Author Linda Weiss
Crocodile Shark
(Pseudocarcharias kamoharai)
Key Features/Appearance
The Crocodile Shark is a small, slender-bodied shark with large eyes that do not have nictitating membranes. They reach a maximum length of 110 cm (3.6 ft) and weigh 4.1 -5.9 kg (9-13 lbs.). They are gray to grayish-brown on their top and sides and cream to white colored underneath. They have 5 long gill slits that extend nearly the full height of their sides. All of their fins are small with lighter, almost white, shading on the edges. The caudal fin is forked with the upper lobe significantly larger than the lower lobe. The snout is somewhat pointed. The jaws are able to be extended well beyond the mouth. Its teeth are long, slender, pointed and without serrations. The front teeth are longer than those behind them and are curved slightly inward. This shark got its name for its long and sharp teeth and snapping its jaws when removed from the water.
Habitat and Distribution
The Crocodile Shark’s geographic range covers the globe’s tropical waters of the Atlantic and Indo-Pacific. In the Atlantic it is found off Cape Verde, Angola, Guinea-Bissau, Guinea, Brazil, South Africa, and Saint Helena Island. It inhabits the Indian Ocean in the Mozambique Channel. In the Pacific, its range extends from Japan, to Taiwan, and the Korean Peninsula down to Indonesia, Australia, and New Zealand. And from Baja California to Chile. It resides far off-shore in depths that range from 0 - 590 m (0 - 1940 ft.).
Diet
Little is known about the preferred prey and diet of this shark species. It is suspected they feed on bony fish, squid and shrimp.
Reproduction
The Crocodile Shark is ovoviviparous. With this form of reproduction embryos are nourished by a yolk-sac inside eggs that are retained inside the female. After that yolk-sac is absorbed, they consume unfertilized eggs to continue their development. There is some speculation that intrauterine cannibalism may occur. Their gestation period is unknown. At birth they are approximately 41.5 cm (16.3 inches) long. The average litter size is 4 pups.
Status
The IUCN Red List of Threatened Species currently lists the Crocodile Shark as Least Concern, with an increasing population trend.
Threats
The Crocodile Shark is routinely taken as bycatch in the tuna and swordfish commercial fisheries. As this species does not hold a high commercial value, it is usually discarded. Some specimens may be kept and traded locally and nationally for their liver, meat and fins. This shark’s natural predators are unknown.
References
ReefQuest Centre for Shark Research
Planet Shark Divers
Shark Research Institute
The IUCN Red List of Threatened Species
Kyne, P.M., Romanov, E., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Jabado, R.W., Liu, K.M., Marshall, A., Pacoureau, N. & Sherley, R.B. 2019. Pseudocarcharias kamoharai (errata version published in 2020). The IUCN Red List of Threatened Species 2019: e.T39337A171964644. https://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T39337A171964644.en. Accessed on 08 February 2022.
ความคิดเห็น