Latin name

Rhizoprionodon oligolinx

Other name

Rhizoprionodon oligolinx

Identification

The grey sharpnose shark has a slender body with a long, pointed snout and large, round eyes with a blinking membrane. The distance from the tip of the snout to the nostrils is 3.7-4.7% of the total length. There are short furrows at the corners of the mouth on the upper and lower jaws. The length of the upper lip furrow is 0.3-1.3% of the total length. There are usually 3-8 dilated pores on each side of the lower jaw. The number of teeth is 21-25 on each jaw. The edges of the teeth are irregularly serrated. In adult males the teeth are longer and narrower.

This species is very close to Rhizoprionodon taylori, but they are geographically separated.

Features of fish fins

The broad, triangular pectoral fins begin below the third or fourth gill slit. The base of the first dorsal fin begins behind the free tips of the pectoral fins. The base of the anal fin is about twice as long as the base of the second dorsal fin. The second dorsal fin is considerably smaller than the first and is located above the last third of the anal fin. The leading edge of the pectoral fins is usually shorter than the length of the first dorsal fin from the beginning of the base to the free tip. The ridge between the dorsal fins is absent. The lower lobe of the caudal fin is well developed, with a ventral notch on the upper lobe near the tip. 

Fish colouring

The colouration of the grey sharpnose shark is plain grey or grey-brown, with a bronze tinge in live sharks. The edges of the fins are dull.

Distribution

This shark species is common in the coastal waters of southern Asia, from the Persian Gulf to northern Australia and possibly southern Japan. It is found in the coastal waters of Cambodia, India, Indonesia, Iran, Malaysia, Pakistan, Palau, Singapore, Sri Lanka and Thailand. 

Habitat

Grey sharpnose sharks prefer to stay at depths of up to 36 metres. 

Size

Maximum length: 84.5 cm for males and 77.5 cm for females. Maximum declared weight: 2.8 kg.

Behavior

A little known coastal and offshore shark that inhabits continental and island shelves.

Food and feeding habits

The diet of the grey sharpnose shark consists of bony fish, cephalopods and crustaceans.

Reproduction

Males and females reach sexual maturity at lengths of 29-38 and 32-41 cm respectively. Like other members of the family, they are viviparous; developing embryos are nourished by a placental connection to the mother formed by an empty yolk sac. There are 3-5 newborns in a litter, 21-26 cm long. Females probably give birth annually. 

Fishing

Of minor commercial interest. Commonly caught in coastal bottom-set nets, particularly off the coast of Java. The International Union for Conservation of Nature has classified the species as Near Threatened.

Relationship with a person

This species is not dangerous to humans. Their meat is used as food and for the production of fishmeal.