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Rafetus swinhoei Photo Credit:
Asian Turtle Conservation Network
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Turtles have cultural importance in the societies of
Southeast Asia. In Vietnamese culture the Ho Guom Turtle (Rafetus swinhoei) is considered holy because of a 15th-century legend
describing how King Le Loi drove out invading Chinese with a magical sword,
which the gods gave him and which he later returned by giving it to the lake's
turtle, which swam it back to the gods. Hoan Kiem Lake is an oasis in urban
Hanoi that attracts tourists and locals alike, and the place to go to catch a
glimpse of the 300-kilogram Ho Guom Turtle, it’s most famous resident (there is
a population of these turtles in the lake, not just one individual). Today
(December 21, 2010), m&cnews.com
is reporting that Vietnamese scientists are urging Hanoi authorities to wipe
out the invasive Red-eared Slider (Trachemys
scripta) which is believed to be a threat to Hoan Kiem Lake's legendary
chelonian. Professor Ha Dinh Duc, an expert on the giant softshell Rafetus swinhoei, said 'Hanoi's
authorities need to make a plan to kill these invaders because if there are no
timely and proper measures, red-eared turtles would eat all foods of our native
turtle...They even eat all plants in the lake, and the lake would not be green
anymore."
Many Hanoians release the North American Red-eared Slider
into Hoan Kiem for good luck at holidays, such as the Tet New Year. Thus, they
have created the situation, said Pham Dinh Quyen, general secretary of the
Vietnam Association for Conservation of Nature and Environment. Red-eared
Sliders are now doing well in the lake.
Rafetus swinhoei
is probably the world’s largest and
rarest softshell turtle species (Family Trionychidae). There are few recent
records of them, and what we known about them suggest they have a discontinuous
and relictual distribution. The species is known from Tai Hu Lake and the
Suzhou area, west of Shanghai, the Red River drainage in Yunnan, in southern
China, and from the same river system in northern Vietnam. Rafetus swinhoei
have also been reported from Thanh Hoa
Province, Vietnam and this is the most southern reported locality for the
species, if its presence can be documented. Rafetus swinhoei was already rare in the 1870’s, when Pierre-Marie Heude
collected some specimens from the Tai Hu Lake area. In 2009 there were only
four captive specimens in China and one in Vietnam, although fishermen’s
accounts indicate that some wild animals existed as recently as 10-20 years ago
(Le and Pritchard, 2009). Search for museum specimens was conducted by Peter
Pritchard, who located about 20 specimens, most of them decades old, and nearly
all had been misidentified as species of Pelochelys. Taxonomic confusion started when Heude (1880) ignored John
Gray’s description of Oscaria
swinhoei (Gray, 1873) and named five species
within the genus Yuen
to a group of swinhoei specimens from the eastern population. This was not sorted out until
1998 when Meylan and Webb (1998) carefully examined Gray’s type specimen in the
British Museum of Natural History and confirmed the validity Rafetus
swinhoei. To add to the confusion, Ha Dinh Duc
(2000) described Rafetus
leloii, based on specimens collected from
Hoan Kiem Lake in downtown Hanoi, but Farkas and Webb (2003) placed leloii into the synonymy of swinhoei.
Rafetus swinhoei
appears
to be on the brink of extinction. Unless immediate action is taken to increase
its populations it seems probable that it won't last the century.
Literature
Farkas, B. L. and
R. G. Webb, 2003. Rafetus leloii Ha Dinh Duc, 2000 – an invalid species
of softshell turtle
from Hoan Kiem Lake, Hanoi, Vietnam (Reptilia, Testudines, Trionychidae). Zoologische Abhandlungen 53: 107-112.
Gray, J. E.
1873. Notes on Chinese mud-tortoises (Trionychidae), with the description of a
new species sent to the British Museum by Mr. Swinhoe, and observations on the
male organ of this family. Ann. Mag.
Nat. Hist. 12:156-161.
Ha, D. D. 2000.
A new species of the genus Rafetus
(Family: Trionychidae) from Hoan Kiem Lake of Vietnam. Archeology Magazine 4:104.
Meylan, P. A . and
R. G. Webb, 1988. Rafetus swinhoei (Gray) 1873, a valid species of living
soft-shelled turtle (family Trionychidae) from China. Journal of Herpetology 22:118-119.