The killies of the Lost World
By
Frans Vermeulen
TABLE OF CONTENTS Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
The Guiana Shield. . . . . . . . . . . . . . . . The rivers and water bodies. . . . . . . . . . . The Killies and their habitats. . . . . . . . . . . A natural way to ďŹ ght malaria. . . . . . . . . . Non annuals, their natural habitat and behavior. Prepare best water for the non-annuals. . . . . Breeding and keeping Rivulids. . . . . . . . . . Collecting Killies in the wild. . . . . . . . . . .
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2. THE NON-ANNUAL GENERA. . . . . . . . . . . . . . . . . . . . . . . . . 22
The genus Fluviphylax Whitley, 1965 . . . . . . . . . . . . . . . . 22 The genus Kryptolebias Costa, 2004. . . . . . . . . . . . . . . . . 24 The genus Rivulus Poey, 1880 . . . . . . . . . . . . . . . . . . . . 26 3. THE ANNUAL GENERA. . . . . . . . . . . . . . . . . . . . . . . . . . . . .100
Breeding annuals. . . . . . . . . . . . . . . . . . . The genus Austrofundulus Myers, 1932 . . . . . . The genus Gnatholebias Costa, 1998 . . . . . . . . The genus Llanolebias Hrbek & Taphorn, 2008 . . The genus Micromoema Costa, 1998 . . . . . . . . The genus Rachovia Myers, 1927 . . . . . . . . . The genus Renova Thomerson, & Taphorn, 1995 . The genus Terranatos Taphorn & Thomerson, 1978. The genus Yssolebias Huber, 2013 . . . . . . . . .
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102 104 116 124 128 132 144 148 149
4. INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .152 5. BIBLIOGRAPHY: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156
Rivulus agilae Hoedeman, 1954 Discovered by the Blijdorp Zoo Team, march 1952.
Hoedeman J J 1954 Rivulus agilae, een nieuwe Soort van Suriname. Het Aquarium 24 (9):203.
Max. size SL: 40 mm Dorsal rays (average): 8.0 Anal rays (average): 12.0 D/A deviation (average): 6.0 LL scale count (average): 33.0
This species was originally described as Rivulus agilae but is also known now as Laimosemion agilae, after the Brazilian scientist W. Costa elevated the Rivulid subgenus Laimosemion into the genus - status. The taxon is maintained herein in Rivulus following latest evidence by Huber (2012) (see page 27 “The genus Rivulus” for better understanding).
Synonymes: R. spec. N.S.C. 4
Rivulus agilae was described by the Dutch scientist H.H. Hoedeman from small creeks between the Surinam villages of Agila and Berlijn. The species is widespread in Guyana, Surinam and French Guiana. First discovered by Geay in 1902, Rivulus agilae appears in a wide variety of coloration and body patterns, and is closely related to Rivulus geayi and Rivulus cladophorus. Their habitatis the open savannah region along the coastal belt. They prefer the sunny and half open areas, mostly in “black water” creeks and the surrounding swamps, usually with a white sandy bottom. They seek the outer boundaries of the creeks, and travel over land to nearby pools, where they live eating mosquito larvae and other insects. Females have a “Rivulus spot” (which is often not very distinct). As they age the spot becomes less distinct, eventually shading into several dark blotches. In many locations Rivulus agilae is sympatric with a member of the Rivulus urophthalmus group. In French Guiana populations show, in general, deep red colors on the body, and are black at the caudal lower margin. The sub marginal yellow lower band is often not present and is replaced by the same red colour of the body.
Alternative name: Laimosemion agilae.
To the west, in neighbouring Guyana, more blue develops on the body, the
yellow submarginal lower band of the caudal fin is often intense, and the black margin is less strong. The body is less elongated, in comparison to their French counterparts. This territorial expansion is known from French Guiana, Surinam, and The Cooperative Republic of Guyana, and probably finishes somewhere east of the Orinoco Delta in Venezuela, or in the western part of Guyana. No collection of Rivulus has been undertaken in the coastal area between the west bank of the Essequibo River and the Orinoco in Venezuela, so it not known where the distribution of this species ends to the west. Reproduction in the aquarium is best when water is moderately acid (pH5.5-6.5), and with low conductivity. Lowering the water level to 5 cm (or less) is not a must, but will trigger egg production. They like sunny places, contrary to most other Rivulid species that live in the primary forest. Eggs need 12 to 16 days to develop, and fry can eat fresh Artemia nauplii from the first day. Their life span can be 2.5 to 3 years, and for most of their life they are productive. Egg production is about 5-10 eggs a day, if the fish are kept in good condition, fed with mosquito larvae, and are given weekly water exchanges. Rivulus agilae is a close relative of Rivulus geayi, the latter appears to be a complementary species inhabiting the interior on laterite iron-rich soils. In contrast and mentioned already , Rivulus agilae prefers white sandy soil from the coastal range, where trees do not form primary forests, but remain shrublike or form secondary forest. Rivulus agilae is probably the most inventive among all Rivulid species, and is able to find the most incredible places in which to live and reproduce. If you understand how to search for them, you will find Rivulus agilae in several types of habitat. Over the years during my collecting expeditions through Surinam and the Guyanas, I often collected them in swamps, but more often in and around black water creeks. The most remarkable place was the 25-degree descending slope of the platform forming the main runway of Timehri Airport (Guyana’s international airport), in the wetlands south of Georgetown. A dirt road (named “Duck Road”) brought me to the foot of that platform. Amazingly, Rivulus agilae were living on that steep hill between hillside grasses, more than 50 meter distant from the creek below. Water was percolating down through the soil, and was hard to see. In that environment we collected many Rivulus agilae just by using our hands, as a net was not useful there anyway. At the opposite end of long the runway there was a pig farm close to a black water creek, next to a swampy area. The swamp was filled with a thick layer of grasses and other aquatic plants. This layer was so dense that we could walk on it without sinking. At places we were able to break a hole in the thick layer, and we collected beautifully colored Rivulus agilae (by the hundreds, if we had wanted to). We only collected some nice subadult ones for scientific purposes, and for breeding back home. See this wonderful fish on top of the next page.
On the image to the right you see a female Rivulus agilae. Sometimes there is also an ocellus (‘spot’) at the caudal peduncle. In Rivulus agilae females this caudal ocellus is not always present, and usually fades away completely with age.
Right: From Loo Creek, a tributary to the Essequibo river, crossing the road to Linden, is this bleu phenotype that was collected several times during our visits to Guyana.
At the right one of the males of the Rivulus agilae that could be collected in a creek that was crossing the Kwakwani village centre. We also could collect some Rivulus aff. stagnatus in the swamp that was next to the creek.
The male at the right was collected in 2010 during a visit to the Berbice river area in Guyana. A small creek, tributari to the Berbice river on the road south from Kwawani we were able to collect only a few of them.
Right: A dominant male also collected in 2010 in a bushcreek that we found at a hill near the Mappa Lake, a dead arm of the Berbice River.
Gnatholebias zonatus (Myers, 1935) Discoverer: Dr F.F. Russell, representative of the International Health Board of the Rockefeller Institution, 1928. Described as Pterolebias zonatus. Max. size: 110 mm. Female: much smaller. Dorsal rays average: 11.6 male only. Anal rays average: 22.4 male only. D/A deviation average: 9.1 male only. LL scale count average: 33.6 Predorsal length (% S.L.) average: 75.2 % Depth (% S.L.) average: 26.5 % male only. Below the female with the same pattern of stripes as the males and more prominent as the weak stripes shown in females of G. hoignei.
Myers, G.S. 1935. Four new Freshwater Fishes from Brazil, Venezuela, and Paraguay. Proc. Biol. Soc. Wash., 48: 7. Type locality: Orinoco basin, Guarico state (without details), Venezuela. The species prefers ponds and pools in open terrain but also lives in bush savannah and on the floodplains near rivers in the Llanos of Venezuela. It is found in the Apure- Barinas- and in Portuguesa state in Venezuela. These planes are filled with water during the rainy season but dry out during long periods in between. So now and then Gnatholebias zonatus is found in the same habitat of its sister species Gnatholebias hoignei. More often it is collected in company of Rachovia maculipinnis and Llanolebias stellifer. The name “zonatus” is given to expresse the “bands” or “zones” this fish shows on its body. Breeding is not much different than for G. hoignei. Only it happened two times in my breeding set-up that I lost the species because of the lack of females in their offspring. Having 120 adult males and no females is frustrating...but gives a spectacular view. It is not known what is the reason for this but I found always more males than females of this species in the wild while collecting. The species can be very different in its appearance as you can see at the various images in the pages hereafter. Keeping this fish in a school is giving a real joy to us as a hobbyists and their behaviour, if kept in a large community tank with friendly other fish species, is a wonderfull spectacle for the eyes. They do not hide like many other Killies do and love to swim in the open water, showing off to other males and driving the females towards a suitable place for reproduction. The only thing is that other fish bite off the long streamers in their fins.
Dear Hobbyist, What you have in your hands is a folder with a few examples about how the content of my book is written and in which way the fishes are shown. It is a 175 page, full color book, 175x250 mm format, covering all known Killie fishes that are living on, and around, the Guiana Shield which is the oldest massive in earths history. It is divided in categories of non-annuals and annuals. This book is the first issue of a series of four books that will cover all the known Killies of the Middle- and South America’s. This book will not only provide data on history and practical keeping or breeding methods. It also provide recent stories of collecting in their countries of origin and give actual info about what to keep in mind if you start collecting yourself. The book will be available very soon and you can put your name on a list of people that are interested in having this unique and up-to date work without any obligation. Just send me an e-mail at vermeulen@setarnet.aw or visit my website www.itrainsfishes.net and fill in the Contact form with your name and full address. (Mention “BOOK” ) The book will cost about 39 Euro (US 54) shipping not included and after it’s release you will get informed by me about the exact costs including shipping and the way to order. Be one of the first to have this work in your collection and enjoy the beauty of your fishes in this beautiful illustrated work. I look forward to your interest.
Frans Vermeulen Aruba.