510 
THE CORAL TRIANGLE: HEARST BIODIVERSITY EXPEDITION 
Figure 43. Hy drop his [Pelamis] platurus (Linnaeus, 1758). 
Photo courtesy of John Tashjian. 
Figure 44. Hydrophis [Pelamis] platurus (Lin¬ 
naeus, 1758). Illustrations by Emily M. Eng. 
guishable from adjacent body scales; head narrow, snout elongate, head scales entire, nostrils supe¬ 
rior, nasal scales in contact with one another; prefrontal in contact with 2*^^ upper labial; 1-2 pre- 
and 2-3 postoculars; 2-3 small anterior temporals; 7-8 upper labials, 4-5 below eye but separated 
from border by subocular; color variable but most often distinctly bicolored, black above, yellow 
or brown below, the dorsal and ventral colors sharply demarked from one another; ventrally there 
may be a series of black spots or bars on the yellow or brown background, or the yellow may 
extend dorsally so that there is only a narrow middorsal black stripe, or a series of black crossbars 
(see Smith 1943:476^77 for a more complete description of the color pattern variants). 
Size.— Total length (3) 720 mm, ($) 880; tail length (3) 80 mm, ($) 90 mm. 
Distribution. — Philippines (widely distributed). Elsewhere: most widely distributed of all 
sea snakes, from east coast of Africa throughout southern and eastern coastal Asia, as far north as 
southern Siberia, throughout Indonesia to Australia and Tasmania, also from Gulf of Panama north 
to Baja California in western North America and Hawaiian Islands. 
Hydrophis [Enhydrina] schistosus (Daudin, 1803) 
Beaked Sea Snake; Hooked-nosed Sea Snake 
Figures 20A, 21B, 22, 45 
Hydrophis schistosus Daudin, 1803:386. 
Enhydrina schistosa. Smith, 1926:36, fig. 17; 1943:449, fig. 144.— MeCarthy, 1993:227.— David and Ine- 
ieh, 1999:92.— Whitaker and Captain, 2004:390, photo (p. 391). 
Disteira schistosa, MeDowell, 1972:239-244. 
Description. — Mental scale small, partly concealed within mental groove; 3^ maxillary 
teeth behind fangs; 5-6 palatine teeth, palatine teeth larger than pterygoid teeth; no suborbital 
stripe; young light brown to dark gray above, whitish below, with dark gray or black annuli; pat¬ 
tern disappears in adults which are uniform gray in color; scales around body variable, in Bay of 
Bengal, scales around neck, (cJ) 40-52, ($) 42-55, scales around midbody, (cJ) 49-60, ($) 51-65, 
scales imbricate or subimbricate, with short central keel; ventrals 239-322, small, usually distinct 
throughout, occasionally missing on anterior part of body; precloacal scales slightly enlarged; color 
of young grey or bluish grey above, whitish below, with dark grey or black rings, broadest dorsal¬ 
ly, that disappear in adults, which are usually uniformly greyish in color. 
