Hardnose sharkCCM

Carcharhinus macloti

Carcharhinus macloti upper and lower teeth

Characteristic features:

  • Second dorsal-fin origin opposite midbase of anal fin
  • First dorsal-fin inner margin extremely long, about 2 thirds length of fin base
  • Interdorsal ridge absent
  • Snout long and pointed, hard (rostral cartilage hypercalcified)
  • Upper teeth with narrow, oblique or nearly erect central cusps; surrounded by strong cusplets
  • lower teeth tall, narrow, upright and smooth edged

Colour:

Dorsal surfaces bronze, fading to greyish brown after death; a faint pale stripe on each side. Fins lacking distinct markings; posterior margins of some fins sometimes pale-edged. Ventral surfaces almost white.

Size:

Maximum size up to 110 cm TL; birth size 31–40 cm TL.

Distribution:

Found in tropical Indo-west Pacific, from east Africa to Papua New Guinea and northwards to south Korea.

Habitat:

A mostly inshore species; found from the surface to 170 meters depth.

Biology:

Feeds primarily on bony fish, but also cephalopods and crustaceans. The only Carcharhinus species to have a hypercalcified rostrum, which can be felt by pinching the snout, most evident in larger individuals. Sometimes forms large sexually segregated aggregations. Length at maturity is at 70–89 and 69–74 cm TL for females and males respectively. Females breed every 2 years and have a viviparous with yolk-sac placenta reproductive mode. The gestation period lasts about 12 months before giving birth in July to 1–2 (usually 2) pups. Attains a maximum age of at least 12 years.

Indonesian fisheries:

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

Similar species:

A distinct species clearly separable from other Carcharhinus species which differ by having the second dorsal-fin origin level with anal-fin origin (vs. second dorsal-fin origin level with the anal-fin midbase).

Rhizoprionodon
Sharpnose sharks
Rhizoprionodon taylori
Rhizoprionodon differ in having an anal fin much larger than second dorsal fin (vs. second dorsal fin and anal fin similarly sized) and an anal-fin posterior margin that is almost straight (vs. deeply notched).

External links:

FishBase
The IUCN Red List of Threatened SpeciesTM