Shark Trust - Angel Shark ID Guide

A guide to angel shark identification

A guide to angel shark identification

Published by: The Shark Trust

Citation: Gordon, C.A. (2022). A guide to angel shark identification.

The Shark Trust, United Kingdom. 46 pp. First edition 2022.

Copyright: All illustrations are copyright to Marc Dando. Featured images are attributed to photographers. Text has been compiled from IUCN Red List entries, Sharks of the World (Ebert et al., 2021) and scientific publications.

Front cover image: Japanese Angelshark (Squatina japonica) © Andy Murch

Funded by

WHAT ARE ANGEL SHARKS?

Angel sharks* are large, dorso-ventrally flattened sharks. They are characterised by having a short snout with large mouth and nostrils, the eyes are positioned on top of the head with large spiracles set behind them. The pectoral fins are broad and allow them to bury into the soft sediment of coastal and continental shelf habitats. Two spineless dorsal fins are set back on the precaudal tail, with the first dorsal originating either over or behind the free rear tips of the large pelvic fins (Ebert et al., 2021). They are demersal “lie-and-wait” ambush predators, with trap-like jaws which protrude to snap up prey at speed. The general diet of angel sharks includes bony fishes, crustaceans, and molluscs.

Squatinidae is the only family in the order Squatiniformes. This contains just one genus (Squatina), currently with 23 accepted valid species** of angel sharks. Many of these species have overlapping ranges, and, due to similarities in morphology, can be challenging to distinguish, causing some confusion with species identification. This unique group of sharks has been repeatedly misidentified around the world. In some regions, angel sharks have been landed as rays, confused with the bony fish ‘monkfish’ (Lophius spp.) or grouped together as aggregated catch.

Recording angel sharks by genus, or in larger aggregated categories, can mask population declines and therefore hinder implementation of effective fisheries management and conservation efforts.

DISTRIBUTION

There are three described species of angel shark in the Eastern Atlantic and Mediterranean Sea; seven in the Western Atlantic (with three in the Northwest/Western Central Atlantic and four in the Southwest Atlantic); two in the Eastern Pacific; six in the Northwest Pacific; four in the Eastern Indian Ocean/Western Central Pacific; and one in the Western Indian Ocean. In this guide, they have been grouped according to geographic region and appear in alphabetical order.

VARIATIONS

Many species display colour and pattern variations, whether between adults/juveniles, females/males, or in different regions. In addition, some species are known only from a few specimens – in some instances just the holotype or paratype – and so variations or maximum sizes are not yet known.

*When used as two words, angel shark refers to multiple species within the family Squatinidae, when used as one word (Angelshark) it relates to a species common name (e.g. Angular Angelshark).

**Two additional nominal species have been described from the Gulf of Mexico – Squatina heteroptera and S. mexicana – however neither are considered as valid species and are likely junior synonyms of Squatina dumeril. The group is poorly known in many regions and further species are awaiting formal description.

Following preservation, colour generally fades, and patternation/spots become more indistinct and may appear to change colour. Therefore, the colouration seen in living specimens varies greatly to those captured in fisheries/seen on markets, or preserved in museum specimens. In the case of Squatina guggenheim, it has been noted that specimens have a mucous layer which causes the spots to appear a different colour – it is possible this also occurs in other species.

The diagnostic features shown on the illustrations included within this guide are based on descriptions in published literature, along with the best available images – which are often limited given the rarity of many species. As such, we would welcome additional images or feedback to enhance future editions of this guide.

EASTERN PACIFIC

Chilean Angelshark Squatina armata

Distribution: Southeast Pacific from Columbia to the Strait of Magellan, southern Chile. May overlap with Squatina californica in the northern parts of its range.

Fisheries: Taken as retained bycatch in trawl and gillnet fisheries. The fisheries within its range have generally been increasing in effort, yet catches have declined. Meat is used locally for human consumption, and in Peru the eggs are also valued.

12

DEPTH: The maximum known depth range for this species.

MAXIMUM LENGTH: Measured from the tip of the snout to the tip of the tail (split by female/male where stated in literature).

FAO cODE: Three letter code assigned by the Food and Agriculture Organization, this is unique to each species.

IUcN RED LIST STATUS: Global conservation status according to the International Union for Conservation of Nature’s Red List of Threatened Species (see page 8).

Chilean Angelshark p12 Squatina armata

EASTERN PACIfIC

Pacific Angelshark p13 Squatina californica

Sawback Angelshark p21 Squatina aculeata

Smoothback Angelshark p22 Squatina oculata

Angelshark p23 Squatina squatina

Philippine Angelshark p25

Squatina caillieti

Taiwan Angelshark p26 Squatina formosa

Japanese Angelshark p27 Squatina japonica

Indonesian Angelshark p28 Squatina legnota

Clouded Angelshark p29 Squatina nebulosa

Ocellated Angelshark p30 Squatina tergocellatoides

WESTERN ATLANTIC

Argentine Angelshark p14 Squatina argentina

David’s Angelshark p15 Squatina david

Atlantic Angelshark p16 Squatina dumeril

Angular Angelshark p17 Squatina guggenheim

EASTERN ATLANTIC AND MEDITERRANEAN

WESTERN INDIAN oCEAN

NoRThWEST PACIfIC

African Angelshark p24 Squatina africana

Small-crested Angelshark p18 Squatina mapama

Hidden Angelshark p19 Squatina occulta

Vari’s Angelshark p20 Squatina varii

EATERN INDIAN oCEAN & WESTERN CENTRAL PACIfIC

Eastern Angelshark p31 Squatina albipunctata

Australian Angelshark p32 Squatina australis

Western Angelshark p33 Squatina pseudocellata

Ornate Angelshark p34 Squatina tergocellata

MORPHOLOGY AND SIMILAR SPECIES

Due to similarities in morphology, species are often grouped in aggregated categories in landings data. Resolution of the taxonomic issues and identification problems associated with this genus in many regions is a high priority to help better monitor catch levels and inform management and conservation efforts.

Many species have distinct geographic ranges and so identification can be narrowed down according to region. However, some regions have multiple species occupying similar habitats. The presence or absence of thorns is a key distinguishing feature to assess, along with whether the pelvic fins extend to the first dorsal fin.

Given their flattened body shape and broad pectoral fins, angel sharks are similar in appearance to many ‘shark-like rays’ – including giant guitarfishes and wedgefishes (collectively known as rhino rays), guitarfishes, sawfishes, and banjo rays. The first step in distinguishing from these rays is to check position of mouth and gills.

See Wedgefishes and Giant Guitarfishes: A Guide to Species Identification (Jabado, 2019). https://tinyurl.com/yckhdh7e

Five paired gill slits on side of head

Terminal mouth

Dorso-ventrally flattened body

Short caudal penduncle

Argentine Angelshark

(Squatina argentina)

Long upper and even longer lower lobe of caudal fin

Two dorsal fins set back on tail (either set behind or meeting the free rear tips of pelvic fins)

Bowmouth Guitarfish

(Rhina ancylostoma)

Five paired gill slits on underside of head

Mouth on underside of head

Dorso-ventrally flattened body

Large first dorsal fin (set above pelvic fins in wedgefishes and well behind tips of pelvic fins in giant guitarfishes)

Second dorsal fin positioned further back Upper lobe of caudal fin longer than lower lobe

Pectoral fin attached to side of head

Blackchin Guitarfish

(Glaucostegus cemiculus)

THREATS AND DECLINES

Despite their ability to hide beneath the sand to avoid detection from potential predators and prey, angel sharks have not been able to escape the intensification of demersal fisheries. The slow growth and demersal nature of angel sharks means they are highly susceptible to fishing activities and they can easily become entangled in towed trawl gear and large-mesh gillnets. Although they are not necessarily directly targeted, bycatch is often utilised.

As a result of population declines, Squatinidae has been identified as one of the most threatened families of chondrichthyans (sharks, skates, rays, and chimaeras) in the world, with many species requiring urgent conservation action (Dulvy et al., 2014; Dulvy et al., 2021). Of the 23 described species, 13 are now listed in a threat category on the IUCN Red List of Threatened Species (eight Critically Endangered, four Endangered, and one Vulnerable), while one species remains Data Deficient and one recently discovered species is Not Evaluated.

Given the drastic declines of Squatina spp. in regions where they have been intensively fished, it’s clear that the family is unable to sustain intense fishing pressure. As such, catches (including of those species classified as Least Concern) should be carefully monitored to understand population trends and inform management. For those species already facing declines, a suite of measures should be considered, including species protection, spatial management, and bycatch mitigation.

CONSERVATION STATUSES

IUCN RED LIST CATEGORIES

NE

DD

Not Evaluated: not yet evaluated against IUCN Red List criteria.

Data Deficient: inadequate information exists to make an assessment.

Least Concern: low risk of extinction.

NT

Near Threatened: close to qualifying for a threatened category in the near future.

Vulnerable: high risk of extinction in the wild.

EN

cR

Endangered: very high risk of extinction in the wild.

Critically Endangered: extremely high risk of extinction in the wild

In many regions of the world angel sharks are still caught and retained. They are sold mainly for their meat, but also for their fins, eggs, and liver oil – as well as being utilised as fishmeal.

Despite all three Mediterranean species having a prohibition banning retention, they are still observed for sale in many fish markets (Gordon et al., 2019). In Libya, shark meat (including angel shark) is marketed as ‘sea dog’ without further clarification of species, and the eggs are sold as a treatment for urinary incontinence in children (pers comms.

Sara A. Al Mabruk).

In South America, angel shark meat is sold fresh or salted and dried for local consumption. Despite being officially protected in Brazil, angel shark meat is marketed as ‘cacao anjo’ and it typically sells for a higher price than other shark meat. In Argentina, angel sharks are retained as bycatch and sold locally for the meat to either be consumed fresh as ‘pollo de mar’ (chicken of the sea) or salted and dried as ‘bacalao argentino’ (Argentine cod) (Chiaramonte, 1998).

Off the coast of Senegal, the fins of the Smoothback Angelshark (Squatina oculata) were prepared under the name of ‘laâf’ and exported (Capapé et al., 2002), while the liver oil was extracted and used to protect fermented dried fishes from infestation by insects.

Angelshark (Squatina squatina) meat in Libyan market

© Sara A Al Mabruk

AFRIcAN ANGELSHARK

SAWBA

VARI’S ANGELSHARK

ANGULAR ANGELSHARK

EASTERN ANGELSHARK

SMALL-cRESTED

INDONESIAN ANGELSHARK

DAVID’S

Chilean Angelshark Squatina armata

Distribution: Southeast Pacific from Columbia to the Strait of Magellan, southern Chile.

May overlap with Squatina californica in the northern parts of its range.

Fisheries: Taken as retained bycatch in trawl and gillnet fisheries. The fisheries within its range have generally been increasing in effort, yet catches have declined. Meat is used locally for human consumption, and in Peru the eggs are also valued.

♂

Dorsal surface is reddish-brown to grey in colour

Narrow head

Heavy thorns on snout and between eyes and spiracles

Enlarged thorns on the leading edge of the pectoral fins

Pelvic fin tips do not reach origin of first dorsal fin base

Narrow and simple barbels with anterior nasal flaps fringed

Double row of large, hooked thorns on midline of back extending beyond dorsal fins to the tail

Depth Max. length FAO

DMZ150cm30-75m

cR

Pacific Angelshark Squatina californica

Distribution: Northeast Pacific from Alaska to Baja California, Mexico (including Gulf of California). Possibly also occurs in the Southeast Pacific where it would be sympatric with Squatina armata, however there is some confusion with species in the region.

Fisheries: Through a ban on gillnet fisheries targeting California Halibut, fishing of Squatina californica is indirectly regulated and minimum retention size limits are in place. In Mexico, some fisheries must record angel shark catches in logbooks, and there are seasonal fishing closures for fisheries targeting elasmobranchs.

Concave between large eyes

Reddish-brown to sandy brown in colour

Scattered spots (set around dark spots in adults)

Large paired dark blotches on back and tail form large ocelli

Dark blotches at base of dorsal fins

Simple, conical nasal barbels with spatulate tips

Weakly fringed anterior nasal flaps

Spotted tail with dark blotch at base

Max. length FAO

White edged pectoral and pelvic fins

Argentine Angelshark Squatina argentina

Distribution: Southwest Atlantic from Santa Catarina, Brazil to Buenos Aires, Argentina.

Fisheries: Formerly common but taken as target and bycatch species along with S. guggenheim and S. occulta in demersal trawl, gillnet, and longline fisheries – despite protective measures. Angel shark landings are typically aggregated.

♀

Purplish-brown in colour (or dark-brown to reddish-brown)

Many scattered dark brown spots, mostly in a circular group around a central spot

No triangular lobes on lateral head folds

Concave between the eyes Enlarged thorns on snout

X No mid-dorsal line of thorns or enlarged dermal denticles

X Squatina

argentina lacks thorns between spiracles (a pair of thorns is present in other Western Atlantic angel sharks).

Large angular pectoral fins which are twice as long as they are wide

Paler dorsal fins

Simple, spatulate nasal barbels

Slightly fringed or smooth anterior nasal flaps

Depth Max. length FAO

cRSUG138cm51-320m

David’s Angelshark Squatina david

Distribution: Southern Caribbean from Panama to Suriname and possibly to northwest Brazil.

Fisheries: Likely taken as bycatch in small-scale artisanal and commercial fisheries – including gillnets, trawls, and longlines.

(Acero et al., 2016; Vaz & de Carvalho, 2018)

Distance between eye and spiracle is 1.5x larger than eye diameter in specimens >60 cm TL

Males have dark spots; females have abundant whitish spots

X No mid-dorsal line of thorns or enlarged dermal denticles

♂

Pelvic fin tips do not reach origin of first dorsal fin base

Nasal flaps have two rod-like barbels

Inner barbel has no fringe Outer barbel is divided

Nasal flap is a rounded triangle pointing downward, without fringes or serrations

Up until 2016, angel sharks caught in the southern Caribbean were thought to be S. dumeril until S. david was formally described.

Grey-brownish yellow in colour

Mature males have narrow patches of denticles on anterior edges of pectoral and pelvic fins (poorly developed in females)

Depth Max. length FAO NT

Unknown Largest described is 79cm 100-326m

ASK

Atlantic Angelshark Squatina dumeril

Distribution: Western Atlantic, from Massachusetts to Florida, Gulf of Mexico and Mexican Caribbean

Fisheries: Protected throughout US waters so there is no directed fishery, however, is still caught as accidental bycatch in trawl fisheries.

NB: Two additional nominal species (S. heteroptera and S. mexicana) have previously been described from the western Gulf of Mexico, however with lack of distinguishing morphological characteristics and DNA studies, there is still some confusion as to whether they are valid species and so they are often regarded as synonyms of S. dumeril.

Blue-grey to ash-grey in colour with reddish hue to head and fin margins

♀

Dark spots can be irregularly present, but can be absent

Strongly concave between the eyes

A few small discrete thorns are present on the snout and between the eyes

Simple, tapering nasal barbels

Weakly fringed or smooth anterior nasal flaps

X No elaborate markings or ocelli

Eye-spiracle space

<1.5 times eye diameter

Pectoral fins are broad and posteriorly angular

Juveniles may have small white spots, along with thorns along the back from head to the dorsal fins (inconspicuous in adults).

SUD152cm0-1290m

Depth Max. length FAO Lc

Angular Angelshark Squatina guggenheim

Distribution: Southwest Atlantic from Rio de Janeiro, Brazil to northern Patagonia, Argentina.

Fisheries: Angel sharks are heavily fished in this region and significant declines have been documented. Taken as target and bycatch species in demersal trawl, gillnet, and longline fisheries, with landings typically aggregated.

NB: Mucous on dorsal surface has blackish pigments that appears to form darker rounded spots over whiter blotches. The dark spots shown on this illustration show the colour of the mucous on the skin – representing how they appear before this layer is washed away.

Small, rounded spots surround some larger blotches, forming irregular rosettes

Spots of variable size, with larger blotches on pectoral and pelvic fins

Dark tan in colour

♀

Short thorns in symmetrical groups on snout, between eyes, and between spiracles

Row of midline thorns from mid-length of pectoral fin base to the first dorsal fin (sometimes to caudal fin)

Pelvic fin tips do not reach origin of first dorsal fin base

S. punctata is a junior synonym of S. guggenheim

Three pairs of dark blotches on tail

Pectoral fins angular, with anterior margins nearly straight

Anterior identifying features

• Broadly concave between the eyes

• Anterior nasal flaps weakly fringed

• Unfringed nasal barbels

• Lateral folds without triangular lobes

Depth Max. length FAO

130m10-80m

EN

Small-crested Angelshark Squatina mapama

Distribution: Known only from the type location off the Caribbean coast of Panama.

Range overlaps with S. david by at least 500 km.

Fisheries: Unknown but may have depth refuge.

(Long et al., 2021)

Small scattered dark spots in males (larger along edge of head, outer half of pectorals & base of pelvic fins)

Colour light brown to tan (prior to preservation)

♀

A few large denticles on top of the head

Moderately angular pectoral fins, with anterior margin mostly straight and posterior margin slightly concave

Single dorsal midline row of slightly enlarged denticles

Species currently known only by two juvenile specimens smaller than 40cm TL.

Pelvic fin tips do not reach origin of first dorsal fin base

Pelvic fins broadly triangular

Edges of pectoral & pelvic fins fade into a lighter brown with a whitish margin

Anterior identifying features

• Narrow mouth

• Distinct nasal flaps protruding from dermal folds above mouth. Nasal flap squared with a fine fringe on ventral edge

• Inner and outer nasal barbels short, flattened and rounded with a fine fringed margin

• Upper-lip arch semi-circular and broader than high

Depth Max. length FAO

Holotype caught at 1190m -1259m

Immature male (holotype) 40cm

ASK

NE

Hidden Angelshark Squatina occulta

Distribution: Southwest Atlantic from southern Brazil (Rio de Janeiro) to Argentina (Buenos Aires Province – possibly further south to northern Patagonia).

Fisheries: Angel sharks are heavily fished in this region and significant declines have been documented. Despite protections in Brazil, enforcement regulations are not sufficient, and they are still caught illegally. In Argentina and Uruguay, there is a TAC for angel sharks.

♀

2-3 enlarged denticles anterior and a pair posterior to each eye; and a pair between spiracles

Some larger white spots are surrounded by many black dots, forming irregular ocellilike markings

Numerous small white to yellowish spots and larger blackish marks

Head concave between eyes

Uniform dark tan in colour

Two rows of 3-4 enlarged denticles between nostrils

Three pairs of large blackish blotches, (adjacent to pelvic fin tip, first dorsal fin, and second dorsal) may be present

High and angular pectoral fins with leading edge straight and posterior edge concave

Anterior nasal flaps are very large with well developed barbels

Nasal barbels have cylindrical bases with unfringed tips

SZJ130m10-350m

Depth Max. length FAO cR

Vari’s Angelshark Squatina varii

Distribution: Southwest Atlantic in eastern Brazil from northern Rio de Janeiro State to Sergipe State.

Fisheries: This species likely has depth refuge as no deepwater fisheries currently operate within its range.

(Vaz & de Carvalho, 2018)

♂

Very few (<20) rounded white spots on trunk and pectoral fins, sometimes absent

Pair of enlarged dermal denticles between spiracles

Dark to light brown in colour

A semi-elliptical lobe projects from the lateral dermal fold of the head (its presence distinguishing S. varii from other Southwest Atlantic angel sharks)

Pectoral-fin spots consistently arranged with one close to the pectoral origin, one on the medial region, and a pair of spots horizontally aligned on the posterior third of the pectoral fin length

Dark spots on dorsal of some specimens – no symmetrical pattern

Pelvic fin tips do not reach origin of first dorsal fin base

Three pairs of dark blotches on tail (on origin, first dorsal-fin base, and second dorsal-fin base)

ASK♀ 132cm 195m -666m

Depth Max. length FAO Lc

Sawback Angelshark Squatina aculeata

Distribution: Eastern Atlantic from Senegal to Sierra Leone, and the Mediterranean Sea.

Despite prohibitions on retention in the Mediterranean,

species is still caught and retained as bycatch.

et al.,

Gordon et al.,

One row of dorsal spines

from other species in the region)

Light grey/brown mottled

darker brown

Large dark blotches on dorsal surface and tail may be present

Concave between eyes

Large thorns on head (spines on the snout and above the eyes)

fin tips extend

origin of

dorsal fin

Irregular small, white spots and regular small, dark brown spots

Heavily fringed nasal barbels and anterior nasal flaps

FAO

Smoothback Angelshark Squatina oculata

Distribution: Eastern Atlantic from Senegal to Ghana, and the Mediterranean Sea (predominantly the central and eastern basins).

Fisheries: Despite prohibitions on retention in the Mediterranean, this species is still caught and retained as bycatch.

et al., 2019; Gordon et al., 2019)

Small white and dark spots

Sometimes symmetrical brown ocelli surrounded by white spots on pectoral fins, tail, and body

Smallest of the three Mediterranean species

Thorns present above the eyes and around the snout

Grey-brown

♀

Dorsal and caudal fin margins are white

Pelvic fin tips do not reach origin of first dorsal fin base

Large dark blotches on base and rear tips of pectoral fins, tail base, and under dorsal fins

Anterior nasal flaps weakly fringed

Strongly concave between eyes

Weakly bifurcate or lobed nasal barbels

Depth Max. length FAO

20m -560m

160cm

145cm

Angelshark Squatina squatina

Distribution: Northeast Atlantic (Celtic Seas ecoregion), Canary Islands and Mediterranean Sea.

Fisheries: Intensification of demersal fishing practices over the past century led to widespread declines and fragmented populations – this species now receives full protection in the UK and Canary Islands. Prohibitions on retention are in place in the Mediterranean, however it is still widely caught and retained as bycatch.

et al., 2019; Gordon et al., 2019)

Reddish or greenish-brown

small white spots and dark dots

Pattern of lighter lines

nasal barbels

Lateral head folds with singular triangular lobe each side

Small patches of thorns on the snout and between the eyes

Concave between the eyes

or weakly fringed anterior nasal flaps

Max. length FAO

Broad pectoral fins

African Angelshark Squatina africana

Distribution: East and southern Africa from Somalia to South Africa, and Madagascar.

Fisheries: Caught in large-scale and small-scale fisheries, many of which are unregulated. The population around KwaZulu-Natal, South Africa appears stable, however suspected declines are anticipated throughout the remainder of its range.

Grey-reddish brown in colour

Young often have large granular centred ocelli

♂

Numerous light and dark spots

Simple, flat nasal barbels with tapering or spatulate tips

Concave between eyes Enlarged thorns on head

No angular lobes on lateral dermal flaps

Darker saddles across bases of dorsal fins

White blotches on tip and base of dorsal fins and tips of caudal lobes

Anterior nasal flaps smooth or slightly fringed

Depth Max. length FAO NT

SUF122cm494m

Philippine Angelshark Squatina caillieti

Distribution: Western Central Pacific – only known from type specimen caught southeast of Luzon, Philippines.

Fisheries: Unknown – deepwater fisheries (including deep-set hook and line) operate in the Philippines.

(Walsh et al. 2011)

Greenish brown in colour

Numerous dark brown spots outlined in white margins

♀

Following preservation, colour fades to deep brown with white spots, and subdorsal saddles/ white margins on pelvic fins no longer visible.

Eyes almond-shaped and close-set

Pelvic fin tips extend to origin of first dorsal fin

Black subdorsal saddles

Upper lip arch semi-oval in shape

Simple, unfringed nasal barbels, with rod-like tips

White margins on pelvic fins

Inter-dorsal space greater than dorsalcaudal space (separating species from S. formosa and S. nebulosa)

Depth Max. length FAO

ASKUnknown Unknown Holotype caught 363-385m

DD

Taiwan Angelshark Squatina formosa

Distribution: Northwest Pacific, endemic to Taiwan.

Fisheries: Subject to fishing pressure across its range. Taken as retained bycatch, in particularly large numbers in demersal trawl fisheries. Retained for meat and fins (which are of low value), with smaller individuals used for fish meal.

Light to dark brown with numerous dark and light spots of varying sizes

♀

Eye-spiracle space less than eye length

Small pairs of dark ocelli

Many small light and dark spots, with larger irregular blotches

Patches of enlarged denticles on snout, between eyes

Head concave between large eyes

Saddle or dark band across base of dorsal fins Lobed caudal fin

Weakly fringed or smooth anterior nasal flaps, no triangular lobes on lateral head folds

Simple, flat nasal barbels, tapering around tips

Upper lip arch semi-circular (height greater than in other Squatinids in the region )

Pelvic fin tips extend to origin of first dorsal fin

Pectoral fins broadly rounded, especially posterior free tip

Colour after preservation fades to a lighterbrown with spots becoming more indistinct.

Depth Max. length FAO EN

SUO150cm100m -400m

Japanese Angelshark Squatina japonica

Distribution: Northwest Pacific from southern Russia to southern Taiwan, including Japan, North Korea, South Korea, and China.

Fisheries: Taken as retained bycatch in fisheries operating down to 300m. Fishing pressure is high across the entire spatial and depth range of this species, providing little refuge.

(Walsh & Ebert, 2007)

Dense dark and small irregular white spots on dorsal surface

Rusty brown in colour with distinct freckled pattern

♀

Small thorns on snout, between eyes and spiracles

Large paired dark redbrown spots from base of head to pelvic fins

Prominent row of midback thorns extending to the caudal peduncle (the only Squatinid in this region with midback thorns)

Wide but shallow upper lip arch

Concave between large eyes

Pelvic fin tips do not reach origin of first dorsal fin base (unique to S. japonica and S. tergocellatoides in this region)

Broad pectoral fins, rounded posteriorly

Weakly fringed or smooth nasal flaps

Cylindrical nasal barbels, with slightly expanded tips

Lateral head folds without triangular lobes

SUJ200cm10-352m

Depth Max. length FAO cR

Indonesian Angelshark Squatina legnota

Distribution: Central Indo-Pacific in southern Indonesia (West Java to Flores Island).

Fisheries: There is intensive fishing pressure across the entire range of this species in Indonesia. It has been reported to be caught incidentally on demersal longline fisheries, but is now only rarely landed.

Pale blotches

Uniformly greybrown

♂

Species known from just a few specimens.

Two dark, subdorsal saddles

Identifying features

• Short snout

• Head weakly concave between large eyes

Anterior nasal flap with unfringed barbels

• Upper lip arch half-oval in shape

First dorsal fin base longer than second

Pelvic fin tips extend to origin of first dorsal fin

ASK134cmUnknown

Depth Max. length FAO cR

Clouded Angelshark Squatina nebulosa

Distribution: Western North Pacific from Japan (including Ryukyu Islands), to Taiwan (including North Korea, South Korea, and China).

Fisheries: Retained bycatch in demersal fisheries (trawl, gillnet, set net, and longline) operating down to 600m.

(Walsh & Ebert, 2007)

Dark brown to blueish-brown

Large rounded dark spot at base of pectoral fin

Scattered light and dark spots of varying sizes

Upper lip arch

half-oval in shapeLateral head folds with two triangular lobes each side

Pelvic fin tips extend to origin of first dorsal fin

Angular pelvic, dorsal, and caudal fins

Weakly fringed or smooth anterior nasal flaps

Simple tapering nasal barbels

Light dorsal fin margins

Dark blotches at base of dorsal fins

Broad, posteriorly rounded pectoral fins

SUL200cm 0-330m possibly deeper

Depth Max. length FAO EN

Ocellated Angelshark Squatina tergocellatoides

Distribution: Northwest and Western Central Pacific in Taiwan and China (South China Sea), as well as Vietnam and Borneo.

Fisheries: Subject to fishing pressure across its entire range. Caught as bycatch in demersal fisheries and retained for meat and fins, with smaller individuals used for fish meal.

(Walsh & Ebert, 2007; Theiss & Ebert, 2013)

Dense scattering of small round white spots

Six pairs of large black spots on pectoral fins, pelvic fins, and tail base

Following preservation, colour fades and spots become almost indistinguishable.

Lateral head folds have two low rounded lobes on each side

Light yellowishbrown

Concave between the eyes

Strongly fringed anterior nasal flaps

Ornate, finely fringed nasal barbels

Black blotch at base of each dorsal fin

Pelvic fin tips do not reach origin of first dorsal fin base (unique to S. tergocellatoides and S. japonica in this region)

Caudal fin triangular in shape, with lower lobe longer than upper lobe (unique to Western North Pacific Squatinids)

Depth Max. length FAO EN

SUN150cm100m -300m

Eastern Angelshark Squatina albipunctata

Distribution: East coast of Australia from Cairns (Queensland) to Lakes Entrance (Victoria). Between Newcastle (central New South Wales) and eastern Victoria, this species overlaps with S. australis

Fisheries: Has been heavily fished and remains a marketable bycatch in the southern part of its range. Captures are much rarer in the northern part of its range, where abundance is anticipated to be lower.

Yellow-brown to chocolate-brown in colour (though colouration and patternation are highly variable)

Spiracles close to eyes, wider than eye-length

Short snout

White nuchal spot

Large dark blotches

Dense pattern of symmetrical small, white, dark-edged spots

Heavy orbital thorns (distinguishing from Squatina australis) Concave interorbital space

Nasal barbels have expanded tips and lobate fringes

Depth Max. length FAO VU

130cm

110cm

Australian Angelshark Squatina australis

Distribution: East and south of Australia from Newcastle (New South Wales) south and west to Rottnest Island, (Western Australia). Between Newcastle (central New South Wales) and eastern Victoria, this species overlaps with S. albipunctata.

Fisheries: Taken as retained bycatch in managed gillnet and trawl fisheries targeting higher valued species.

(Last & Stevens, 2009)

Dull greyishbrown in colour

♀

Small spiracles

X No large thorns in adults, young have enlarged denticles on snout, head, and multiple predorsal rows

Dense white spots with small darker brown spots (some individuals have more darker brown medium spots, often arranged in small rosettes with fewer paler spots, others have more whiter spots and so the individual appears paler in colour)

White-edged fins

Spots on leading edge of pale dorsal fins

Head flat or convex between eyes

Heavily fringed nasal barbels and anterior nasal flaps

No triangular lobes on lateral head folds

Numerous dark spots on lower lobe of caudal fin

Depth Max. length FAO Lc

0m -130m

SUU152cm

Western Angelshark Squatina pseudocellata

Distribution: Northwest Australia from Cape Leveque to Shark Bay (Western Australia).

Fisheries: Poorly known, but likely only minor bycatch as fishing effort is low within the species range. Its range also overlaps with some areas closed to trawling, offering additional refuge.

Pattern of widely spaced grey-blue spots and brown blotches

Medium to pale brown or grey

♂

Short snout

Single small white nuchal spot

Medial row of predorsal thorns

Strong orbital thorns

Head concave between eyes

Nasal barbels with expanded tips and lobate fringes

Light unpaired fins

Depth Max. length FAO

ASK

Lc

-312 m

Ornate Angelshark Squatina tergocellata

Distribution: Southwest Australia from Port Lincoln (South Australia) to Geraldton (Western Australia).

Fisheries: Commonly taken as bycatch in managed fisheries (Great Australian Bight Trawl Sector of the Southern and Eastern Scalefish and Shark Fishery).

(Last & Stevens, 2009)

Pale yellow-brown

Strongly concave between the eyes

Grey-blue or white spots

Strongly fringed nasal barbels and anterior nasal flaps

Fins pale with spots/blotches

Three pairs of large ocelli, dark rings around centres with amitotic pattern

Max. length FAO

140cm

SUE

Japanese Angelshark (Squatina japonica) © Martin Voeller

SPECIES CHECKLIST

* where no individual code has been assigned, ASK is used for the family Squatinidae (‘Angelsharks, sand devils nei’)

ScIENTIFIc NAME cOMMON NAME AUTHORITY STATUS

Squatina aculeata Sawback Angelshark Cuvier, 1829

Squatina africana African Angelshark Regan, 1908

FAO cODE DISTRIBUTION

CR SUA Eastern Atlantic & Mediterranean

NT SUF

Squatina albipunctata Eastern Angelshark Last & White, 2008

Squatina argentina Argentine Angelshark (Marini, 1930)

Squatina armata Chilean Angelshark (Philippi, 1887)

Squatina australis Australian Angelshark Regan, 1906

Squatina caillieti Philippine (or Cailliet’s) Angelshark Walsh, Ebert & Compagno, 2011

Squatina californica Pacific Angelshark Ayres, 1859

Squatina david David’s Angelshark Acero P., Tavera, Anguila & Hernández, 2016

Squatina dumeril Atlantic Angelshark Lesueur, 1818

VU ASK

Western Indian Ocean (Kenya, Madagascar, Mozambique, Somalia, South Africa, Tanzania)

Australia (Queensland, New South Wales, Victoria)

Argentina, Brazil, Uruguay

CR SUG

CR DMZ Chile, Colombia, Ecuador, Peru

LC SUU

Australia (Victoria, Tasmania, South Australia, Western Australia, New South Wales)

Western Central Pacific (Philippines)

DD ASK

NT SUC Northeast Pacific (Canada, Mexico, USA)

NT ASK

Southern Caribbean (Panama –Suriname)

LC SUD

Squatina formosa Taiwan Angelshark Shen & Ting, 1972 EN SUO

Squatina guggenheim Angular Angelshark Marini, 1936

EN SWV

From southern New England to Florida and the Gulf of Mexico

Northwest Pacific (China, Taiwan)

Argentina, Brazil, Uruguay

* where no individual code has been assigned, ASK is used for the family Squatinidae (‘Angelsharks, sand devils nei’)

ScIENTIFIc NAME cOMMON NAME AUTHORITY STATUS FAO cODE DISTRIBUTION

Squatina japonica Japanese Angelshark

Squatina legnota Indonesian Angelshark

Squatina mapama Small-crested Angelshark

Squatina nebulosa Clouded Angelshark

Squatina occulta Hidden Angelshark

Squatina oculata Smoothback Angelshark

Squatina pseudocellata Western Angelshark

Bleeker, 1858

CR SUJ

Last & White, 2008

CR ASK

Northwest Pacific (China, Japan, Korea, Taiwan)

Central Indo-Pacific (Southern Indonesia)

Long, Ebert, Tavera, Acero & Robertson, 2021

Regan, 1906

Vooren & da Silva, 1991

Bonaparte, 1840

Last & White, 2008

NE ASK

Caribbean coast of Panama

EN SUL

Northwest Pacific (Japan, China, Taiwan)

Argentina, Brazil, Uruguay

CR SZJ

CR SUT

Eastern Atlantic & Mediterranean

LC ASK

Squatina squatina Angelshark (Linnaeus, 1758)

Squatina tergocellata Ornate Angelshark McCulloch, 1914

Squatina tergocellatoides Ocellated Angelshark Chen, 1963

Squatina varii Vari’s Angelshark

Western Australia

CR AGN Northeast Atlantic & Mediterranean

LC SUE Australia (South Australia, Western Australia)

EN SUN

Northwest & Western Central Pacific (South China Sea)

Vaz & Carvalho, 2018 LC ASK Brazil

EASTERN PACIFIC

On the Pacific coast, management measures (including a ban on nearshore gillnets and minimum size limits) have significantly reduced landings of S. californica. With ground fisheries managed, the threat of targeted commercial fishing in the United States has ceased for this species, though they can still be caught as accidental bycatch in fisheries.

WESTERN ATLANTIC

In Brazil, retention of angel sharks (S. argentina, S. guggenheim, and S. occulta) has been prohibited since 2004, following inclusion on the Brazilian Endangered Species List (Casselberry and Carlson, 2015). Squatina varii was described (Vaz and de Carvalho, 2018) after this and so is not formally included and no species-specific conservation measures are in place. Trawling in Brazilian inshore waters is prohibited, offering some refuge to these species. However, enforcement regulations are not sufficient as they are still caught in trawl and gillnet fisheries and retained to be sold in markets (Almerón-Souza et al., 2018).

In the Argentinian-Uruguayan Common Fishing Zone (AUCFZ), there is a TAC for angel sharks (S. argentina, S. guggenehim, S. occulta) along with a managed fishing area which has a seasonal closure (October – March) to all vessels using bottom net trawling.

There is also a Maximum Permitted Catch for angel sharks in Argentinian waters south of the AUCFZ, however this is often exceeded.

In Atlantic US waters, angel sharks are prohibited under the Federal Management Plan for Atlantic Tunas, Swordfish and Sharks as a precautionary management measure, and so they are typically discarded alive at sea.

S. david and S. mapama have no known conservation measures in place.

California Angelshark (Squatina californica) © Andy Murch

EASTERN ATLANTIC

The Angelshark (S. squatina) has the most protective measures in place (Lawson et al., 2019). As well as being designated a Prohibited species for EU and UK commercial vessels, it is included in Appendix I and II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) and Annex I of the CMS Memorandum of Understanding on the Conservation of Migratory Sharks (CMS Sharks MOU). In addition, it is listed on domestic wildlife protection orders in the UK and Canary Islands. This species, along with Squatina aculeata and S. oculata, is also listed on Annex II of the Barcelona Convention, under the General Fisheries Commission for the Mediterranean (GFCM) binding Recommendation, and all three receive domestic protection in multiple Mediterranean countries (Lawson et al., 2019; Gordon et al., 2019).

WESTERN INDIAN OCEAN

While no species-specific measures are in place, the habitat of Squatina africana falls within extensive Marine Protected Areas (MPAs) on the east coast of South Africa, which are closed to fishing and generally well policed.

NORTHWEST PACIFIC

There are no species-specific conservation measures in place for any of the six species encountered in the Northwest Pacific. A number of regions (e.g. Japan, China, Taiwan) have some fisheries management measures in place to control fishing effort (including demersal trawling bans), which will provide some refuge for angel sharks.

EASTERN INDIAN OCEAN AND WESTERN CENTRAL PACIFIC

No species-specific measures are in place; however, some areas are closed to trawling which offers refuge for demersal species such as angel sharks. Three of the species encountered in Australian waters are listed as Least Concern and are all taken as bycatch in managed fisheries. In contrast, S. albipunctata has been heavily overfished and is subsequently considered Vulnerable, despite this, there are no conservation measures in place and bycatch is marketed.

ANGEL SHARK CONSERVATION NETWORK

The Angel Shark Conservation Network (ASCN) represents a community working to better protect angel sharks. The Network was collaboratively founded by the Angel Shark Project, International Union for the Conservation of Nature (IUCN) Species Survival Commission Shark Specialist Group, Shark Trust, Submon, Universidad de Las Palmas de Gran Canaria (ULPGC), Zoological Research Museum Alexander Koenig (ZMFK) and the Zoological Society of London (ZSL). The ASCN was established to facilitate dialogue and information sharing on angel shark conservation efforts, in particular across the range of the three species found in the Eastern Atlantic and Mediterranean Sea. However, collaborators are welcomed from all regions so if you’re interested in finding out more, and to record any angel shark sightings, visit www.angelsharknetwork.com.

CONSERVATION STRATEGIES

ASCN partners have coordinated the development of several strategic conservation planning documents, with input from multiple stakeholders. These include the Eastern Atlantic and Mediterranean Angel Shark Conservation Strategy which provides a broad framework for protection for S. aculeata, S. oculata, and S. squatina; the Angelshark Action Plan for the Canary Islands (S. squatina); the Wales Angelshark Action Plan (S. squatina); the Mediterranean Angel Sharks: Regional Action Plan (S. aculeata, S. oculata, S. squatina); along with SubRegional Action Plans for a number of Mediterranean regions (including Aegean Sea/ Crete, Cyprus, Libya and Turkey).

The Angel Shark Project are collecting genetic samples to understand how populations are connected across their range. If you have samples or data you would like to contribute, get in touch with them at info@angelsharkproject.com.

The inaugural International Angel Shark Day was held in 2020, and is now celebrated annually on 26 June. #AngelSharkDay

BEST PRACTICE HANDLING GUIDE

This guidance has been developed with fishers to reduce mortality if angel sharks are accidentally caught in regions where prohibitions are in place.

Check the national regulations in your region to find out

if there are any species-specific conservation measures in place that prohibit retention of angel sharks.

1. Unhooking

Record the size and sex of the shark. Male sharks have two claspers (long appendages) behind the pelvic fin.

This helps us to understand population structure.

Unhook the angel shark in the water on the side of the boat. If you have to cut the leader, cut it as close to the hook as possible.

Water supports the internal organs.

2. Releasing

Release the shark as soon as possible after unhooking. Lower it into the water facing the tide or waves. Forces oxygen through its gills so that it can quickly swim away.

If there are, follow these best-practice guidelines to safely release any individuals caught.

Report your capture using your national recording procedure (by FAO code if confident of species ID) and to the Angel Shark Sightings Map at angelsharknetwork.com/#map.

Advice on fishing tackle

Always use barbless non-stainless circle hooks (or a circle hook with the barb flattened down).

This reduces the chance of gut-hooking so that it is easier to unhook the shark.

Use a strong line.

This reduces the likelihood of the line snapping and the shark trailing gear.

Handling (ONLY if necessary)

Never hold the shark just by its tail, its fins or by the gills; you need to support the underside of the shark.

Support the internal organs to reduce a chance of injury.

3. Reporting

Report your accidental capture on angelsharknetwork.com/#map

We will use this information to better understand and conserve angel sharks.

Landing aboard the boat (ONLY if necessary)

All interaction with sharks should be minimised. If you need to land aboard the boat to unhook safely, use a large landing net. Never use a gaff.

Support the internal organs to reduce a chance of injury.

Place it on a cool, wet, soft surface (e.g. a wet towel).

Place a towel soaked in seawater over the eyes.

To keep it calm and stop it thrashing.

ACKNOWLEDGEMENTS

It is hoped that this guide will help expose more images of angel sharks in different regions, along with more speciesspecific information to help better understand angel sharks around the world. We would welcome additional content as it becomes available so that we may improve upon the information provided here, email angels@sharktrust.org.

Images of live angel sharks are scarce for many species, and so we are especially thankful to those who donated photos for use both within this guide and as reference material to aid the creation of species illustrations - this includes Andy Murch, Nathan Bass, Vincent Raoult, and Francisco Concha. All illustrations were created by Marc Dando for which we are grateful, and the guide was designed by Rob Bowker who we thank for his patience!

Thank you to those who have reviewed draft content and offered comments, including Dave Ebert, Will White, Diego Vaz, Francisco Concha, and of course Marc Dando.

The development of this identification guide was made possible through the generosity of the Disney Conservation Fund, for this we extend our gratitude. Our thanks are also extended to the Shark Conservation Fund for progressing work on angel sharks.

Angular Angelshark (Squatina guggenheim) © Andy Murch

REFERENCES

Acero, A.P., Tavera, J.J., Anguila, R. and Hernández, L. 2016. A New Southern Caribbean Species of Angel Shark (Chondrichthyes, Squaliformes, Squatinidae), Including Phylogeny and Tempo of Diversification of American Species. Copeia 104, No. 2, 577–585.

Almerón-Souza, F., Sperb, C., Castilho, C.L., Figueiredo, P.I., Gonçalves, L.T., Machado, R., Oliveira, L.R., Valiati, V.H. and Fagundes, N.J. 2018. Molecular identification of shark meat from local markets in Southern Brazil based on DNA barcoding: Evidence for mislabeling and trade of Endangered species. Frontiers in Genetics; 9.

Capapé, C., Seck, A.A., Gueye-Ndiaye, A., Diatta, Y. and Diop, M. 2002. Reproductive biology of the smoothback angel shark, Squatina oculata (Elasmobranchii, Squatinidae), from the coast of Senegal (eastern tropical Atlantic). Journal of the Marine Biological Association UK; 82: 635640.

Casselberry, G.A. and Carlson, J.K. 2015. Endangered Species Act Status Review of the spiny angel shark (Squatina guggenheim). Report to the National Marine Fisheries Service, Office of Protected Resources. SFD Contribution PCB-15-10. Chiaramonte, G.E. 1998. Shark fisheries in Argentina. Marine and Freshwater Research; 49(7): 601-609.

Dulvy, N.K., Fowler, S. L., Musick, J.A., Cavanagh, R.D., Kyne, P.M., Harrison, L.R., Carlson, J.K., et al. 2014. Extinction risk and conservation of the world’s sharks and rays. eLife, 3: e00590.

Dulvy, N.K., Pacoureau, N., Rigby, C.L., Pollom, R.A., Jabado, R.W., Ebert, D.A., Finucci, B., et al. 2021. Overfishing drives over one-third of all sharks and rays toward a global extinction crisis. Current Biology 31 (22), 5118–5119.

Ebert D.A., Dando, M. and Fowler, S. 2021.

Sharks of the World: A Complete Guide. Wild Nature Press.

Gordon, C.A., Hood, A.R., Al Mabruk, S. A. A., Barker, J., Bartolí, A., Ben Abdelhamid, S., Bradai, M.N., Dulvy, N.K., Fortibuoni, T., Giovos, I., Jimenez Alvarado, D., Meyers, E.K.M., Morey, G., Niedermuller, S., Pauly, A., Serena, F. and Vacchi, M. 2019. Mediterranean Angel Sharks: Regional Action Plan. The Shark Trust, UK.

Jabado R.W. 2019. Wedgefishes and Giant Guitarfishes: A Guide to Species Identification. Wildlife Conservation. Society, New York, United States.

Last, P.R. and Stevens, J.D. 2009. Sharks and Rays of Australia. Second Edition. CSIRO Publishing, Collingwood.

Lawson, J.M. Pollom, R., Gordon, C.A., Barker, J., Meyers, E.K.M., Zidowitz, H., Ellis, J.R., Bartolí, A., Morey, G., Fowler, S.L., Jiménez Alvarado, D., Fordham, S., Sharp, R., Hood, A.R., & Dulvy, N.K. 2019. Extinction risk and conservation of Critically Endangered angel sharks in the Eastern Atlantic and Mediterranean Sea. ICES Journal of Marine Science; 77:12–29.

Long, D.J., Ebert, D.A., Tavera, J., Acero, A., Robertson, D.R., 2021. Squatina mapama n. sp., a new cryptic species of angel shark (Elasmobranchii: Squatinidae) from the southwestern Caribbean Sea. Journal of the Ocean Science Foundation; 38.

Theiss, S.M. and Ebert, D.A. 2013. Lost and found: recovery of the holotype of the ocellated angelshark, Squatina tergocellatoides Chen, 1963 (Squatinidae), with comments on western Pacific squatinids. Zootaxa 3752 (1): 073–085

Vaz, D.F.B. and de Carvalho, M.R. 2018. New Species of Squatina (Squatiniformes: Squatinidae) from Brazil, with Comments on the Taxonomy of Angel Sharks from the Central and Northwestern Atlantic. Copeia 106, 144–160.

Walsh, J.H., and Ebert, D.A. 2007. A review of the systematics of western North Pacific angel sharks, genus Squatina, with redescriptions of Squatina formosa, S. japonica, and S. nebulosa (Chondrichthyes: Squatiniformes, Squatinidae). Zootaxa 1551: 31-47.

Walsh, J.H., Ebert, D.A. and Compagno, L.J.V. 2011. Squatina caillieti sp. nov., a new species of angel shark (Chondrichthyes: Squatiniformes: Squatinidae) from the Philippine Islands. Zootaxa 2759: 49–59.

Australian Angelshark (Squatina australis) © Nathan Bass

Squatina spp. have declined dramatically in many regions, it’s clear that this family is unable to sustain intense fishing pressure. Catches should be carefully monitored to understand population trends and better inform management and conservation measures.