Huan D. et al. (2004), Hepatoprotective activity of Terminalia catappa L. leaves and its two triterpenoids, Journal of Pharmacy and Pharmacology, vol. 56, no. 11, 1449-1455. Lutomski J. (2001), Znaczenie ziół w terapii i dietetyce, Postępy Fitoterapii 6 (2-3). Ngugi C.C, Oyoo-Okoth E., Mugo-Bundi J., Sagwe Orina P., Jepyegon Chemoiwa E., Aloo P.A. (2015), Effects of dietary administration of stinging nettle (Urtica dioica) on the growth performance, biochemical, hematological and immunological parameters in juvenile and adult Victoria Labeo (Labeo victorianus) challenged with Aeromonas hydrophila, Fish & Shellfish Immunology, Volume 44, Issue 2, 533-541. Nya E.J., Austin B. (2009), Use of garlic, Allium sativum, to control Aeromonas hydro-phila infection in rainbow trout Oncorhynchus mykiss (Walbaum), J. Fish Dis. Nov, 32 (11), 963-970. Zanuzzo F.S., Sabioni R.E., Montoya L.N.F., Favero G., Urbinati E.C. (2017), Aloe vera enhances the innate immune response of pacu (Piaractus mesopotamicus) after transport stress and combined heat killed Aeromonas hydrophila infection, Fish & Shellfish Immunology, Volume 65, 198-205.

Paweł CZAPCZYK, PhD For nearly 40 years a passionate aquarium and terrarium hobbyist, writer, editor and breeder; organizer of exhibitions and conferences on aquarium and terrarium hobby; author of many books and press articles, as well as radio broadcasts and screenplays for documentary films; nature photographer, editor-in-chief of “Aquarium Magazine”.

Carnivorous, herbivorous, omnivorous.

ABOUT

PIRANHAS

in aquarium (and not only there) – part 1

In old stories of travelers who reached the queen of rivers, the Amazon, we can read about many brave wanderers who had the courage to venture deep into the Amazon basin and who were attacked by bloodthirsty piranhas.

In contemporary Hollywood B- or C-grade movies,

fish try to escape or become invisible. They hide among

mutant fish are usually a threat to the entire local area,

the plants in the corners of the tank, cling in panic to

terrorizing people on beaches or in swimming pools.

the bottom and lie sideways on the sand.

The movie makers do not care much about reality, but they are right about one thing: the fish would have

INCREASING INCIDENCE

to be really mutated, because even the notorious red

After all, the need for fear is great in our society. Sen-

piranha (Pygocentrus nattereri) is a surprisingly timid

sational reports about piranhas’ habitats far from their

species. It only becomes brave in a group. And that’s

natal biotope and places where they can be ”hunted”

usually when a sudden but completely unexplained

are circulating the world, electrifying ichthyologists,

stimulus or impulse sweeps through the entire group.

anglers and aquarists.

One of my friends is always surprised that when he is

It was really surprising when in 1977 a stock of Ser-

desludging his piranha-inhabited tank, the terrified

rasalmus rhombeus was discovered in the pond of an

Colossoma brachypomum

Pygocentrus nattereri

abandoned amusement park in the Miami area. Ich-

In nearly fifteen years, the number of public, semi-se-

thyologists alarmed that the fish, most likely released

cret, and secret cases nationwide has increased signi-

by an extremely irresponsible aquarist, overwintered in

ficantly...

Florida.

Ichthyologists and fishermen alarm that thoughtlessly

Not to look far, in Europe the Czechs confirmed a pi-

allowing predators and omnivores from the Amazon

ranha catch in the Oder River near Ostrava as early as

into Polish reservoirs is a violation of common sense,

1998. After all, it is no wonder that the piranha is now

lack of imagination on the part of aquarists unworthy

included in some lists and atlases of animals occurring

of the name, and above all, a violation of the law, i.e.

in the Czech Republic.

exceeding the Act on the Protection of Native Species.

And judging by journalistic reports and stories told by

For the most part piranhas are hardy fish and they

numerous witnesses and breathtaking adventures of

adapt and acclimatize relatively easily to new types of

anglers („Lord, what a fish it was!!!”), Poland today is

water.

a country where piranhas can often be caught without

Around the middle of the last century, these fish began

sophisticated lures (live bait and red worm).

to appear in the homes of American hobbyists. Soon

In 2006, the media reported that an angler caught

after they spread to European aquariums…

a thirty-centimeter piranha in Lake Wonieść using a red worm. Within a year and a half it was the fourth officially reported case of catching a piranha in Wielkopolska.

A BIT OF SYSTEMATICS

to the bone in a matter of minutes. However, other pi-

Piranhas or pirañas are now classified in the rank of the

ranhas remain omnivores and even food opportunists,

family Serrasalmidae, and less commonly the subfamily

performing important sanitary functions in their home

Serrasalminae. The piranha family today includes more

biotopes. Others are specialized herbivores.

than a dozen genera of freshwater fish that inhabit the

The popular tambaqui (Colossoma macropomum),

tropical waters of South America. However, it is impor-

which incidentally have a part of their dentition decep-

tant to remember that new species and geographical

tively similar to that of humans, have adapted to split-

varieties are still being discovered from time to time.

ting the hard shells of tropical fruits and seeds. Cato-

Therefore, the systematics of this group is still subject

prion mento, commonly know as the wimple piranha,

to numerous discussions and revisions and the need for

is counted among the so-called lepidophages, i.e. fish

further genetic and anatomical studies is consistently

eating the fins and scales of other fish.

indicated.

Piranhas generally take care of their offspring – just like

Only some piranhas, especially from the genera Pygo-

large American cichlids.

centrus and Serrasalmus, are called ”proper piranhas”, and some people consider them – and only them! – to

The rest of the article will be published in the next

be really dangerous for humans. They are famous for

issue of our Tropical EDU Magazine.

their predation and group attacks on their prey. They are also able to eat mammals like a tapir or an ox down Pygocentrus nattereri

Photos: Paweł Czapczyk

Kamil HAZY A biotope aquarist with experience in international competitions. Advocate of systematization of environmental aquaristics. Organizer – together with ”Aquarium Magazine” – of the Polish Biotope Contest. He offers services of consulting and arrangement of biotope, habitat and environmental aquariums. He believes that aquaria are primarily intended to meet the needs of their inhabitants.

THE BRAZILIAN-BOLIVIAN BORDERLAND CLOSED IN A GLAS

My first biotope story (part 2)

I remember my first aquarium as clearly as if I had started it yesterday... I guess each experienced aquarium hobbyist could start their story this way. Most of us, especially at the beginning of our adventure, are looking for ideas in one moment, and end up with several tanks at home in another. The longer you are in this hobby, the harder it is to find limits.

BADC 2018 competition arrangement – Guapore River floodplain

The start of the new project was born after the com-

FREE EXPANSION

plete remodeling of the concept concerning inani-

The beauty of this tank, its transformation, stabili-

mate matter in the aquarium. I was now focused on

zation and fish behavior gave me enormous joy for

flooded meadow lying on the Bolivian side of the Rio

months. Towards the end of its existence I experiment-

Itenez... The arrangement in the tank was to depict

ed a bit with planting and deliberately remodeled the

the exposed, shallow root of a nearby tree, around

ecosystem to watch the sometimes surprising results.

which Helanthium bolivianum ”Angustifolius” grows

To those who want to understand how expansive

luxuriantly. So I took all the wood out of the tank (it oc-

plants can be and how they can completely change

cupied a capacity of several dozen liters) and decided

a habitat, I recommend introducing such a plant to

to get a new root, chosen specifically for this arrange-

your tank and allowing it to develop completely free-

ment.

ly. I used a popular Pistia (Pistia stratiotes) and let it spread over Helanthium bolivianum. It only took

Tank during rearrangement period, winter 2018

a few weeks for the reservoir to take on a completely

Driven by nostalgia for my first ”root arrangement”,

different character, which in nature would most likely

I thought back to the Noel Kempff Mercado National

attract different species of fish to this place than those

Park, located on the Bolivian side of Rio Itenez, spe-

that existed here before. I like observing these stag-

cifically in the area of one of the river’s tributaries: Rio

es of change because of two aspects. The first is the

Paragua. As an idea for the arrangement I used a hab-

”wildness” and ”dynamism” of the tank and the other

itat corresponding to a small forest stream flowing into the mentioned river. The stream was rolling tannin-rich waters, but near its right bank the incident light gave a clump of Eichhornia diversifolia a chance to thrive. For the first time I used exposed pebbles in my arrangement. The animal stock in the aquarium has also changed. I said goodbye to a large group of Hyphessobrycon eques, and in their place I purchased Aphyocharax rathbuni and, a little later, Hyphessobrycon herbertaxelrodi. Also Hydrocotyle leucocephala returned to my tank. As before it was supposed to create an interesting looking overwater part. A DIGRESSION ON TRANSITIONAL ENVIRONMENTS This is a good moment to make a brief digression, as

a chance to take the greatest photos of Apistogram-

in the previous part of the article. With time, as my

ma trifasciata I’ve been able to take in all my several

knowledge and aquaristic experience developed, I be-

years of adventure with these fish. Of course during

came dangerously attracted to the specifics of tran-

the expansion of the floating plant I made some ad-

sitional ecosystems, i.e. zones where water meets air.

justments to the hardscape, but these were not inter-

I mean all coastal areas, periodically flooded meadows

ferences that completely changed the nature of the

or watercourses with fluctuating water levels. This is

tank. After a period of dynamic changes caused by

because the adaptation processes of plants and ani-

the wilderness of the ecosystem, I decided to tidy up

mals to the environment that changes over time are

the concept a bit and see how other, and new to me,

much more interesting to observe than a permanent-

plant species would cope. All this with the intention

ly flooded water habitat. Simulating the dry and rainy

for a greater change that was soon to come.

seasons in a tank is an interesting experience that

Tank during rearrangement period, winter 2018

I recommend hobbyists to try on their own, because

any aquarist, is to use commercially available plants

the conclusions will give any keen nature observer

that look almost exactly like ”biotope correct” plants.

a lot to think about. Learning about the defense

Related species, growing in the same region of the

mechanisms of fish (changed way of feeding, staying

world and similar habitats, are after all used by many

in other parts of the tank, etc.) and plants (changes in

aquarists as substitutes for the originals. If the differ-

leaf structure, dying out of the mother plant in favor of

ences in the structure of the plant and in the way it

offspring plants, etc.), as well as noticing the impact of

grows or affects the ecosystem are, in principle, minor,

changes on the reproductive cycle of organisms gives

then they can be easily accepted. Although I prefer to

a complex insight into life processes and a chance for

call a reservoir created in this way a habitat reservoir,

very satisfactory observations.

instead of a biotope, it does not absolutely undermine

My arrangements are increasingly moving towards

its value, and in this case I am not offended by the use

depicting these transitional zones. Of course, I en-

of a name that is not entirely correct.

counter new challenges and problems along the way, mainly in the availability of plants from restored hab-

BIOTOPE AESTHETICS

itats.

I have to admit that with time I have more humility in

Here I have to mention one of the rules of biotope

me. These days, my perspective on aquariums is start-

aquaristics, which says that the planting density of the

ing to get a little broader. After all, I’m not just talking

tank should closely reflect the nature. When creating

about biotope aquariums anymore, but I’m focusing

transition zones, however, it quickly becomes appar-

on the whole issue of environmental aquariums as

ent that the availability of ”biotopically correct” plants

a resultant of biotope, habitat and area tanks (as well

is very difficult. One approach, which I recommend to

as others related to them and less popular).

BADC 2019 competition arrangement – a small tributary of the Rio Paragua, Bolivia

aquaristics because the latter simply has different goals. This is still true today and does not conflict with the use of solutions that allow a better visual perception of the tank and at the same time do not worsen the living conditions of the animals. Of course I do not approve of creating tanks only for the sake of calling them ”biotope tanks”, in which the only emphasis is placed on the arrangement, and the aspect of longterm functioning of the tank is totally ignored. Unfortunately, aquaria set up only for competitions, for Additionally, at this point I must give due credit to the best aquarium artists who arrange nature style aquariums. Certain techniques, which they introduced to aquaristics and refined over the years, developed certain habits in their audience and tendencies to search for the universal canon of beauty. Today, all over the world, this „aesthetic” direction is visible in the development of works in competitions for the arrangement of biotope tanks. Thanks to applying techniques learned from others, many biotope aquarists, including myself, have improved their skills and more proficiently focus the attention of the viewer, who is not an expert in most cases. I believe that the greater influence of arrangement techniques can be a positive contribution to the development of environmental aquaristics. PRIORITIES However, do not think I’m changing my mind very easily. After all, I have always claimed that aquascaping cannot be completely compatible with biotope

a single photo or a film, are often a desert in terms of biodiversity (completely fresh, with no trace of uncontrolled 100% influence of natural processes) or so overloaded with decaying organic matter that maintaining biological stability in them is nearly impossible. They are undoubtedly beautiful and often faithfully represent the biotope at a precise moment of the year, but – losing the sense of stability in biodiversity – they are much further away from biotope aquaristics than many of us might think. And yet the most important principle of all environmental aquaristics is the well-being of the organisms inhabiting the tanks and that’s what the emphasis should be put on. But let’s let aquarists decide themselves which approach to showing biotopes is ultimately more appropriate. Let them do it according to their own conscience and preferably after trying to run the tank in both ways for a while. FINAL ARRANGEMENT The next step in my journey of finding a perfect arrangement was to try to combine three habitat sec-

Arrangement in early 2020

tions into one biotope. Such a diverse ecosystem was

already mostly farmed specimens, often possessing

to include plants that were flooded for a very short pe-

selected traits, so I must humbly accept that I have

riod of the year but rooted in wet substrate, plants that

condemned myself to the previously described inac-

were periodically exposed and flooded, and plants

curacy and my tank has become more of a habitat

that were flooded most of the year. I approached the

one.

creation of the final arrangement gradually, after all

The plant in the first stage of my adventure landed

I was working on a living ecosystem as usual. The tran-

on top of the ”rooting area” and it was inserted be-

sition zone of the reservoir received a typically emer-

tween the shoots of a luxuriantly growing Hydro-

sive plant, which tolerates short-term flooding very

cotyle leucocephala. I lowered the water level in the

well, and grows well with roots submerged in water

tank by few centimeters to be able to simulate dry

or flooded substrate. I’m talking about Spathiphyllum

and rainy season better. The right side of the tank

sp. Unfortunately, it is impossible to determine a spe-

was elevated to accommodate future low plants to

cific species, and commercially available plants are

create something like the ”carpet grass” so popular

Evolution of the 2020 arrangement – Las Torres stream bank in the Rio Guapore basin, Bolivia

in planted aquariums. After a few months of gaining experience and watching carefully the changes taking place, I made the final moves in my first aquarium adventure. I remodeled the left side of the tank. I created peculiar ″islands” (″pots” made of pebbles and small roots covered with substrate) for Spathiphyllum sp., shaped the substrate accordingly and to this day I’m still enjoying an arrangement showing the bank of the Las Torres stream in Bolivia, to be more precise, a place where its two branches join. The arrangement will be the last change that I am combining with my exploration of the Pantanal area and the Rio Guapore basin. So inevitably the time for testing new solutions is approaching. And I will certainly try them in the future. The fish I have are mostly aged now, so I’m gonna wait until they go away, and then I’m going to turn to completely different parts of the world. Where exactly? I honestly don’t know. I have a few biotopes which I find appealing, but I’m sure of one thing: I’ll be focusing on replicating the transition zones as closely as possible. Of course, such an approach will lead me towards thorough understanding of the nature of biodiversity in time-varying ecosystems. *** That’s the story for the next few years. My agreement with my wife regarding the number of aquariums is in effect and I have to admit that it works for me as well. I enjoy the bond with nature, I have wonderful experiences, and at the same time I don’t spend all my free time maintaining the aquariums. I now can spend it on sharing my own perspective on environmental aquariums with others. See you on the pages of Tropical EDU Magazine and on the Tropical EDU channel on YouTube. Keep on biotoping!

Photos: Kamil Hazy

MARINE FISH

for beginner aquarists

– features and selection (part 2)

Bartłomiej STAŃCZYK Marine biologist, graduate of the Department of Invertebrate Zoology and Hydrobiology at the University of Łódź. The author of Reefhub.pl, a popular blog about marine aquaristics. Since 2018 Tropical expert on products dedicated to marine tanks – Marine Power.

When you look at the lush coral reef, the first thing you notice is the myriad of fish. Tiny, medium and huge, in all sorts of colours and shapes – that’s what make the coral reef alive. Not only because fish bring energy and movement to a rather immobile biotope, but also because they are essential to the health and growth of coral reefs as an ecosystem: they nurture them by eating excess algae and parasites and clean the rock for new corals. And they feed corals with their feces at the same time.

BEFORE YOU BUY

first part of this article (TEM 2). This time I will mainly

Home reef aquariums are no different. Even though

focus on those aspects that I believe directly affect

the aforementioned functions of fish are somewhat

easy maintenance of specific species in an aquar-

limited in our tanks, fish still have a positive effect on

ium. I am thinking here of such fish characteristics

the condition of corals. In addition, they are an excel-

as size, aggression and diet.

lent ornaments and perfect objects of observation

(especially because of their wide variety of behaviors

SIZE MATTERS

and habits).

Before buying any fish a future tank owner should

However, there are several issues to consider when

definitely consider how the fish will look in the aquar-

deciding to buy fish; I’ve mentioned some in the

ium in six months or in a year. You can, of course, buy

a two-centimeter hepatus for a one-hundred-liter

Fish that are not very picky and accept any type of

aquarium, only that in six months the fish will be five

food are generally well nourished, provided that they

times bigger. And then what to do? It’s not that bad

are given food (with the vitamins, trace elements

if the aquarist is willing to give it back to the store for

and nutrients such as proteins and Omega-3 acids)

free. Keep in mind, however, that just catching the

that meets their nutritional requirements.

fish alone can be difficult, not to mention the stress

Aquarists who decide to introduce a particular spe-

it will cause. And a stressed fish is more vulnerable

cies to their tanks should be aware of the conse-

to diseases and parasite attacks than fish that live in

quences – that is, to anticipate not only how the fish

comfortable conditions.

will feel in the tank, but also how its presence will

Size often translates into swimming dynamics. Fast

affect their cohabitants.

and dynamic fish will get tired in a small aquarium, often hurting themselves on rocks and breaking more delicate SPS corals. They will also frighten away other, much calmer species that may simply have problems with access to food. A large individual in a small aquarium (as well as too many fish in the tank) means intensive feeding and a large nutrient load, the excess of which a small tank cannot handle. Many fish, regardless of size, may also exhibit aggression directed at other fish under certain conditions. Aggression may result from innate territorialism or competition between males for access to females – but whatever the reason, the fact remains that an aggressive aquarium inhabitant may pose a threat to more delicate and calmer fish. The area defended by a given fish may be small and in bigger tanks it will not be a problem. The fish will not get in each other’s way and their peaceful coexistence will

On the aquarium market we have a large selec-

be possible, and the aggression in such case will be

tion of different species of reef fish, which will

limited to chasing the intruder away from its own

feel comfortable in a home aquarium, if you meet

territory. However, if the guarded area is potential-

certain conditions. While experienced hobby-

ly larger than the bottom area, two competing fish

ists know these requirements, the matter gets

will always fight in the tank. Sometimes it will be just

more complicated in case of people who are just

spreading their fins, but sometimes it can take the

beginning their adventure with marine aquaris-

form of a fight to the death.

tics. Therefore, I will briefly characterize the popular species, highlighting those features that

DIFFERENT SPECIES, DIFFERENT REQUIREMENTS

I believe are most important when deciding to pur-

The size of the fish and its aggression are undoubt-

chase them.

edly important factors affecting the maintenance of fish in a tank. However, the dietary requirements of

THE MORE, THE MERRIER

the fish and their resistance to diseases often play

The first question a beginning marine aquarist often

a decisive role in this regard.

asks is: How many fish can I keep in my aquarium?

In the tank, clownfish can live in euphyllia, for example

It’s not possible to answer the question formulated

algae or sift the sand. Nothing stands in the way of

this way.

using these predispositions in the aquarium as well,

Of course one of the main criteria is the size of the

if possible. If you do not plan this at the beginning, it

tank and it is much easier to select fish for a large

may happen that you do not have enough room in

one. However, it often happens that that beginners

the aquarium for more fish.

set up small homes for a start. This automatically limits the choice in terms of both the number and type of fish that can be selected. It is impossible to unambiguously convert the volume of an aquarium into the number of fish that can be kept in it (although such attempts were made in the past). In practice, one would have to take into account both the dynamics of the fish and their size and character, and even the filtration in the aquarium or the arrangement of the tank itself. When people ask me what fish and how many they can keep in an aquarium, I reply that they should consider functional fish first and only then ornamental fish. After all, on wild reefs fish perform various functions, for example, they eat parasites and

So let’s take a look at the popular species recom-

Farmed fish usually do not exceed 5 cm but you can

mended especially for beginner aquarists. Below

find wild specimens reaching 10 cm. Clownfish are

I will try to summarize the most important, in my

born with both female and male pairs of gonads and

opinion, features of popular fish.

become male first. Only when there is a shortage of females in the group does the largest male turn

CLOWNFISH

into an alpha female, and the second largest male

Pomacentridae family is a group of relatively small

becomes the alpha male. If you buy two sexually im-

fish. It includes popular clownfish (subfamily Am-

mature clownfish, after a while you can be sure that

phiprioninae, damselfish, subfamily Pomacentri-

you will have a male and a female.

nae), and chromis (subfamily Chrominae).

These fish are not dynamic swimmers and tend to

Clownfish are a group of fish considered almost

stay around the nest or anemone they live in. While

iconic for reef tanks, which was further popularized

in the wild they are unlikely to be able to survive

by the movie ”Finding Nemo”.

without an anemone, in an aquarium they do not

There are over a dozen different species of clownfish,

need to inhabit it at all. Sometimes these fish choose

varying in coloration, patterns and shape. In recent

other corals as their home. Some LPS corals (e.g. of

years, artificially derived hybrid varieties, which are

the genus Euphyllia) or even some soft corals (for ex-

a mixture of patterns and coloration, are also

ample Sarcophyton) are used as substitutes for the

a pearing.

anemone. In my opinion, the absolute minimum for

Chrysiptera parasema is one of the calmer damsels, but it can attack even bigger fish

a pair of clownfish is a 50-liter aquarium (without

DAMSELS

other fish).

Another group of fish which are easy to keep in an

Clownfish are relatively calm fish, unless they guard

aquarium are damselfish, relatively small and very

the eggs. Then, as a rule, they show territorialism

nicely colored fish. They are dominated by vivid blue,

and defend their nest, although most often the de-

yellow, white and black colors. The most popular

fense takes the form of deterring intruders. How-

aquarium species rarely exceed 5-6 cm. Males and

ever, they often show aggression towards strange

females look the same and in most cases the sexes

pairs of clownfish – especially those that do not live

cannot be distinguished. In a 50-liter aquarium with

in another anemone. Fish, especially imported ones,

enough hiding places in the rocks, it will be difficult

may attack aquarist’s hands, which can be pain-

to keep more than 2-3 individuals.

ful, but almost always is an unpleasant surprise for

Despite their small size they are very territorial fish

a person who does not expect aggression.

and can scare away even much bigger intruders.

Clownfish accept different types of food rather eas-

In aquariums they usually choose crevices in rocks

ily. They will be more than happy to feed on flakes

or under some coral to spend the night, although

and softened granules after a short training session.

there are species that, like clownfish, live in anem-

They also do not pose a threat to other aquarium in-

ones. During the day they guard their spots, show-

habitants.

ing high aggressiveness especially towards other damsels. They can of course attack the aquarist’s hands, although due to their size they are unlikely to

If the aquarium is large enough, a flock of chromis will be a perfect ornament

cause any harm. Although they are not very dynam-

Yellowtail damselfish are not picky eaters and will

ic swimmers, they can be very fast when attacking.

happily eat frozen food and flakes. Like most Pom-

In my opinion, one of the calmer damsels is Chry-

acentridae, they are also quite tolerant of adverse

siptera parasema – although it is definitely not

conditions in the water. Some sources recommend

a peaceful fish. A few yellowtail damselfish dropped

them as the first fish to initiate the nitrogen cycle in

into the aquarium will share all available space be-

aquariums started on synthetic substrate. However,

tween them. Unfortunately, when fighting over ter-

keep in mind that when stocking the aquarium the

ritory, the weakest individuals are likely to die.

territorial and aggressive fish should be introduced

In yellowtail damselfish it is usually the male who

at the very end.

prepares the nest and invites the female to spawn. If the female accepts the courtship, she enters the

CHROMIS

male’s hiding place for several minutes to lay her

Another group of fish I would like to mention are

eggs, after which she returns to her territory. I have

chromis belonging to the subfamily Chrominae.

observed this ritual many times, admiring the ma-

The most popular chromis is Chromis viridis (but

ture yellowtail damsels eggs with the larvae’s eyes

representatives of the genera Dascyllus and Acan-

visible. Unfortunately, as with clownfish, it is impos-

thochromis are also sometimes offered for sale).

sible to breed adults in the main aquarium. The big-

These fish grow up to about 5-6 cm in an aquar-

gest obstacle is the lack of suitable food for fry and

ium. In white light, they are silver with a hint of

the presence of other fish.

green or blue. However, in an aquarium with

Apogon cyanosoma juveniles stick together, but will disperse around the aquarium when sexually mature

Adult female Pterapogon kauderni

The 4-week-old Pterapogon kauderni fry must be kept outside the main aquarium at all times in order not to become food for other fish

a predominantly blue spectrum they acquire

enough tank. Then the whole group swims along

a beautiful blue (rarely green) color. Their big-

the front glass of the tank.

gest advantage is that they are group-living fish.

They are rather peaceful fish, and their aggression is

A few or a dozen chromis in a large enough aquari-

less than in the other mentioned representatives of

um will swim in a school, glowing silvery blue.

Pomacentridae.

It should be noted here, of course, that in order to

Chromis have no problems with accepting substi-

enjoy a school of chromis, you need to have a large

tute food and as soon as they sense it in the depths

they start a mad chase for food particles. This few

Intra-species aggression is mainly manifested by

minutes of chaos in the aquarium, while quite pleas-

scaring off the intruder. However, during spawning,

ing to the aquarist’s eye, can cause more delicate

two Pterapogon kauderni males may fight to the

and timid fish to have trouble accessing food.

death for the female. Unfortunately, only an expe-

Generally all mentioned fish from Pomacentridae

rienced breeder is able to distinguishing the sex in

family are relatively easy to keep in good condition

these fish.

in an aquarium and they will successfully perform

A very interesting feature of some representatives of

mainly decorative function. They also do not pose

Apogonidae family is that the eggs are incubated in

a threat to invertebrates in the tank.

the mouth of the male, while the males of Pterapogon kauderni also protect the hatched fry in this

CARDINAFISHES

way. Keeping a pair of spawners gives a lot of oppor-

Other ornamental fish which are relatively easy to

tunities to observe their mating habits, and addi-

breed include representatives of the family Apogo-

tionally these fish can be relatively easily reproduced

nidae. The Apogonidae family is large so the aquar-

in captivity. Of course this is not possible in the main

ium keepers have wide options to choose from. The

aquarium in the presence of other fish, and besides,

most common are Pterapogon kauderni, Sphaer-

raising offspring requires technical facilities, skill and

amia nematoptera, Apogon leptacanthus, Apogon

experience. However, if a beginner hobbyist wants to

parvulus and Apogon cyanosoma. These fish are

take up breeding of marine aquarium fish, Pterapo-

rather calm and quite static when it comes to swim-

gon kauderni seems the best first choice.

ming. At the same time a lot of cardinalfishes are

Cardinalfishes are safe for other inhabitants of the

nocturnal feeders and although this feature can be

aquarium and do not have problems with eating

disturbed in an aquarium, during the day these fish

flakes and frozen food. They are also quite disease

will rather stick to dark places and therefore they

resistant, and relatively easy for beginner aquarists

may not be very visible for the owner.

to maintain healthily.

Salarias fasciatus often stops among corals observing the surrounding world

ALGAE BLENNY

But whatever you say, algae blennies are very grace-

Another species often recommended for a start is

ful and sociable fish. Juveniles available in the shop

Salarias fasciatus – from a large family of Blennii-

are about 5 cm long, and in an aquarium in appro-

dae. Despite its rather uninteresting coloration it is

priate conditions they grow up to a dozen or so cen-

a very nice fish whose main function in aquarium

timeters. They have an elongated, cylindrical shape,

is eating algae. The English common name for sal-

so length does not translate to their weight. Salari-

arias is also “lawnmower blenny” referring to mow-

as love to sit in corners and watch what’s going on

ing grass. However, in my experience, this feature

around them. They often stay near the front glass,

is a bit overrated, as none of the salarias I had were

looking at what is going on outside the aquarium.

eating hair algae. All of them, however, scraped the

Just like dogs watching their owners.

biological sediment off the glass and rocks. Wikipe-

An interesting fact is that many Blenniidae, includ-

dia states that this fish is more of a detritivore, with

ing salarias, do not have a swim bladder – this is why

plant foods only making up to 15 percent of its diet.

these fish cannot keep still in the water. After swim-

ming some distance, they settle down on a rock

***

or sand, exploring the surroundings with curiosity.

Beginner aquarist has a wide choice of easy-to-

However, despite these nice habits, they can be ag-

maintain and beautifully colored fish. Apart from

gressive towards other Blenniidae, so if you decide

the species I have described above, there are also

to keep them, you should consider having only one

wrasses, unicornfishes and gobies. I will write about

individual.

these and other fish recommended for beginner

Other than specialized reports, I have not heard of

aquarists in the third part.

successful reproduction of these fish by amateurs. Photos: Bartłomiej Stańczyk

RULES OF PROPER

mineral and vitamin SUPPLEMENTATION in reptile nutrition

Dawid KRÓTKI A graduate of the Faculty of Animal Breeding and Biology at the University of Agriculture in Krakow. Breeder of African and South American cichlids. An expert in the feeding and breeding of reptiles, amphibians and all kinds of invertebrates. Author of many aquarium and terrarium articles.

The subject of this article is one of the most widely discussed issues at trade fairs, expert meetings, and online. It does not surprise me at all, because – apart from proper terrarium equipment and diet – mineral and vitamin supplementation is one of the key factors that determine good condition of the animals and our breeding success. WHY IS SUPPLEMENTATION SO IMPORTANT?

centipedes, spiders, and crustaceans. There is

Despite their caretakers’ efforts, reptiles living in

a reason why ”meadow plankton” was once con-

terraria do not receive food as rich in minerals and

sidered the best food source for insectivorous

vitamins as they would in their natural environ-

reptiles. Today, due to the widespread use of pes-

ment. Farmed insects, while rich in protein and

ticides, it is unfortunately too risky to feed reptiles

fat, are poor in calcium. They also have an abnor-

with. Furthermore, the soils and rocks in the nat-

mal calcium to phosphorus ratio. Hence this food

ural habitats of our reptiles are very often much

is not as varied as in nature. Typically, the reptile

richer in essential minerals and the animals can

menu in terraria is limited to 4-5 types of insects

lick them off. Many reptiles also tend to instinc-

(crickets, cockroaches, locusts, mealworms, su-

tively swallow bits of substrate.

per worms), which is only a small fraction of what

Hobbyists generally do not have access to plants

is available for animals to eat in the wild.

and animals typical of the area in which their

In addition to insects, reptiles often eat snails,

reptiles originate, so they have to use substitutes

Choosing the right diet is one thing, but adequate supplementation with calcium compounds and vitamins is equally important

that do not always cover the reptiles’ nutrient, vi-

the mechanisms regulating calcium-phospho-

tamin, and macro- and micronutrient needs.

rus balance in the body. The effects of an over-

Plants from arid and semi-arid areas often have

dose are just as dangerous as a deficiency.

much higher tissue calcium levels than green

Why is it that there is no strict guidelines on the

plants we provide in terrariums. Access of reptiles

nutritional requirements for specific nutrients,

to sunlight is also of great importance. It not only

vitamins and minerals in specific reptile species?

provides life-giving warmth needed to maintain

I will try to answer this question and others in the

metabolism at an appropriate level, but also en-

following text.

ables the production of vitamin D3, which is syn-

Proper mineral-vitamin balance is very impor-

thesized in the skin under the influence of UV-B

tant as it improves appetite, vitality, condition

radiation. Under terrarium conditions, the quality

and ability to fight infections. We have little re-

and timing of illumination are not always suffi-

search on the nutritional requirements of specif-

cient to ensure adequate vitamin D3 production.

ic reptile species, and this issue has never been

This is why supplements, which ensure essential

studied on a large scale. (Definitely the situation

vitamins and minerals, are so important in reptile

looks better in the case of dogs and cats – after

diet. However, application is not as simple and

all, these animals have been accompanying hu-

obvious as it might first appear. Developing the

mans for centuries – but even here it should be

right dietary supplementation system for your

noted that while the veterinary dietetics of dogs

reptile requires a great deal of knowledge on the

is already relatively well known, with cats scien-

biology of the species, its environmental and nu-

tists are still at the beginning of the road and we

tritional requirements, and an understanding of

are only just learning about the exact cats de-

Mineral and mineral-vitamin supplements given with fresh greens should be evenly distributed by careful mixing

mands for nutrients, minerals and vitamins). Pre-

WHAT IS THE PROBLEM AND WHAT NEEDS

vious studies in reptiles have shown interspecies

SPECIAL ATTENTION?

and geographic variation in the requirement for

There are usually three undesirable situations:

these components. Although there are referenc-

1. Too little calcium in the diet and too little cal-

es to the first terrariums dating back to the 19

cium relative to phosphorus

century (some were heated with glowing coal),

Calcium has an important function in many

the trend of keeping exotic reptiles in home ter-

metabolic processes. Among other things, it is

rariums emerged in the last century and only be-

responsible for muscle contractility, nerve con-

came popular after 2000.

duction, blood clotting, cell membrane permea-

However, various studies have been conduct-

bility, enzyme activity, and bone metabolism. In

ed on reptile metabolism and mechanisms of

the life of every reptile there are several stages

mineral and vitamin regulation. Based on their

during which it is very important to provide the

results, knowledge of the biology of the species

right amount of calcium in the diet.

and experience in working with ectothermic ani-

The first is the process of growth, when a large

mals such as reptiles, the breeders must work out

amount of calcium is required to support the

their own system of calcium and vitamin supple-

building of the skeleton as other tissues grow. As

mentation. The basis will always be an adequate

the animal reaches maturity, the demand for cal-

diet, as varied as possible.

cium drops because the growth is stunted. Reptiles grow throughout their lives, but this growth

In calcium supplementation, special attention should be given to mating females because of the production of eggs in calcareous shells; photo by Dawid Krótki

Before feeding the reptiles with insects, place them in a container with an appropriate amount of the product and shake gently

is slower as they reach maturity and tends to de-

cium-containing tissues, especially bone and

crease with age ever after.

calcium itself is lost with urine. If we then fail to

Females, on the other hand, need extra calcium

supply the body with adequate amounts of cal-

when they go into reproduction. The formation

cium, this condition will lead to metabolic bone

of eggshells calls for huge amounts of calcium.

disease (MBD). The most common dietary source

If you don’t provide enough in the diet, the body

of calcium is a common calcium carbonate. It is

will “steal” calcium from the bones to make an

characterized by relatively high calcium content

eggshell. According to many authors, the opti-

(about 40% Ca), but its absorption in the intes-

mal dietary calcium content is 1-2%. All reputa-

tines is poor. Compounds such as calcium lactate

ble reptile food companies declare this value in

(17.5% Ca), calcium gluconate (9% Ca) or calcium

their products. These data are based primarily on

citrate (24% Ca) contain a lower percentage of

studies of the nutritional requirements of chicks

calcium than carbonate, but the possibility of

and other poultry and on many years of observa-

absorption, or its availability to the body, is much

tion. The calcium to phosphorus ratio is also im-

greater than of calcium from carbonate. The best

portant. Optimally, it should be 2:1 (calcium:phos-

option is to use products that contain diverse

phorus). This is the ratio obtained in blood serum

sources of calcium and at the same time do not

analysis of most vertebrates.

contain vitamin D3. They can be administered

When the ratio in serum is reversed in favor of

with each meal without the risk of overdosing vi-

phosphorus (due to a decrease in calcium), the

tamin D3.

body seeks to achieve adequate levels by re-

It’s important to know the exact calcium percent-

covering calcium from blood plasma from cal-

age in the formula so you can calculate the right

dose for your reptile. With a 29% calcium formula-

the proportions how many grams of the product

tion, 6 g of the formulation would need to be fed

should be given. Special attention should be paid

per 100 g of food to achieve the desired calcium

to preventing calcium deficiencies in the diet in

content in the diet (1-2% Ca). Plant foods should

times of increased demand (growth, reproduc-

be sprinkled with the product and stirred thor-

tion) and during convalescence.

oughly. Insects for insectivorous animals should

be put into a small box or bag, then sprinkled

2. Vitamin D3 deficiency

with the preparation and shaken gently several

Vitamin D3 is the most important vitamin in rep-

times so that the powder covers the insect bo-

tile nutrition. Its deficiency causes inhibition of

dies. When you give the preparation to your pet

calcium absorption from the gastrointestinal

the first time it’s a good idea to weigh the stand-

tract into the blood and results in the disrup-

ard portion you give your pet, to calculate from

tion of the correct calcium-phosphorus ratio.

The Dubia Roach (Blaptica dubia)

Jamaican Field Cricket (Gryllus assimilis)

In such a situation, as in the case of dietary cal-

dergoes photoisomerization under the influence

cium deficiency, the body seeks to balance this

of UV-B radiation of 290-315 nm wavelength.

ratio by recovering the calcium stored primarily

This then converts to the inactive form of vita-

in the bones. The accompanying disease, called

min D3 – cholecalciferol – under the influence of

secondary hyperparathyroidism, leads to MBD.

heat. Cholecalciferol binds to plasma proteins,

As a result, the parathyroid glands release par-

which are transported to the liver and convert-

athormone, under whose influence calcium is

ed to calcifediol. Calcifediol is then transported

released from the bones, which directly contrib-

to the kidneys and converted to calcitriol, the

utes to rickets. Advanced symptoms of the dis-

active form of vitamin D3. It is calcitriol that fa-

ease include a limp jaw (as if made of rubber),

cilitates the absorption of calcium from food in

broken or deformed limbs, ribs and spine.

the digestive tract. Therefore, providing calcium

Under natural conditions, vitamin D3 is synthe-

in the diet alone is not enough. In case of vitamin

sized by the action of ultraviolet radiation from

D3 deficiency, calcium from food will not be ab-

the sun. In the skin of reptiles, previtamin D3 is

sorbed into the blood. This vitamin is also found

formed from 7-dehydrocholesterol, which un-

in the liver and kidneys of vertebrates. Therefore,

Mealworms (Tenebrio molitor)

The desert locust (Schistocerca gregaria)

Young reptiles have an increased demand for calcium due to the growth and development of their bony skeleton; photo by Dawid Krótki

animals that eat whole vertebrates – for exam-

their efficiency drops noticeably after just a few

ple, snakes, monitors or crocodiles – rarely suffer

months of use, so they should be replaced regu-

from deficiencies of this vitamin and the supple-

larly with new ones. Metal halide lamps are much

mentation is not needed.

more durable and effective in UV-B emissions,

Most captive-bred reptiles are kept indoors, with-

but their spectrum is also depleted over time. It

out access to natural sunlight. In such conditions,

is worth to regularly check the efficiency of the

if the terrarium is not equipped with specialized

lamps with a suitable meter.

lamps that provide UV-B radiation for the pro-

We treat supplementation only as a way of cov-

duction of vitamin D3 in the skin, there is a high

ering up for any deficiencies that we should not

risk of deficiency of this vitamin. This deficiency –

allow. It is difficult to determine the exact dose

due to impaired calcium absorption from food –

without knowing the needs of the animal – so

lead in a straight line to weakened bones, rickets,

be careful not to overdose on vitamins. Optimal

convulsions and neurological disorders.

solution is using products containing 20 000-

Therefore, reptiles should be given free access to

-60 000 IU/kg of D3, which are generally consid-

UV-B radiation, as this is the safest way to ensure

ered safe for reptiles. For reptiles that are active

adequate production of vitamin D3. However,

during the day, and are within range of good

note that the UV-B emission efficiency of special-

quality UV-B radiation, it is sufficient to add a vi-

ist terrarium lamps decreases with time. In the

tamin supplement with D3 to the food 3-4 times

case of tubular and compact fluorescent lamps,

a month. Satisfying the needs of nocturnal spe-

cies may prove more difficult, as these reptiles are

previous negligence and deficiencies in supple-

active from dusk to dawn and will avoid light and

mentation. Large doses of calcium will not pro-

thus will not benefit from the presence of UV-B

duce the same results as smaller amounts giv-

in the terrarium. So in their case we should use

en at each feeding. If extremely large amounts

vitamin D3 supplementation more often, even

of calcium are served at one time, there may be

every second or third feeding. Herbivorous rep-

a risk of ”concreting” the lumen of the digestive

tiles, such as tortoises and green iguanas, need

tract, especially in small and delicate species.

the most attention in vitamin D3 supplementa-

Insects should be lightly sprinkled with miner-

tion, as it is assumed that these animals have

al preparation, not coated with it. If we provide

limited capacity to absorb this vitamin through

too much vitamin D3 in the diet, there is a risk

the oral route.

of excess calcium being deposited in the tissues, which is also not good.

3. Too much calcium and vitamin D3 in the diet In general, there is little risk of calcium overdose

OTHER VITAMINS

without excessive amounts of vitamin D3. Howev-

The next vitamins – the most important from the

er, too much calcium given at once can affect the

reptile keeper’s point of view – are vitamin A and

efficiency of digestion by neutralizing stomach

K2. Vitamin A is a group of organic compounds

acids and raising the pH in the stomach, which

called retinoids, the most important of which is

is not desirable. That’s why we don’t give reptiles

retinol. Retinol is responsible for eyesight. It also

calcium in the form of mineral preparations for

affects bone growth and development. In the

the future, nor do we try to quickly make up for

body, it is responsible for the proper function-

Snakes and monitors that feed on whole invertebrates (rodents, birds) do not need additional mineral-vitamin supplementation; photo by Dawid Krótki

ing of epithelial tissue: skin, cornea, gastroin-

building it into bone tissue. Vitamin K deficiency

testinal tract and respiratory system. It is mainly

is relatively rare and has been observed mainly

contained in the liver of vertebrates and fish oil.

in crocodiles. Vitamin K is a collective name that

However, its precursors, or previtamins, are carot-

includes a group of derivative compounds found

enoids derived from plant matter, of which be-

in the form of vitamin K1 (phylloquinone), synthe-

ta-carotene is the most significant. Omnivores

sized by plants, and vitamin K2 (menaquinone),

and herbivores have the ability to convert carote-

synthesized by bacteria. Vitamin K2 is mainly

noids into retinol. Besides, carotenoids are great

found in animal products and soy fermentation

antioxidants and they enhance coloration, espe-

products. The third form is vitamin K3, or menadi-

cially orange and red colors. They are an impor-

one, a synthetic analogue of vitamin K that may

tant element of a balanced diet. It is questionable

be a precursor to vitamin K2 in vertebrate organ-

whether carnivorous reptiles such as snakes and

isms. Vitamin K2 is normally produced by bac-

monitors can convert carotenoids into vitamin A

teria in the digestive tract. However, long-term

and more research is needed to be sure they do

administration of antibiotics can significantly re-

not have this ability.

duce the number of probiotic bacteria, causing

Vitamin K plays an important role in bone and

insufficient production of vitamin K2. Its deficien-

blood vessel metabolism, cell growth and apop-

cy is usually manifested by spontaneous hemor-

tosis as well as prevention of vessel and soft tissue

rhages, similar to bleeding gums.

calcification. In bone metabolism, it is responsible for capturing calcium from the blood and

SUMMARY As you can see, the problem of mineral and vitamin supplementation is an extremely complex one, and it depends on many factors. There are no sufficient data to determine specific mineral and vitamin requirements for specific species. However, with appropriate knowledge and experience, we can successfully reduce the risk of both deficiencies and overdoses of these substances in terrarium animals. I would like to stress again that the most important in prevention of metabolic bone diseases in reptiles is to provide appropriate environmental conditions in the terrarium, the most varied and high quality diet possible and a sensible supplementation with mineral and mineral-vitamin products.

LITERATURE Frye F.F., Stosunek wapnia do fosforu w diecie legwana zielonego, Biuletyn SOZ PTZool, nr 10, 2003. Kolb S., Nutritional Secondary Hyperparathyroidism in reptiles, Veterinary Nursing in Action (Oct/Nov), 2017. Konkol D., Cholewińska P., Błędy żywieniowe i wynikające z nich choroby metaboliczne gadów, Życie Weterynaryjne 93(8), 2018. Laing C.J., Fraser D.R., The vitamin D system in iguanian lizards, Comparative Biochemistry and Physiology, Part B 00 373–379, 1999. Mancinelli E., Overview of common nutritional disorders of captive reptiles, Vet Times – The website for the veterinary profession, September 21, 2015, https://www.vettimes.co.uk. McWilliams D.A., Nutrition research on calcium homeostasis. I. Lizards (with recommendations), Int. Zoo Yb. 39, p. 69–77, 2005. Pough F.H., Recommendations for the Care of Amphibians and Reptiles in Academic Institutions, National Academy Press, 33(4), Washington 1991. Stahl Scott J., Feeding carnivorous and omnivorous reptiles, DVM, DABVP (Avian) Proceedings, Association of Reptilian and Amphibian Veterinarians, 2000. Xie S., Low Ji Z., Vitamin A Balance in Reptiles, Conference: Singapore Veterinary Association/Asian Society of Zoo and Wildlife Medicine/Unusual and Exotic Pet Veterinarians/Association of Avian Veterinarians – Australasian Committee Joint Conference, 2013.