Nurse shark

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Ginglystoma cirratum

Type: fish

Status: stable

Species Guide

Nurse shark

Ginglystoma cirratum

Species Type: fish

Conservation Status: stable

IDENTIFICATION

This is a bottom-dwelling species with a somewhat flattened body – not the typical torpedo-shaped shark body. The nurse shark may grow to a length of almost 10 feet. Its body color is uniform and ranges from light tan to dark chocolate brown with a lighter underside. The mouth is on the underside of its low, broad head and there are two long fleshy barbels near the mouth. There are small spiracles on the head behind the eyes.

The dorsal fins are rounded with the first being larger than the second. The pectoral fins are broad but short and the upper lobe of the tail is much longer than the lower.

Distribution & Habitat

Nurse sharks can be found in temperate and tropical coastal waters along the eastern Pacific Ocean and on both sides of the Atlantic. They are often found resting on the bottom near reefs or sand flats along the continental shelf.

Diet

Nurse sharks feed on bottom-dwelling invertebrates, bony fish, and stingrays. They suck food into their mouth and then grind it using their teeth. They feed at night and are generally not considered to be dangerous to humans. However, they may bite if provoked and they are known to not let go easily after biting.

Life Cycle

Nurse sharks are nocturnal and social, often lying motionless on the bottom in groups during the daytime.

Females are sexually mature at 15-20 years old and males at 10-15 years. During mating, the male will bite down on one of the female’s pectoral fins before each roll over on the seabed to mate.

Nurse sharks are ovoviviparous and may have 20-30 pups per litter. Females may give birth during the late spring or summer every other year following a 5-month gestation period.

Current Threats, Status, and Conservation

The nurse shark currently has no federal conservation status. It also has no legal conservation status in New Jersey and may be caught and landed, with restrictions on catch size and number.

This species is currently considered to be fairly common across its range. However, it does have a small home range, so individual populations are subject to local extirpation. Like other sharks, it is captured for its fins and becomes entangled in fishing gear. It has also been harvested for its skin. Marine pollution, especially from plastics, as well as climate change may also threaten this and many other marine species.

Nurse sharks are hardy in captivity and are kept in many aquariums. They are typically docile around divers and an attraction at many dive locations.

 

References

Compagno, Leonard, M. Dando and S. Fowler. 2005. Sharks of the World.

Text written by Michael J. Davenport in 2016.

Scientific Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Chondrichthyes
  • Order: Orectolobiformes
  • Family: Ginglymostomatidae
  • Genus: Ginglymostoma
  • Species: G. cirratum