Adult nurse sharks generally range from light yellowish tan to dark
brown in color. Averaging 7.5 to 9 feet in total length and weighing 167 to 233
lbs., adult females reach a larger size than adult males.
Class: Fish (Pisces)
Range: Nurse sharks are common in tropical and subtropical coastal waters on both sides of North America.
Habitat: The nurse shark is a nocturnal animal that rests on sandy bottoms or in caves or crevices in rock in shallow waters during the day. Large juveniles and adults are usually found around deeper reefs and rocky areas at depths of 10 to 250 feet during the daytime and migrate into shallower waters of less than 70 feet deep after darkness. Juveniles are generally found around shallow coral reefs, grass flats or mangrove islands in 3 to 13 feet of water.
Lifespan: Unknown, but maturity is reached around 15 – 20 years of age.
Wild Diet: A nocturnal predator, the nurse shark feeds mainly on fish, squid, clams
and crustaceans. Algae and corals are occasionally found in the stomachs as
well. The nurse shark has small mouth, but its large, bellows-like pharynx
allows it to suck in food items at high speed.
They occasionally occur in groups of up to 40 individuals, as they lie
very close together sometimes even piling upon one another. Nurse sharks are
very active during the night. In addition to swimming near the bottom or well
off it, the nurse shark can clamber on the sea floor, using its flexible,
muscular pectoral fins as limbs.
The nurse shark is an ovoviviparous species. Females produce a littler
of 20 – 30 pups every other year. A large number of males generally try to mate
with a single female, often leading to females bearing numerous scars and
bruises from male bites. Females frequently try to avoid contact with males by
swimming in very shallow water, where they can bury their pectoral fins in the
- Nurse sharks show a strong preference for certain resting sites, and repeatedly return to the same caves and crevices after a nocturnal activity.
- Because this shark can pump water over its gills, it does not need to swim in order to breathe.
- The name nurse shark is thought to be a corruption of nusse, a name which once referred to the catsharks of the family Scyliorhinidae. The nurse shark family name, Ginglymostomatidae, derives from the Greek: from gynglimos meaning "hinge" and stoma meaning "mouth".