Carcharhinus borneensis

Author: (Bleeker, 1859)

Field Marks:
A small grey shark with a long pointed snout, unique (for the genus) enlarged hyomandibular pores alongside mouth corners, large eyes, oblique-cusped serrated teeth in both jaws, upper teeth with cusplets, usually 12/11 rows of anteroposterior teeth, no interdorsal ridge, small pectoral fins, a small first dorsal with a short rear tip and a small low second dorsal with a short rear tip and its origin aboyt over the anal midbase, and no conspicuous markings on the fins.

Diagnostic Features:
A small, slender species (up to possibly 1 m). Snout long and pointed; internarial width 1.3 to 1.5 times in preoral length; eyes circular and moderately large, their length 2.1 to 2.6% of total length; anterior nasal flaps high and narrow, nipple-shaped; upper labial furrows short and inconspicuous; hyomandibular line of pores just behind mouth corners conspicuously enlarged; gill slits short, the third 2.5 to 2.9% of total length and less than a third of first dorsal base; usually 12/11 rows of anteroposterior teeth in each jaw half but varying from 11 to 12/11 to 12; upper teeth with narrow, strongly serrated, oblique, moderately high cusps, and crown feet with large distal cusplets; lower teeth with oblique narrow serrated cusps, weak cusplets or large serrations and transverse roots. No interdorsal ridge. First dorsal fin moderately large and triangular, with bluntly pointed apex and posterior margin curving posteroventrally from fin apex; origin of first dorsal fin slightly anterior to pectoral rear tips; inner margin of first dorsal moderately long, half dorsal base or slightly less; second dorsal fin small and low, its height 1.8 to 2% of total length, its inner margin long and 2.2 to 2.4 times its height; origin of second dorsal over or slightly behind anal midbase; pectoral fins small, falcate, with narrowly rounded or pointed apices, length of anterior margins about 13 to 14% of total length; 118 to 121 total vertebral centra, 61 to 63 precaudal centra. Colour brown above, white below, tip of first dorsal and dorsal caudal margin dusky, paired fins and anal fin with light edges, but markings not conspicuous.

Geographical Distribution:
Indo-West Pacific: ? Java, Borneo, China, ? The Philippines.

Habitat and Biology:
A rare coastal, inshore, tropical shark, with biology virtually unknown.

Size:
Maximum estimated at about 70 cm.

Interest to Fisheries:
Apparently rare, but undoubtedly taken in local fisheries.

Type material:
Holotype: Rijksmuseum van Natuurlijke Historie, Leiden, RNH 7386, 238 mm immature male. Type Locality: Singkawang, Borneo.

%LABEL% (%SOURCE%)