Ganges sharkCCX

Carcharhinus borneesis

Carcharhinus borneensis ventral head
Carcharhinus borneensis upper and lower teeth

Characteristic features:

  • Second dorsal-fin origin opposite anal-fin insertion
  • Anal fin larger than second dorsal fin, its posterior margin shallowly concave
  • Preanal ridges very long, about equal to length of anal-fin base
  • Snout long and narrowly rounded
  • Upper labial furrows long and prominent, 1.4–2% of TL
  • Upper and lower teeth narrowly triangular and oblique (smoothedged to finely serrate)

Colour:

Dorsal surfaces bronze to greyish, fading to grey after death. Pectoral, pelvic, anal and lower caudal-fin tips and pectoral-fin posterior margins pale; upper lobe of caudal edged with black and with a dusky tip. Ventral surfaces white.

Size:

Maximum size up to 100 cm TL; birth size 31–39 cm TL.

Distribution:

Found in the eastern Atlantic and Indo–west Pacific.

Habitat:

Found throughout the water column, usually near the bottom, on coastal and continental shelves. Found from close inshore to at least 200 meters depth.

Biology:

Feeds primarily on small bony fish, and also crustaceans and cephalopods. Populations appear to have increased in some areas where there have been declines in large inshore sharks (e.g. South Africa). Regional differences in some DNA sequences suggest this may represent a complex of species. Length at maturity is 70–81 cm TL and 68–72 cm TL for females and males respectively. Age at maturity is around 1.8 years for females and 1.1 years for males. Reproductive mode is viviparous with yolk-sac placenta; females give birth to 1–8 (usually 2–5) pups after a gestation period of about 12 months. Females have no reproductive seasonality and probably give birth each year. Maximum age of northeastern Australian populations reported for females and males as 8.1 and 4.5 years respectively.

Indonesian fisheries:

Commonly caught by inshore demersal gillnet fisheries. Utilised for its fins and meat, but of limited value due to its size.

Similar species:

Rhizoprionodon oligolinx
Grey sharpnose shark
Rhizoprionodon oligolinx
Rhizoprionodon oligolinx differ in having short upper labial furrows (vs. long and prominent).
Rhizoprionodon taylori
Australian sharpnose shark
Rhizoprionodon taylori
Rhizoprionodon taylori differ in having short upper labial furrows (vs. long and prominent).

External links:

FishBase
The IUCN Red List of Threatened SpeciesTM