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Wedgefishes and giant guitarfishes: a guide to species identification

Authors:
  • Elasmo Project
Wedgefishes and
Giant Guitarfishes
Wedgefishes and
Giant Guitarfishes
A Guide to Species Identification
2019
Rima W. Jabado
Published by: Wildlife Conservation Society, 2019
Citation: Jabado RW. 2019. Wedgefishes and Giant Guitarfishes: A Guide to Species Identification. Wildlife Conservation
Society, New York, United States. 30 pp
Illustrations: © Marc Dando - Wild Nature Press
Cover photo: © Guy Stevens -- Manta Trust -- Bottlenose Wedgefish (Rhynchobatus australiae), Maldives.
All material appearing in this publication is copyrighted and may be reproduced only with permission.
What are ‘shark-like rays’?
The term ‘shark-like rays’ refers to 63 species from five families in the order Rhinopristiformes: the sawfishes (Pristidae),
wedgefishes (Rhinidae), giant guitarfishes (Glaucostegidae), guitarfishes (Rhinobatidae), and banjo rays (Trygonorrhini-
dae). Their flattened body is perfectly adapted for life on the seabed, either swimming close to the bottom or resting and
lying concealed within the sediments. All species are characterized by a life-history of slow growth, late maturity, and low
fecundity, making them extremely susceptible to population decline from overexploitation. In fact, except for the banjo rays,
the remaining four families are considered amongst the top shark and ray families most at risk of extinction. Specifically, all
but one species of sawfishes, wedgefishes, and giant guitarfishes that have been assessed on the International Union for
the Conservation of Nature (IUCN) Red List of Threatened Species are considered threatened (Critically Endangered).
Despite this elevated extinction risk, little to almost no management has been put in place for these species.
Schematic chondrichthyan phylogenetic tree
representing the relationship among sharks,
rays, and chimaeras, and highlighting the
order Rhinopristiformes which includes the
wedgefishes (Rhinidae) and giant guitarfishes
(Glaucostegidae).
1
Threats and population declines
Wedgefishes and giant guitarfishes are shallow-water inshore and coastal species with much of their distributional range
overlapping with areas of high fishing pressure on the continental shelf. They are susceptible to capture in commercial and
artisanal fisheries using various types of gears including nets, trawls, longlines, and handlines. Species are either targeted
or retained when caught as bycatch, with the primary driver for retention being their fins. Indeed, while their meat is often
consumed locally, unprocessed and processed fins enter the international shark fin trade and are considered the most
valuable on the market due to their high ceratotrichia content (‘fin needles’ used in shark fin soup). Due to their quality and
texture, dried fins labelled as Qun chi (meaning ‘king of shark fins’ in Cantonese), can be sold for up to USD$964/kg in
Hong Kong, one of the world’s most important trade hubs and consumer markets for shark fins.
Currently, little is known at the species-specific level on wedgefishes and giant guitarfishes. Much of the available literature is
incomplete with often inaccurate information due to frequent species misidentification and limited research effort. However,
the available family-level catch and landings data from across their range in the Indo-Pacific and West Africa suggest severe
population declines and localized extinctions highlighting the need for immediate conservation measures. For example,
a recent assessment of the conservation status of sharks and rays in the Arabian Sea and adjacent waters concluded that
the Bottlenose Wedgefish (Rhynchobatus australiae) and Whitespotted Wedgefish (R. djiddensis) have suffered significant
population declines estimated between 50-80% over the last three decades. In Pakistan, wedgefishes and guitarfishes
used to be abundant in commercial landings, however, catches of these species have considerably dropped, with almost
all wedgefishes having disappeared from landings and are now rarely recorded. In Indonesia, landings data indicate sig-
nificant declines (over 80%) in the target gillnet fisheries for wedgefishes that began in the mid-1970s and reached a peak
in 1987. Similar declines are noted throughout the range of all wedgefish and giant guitarfish species.
Wedgefishes and giant guitarfishes are morphologically similar and experience the same level of fishing pressure that
has driven sawfishes (family Pristidae) to near extinction over the past few decades. Sawfishes have now been afforded
2
© Demian Chapman
© Rima Jabado© Rima Jabado
© Stan Shea 3
species-specific protections in a number of countries and have been listed on international agreements including Appen-
dix I of the Convention on International Trade in Endangered Species of Flora and Fauna (CITES), effectively banning all
commercial trade. However, wedgefishes and giant guitarfishes are largely unmanaged and it is highly likely that without
regulations to ensure sustainable trade, the exceptionally high value of their fins will drive additional declines globally, thus
threatening the survival of wild populations.
Benefits of listing wedgefishes and giant guitarfishes on CITES
Current CITES proposals are for the inclusion of R. australiae and R. djiddensis from the family Rhinidae as well as the
Blackchin Guitarfish (Glaucostegus cemiculus) and the Sharpnose Guitarfish (Glaucostegus granulatus) from the family
Glaucostegidae in Appendix II. These proposals include the listing of all look-alike and putative species from the family
Rhinidae: Clown Wedgefish (R. cooki), Taiwanese Wedgefish (R. immaculatus), Smoothnose Wedgefish (R. laevis), Afri-
can Wedgefish (R. luebberti), Eyebrow Wedgefish (R. palpebratus), Broadnose Wedgefish (R. springeri), False Shark Ray
(Rhynchorhina mauritaniensis), Bowmouth Guitarfish (Rhina ancylostoma), as well as the family Glaucostegidae: Halavi
Guitarfish (G. halavi), Giant Guitarfish (G. typus), Clubnose Guitarfish (G. thouin), Widenose Guitarfish (G. obtusus).
In 2017, Parties to the Convention on the Conservation of Migratory Species of Wild Animals (CMS) listed R. australiae on
Appendix II of the Convention, recognizing that this species is in need of collaborative international conservation action. In
2018, the CMS Sharks Memorandum of Understanding (MoU) also listed this species on its Annex along with two look-
alike species (R. djiddensis and R. laevis). Given the recent nature of these listings, no collaborative measures have yet been
taken and a listing on CITES Appendix II would represent a strong commitment towards cooperative and global action by
those CITES Parties that are also signatories to CMS and the Sharks MoU. It is clear that coordinated and comprehensive
action is needed and a listing in Appendix II of CITES would encourage sustainable trade and management of these species
while preventing international trade in their high value fins from driving them to extinction.
4
Objectives of this guide
The primary objectives of this guide are to illustrate and provide a tool for the identification of all known species of wedgefish-
es and giant guitarfishes. The inability to adequately identify wedgefishes and giant guitarfishes has been a widespread and
common problem for fisheries managers with catches of these species often going unmonitored. Also, the taxonomic status of
several species remains unclear with some species challenging to identify due to similar body shape, colour, and overlapping
distributions. Essential to our understanding of the status of wedgefishes and giant guitarfishes, and the successful implemen-
tation of CITES listings, is accurate species identification along with the strict enforcement of fishing, trade, and protection
measures. This guide will support and assist field biologists, researchers, fisheries enumerators, and customs officials to rapidly
and accurately identify wedgefishes and giant guitarfishes as whole animals or from their fresh or dried unprocessed fins.
How to use this guide
For each known species of wedgefish and giant guitarfish, information on the key features used in their identification is pro-
vided. Key features for each species should be used in conjunction with the more general family characteristics provided
on page 11. Common names used here follow Last et al. (2016) or the most commonly accepted name across the majority
of their range (e.g., Bowmouth Guitarfish is used instead of the Australian name Shark Ray for Rhina ancylostoma).
Key features and illustrations
The key features presented are those by which a species can be most easily identified in the field. These characteristics
include body shape, fin positions, and colour patterns. It is important to note that typical of many chondrichthyan fishes,
wedgefishes and giant guitarfishes undergo ontogenetic changes (as they develop from juveniles to adults) in fin shape
that typify development. Specifically, dorsal fins change shape to become taller and more erect as they develop. The illus-
trations of each species in this guide are re-creations based on available photographs (mostly from the Northwest Indian
5
Ocean region and West Africa) and available illustrations. It is however important to note that body coloration can vary
depending on the state of the animal (i.e., fresh, frozen, dried, preserved, etc.). Furthermore, many of these illustrations are
based on morphological characteristics exhibited by adults and some features, colours, patterns might differ in juveniles
and are therefore mentioned in the identifying features. Species within each family are arranged based on their closest
morphological species or ‘look-alike’.
Finally, it is important to note while the identification features presented here are based on the best available information,
the taxonomy of many of these species (especially wedgefishes) is currently being revised and it is possible that specimens
observed at landing sites might have differing features. If readers encounter specimens that are rare, not identifiable by
using this guide, or are unsure of their identifications, it is recommended to retain them for further investigation and take ap-
propriate photographs and tissue samples. Readers can also contact the author for assistance on info@elasmoproject.com.
Distribution
Species distributions are mapped as overlays of individual distributions to show species richness for each family. These have
been mapped based on Last et al. (2016) (except for the Clubnose Guitarfish that is not considered to occur in the Red
Sea), Jabado et al. (2017), and confirmed photographic records.
IUCN Categories
The IUCN Red List of Threatened Species is the most comprehensive framework for assessing the extinction risk of the world’s
plant and animal species. The current conservation status of each species is indicated by a logo under each species name.
Abbreviations for these categories in order of decreasing threat are: EX, Extinct; EW, Extinct in the Wild; CR, Critically En-
dangered; EN, Endangered; VU, Vulnerable; NT, Near Threatened; LC, Least Concern; and DD, Data Deficient.
CR EN VU NT LC DDEX EW
6
Lower caudal fin
Pelvic fins
First dorsal fin Second dorsal fin
Snout
Pectoral fins
Key identifying features
base – part of a projection (e.g. fin) connected to body
blotch – variably sized area or patch that is different in
colour to adjacent areas
bulbous – a shape, swollen or bulging
denticle – a small, tooth-like structure on the skin
dorsal – pertaining to the upper part or surface of back
indentation – notch or concavity on the surface of some-
thing
margin – edge or rim
ocellated – having eye-like markings
posterior – relating to back of or tail end of an animal
rostral - on upper part of the snout
spiracle – a respiratory opening behind the eyes
snout – part of head in front of eyes
translucent – allows light in but not totally transparent
ventral – pertaining to the lower part or surface
Upper caudal fin
Mouth
Trunk
Free rear tips
Spiracle
Fin origin
Key terms
7
© Philippe Lecomte
© Andy Murch
8
THE FACTS
16 species
80%
decline in the
population of most
species
Meat often consumed
by coastal communities
Sold for shark fin soup
in Hong Kong and
China as Qun Chi
Highest value fins of all
sharks and rays
USD$964/kg
Live in coastal and
inshore areas
Slow-growing
Late to mature
Long gestation
Visual identification of
dried unprocessed fins
possible
© Andy Murch
9
WEDGEFISHES - Family Rhinidae
The family Rhinidae includes 10 valid species from three genera: Rhina,
Rhynchobatus, and Rhynchorhina. Wedgefishes are medium to large rays
(reaching up to 3.1 m total length as adults) that are mostly found in warm
temperate to tropical inshore continental seas, and rarely occur deep-
er than 400 m. They have a primarily Indo-Pacific distribution with only
two species occurring in the eastern Atlantic. Most species have rows of
white spots or ocelli on their bodies, and often a black marking on each
pectoral fin that is variably surrounded by white spots. This black marking
is generally most obvious in young and can fade or disappear in adults.
GIANT GUITARFISHES - Family Glaucostegidae
The family Glaucostegidae includes six valid species from one genus:
Glaucostegus. Giant guitarfishes are medium-sized to large rays (adults
of most species exceed 3 m total length) that primarily inhabit subtropical
and tropical inshore continental and insular seas across the Indo-Pacific
and eastern Atlantic, including the Mediterranean Sea. They occur at
depths up to 100-120 m but are mostly found in intertidal habitats with
some species having been recorded in fresh and brackish waters. Most
species have no spots, stripes, or blotches.
Species richness 1 2 3 4 5
10
Origin of first dorsal
fin well behind the
tips of pelvic fins
Origin of first dorsal fin
above pelvic fins
Caudal fin with very
distinct lower lobe
2-3 short series of thorns on
each shoulder
Head angular and wedge-
shaped (only in the Rhynchobatus
genus; rounded in Rhina and
Rhynchorhina)
Head spade-like to wedge-
shaped with translucent snout
Small thorns confined to a
row along mid-line of body
Caudal fin lacking
obvious lower lobe
Pectoral fins not joined to
the body to form a disc
Pectoral fins joined to the
body to form a disc
Upper jaw of mouth
straight without
indentations
Underside of head
Upper jaw of mouth with
at least one indentation in
the middle
11
WEDGEFISHES - Family Rhinidae
© Elke Bojanowski -- Red Sea Sharks
12
Bowmouth Guitarfish - Rhina ancylostoma False Shark Ray - Rhynchorhina mauritaniensis
Clown Wedgefish - Rhynchobatus cooki
The Clown
Wedgefish is the small-
est of the wedgefishes and
reaches 82 cm total length. It is
known from less than 20 speci-
mens and has not been recorded
since 1996, despite extensive
fish market surveys across
Southeast Asia.
Prominent ridges with
large thorns on back
Broad, rounded
head
Caudal fin
lunate
Flattened blunt snout with large trans-
verse black blotch on underside
Thorny patches of ridges above eyes,
spiracles, shoulder, and mid-line of back
Caudal fin with distinct
small lower lobe
2 irregular rows
of large thorns on
snout
Prominent white margin
along body
Lacks pectoral fin markings
13
Bottlenose Wedgefish - Rhynchobatus australiae Whitespotted Wedgefish - Rhynchobatus djiddensis
Smoothnose Wedgefish - Rhynchobatus laevis Taiwanese Wedgefish - Rhynchobatus immaculatus
3 white spots aligned over the pectoral
marking (usually 2 spots below)
Bottle-shaped snout slightly constricted near tip
Dorsal surface can
be almost uniformly
blackish with no mark-
ings in some adults
Spots with ring-like
dusky colour pattern
in adults
Fin tips dusky
No black pectoral marking
Row of small white spots
originating over origin of
pelvic fin and coalescing to
form a line on tail
Prominent black bars
between eyes
Pectoral marking often ocellated,
surrounded by 4-7 white spots
Black pectoral marking usually
surrounded by 4 or more white spots
Snout underside usu-
ally with dark blotch
Single white spot above
pelvic fin origin
4-5 rows of white spots
along each side beneath
first dorsal fin
14
Broadnose Wedgefish - Rhynchobatus springeri Eyebrow Wedgefish - Rhynchobatus palpebratus
2 eyebrow-like black
markings often present
Black pectoral marking usually surrounded by 3-4 white
spots with outermost pair closer together than inner pair
Black pectoral marking usually
surrounded by 3-4 equally
spaced white spots
2-4 rows of spots on each side under 1st
dorsal fin forming a pale faint line continuing
along the body but ending before tail
African Wedgefish - Rhynchobatus luebberti
Faint dark bars
between eyes
in young
2 large blackish blotches on
shoulders (fading in adults)
Dense white spots with
black contour extend all
the way to the tail
3-4 rows of spots on each
side extending along the
tail sometimes forming
pale lines
Usually dark markings
on and/or behind eyes
The African
Wedgefish is the only
Rhynchobatus species to
occur in the Atlantic Ocean. It is
endemic to West Africa and has
been recorded from Maurita-
nia to Congo. It has already
disappeared from much of
its former range.
Paired rows of
rostral thorns on
the snout 15
GIANT GUITARFISHES - Family Glaucostegidae
© Danny Copeland
16
Blackchin Guitarfish - Glaucostegus cemiculus Giant Guitarfish - Glaucostegus typus
Halavi Guitarfish - Glaucostegus halavi
Dorsal surface sometimes with
irregular dark-greyish blotches
Entire length of
rostral ridges
almost joined
Snout underside usually with dark blotch
Ventral surface entirely white
Snout underside usually with dark blotch in juveniles
Rostral ridges
separated at the
back
1-3 thorns on each
shoulder
Single large
thorn on each
shoulder
The fins of giant
guitarfishes are smaller
than those of wedgefishes but
are also extremely valuable. In
several African countries, pups
are removed from pregnant fe-
males so their fins can also be
traded internationally.
© Danny Copeland
17
Clubnose Guitarfish - Glaucostegus thouin Widenose Guitarfish - Glaucostegus obtusus
Dorsal fins short with
rounded apices
Very short and obtuse snout
Bulbous snout tip projecting forward
Lacks dark blotch on snout Thorns along mid-line of body can be
enlarged and irregular
Sharpnose Guitarfish - Glaucostegus granulatus
Very long, narrow, translucent,
and triangular snout
Pair of 2-3 large thorns on
each shoulder The six valid
species of giant gui-
tarfishes were only recently
recognized as a separate family
and genus. Genetic analyses in-
dicate that they are more closely
related to sawfishes than other
species of guitarfishes.
18
Overview of fin identification
This quick overview of wedgefish and giant guitarfish fin identification covers fins that are likely to be encountered dried for
sale at landing sites or fishing ports, sold by fin traders, or packed as batches destined for the international trade. Batches
of dried fins usually include all the different fins of sharks and shark-like rays and are most easily identified when dried and
unprocessed (skin on). Fins from wedgefishes and giant guitarfishes are distinctive when compared to shark fins. Furthermore,
dried and unprocessed fins can easily be visually identified because of their size, shape, colour, and texture. On the other
hand, wedgefish fins are morphologically similar to those from giant guitarfishes once removed from the whole animals
making identification to a species-level challenging. However, visual fin ID is possible at the family level (Rhinidae vs Glau-
costegidae). This ability to visually identify the primary product in trade will aid in the implementation and enforcement of
these proposed CITES Appendix II listings.
In general, the primary fins derived from wedgefishes and giant guitarfishes that are traded internationally for shark fin soup
are the two dorsal fins and the entire caudal fins. This overview provides a breakdown of the main characteristics that can
be used to quickly and easily separate dorsal fins from other types of fins (i.e., pectoral fins) as well as caudal fins to the
family and sometimes genus level for the family Rhinidae. Visually distinguishing unprocessed dorsal fins of wedgefishes from
those of morphologically similar hammerhead shark species (Scalloped Hammerhead Sphyrna lewini, Smooth Hammer-
head S. zygaena, and Great Hammerhead S. mokarran) is described in more detail in Abercrombie & Hernandez (2017).
Dorsal fins
Unlike many shark species that have a second dorsal fin that is much smaller than the first, the first and second dorsal fins of
wedgefishes and giant guitarfishes are large and tall, often very similar in height and shape. They are usually sold as a set
and every two dorsal fins found in fin batches can be considered to represent one individual.
19
Caudal fin
The whole caudal fin of wedgefishes and giant guitarfishes is typically retained and dried. In comparison, for sharks, the lower
lobe of the caudal fin is the most valuable and retained separately to the upper lobe (which is sometimes discarded). When
whole, caudal fins are distinctive and easily distinguished by the presence or absence of distinct upper and lower lobes.
Below are some guidelines to help distinguish between dorsal and caudal fins of wedgefishes and giant guitarfishes.
Step 1. Find dorsal fins and caudal fins from batches of fins and distinguish them from other fins such as pectoral fins. It is important
to note that pectoral fins found in the trade will usually only belong to sharks and not wedgefishes or giant guitarfishes.
Pectoral fins are usually darker on the top side/dor-
sal view (a) and lighter underneath/ventral view (b)
Dorsal (a) and caudal fins (b) are the same colour on
both sides. Dorsal fins (a) also have a free rear tip
(a) (b) (a) (b)
The landmarks used to describe key features of
fins are the same for sharks and rays and are
presented here for dorsal fins:
Apex
Trailing edge
Leading edge
Origin
Free rear tipFin base
20
Hammerhead dorsal fins have
small cartilaginous blocks present
along almost the entire fin base
Step 4. For dull brown or light grey tall fins (fin height > fin length), check and confirm that they do not belong to hammerhead sharks
Step 2. Distinguish between shark and wedgefish and giant guitarfish dorsal fins
Denticles visible but
texture is smooth
Enlarged denticles visible
and texture is rough
Wedgefishes -- Rhinidae Giant Guitarfishes -- Glaucostegidae
Cartilaginous blocks in wedgefish and
giant guitarfish dorsal fins do not extend
across the entire fin base and can be split
in one or two big sections
row of cartilage along entire fin base small row of cartilage
Step 3. Check the texture of the fins to determine if they are smooth and shiny or have enlarged denticles
Dorsal fins of wedgefishes and giant guitarfishes have a free
rear tip that starts anterior or before the apex and which is
moderately longer when compared to the fin base.
Sharks Wedgefishes Giant Guitarfishes
21
Is the fin the same col-
our on both sides?
Key to identification based on dorsal fins
Does it have a free rear
tip?
Is the fin tall and nar-
row with the fin height >
fin length?
Does it have white
spots close to the base?
Is the free rear tip short
and rounded?
This is not a dorsal fin
NO
YES
YES
YES
YES
NO
YES
If the colour is dark brown/
grey, this is likely a fin from
Rhina ancylostoma
If the colour is dull brown/light grey, with a
smooth and shiny texture, this is likely a fin from a
Rhynchobatus spp.
NO Does it have enlarged
denticles on the upper half
of the fin?
YES If the colour is dull brown/light grey,
this is likely a fin from a
Glaucostegus spp.
NO
Do the cartilaginous
blocks extend across the
entire fin base?
NO If the cartilaginous blocks are few or
not visible, this is likely a fin from a
Rhynchobatus spp.
YES
This is likely the fin of a hammerhead shark Sphyrna spp.
This species is already listed on CITES Appendix II
22
Key to identification based on caudal fins
Is the fin the same
colour on both sides?
Is there a distinct up-
per and lower lobe?
Is the lower lobe
long, almost or more
than half the length
of the upper lobe?
This is not a caudal fin
YES
YES
YES
If the fin is lunate with almost sym-
metrical upper and lower lobes,
this is likely from
Rhina ancylostoma
If the lower lobe is less than half the length of the
upper lobe with no distinct notch visible on the pos-
terior margin, this is likely a fin from a
Rhynchobatus spp. or Rhynchorhina mauritaniensis
NO
If the lower lobe is absent and the upper half is cov-
ered with enlarged denticles, this is likely a fin from
a Glaucostegus spp.
NO
Note -- This fin identification overview was compiled to highlight that it is possible to visually identify fins from wedgefishes
and giant guitarfishes. Several other key characteristics have been omitted including the differences between these fins
and those of other CITES listed species such as the Whale Shark (Rhincodon typus) and sawfishes (Pristidae). A com-
prehensive guide to fin identification will be developed if these species are listed on CITES.
NO
23
Species checklist
IUCN STATUSAUTHORITYSCIENTIFIC NAMECOMMON NAMEFAMILY
Rhinidae -- Wedgefishes
Critically EndangeredBloch & Schneider, 1801Rhina ancylostomaBowmouth Guitarfish
Critically EndangeredWhitley, 1939Rhynchobatus australiaeBottlenose Wedgefish
Critically EndangeredLast, Kyne & Compagno, 2016Rhynchobatus cookiClown Wedgefish
Critically Endangered(Forsskål, 1775)Rhynchobatus djiddensisWhitespotted Wedgefish
Critically EndangeredLast, Ho & Chen, 2013Rhynchobatus immaculatusTaiwanese Wedgefish
Critically Endangered(Bloch & Schneider, 1801)Rhynchobatus laevisSmoothnose Wedgefish
Critically EndangeredEhrenbaum, 1915Rhynchobatus luebbertiAfrican Wedgefish
Near ThreatenedCompagno & Last, 2008Rhynchobatus palpebratusEyebrow Wedgefish
Critically EndangeredCampagno & Last, 2010Rhynchobatus springeriBroadnose Wedgefish
Critically EndangeredSéret & Naylor, 2016Rhynchorhina mauritaniensisFalse Shark Ray
Glaucostegidae -- Giant Guitarfishes
Critically Endangered(Geoffroy St Hilaire, 1817)Glaucostegus cemiculusBlackchin Guitarfish
Critically Endangered(Cuvier, 1829)Glaucostegus granulatusSharpnose Guitarfish
Critically Endangered(Forsskål, 1775)Glaucostegus halaviHalavi Guitarfish
Critically Endangered(Müller & Henle, 1841)Glaucostegus obtususWidenose Guitarfish
Critically Endangered(Anonymous, 1798)Glaucostegus thouinClubnose Guitarfish
Critically Endangered(Bennett, 1830)Glaucostegus typusGiant Guitarfish
24
Acknowledgements
The development of this guide was made possible through the generous support of Vulcan, Inc. A number of individuals have provided
support, information, and reviewed this document and are gratefully acknowledged: Luke Warwick (Wildlife Conservation Society),
Megan O’Toole (International Fund for Animal Welfare), Daniel Fernando (Blue Resources Trust), Dr. David Ebert (Pacific Shark Research
Center), and Benaya Simeon (Wildlife Conservation Society-Indonesia). Special thanks go to Debra Abercrombie (Abercrombie & Fish)
for her guidance and support with the fin identification flowcharts and for providing pictures of dorsal fin cross-sections for wedgefishes
and hammerhead sharks. Many thanks also go to Dr. Peter Kyne (Charles Darwin University) for his helpful and constructive review.
Stan Shea (Bloom Association) and Demian Chapman (Florida International University) are acknowledged for providing pictures of
traded specimens and products. Finally, with the declines of many wedgefishes and giant guitarfishes around the world, sourcing live
pictures of specimens proved to be extremely hard. I would like to thank Dr. Simon Pierce for his support as well as all those individuals
who provided pictures including Guy Stevens (Manta Trust), Andy Murch (Elasmodiver.com), Philippe Lecomte, Elke Bojanowski (Red
Sea Sharks), Danny Copeland, Dan Beecham, and Al Dove (Georgia Aquarium).
25
Abercrombie DL, Chapman DD, Gulak SJB & Carlson JK. 2013.
Visual identification of fins from common elasmobranchs in the
northwest Atlantic Ocean. NMFS-SEFSC-643. 51 p
Abercrombie DL & Hernandez S .2017. Identifying shark fins:
implementing and enforcing CITES. Abercrombie & Fish, Marine
Biological Consulting, Suffolk County, NY. 21 pp
Ahmad A, Lim APK, Fahmi & Dharmadi. 2013. Field guide to
look-alike sharks and rays species of the southeast Asian region.
SEAFDEC/MFRDMD/SP/22: 107 pp
CITES. 2019. Convention on International Trade in Endangered
Species: Proposals for amendment of Appendices I and II.
Geneva, Switzerland. Available from: https://cites.org/eng/
cop/18/prop/index.php
CITES Management Authority of Pakistan. 2018. Proposals for
possible consideration at CoP18. Wedgefishes and Guitarfishes.
AC30 Inf. 12 (also available at www.cites.org/sites/default/
files/eng/com/ac/30/Inf/EAC30-Inf-12.pdf)
Compagno LJV & Last PR. 2008. A new species of wedgefish,
Rhynchobatus palpebratus sp. nov. (Rhynchobatoidei: Rhyncho-
batidae), from the Indo–West Pacific, In: PR Last, WT White &
JJ Pogonoski (eds). Descriptions of new Australian chondrich-
thyans. CSIRO Marine and Atmospheric Research Paper 022,
pp 227–240
Compagno LJV & Last PR. 2010. A new species of wedgefish,
Rhynchobatus springeri (Rhynchobatoidei, Rhynchobatidae),
from the Western Pacific. 77-88 pp. In: Last PR, White WT &
Pogonoski JJ (eds). Descriptions of new sharks and rays from
Borneo. CSIRO Marine and Atmospheric Research Paper no.
32, 165 pp
Diop M & Dossa J. 2011. 30 years of shark fishing in West Afri-
ca. Regional Marine and Coastal Conservation Programme for
West Africa, and the Sub-Regional Fishing Commission. Corlet/
Condé-sur-Noireau (France): Fondation Internationale du Banc
d’Arguin
Dulvy NK, Fowler SL, Musick JA, Cavanagh RD, Kyne PM, Har-
rison LR, Carlson JK, Davidson LNK, Fordham SV, Francis MP,
Pollock CM, Simpfendorfer CA, Burgess GH, Carpenter KE,
Compagno LJV, Ebert DA, Gibson C, Heupel MR, Livingstone
References
26
SR, Sanciangco JC, Stevens JD, Valenti S & White WT. 2014.
Extinction risk and conservation of the world’s sharks and rays.
eLife 3: e00590
FAO. 2016. SharkFin Guide: identifying sharks from their fins, by
Lindsay J. Marshall and Monica Barone. Rome, Italy: 144 pp
Fields AT, Fischer GA, Shea SKH, Zhang H, Abercrombie DL, Feld-
heim KA, Babcock EA & Chapman DD. 2017. Species composition
of the international shark fin trade assessed through a retail-market
survey in Hong Kong. Conservation Biology 32(2): 376–389
Hau CY, Abercrombie DL, Ho KYK, Shea KHS. 2018. ‘King of
shark fins’ not quite sharks... so what’s in my soup?: a rapid survey
on the availability of shark-like batoid fins in Hong Kong SAR and
Guangzhou, China retail markets. Bloom and Hong Kong Shark
Foundation. pp 30
Jabado RW. 2018. The fate of the most threatened order of elas-
mobranchs: shark-like batoids (Rhinopristiformes) in the Arabian
Sea and adjacent waters. Fisheries Research 204: 448–457
Jabado RW, Kyne PM, Pollom RA, Ebert DA, Simpfendorfer CA,
Ralph GM & Dulvy NK (eds.) 2017. The conservation status of
sharks, rays, and chimaeras in the Arabian Sea and adjacent wa-
ters. Environment Agency – Abu Dhabi, UAE and IUCN Species
27
Survival Commission Shark Specialist Group, Vancouver, Canada
236 pp
Giles, JL, Riginos C, Naylor GJP, Dharmadi, Ovenden JR. 2016.
Genetic and phenotypic diversity in the wedgefish Rhynchobatus
australiae, a threatened ray of high value in the shark fin trade.
Marine Ecology Progress Series 548: 165–180
Last PR, Kyne PM, Compagno LJV. 2016. A new species of
wedgefish Rhynchobatus cooki (Rhinopristoformes, Rhinidae) from
the Indo-West Pacific. Zootaxa 4139(2):233–247
Last PR, Ho H-C & Chen R-R. 2013. A new species of wedgefish,
Rhynchobatus immaculatus (Chondrichthyes, Rhynchobatidae),
from Taiwan. Zootaxa, 3752(1), 185– 198
Last PR, Séret B & Naylor GJP. 2016. A new species of guitarfish,
Rhinobatos borneensis sp. nov. with a redefinition of the family-lev-
el classification in the order Rhinopristiformes (Chondrichthyes: Ba-
toidea). Zootaxa 4117: 451–475
Last PR, Séret B & Naylor GJP. 2019. Description of Rhinobatos
ranongensis sp. nov. (Rhinopristiformes: Rhinobatidae) from the An-
daman Sea and Bay of Bengal with a review of its northern Indian
Ocean congeners. Zootaxa 4576: 257–287
Last PR, White WT, Carvalho MR de, Séret B, Stehmann MFW
and Naylor GJP (eds) 2016. Rays of the world. CSIRO Publishing:
Melbourne
Mohanraj G, Rajapackiam S, Mohan S, Batcha H & Gomathy
S. 2009. Status of elasmobranchs fishery in Chennai, India. Asian
Fisheries Science 22: 607–615
Moore ABM. 2017. Are guitarfishes the next sawfishes? Extinction
risk and an urgent call for conservation action. Endangered Spe-
cies Research 34: 75–88
Newell BM. 2017. Status review report of two species of guitar-
fish: Rhinobatos rhinobatos and Rhinobatos cemiculus. Report to
National Marine Fisheries Service, Office of Protected Resources.
62 pp
White WT, Baje L, Sabub B, Appleyard SA, Pogonoski JJ, Mana
RR. 2017. Sharks and rays of Papua New Guinea. ACIAR Mon-
ograph No. 189. Australian Centre for International Agricultural
Research: Canberra. 327 pp
White J, Heupel MR, Simpfendorfer CA, Tobin AJ. 2013. Shark-like
batoids in Pacific fisheries: prevalence and conservation concerns.
Endangered Species Research 19: 277–284
28
A lack of management action for wedgefishes and giant guitarfishes has contributed to
their current threatened status. Some populations have collapsed globally, with declines of
more than 80% in many regions. Action is needed now to halt declines and secure a future
for these species.
Published by
Wildlife Conservation Society
Sharks and Rays Program
2300 Southern Boulevard
Bronx, NY 10460
www.wcs.org/our-work/wildlife/sharks-skates-rays
The objective of this guide is to provide a tool for the identification of 16 species of wedgefish and giant guitarfish
(order Rhinopristiformes: families Rhinidae and Glaucostegidae) being proposed for listing on the Convention on
International Trade in Endangered Species of Flora and Fauna (CITES). It can be used in the identification of species
for fisheries purposes or for the implementation of CITES listings (if these species are listed). The content is divided into
three sections: (1) an overview of the status of species around the world, (2) information on each species and key iden-
tification features that allow these species to be visually separated in the field, and (3) an overview of fin identification
showcasing how to visually identify fins of wedgefishes and giant guitarfishes to the family level.
... In addition to the fins, other parts of the body, such as skin, bones, and meat are also sold and utilized locally (Simeon et al 2019). The intensity of the wedgefish trade determined the over-exploitation of wedgefish (Jabado 2019). Overexploitation can threaten the wedgefish populations in nature (Dulvy et al 2014;FAO 2015). ...
... The trade value of shark fins was IDR 124 billion from the year 2000 to 2011 (Dent & Clarke 2015). According to Jabado (2019) about 100,000 tons of shark were caught annually in Indonesia, from which 18 % of the catches were wedgefish. The international market price of the wedgefish is high, of about US$ 964/kg in the shark fin market in Hong Kong (Jabado 2019). ...
... According to Jabado (2019) about 100,000 tons of shark were caught annually in Indonesia, from which 18 % of the catches were wedgefish. The international market price of the wedgefish is high, of about US$ 964/kg in the shark fin market in Hong Kong (Jabado 2019). ...
Article
Full-text available
Indonesia has been considered the largest producer of shark and rays, as well as wedgefish (Rhynchobatus spp.) (Dent et al 20015). The high demand of wedgefish fins with high economic value in shark fin market, has promoted overexploitation and threathens the wild populations. However, the scientific information on the wedgefish fishery in Indonesia is limited, particularly as a basic input for sustainable management. This study aims to determine the catch composition, sex ratio, and clasper maturity of wedgefish caught from the Java Sea. Fish landing data were intensively collected from January to February 2020 at the Tegalsari Fishing Port. Additional monitoring data of wedgefish landing at some fishing ports from April 2019 to February 2020 was used as secondary data. Then the data was analyzed on catch composition, sex ratio, and clasper maturity level of the fish. The results showed that wedgefish landed in Tegalsari Fishing Port consisted of three species: Rhynchobatus springeri (37%), Rhynchobatus laevis (37%), and Rhynchobatus australiae (26%). The sex ratio (male : female) of the wedgefish was 1:3. The maturity levels of males wedgefish were composed of 42% NC (Non-Calcification), 51% NFC (Non-Full Calcification), and 7% FC (Full Calcification). The non-calcificatio category has the clasper length between 3-15 cm with 50-115 cm total length (TL). The non-full calcification category of the fish had a clasper length of 16-28 cm with 85-148 cm TL. The full calcification category had 29-50 cm clasper length with 120-296 cm TL. Meanwhile, based on monitoring landing data from April to December 2019, the maturity level of males wedgefish were 26% NC, 25% NFC, and 49% FC. The non-calcification, non-full calcification and full calcification categories had the clasper length of 3-15 cm (50-246 cm TL), 5-23 cm (54-227 cm TL), and 7-30 cm (55-296 cm TL), respectively. Spatial and temporal variations of the fishing ground affect the relationship of the total body length and the claspers' maturity of the wedgefish.
... Retention of rhino rays in fisheries is driven by the value of their meat and especially their fins (Jabado, 2019;Kyne et al., 2020). In many coastal communities around the world, the meat of rhino rays continues to be an important source of protein (Moore, 2017;Jabado, 2018). ...
... Simultaneously, the demand for fins to supply the global fin trade in Southeast Asia (especially in Hong Kong, mainland China, and Singapore) has exploded over the last three decades and has been a major driver in the exploitation and retention of rhino rays (Fig. 3C) (Hau et al., 2018). This has particularly been the case for species that have high value fins such as sawfishes, wedgefishes, and giant guitarfishes (Jabado, 2019). These species have a large body size and therefore large fins that are high in ceratotrichia content (fin needles used in shark fin soup). ...
... These species have a large body size and therefore large fins that are high in ceratotrichia content (fin needles used in shark fin soup). These are considered high grade fins ("white fins") and the best quality for consumption (Hau et al., 2018;Jabado, 2019). In fact, fins from wedgefishes are called the "king of shark fins" in Hong Kong and can be sold for up to US$964 per kilogram (Hau et al., 2018;Jabado, 2019). ...
Chapter
Rhino rays comprise 64 species of shark-like rays from five families. Over two-thirds (69%) are threatened with extinction with 41% Critically Endangered (these face an extremely high risk of extinction). All sawfishes and giant guitarfishes, 90% of wedgefishes, 59% of guitarfishes, and 38% of banjo rays are threatened. The major driver of endangerment is overexploitation either through targeted fishing or bycatch. Considering the continuing high levels of exploitation, the growing demand for their fins, and pressure on coastal habitats from human activities, the situation for these species is alarming in most areas of the world. Hotspots of threat (high levels of fishing pressure and habitat loss and degradation) include West Africa, the Northern Indian Ocean, Southeast Asia, and the Eastern Central Pacific. These areas support the majority of threatened rhino rays. Local, regional, and global efforts are required to restore and secure rhino rays. Actions need to be taken immediately and governments need to ensure that management measures are properly implemented to enable successful recovery of populations. Species protections for the most imperiled species and the effective enforcement of existing international trade regulations for sawfishes, wedgefishes, and giant guitarfishes are critical.
... Batoid fishes are commonly caught as bycatch in many parts of the world, especially in trawlers, and they may include commercial and non-commercial species (Blaber et al., 2009;Stevens et al., 2000;D'Alberto et al., 2019;White et al., 2019). Fishers often target the commercially valuable ray species in the Arabian Sea due to high demand (Jabado et al., 2017), and such targeted fishing has resulted in the population decline of many species, and even localized extinctions of some rhinopristoids across the world (Jabado, 2019). All the batoid species are characterized by a life-history of slow growth, late maturity, and low fecundity, * Corresponding author. ...
... Kumar). making them extremely susceptible to population decline from overexploitation (Jabado, 2019). ...
... In contrast, more than half of the common commercial species in fishery belongs to the threatened category (CMFRI, 2010(CMFRI, -2018. Ray fishes have K-selected life-history strategies making them more vulnerable to overutilization (Kyne, 2016;Jabado, 2019). Therefore, documenting these data deficient species is relevant not only for strengthening the database but also for furthering management and conservation initiatives. ...
Article
Bycatch of trawl fishery is a global concern and batoid fishes, including skates, rays and guitar fishes, are caught frequently as non-targeted species in commercial trawl fishery of India. While the commercial batoid species are documented separately in fishery data, a large number of non-commercial species do not form part of fishery data, even though many such species are listed as ‘Data Deficient’ in IUCN red list. A survey was conducted from July 2018 to June 2019 in the major harbours and landing centers of the south coasts of India to monitor the non-commercial batoid species in the trawl bycatch. Massive landings of non-commercial batoid species such as Torpedo sinuspersici, Narcine cf maculata, Orbiraja powelli Acroteriobatus variegatus and the occasional occurrence of Dipturus johannisdavisi, Benthobatis moresbyi, Narcine timlei and Plesiobatis daviesi have been recorded, besides the juveniles, sub-adults and few adults of commercial species Rhinobatos annandalei, Brevitrygon imbricata and Neotrygon indica from south India. The non-commercial batoids mainly inhabit continental shelf and slope regions of Indian coast where fishing pressure and efforts are high. When these k-selected species live in fishing zones with intense fishing pressure, data deficient species of batoids should be considered as threatened, and this paper discuss challenges in the sector, and forwards strategies for conserving non-targeted batoids.
... For morphological identification of CITES-listed shark fins, there are a number of fin identification guides (e.g., Abercrombie, 2019;Abercrombie & Hernandez, 2017;Jabado, 2019;Marshall & Barone, 2016) as well as the landmark-based software iSharkFin (FAO & University of Vigo, 2014). In Germany, only CITES regulated species can be confiscated under the German federal law on nature protection (Bundesnaturschutzgesetz [BNatSchG]; article 51 paragraph 2 sentence 1). ...
... For morphological identification, we tested four morphological fin guides (Abercrombie, 2019;Abercrombie & Hernandez, 2017;Jabado, 2019;Marshall & Barone, 2016) on images of all 115 fins analyzed above. Used keys are intended to identify shark fins of CITES listed species only and do not provide species level identification for nonregulated species. ...
Article
A three‐ton shipment of dry shark fins was examined by German customs in 2017 leading to the confiscation of 405 kg of potential CITES species. We analyzed a subsample of this material (115 specimens) using DNA sequence‐based identification and compared results to morphological screening of CITES species. We found a mixture of CITES regulated (4 of 11 species) and unregulated shark species. Our results demonstrate the difficulties of identifying CITES species morphologically in large fin shipments of mixed species composition. Correct identification of CITES species based on morphology alone may be hindered by missing characters or those altered by drying. We therefore suggest random molecular screening as a uniform approach for German customs authorities to check species composition and identify CITES regulated species in transit shipments. The shark fin trade often relies on transportation routes and transit countries. Precise identification of CITES species based on morphological characters when handling very large shipments could be challenging. We suggest random molecular screening by customs authorities as a uniform approach for checking species composition of in‐transit shipments.
... When wedgefishes and giant guitarfishes were imported or landed whole (with snout and body intact, but usually lacking caudal and dorsal fins), identification was performed to species level based on morphological characteristics [27]. For each individual, the sex (external examination for presence or absence of claspers in males) [12], presence of caudal and dorsal fins, and the estimated total length (TL in m) were recorded. ...
Article
Wedgefishes (Rhinidae) and giant guitarfishes (Glaucostegidae) are amongst the most threatened marine taxa globally. Research was undertaken in Singapore, a globally significant trading hub for shark and ray products, between May 2019 (two months after they were proposed for listing on the Convention on International Trade in Endangered Species of Flora and Fauna (CITES)) and August 2019 (three months before listings entered into force). The study documents the composition of imports and landings, estimates the scale of the trade, describes the supply chain, and analyzes completeness of product labels through surveys in fishery ports and retail markets as well as informal interviews with traders. Of 590 individuals recorded at fishery ports, 215 from six species could be identified to the species-level. Rhynchobatus australiae was the most commonly encountered wedgefish species (66%) while only one species of giant guitarfish (Glaucostegus typus) was recorded. Individuals were primarily claimed to be imported from Indonesia and Malaysia. The high value of wedgefish fins was evident as a large proportion of individuals without fins (66%) were recorded. Businesses in Singapore were utilizing by-products of the fin trade which appeared to have a distinct supply chain. Traders noted declining supplies of wedgefishes and dried shark fins in recent years. Shark and ray products notably lacked information on species and country of origin on their labels. Findings here provide baseline data for determining the effectiveness of new trade controls and suggest that a multi-pronged approach with trade monitoring, additional traceability and labeling requirements, and enhanced fisheries management would conserve globally declining, wild populations.
... Taxonomic information is crucial mainly because of inherent variation in biological characteristics among species influences their vulnerability. For instance, Rhinopristiformes rays (sawfish Pristidae, wedgefish Rhinidae, guitarfish Rhinobatidae, giant guitarfish Glaucostegidae) were identified to be the most threatened by many studies [14][15][16]24] as opposed to many shark species capable of supporting sustainable fisheries [17]. Moreover, this specific information help contextualise the fishery problems that can differ geographically and where catch reports are patchy or conservative. ...
Article
Full-text available
Sharks and rays are at risk of extinction globally. This reflects low resilience to increasing fishing pressure, exacerbated by habitat loss, climate change, increasing value in a trade and inadequate information leading to limited conservation actions. Artisanal fisheries in the Bay of Bengal of Bangladesh contribute to the high levels of global fishing pressure on elasmobranchs. However, it is one of the most data-poor regions of the world, and the diversity, occurrence and conservation needs of elasmobranchs in this region have not been adequately assessed. This study evaluated elasmobranch diversity, species composition, catch and trade within the artisanal fisheries to address this critical knowledge gap. Findings show that elasmobranch diversity in Bangladesh has previously been underestimated. In this study, over 160000 individual elasmobranchs were recorded through landing site monitoring, comprising 88 species (30 sharks and 58 rays) within 20 families and 35 genera. Of these, 54 are globally threatened according to the IUCN Red List of Threatened Species, with ten species listed as Critically Endangered and 22 species listed as Endangered. Almost 98% juvenile catch (69–99% for different species) for large species sand a decline in numbers of large individuals were documented, indicating unsustainable fisheries. Several previously common species were rarely landed, indicating potential population declines. The catch pattern showed seasonality and, in some cases, gear specificity. Overall, Bangladesh was found to be a significant contributor to shark and ray catches and trade in the Bay of Bengal region. Effective monitoring was not observed at the landing sites or processing centres, despite 29 species of elasmobranchs being protected by law, many of which were frequently landed. On this basis, a series of recommendations were provided for improving the conservation status of the elasmobranchs in this region. These include the need for improved taxonomic research, enhanced monitoring of elasmobranch stocks, and the highest protection level for threatened taxa. Alongside political will, enhancing national capacity to manage and rebuild elasmobranch stocks, coordinated regional management measures are essential.
... Dusky shark fins belong to a specific category (Hai Hu Fin [海虎翅]) and can fetch US$ 240-430 in China and Hong Kong (Clarke et al., 2006;Wu, 2016). Similarly, fins from shark-like batoids (order Rhinipristiformes) are categorized as Qun chi (群翅/裙 翅), and recognized as "king of shark fins" due to their high quality and fin-needle yields (Hau et al., 2018;Jabado, 2019). Processed Qun chi are sold for US$ 560/kg on average, and can fetch over US$ 1,600/kg (Hau et al., 2018). ...
Article
Full-text available
Understanding wildlife markets is central to effective conservation: it can help managers and policy‐makers to predict how interventions might influence supply and demand of wildlife products, and economic welfare of wildlife users; and thus, design interventions which have better outcomes for wildlife and people. Here we apply a revealed preference method of economic valuation—hedonic price analysis (HPA)—to understand shark markets and explore the economic costs of shark conservation for small‐scale fishers. We focus on a targeted semi‐commercial shark fishery in Indonesia—which poses a threat to some shark species, but provides important economic and subsistence value for a coastal community in an impoverished region of Indonesia—and use HPA to estimate market prices and welfare measures for threatened and CITES‐listed sharks. This represents a pertinent case study with practical implications because Indonesia is the world's largest shark fishing nation, where management interventions to reduce shark fishing mortality are needed. However, such interventions will create short‐term socio‐economic trade‐offs for fishing communities, which may hamper cooperation and compliance, and raise concerns regarding the fairness and equity of conservation. Our results give significant marginal price estimates for five species of conservation and commercial importance. Dusky sharks (Carcharhinus obscurus) and bottlenose wedgefish (Rhynchobatus australiae) have the highest implicit marginal prices, at US$ 157 and US$ 144, respectively. Our estimates suggest that conservation measures, such as catch limits for endangered and CITES‐listed species, could have significant economic opportunity costs (i.e., 3.4–17.6% revenue foregone) for low‐income fishers. Innovative policy instruments are required to transform shark markets and fisheries—to effectively reduce threats to endangered species and implement CITES, whilst doing no harm to vulnerable coastal communities. Methods from econometrics can help conservation scientists to better understand wildlife markets, and make management decisions which create better outcomes for wildlife and people. We apply a revealed preference method of economic valuation—hedonic price analysis—to understand shark markets, and explore the economic costs of shark conservation to small‐scale fishers. Our results give significant marginal price estimates for five species of conservation and commercial importance: dusky sharks (Carcharhinus obscurus) and bottlenose wedgefish (Rhynchobatus australiae) have the highest implicit marginal prices, at US$ 157 and US $144, respectively. Econometric methods can help can help managers and policy‐makers to predict how interventions might influence supply and demand of wildlife products, and economic welfare of wildlife users, and thus design interventions which have better outcomes for wildlife and people.
... Rhino ray landing data were opportunistically collected to support and validate fisher's catch recorded in the interviews and create a preliminary species list of rhino rays predominantly caught in artisanal fisheries in Bangladesh. Only whole specimens and/or those with clear diagnostic characteristics were included, with identification based on Last et al. (2016) and Jabado (2019). Sex was determined by the presence (male) or absence (female) of claspers, where possible. ...
Article
Rhinopristioid rays are among the most globally threatened cartilaginous fishes, almost all of which are Critically Endangered. Fishery pressure and lack of knowledge, especially where these elasmobranch fish overlap their habitats off developing countries in the Indo-West Pacific, impede their biological conservation which in turns result in unnoticed population depletion. Rhino rays are an important component of the Bangladeshi artisanal fishery; however, an understanding of these fisheries and their trade is limited. Fishers and traders were interviewed between June 2018 and June 2019 in four areas of southeast Bangladesh to characterize rhino ray fishing, trade and fishers' perception of population trends. All interviewed fishers reported lifelong rhino ray catch in sizable numbers and noted a steep decline in the catch over time, especially for Rhynchobatus spp. Seven species were documented-not only targeted by un-baited longlines but also by-caught in gillnets and set-bag nets. Unregulated and undocumented catch fuelled by substantial international trade to Myanmar on high-quality skin, meat and fins; and national usages of meat, liver, cartilages and intestines. Between 9000 and 33000 kg (avg. 23000 kg) of rhino rays were bought annually by each trader during 2015-2018. Southcentral shallow-water char (sand island) areas are perceived as essential habitats, hence providing important fishing grounds. The predominant threats are overexploitation by unselective gear use, bottom trawling, target catch, international trade and source of protein and income. Compliance with international trade control treaties or the Bangladeshi law was low, with most fishers (78%) unaware of specific regulation regarding rhino rays. It is crucial to adopt precautionary principles to prevent further rhino ray population declines. We propose a combination of actions rooted in sustainability and inclusiveness in this regard; e.g. a) trade mitigation, monitoring and enforcement, b) need for sustainable fisheries management regimes, c) need for habitat protection; finally, d) the importance of fishers' inclusiveness in conservation decision making.
... With 225 cm TL, the specimen is half a meter shorter than the maximum size reported for the species, 275 cm TL (Weigmann 2016). The species is included as critically endangered in IUCN Red List Assessments and urgently requires conservation management (Kyne et al. 2019a Distinctive characters: Rhynchobatus australiae is characterised by having a long and pointed, bottle-shaped snout that is slightly constricted near tip; posterior tip of pectoral fins ending before pelvic fins; no prominent ridges on head and body; spiracle with two folds; upper caudal-fin lobe longer than the lower one (Weigmann 2011;Last et al. 2016b;Jabado 2019). ...
Article
Full-text available
The species composition of batoid fishes from coastal waters of the Socotra Archipelago is reviewed, with confirmed records of the wedgefish Rhynchobatus djiddensis (Forsskål, 1775) and four new records of sharkrays, wedgefishes, and guitarfishes based on collected specimens, including one species from Abd al-Kuri Island, Rhina ancylostoma Bloch & Schneider, 1801 (Rhinidae), and three species from the main island Socotra, Acroteriobatus salalah (Randall & Compagno, 1995) and Rhinobatos punctifer Compagno & Randall, 1987 (Rhinobatidae), and Rhynchobatus australiae Whitley, 1939 (Rhinidae). Among the new records for the Socotra Archipelago, R. australiae represents the first verified record for the Arabian region. In addition, records of four stingray species (Dasyatidae) are verified based on underwater observations accompanied with photographs. All recorded batoid fishes are commercial species caught in the local small-scale fishery. Information on the identification and distribution of each species is provided.
Article
Information on the movement ecology of endangered species is critical for the implementation of effective conservation measures. This study made use of a long-term dart tagging dataset to reveal the movement patterns and growth rates of two size classes of the Critically Endangered whitespotted wedgefish Rhynchobatus djiddensis within its southern African distribution, which can have important implications for fisheries management. A total of 4 768 individuals were tagged with 340 recaptures recorded, ranging from 1 to 2 639 days (7.2 years) at liberty. Most of the tag releases and recaptures occurred within the KwaZulu-Natal central region in South Africa, with catches increasing significantly during summer (October to March). Most recaptures (43%) were recorded within 5 km of the tagging (release) site. Tagged adults recorded significantly greater distances moved than juveniles (p < 0.002) but there was no significant difference between juveniles or adults in terms of their direction of movement (p > 0.30). A Francis growth model showed that smaller individuals had a substantially faster growth rate (198.69 [SE 21.75] mm year⁻¹) compared with larger individuals (57.41 [SE 27.83] mm year⁻¹) confirming that the species is relatively slow-growing. Ultimately, this study identified important knowledge gaps in the broadscale movement patterns of R. djiddensis and provided new information on the growth rate of this Critically Endangered species. Filling in these knowledge gaps will aid in conservation measures for two important size classes of the R. djiddensis population as the species faces increasing targeted fishing pressure.
Article
Full-text available
The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species-specific basis. Species-specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999–2001. We randomly selected and genetically identified fin trimmings (n = 4,800), produced during fin processing, from the retail market of Hong Kong in 2014–2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one-third of identified species face serious risk of extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1-64.2% for blue [Prionace glauca]; 0.2-1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, including the most common species in trade, the blue shark. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals.
Technical Report
Full-text available
Identifying Shark Fins was created to help enforcement personnel to provisionally identify the dried and wet fins of commercially traded CITES listed shark species based on morphological characteristics of their most distinctive fins in their commonly traded form (frozen and/or dried and unprocessed) at the first point of trade. A preliminary visual identification will establish reasonable or probable cause in enforcement settings so that expert opinion can be sought or genetic testing can confirm field identification, aiding governments in successfully implementing and enforcing the CITES shark listings and promoting legal, sustainable trade
Article
Full-text available
Focusing on the most critical conservation priorities to prevent extinctions risks missing declines of lower priority taxa that may become tomorrow’s emergency. Sawfishes (5 species) underwent catastrophic but largely unnoticed global declines in the latter 20th century, and are now the subject of intensive research and conservation efforts. Guitarfishes (at least 55 species) share many characteristics with sawfishes: they are shark-like batoids with an often large body, prefer sedimentary habitats in warm shallow coastal waters exposed to intensive fisheries, and have high value fins and good quality meat. Guitarfishes represent a unique element of evolution and biodiversity and are vital components of complex coastal socio-ecological systems. Existing global IUCN Red List of Threatened Species assessments for nearly 60% of guitarfish species are 10 or more years old, and over 70% of species are either in threatened categories or Data Deficient. Recently described taxa not yet assessed include those likely to be at risk of extinction. Severe declines and localised extinctions have already been reported for guitarfishes. In notable contrast to sawfishes, total extinction of several guitarfish species is plausible given small distributions occurring solely in developing or least developed countries where conservation is highly challenging. Furthermore, species identification of guitarfishes is often problematic and they may lack the appeal often needed to promote conservation. To ensure that they do not follow the same trajectory as sawfishes, there is an urgent need for comprehensive and coordinated action on guitarfishes, which in many cases could integrate with sawfish conservation efforts.
Article
Full-text available
Rhynchobatus spp. (wedgefishes) are large benthopelagic shark-like rays with fins that are highly prized in the international shark fin trade. They are among the most threatened groups of sharks and rays globally. While Rhynchobatus spp. are known to be under considerable fishing pressure as a group, taxonomic confusion among species within the genus has compromised species-specific fishery and demographic data that are urgently needed for developing effective management strategies. Rhynchobatus australiae (Whitley, 1939) is a large Indo-West Pacific species reaching 2 to 3 m that is classified as Vulnerable on the IUCN Red List. This study combines new empirical data from field surveys with data obtained from verified reference specimens to investigate genetic and phenotypic variation in R. australiae and its relative incidence in fisheries. R. australiae dominated Rhynchobatus catch in fisheries surveys across Southeast Asia, and was the most commonly recorded species of the genus in Australia (94% and 58% of captures respectively, n = 207). Study specimens were consistent with a single species with moderate spatial mtDNA variation (ΦST = 0.198, p < 0.0001). We show that R. australiae can be reliably differentiated from other Indo-Pacific species with nadh2 (1044bp), and a section of the control region (456bp) short enough to amplify DNA from processed fins in international trade. We document aspects of morphological variability to assist in the description of external characters that differentiate this species. This is the first range-wide intraspecific study on any wedgefish species, and provides the most complete synthesis of mtDNA data to date for identifying Rhynchobatus fins in the global shark fin trade.
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A new species of wedgefish, Rhynchobatus immaculatus sp. nov., is described from a small collection of specimens obtained from fish markets in northern Taiwan. It is probably a medium-sized species (probably attaining ca. 1.5 m TL) because the largest known specimen, an immature male (ca. I m TL), has prolongated dorsal and caudal fins typical of adult wedgefishes. Rhynchobatus immaculatus is unique within the family in having a very high vertebral count (within the range of 165-170 total free centra) and in lacking a dark pectoral marking. Other Rhynchobatus species occurring in Taiwanese seas appear to attain a larger adult size, possess a dark pectoral marking at least in young, and have lower vertebral counts (fewer than 161 total fee centra). Rhynchobatus yentinesis, which was described from a specimen taken nearby at Wenzhou, China, has not yet been attributed to a currently recognised species. However, based on the illustration of the holotype, which reveals a broad-snouted species with a dark pectoral spot, it is closest to either R. palpebratus or R. springeri.
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A new species of guitarfish, Rhinobatos ranongensis sp. nov., is described from 5 preserved specimens, and images and tissue samples of additional material, collected from the Andaman Sea and Bay of Bengal. This species co-occurs in the eastern sector of the northern Indian Ocean with two poorly defined congeners, R. annandalei Norman and R. lionotus Norman, which have been misidentified and confused with Indo-Pacific congeners since they were first described in 1926. Norman's species are rediagnosed based on limited new material and a re-examination of the types. In the western sector of the northern Indian Ocean, Rhinobatos annandalei has been confused in recent literature with the sympatric R. punctifer Compagno and Randall, which is represented by four primary colour morphs, including a white-spotted colour morph resembling R. annandalei. Rhinobatos punctifer also displays strong intraspecific variability and sexual dimorphism in some body dimensions. These four species of Rhinobatos have unique MtDna sequences and belong to a clade of Indo-West Pacific species that are morphologically similar. Despite the relatively small numbers of specimens available for investigation , these species exhibit some clear differences in body proportions, meristics and squamation. Rhinobatos ra-nongensis sp. nov. differs from its northern Indian Ocean congeners through a combination of a relatively narrow disc and mouth, high vertebral count, long snout, low dorsal fins, and being largely plain coloured. A new lectotype and a paralec-totype are designated for the syntypes of R. annandalei, and the four primary colour forms of R. punctifer, the plain, white-spotted and ocellated morphs, are described and the three nominal species rediagnosed. A key is provided to the four known members of the genus in the northern Indian Ocean.
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Shark-like batoids (Rhinopristiformes) represent of some of the most threatened families of sharks and rays. In certain regions, they are a relatively important component of elasmobranch fisheries, commonly taken as by-catch in gillnets and longlines, but also increasingly targeted for their high value fins and meat. This demand, combined with intense fishing pressure, has resulted in global population declines as well as localized extinctions of many rhinopristoids. Yet, information on the life-history, ecology, and conservation status remains scarce for most species. From 2010-2012, data was opportunistically collected from thirteen rhinopristoid species, including four endemic to the Arabian Sea and adjacent waters, landed from fisheries in the United Arab Emirates or transported from Oman. Four taxa dominated and comprised 92% of total shark-like batoid landings by number, namely Rhynchobatus spp., the Halavi guitarfish (Glaucostegus halavi), bowmouth guitarfish (Rhina ancylostoma), and Bengal guitarfish (Rhinobatos annandalei). Details of the biological characteristics, including size composition and sex ratios, are presented for each species. While there remain identification challenges related to some unresolved taxonomic issues, with several likely undescribed species occurring in the region, the first regional checklist of rhinopristoids is provided. Evidence of significant declines in landings combined with increasing fishing effort over a short time period raises concern about the status and long-term persistence of many species. Increased research to understand the biology, ecology, diversity, and resilience to harvest by fisheries is critical to the effective management of these species and an urgent precautionary approach to their conservation is warranted.
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A new dwarf wedgefish, Rhynchobatus cooki sp. nov. is described from a single female from a Jakarta fish market (Indo-nesia) and 11 specimens collected at Jurong fish market (Singapore). First collected in 1934, the broader ichthyological community have been aware of this distinctive but little known ray since the late 1990's. Rhynchobatus cooki is the small-est of the wedgefishes (to 81 cm TL) and has the lowest vertebral count (fewer than 107 centra). It is also distinguishable from its congeners based on its long, hastate snout, very strongly undulate anterior pectoral-fin margin, coloration and aspects of its squamation. The dorsal coloration is mainly dark and distinctively marked with white blotches, spots and streaks, and has a dark cruciate marking on the interorbit and a prominent white border around the body margin. Unlike most other wedgefish species, the snout tip lacks dark blotches and there is no black pectoral-fin marking. It shares well-developed rostral spines with a much larger Atlantic species (Rhynchobatus luebberti), but these spines are confined to the snout tip (rather than being more numerous and extending in paired rows along the rostral ridges nearly to the eyes). No additional specimens have been observed since 1996, despite an increased recent effort to survey the chondrichthyan fauna of South-East Asia and collect biological data for species, raising concerns over its conservation status.
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A new guitarfish, Rhinobatos borneensis sp. nov., is described from material collected at fish markets in Malaysian Borneo (South China Sea). This ray, which is almost plain coloured with faint orange blotches in adults, has a more colourful embryo marked with small pale ocelli with dark centres. Confused with R. Schlegelii (Japan to Taiwan) and its junior synonym R. formosensis, new molecular data suggests it is more closely related to a subgroup of Rhinobatos from the Indo-Malay Archipelago that includes R. jimbaranensis, R. Sainsburyi and R. whitei. Based on evidence from recent phylogenetic studies, the genus Rhinobatos is non-monophyletic, nor is the Rhinobatidae a monophyletic family-level group. Former subgenera of Rhinobatos, Acroteriobatus and Glaucostegus, are valid genus-level taxa supported by both morphological and molecular evidence. Moreover, amphi-American members of Rhinobatos, assigned herein to a new genus Pseudobatos, are not monophyletic with Rhinobatos, Acroteriobatus and Glaucostegus and its position within the newly erected order Rhinopristiformes needs to be reassessed. Several molecular studies have suggested that the family Rhinobatidae is polyphyletic and needs to be redefined. We propose a revised classification of the order Rhinopristiformes based on molecular analyses and supported by morphological data, making strong use of oronasal morphology. The group now contains 5 family-level taxa: three valid nominal taxa, Pristidae (2 genera, 5 species), Rhinidae (incorporating Rhynchobatidae, 2 genera, 9 species), Rhinobatidae (3 genera, 31 species); and two new taxa, Glaucostegidae (single genus, 6 species) and Trygonorrhinidae (3 genera, 8 species).