Whitetip reef sharkTRB

Triaenodon obesus

Tri.obe. S-HV
Triaenodon obesus upper and lower teeth

Characteristic features:

  • Second dorsal fin relatively large, about half size of first
  • First dorsal and upper caudal fins with distinctive white tips
  • Snout very short, blunt and broadly rounded
  • Nasal flaps extended slightly
  • First dorsal-fin origin well behind pectoral-fin free tips
  • Upper and lower teeth smooth-edged, with long, narrow central cusp, flanked either side by a strong cusplet

Colour:

Dorsal surfaces greyish brown, often with a few scattered dark-brown spots. First dorsal and upper caudal-fin tips (also sometimes second dorsal- and lower caudal-fin tips) white; fins may be dark-edged. Ventral surfaces white.

Size:

Maximum size up to 170 cm TL; birth size 52 – 60 cm TL.

Distribution:

Widespread in the Indo-Pacific from south-eastern Africa to Central America.

Habitat:

A reef-associated shark often found resting on the bottom, in caves or under ledges during the day, and actively foraging over the reef at night. Found from the surface to 300 meters depth, but usually 8 – 40 meters.

Biology:

Feeds primarily on bony fish, crustacean and octopuses. This species has a relatively narrow home range, returning to the same resting places by day. A curious species that is rarely aggressive to divers; popular for dive ecotourism. Length at maturity is 105 – 122 cm TL and 105 – 116 cm TL for females and males respectively. Age at maturity is 8 and 7 years for females and males respectively. Reproductive mode is viviparous with yolk-sac placenta. Females give birth to 1 – 5 (usually 2 – 3) pups after a gestation period of 10 – 12 months, and breed every second year. Maximum age of Australian populations is as at least 19 and 14 years for females and males respectively.

Indonesian fisheries:

Caught by inshore longline and gillnet fisheries, and probably adversely affected by dynamite fishing. Utilised for its fins and meat, but of limited value due to its small size.

Similar species:

A distinctive species, unlikely to be confused with other members of the family because of the combination of its large second dorsal and anal fins, and white tipped first dorsal and upper caudal fins.

External links:

FishBase
The IUCN Red List of Threatened SpeciesTM