The IUCN/SSC Shark Specialist Group
Shark News 9: June 1997
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River Shark Discovered in Sabah
Sarah Fowler, Shark Specialist Group, UK
The first preserved specimen of river shark Glyphis sp. from the Kinabatangan
River, kept by local fishermen for the Darwin project team in Sabah, Malaysia.
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Specimens of one of the world's most elusive genera of
sharks, the river sharks, Glyphis, have finally been
obtained from Sabah's Kinabatangan River in Northern
Borneo. They were discovered over a year after the
start of the 18 month Shark Specialist Group's (SSG)
Darwin project on Elasmobranch Biodiversity and
Conservation in Sabah. This project, funded by the UK
Darwin Initiative for the Survival of Species, is being
undertaken in cooperation with the Sabah Department
of Fisheries, and with help from WWF-Malaysia.
The river shark is the rarest of the very scarce freshwater species
of sharks and rays for which the Shark Specialist Group survey team
had been searching. The researchers were beginning to believe that
the occasional reports of a freshwater shark whose description appeared
to match that of the almost mythical Borneo river shark (see box below)
would never be substantiated. Heavy rainfall
and continual river flooding had severely
hampered fieldwork in 1996, preventing
successful fishing for river sharks and rays.
Only a single small specimen of the giant
freshwater stingray (Himantura chaophyra)
was obtained. But, as the river level eventually
began to subside, the message came in from
a small riverside kampong (village) on the
Kinabatangan River that a shark had finally
been caught.
It is extremely unlikely that the
breakthrough could have been made without
the invaluable help of local fishermen who
offered their assistance. The villagers were
provided with a tank of formalin and a single-use
camera in case they caught any freshwater
sharks or stingrays while carrying out their
usual fishing operations. At last, some months
ago, they found several juvenile River Sharks
answering to the description of Glyphis in
one of their nets and carefully preserved one
for the researchers. Others were photographed
before being discarded. Another four females,
about 60 cm in total length (probably new-borns)
were taken at the end of May. This time
all were kept.
The excitement of those who were shown
the first shark had been intense. Darwin Project
officer Mabel Manjaji and UK volunteers
Rachel Cavanagh and Scott Mycock reported
their delight over the find: "The family led us
to the tank of formalin which they had been
keeping locked up at the back of their stilt
house, insisting that they had a shark for us in
there. They looked on in bewilderment; we could barely contain
ourselves - could it really be Glyphis? We all crowded round as the
tank was opened, oblivious to the formalin fumes. There it was, black
beady eyes, blunt snout, fins like we'd never seen before but just like
those in the books - there was no doubt about it: this was Glyphis, at last!"
Shark Specialist Group expert, Dr Leonard Compagno (Curator
of Fishes and Head of the Shark Research Center, South African
Museum) has studied the few existing museum specimens of this
group, most of which were collected in the 19th Century. He remarked:
"We have very little idea of the geographic distribution of these sharks,
much less their general biology. They show up like ghosts, few and far
between, in a handful of scattered localities.
Finding one is cause for celebration ...
External differences between the known
species are subtle, but body and fin shape
shown in the photos suggest that the
Kinabatangan shark may be closer to
another undescribed species, Glyphis
'species A' from Queensland, Australia,
than to the original Borneo river shark."
Fortunately the wet weather last year
did not interrupt the remainder of the
Darwin project's work programme. Regular
visits to coastal fish markets have resulted
in the collection and curation of a wide
range of sharks and rays from the coastal
waters of northern Borneo. Discoveries
include some sharks which are completely
new to science, as well as new species
records for the region. This area has been
confirmed as one of the international
centres of shark and ray biodiversity.
The collection of sharks and rays made
during the Darwin project will be retained
in Sabah for future research. It represents a
unique resource for biodiversity and
taxonomic research in the region. Duplicate
specimens will be housed in other
international fish collections.
Conservation footnote: The River
Sharks were caught as incidental catch in
fishing operations targeted at other fish.
They were found dead in the nets, not
killed by the villagers to provide research
specimens, and were not sold, but given to
the project team. The Darwin project
leaders are anxious that their research programme does not create an
artificial market and fishery for these rare species, but educates the
local fishermen about the rarity of their freshwater sharks and rays and
encourages them to conserve these fish and their habitat.
Sarah Fowler
Nature Conservation Bureau, 36 Kingfisher Court
Hambridge Road, Newbury, Berkshire, RG14 5SJ, UK.
Email: sarahfowler@naturebureau.co.uk
The genus Glyphis, river sharks
These are large sharks, probably reaching about 3 m in
length, although most specimens known are juvenile or
new-born (because of the difficulty of preserving large
adults). The smallest from the Kinabatangan was just
60 cm long and had an open umbilical scar, indicating
an age of only one or two months. River Sharks have
characteristic small eyes and a relatively large second
dorsal fin. Their small eyes and slender teeth suggest that
they are primarily fish-eaters adapted to life in turbid
river waters. Some may also enter seawater.
It is uncertain how many species of Glyphis exist, but
there are at least four or five. The Ganges river shark
Glyphis gangeticus is listed as Critically Endangered in
the 1996 IUCN Red List of Threatened Species. It was
known from only three museum specimens collected
over 100 years ago, until a freshly caught adult female
(280 cm long) and two fresh jaws were seen last year.
The speartooth shark Glyphis glyphis was originally
known from eight specimens. One small stuffed fish is in
a Berlin museum, two small preserved specimens have
been destroyed by poor curation and the rest are dried
jaws. Its original geographic origin is unknown.
There may be three undescribed species. The Bizant
river shark, Glyphis species 'A', is known from two
specimens, one lost, from Queensland, Australia. The
Borneo river shark, Glyphis species 'B', is recognised
from just one preserved specimen found in a museum in
Vienna, taken from an unknown river in Borneo over
100 years ago. The New Guinea river shark, Glyphis
species 'C', may possibly be identical to Glyphis glyphis.
Of seven specimens collected, two whole young have
been lost, and five are only represented by jaws.
Leonard Compagno
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