Enhydris pahangensis Tweedie, 1946: 142. Holotype: BMNH 1947.1.1.70. Type locality: Kuala Tahan, River Tembeling, Pahang, between 500 and 1,000 feet altitude (152–308 m).
Size. The only known male specimen has a total length of 220 mm with a 40
mm tail. Presumably it is a juvenile.
External Morphology. This species is known from a single male specimen
and the basis for the following description. The head is slightly distinct from
the neck, the body is cylindrical, and the tail is slightly compressed. The
eyes of this species are relatively large, being only slightly smaller in
diameter than the eye-mouth distance.
On the head the
rostral is slightly broader than tall and is in contact with the first two
upper labials; it is not strongly notched. The nasal scales are in contact,
they are divided and the nasal cleft touches the seam between the first and
second labials. The nare is located toward the center of the posterior edge of
the scale. The internasal scale is single, diamond-shaped and is isolated from
the loreal. The prefrontal scales are smaller than the nasals and make broad
contact with the loreal scales. The frontal is pentagonal and slightly shorter
than the parietals. The parietals are broad and entire, and bordered by large
occipital scales on the sides and smaller occipitals at the posterior edge. The
supraocular is single, the preocular is single, and the two postocular scales
are about equal in area. Labial number four is under the orbit. The loreal
contacts upper labials two and three. Upper labials number eight, and the
second and third contact the loreal, the third and fourth contact the
preocular; tallest upper labial is number six. There is one primary temporal and
two secondary temporal scales. In the secondary row, the ventral scale is
largest.
On the chin the lower
labials number 10. Lower labials 1 - 5 are in contact with the first chin
shield and the sixth lower labial is the largest. There are two pair of chin
shields with the anterior pair being longer than the second pair. Gular scales
number five.
On the body dorsal
scale rows number 26 on the neck, 25 at mid-body, and 21 in front of the vent.
The dorsal scales are smooth and lanceolate, even those in the first row, when
compared to most other members of the genus. The ventral scales are broad,
round, and number 126.
On the tail the
subcaudal scales are divided number 57. The scales on the dorsum are similar to
those on the body.
Color and Pattern. The
ventral pattern is a zigzag stripe on the outer edge of each ventral and scale
row one. Scale rows 1 - 4 have a cream stripe. Other dorsal rows are uniform
brown with scattered dark spots on the back.
Natural History. This snake is known only from the type specimen.
Nothing is known about its natural history. Based on its type locality it is
probably endemic to the Peninsular Malaysian rain forest ecoregion of the Sunda
Shelf and Philippines Bioregion (Wikramanayake et al., 2002). The Pahang River
is 435 km long, and is associated with several important wetland complexes. It
is formed by the confluence of the Jelai and Tembeling Rivers and the Kuala
Tahan area is popular for ecotourism. Thus, it is somewhat surprising that more
specimens of this snake have not been forthcoming.