Ginglymostoma cirratum - Nurse Shark
Habitat The nurse shark is a common inshore bottom-dwelling shark. Nurse sharks can found in tropical and subtropical waters on the continental and insular shelves. They are commonly found at depths of one meter or less but may occur down to 75 m (246 ft). Its common habitats are reefs, brackish waters, and channels between mangrove islands and sand flats.
Range It can be seen in the Western Atlantic from Rhode Island down to southern Brazil including the Gulf of Mexico and Caribbean, Antilles; Eastern Atlantic: Cape Verde to Gabon; accidental to France; Eastern Pacific: Gulf of California and southern Baja California, Mexico to Peru.
Description Nurse sharks can be black, brown, grey, and white. They also have smooth skin. They can be 2.5-4.3m (8-14ft) long and weigh 90-150kg (198-330lbs). They have large tail fins and rounded dorsal fins. Their caudal fin can be moderately long, over 1/4 of total body length.
Ecological Notes Nurse sharks feed on bottom invertebrates such as spiny lobsters, shrimps, crabs, sea urchins, squids, octopuses, snails and bivalves, and fishes such as catfishes, mullets, puffers and stingrays. Their predators are humans, bull sharks, and tiger sharks. Nurse sharks tend to live 25 years. Nurse sharks live a solitary life. They are also on the endarngered species list. They are very docile animals and will swim away when seen. Nurse sharks can switch to a second respiratory system when they are at rest, saving energy and the necessity to swim to move water and oxygen over their gills. This dual respiratory system is especially important for bottom dwellers such as nurse sharks. Nurse sharks are ovoviviparous they give birth to 21-28 pups in a litter. Young in the uterus are sustained by a large supply of yolk. Females give birth in late spring and summer in waters off Florida.
Personal Information We saw them at the shark tank at the North Carolina Roanoke Aquarium. Their behavior was very docile and they didn't approach the front of the tank as often as the other sharks did.
Additional Information Harold L. Pratt Jr., Jeffrey C. Carrier. A Review of Elasmobranch Reproductive Behavior with a Case Study on the Nurse Shark, Ginglymostoma cirratum. Environmental Biology of Fishes February 2001, Volume 60, Issue 1-3, pp 157-188
This study looked at nurse shark reproductive behavior and presented it so that it may be used as a template for future work on shark reproductive behavior of other species. Their studies used diver identifiable tags and in situ behavioral observations, which provide information on social structure and mating behavior in this species.
Sven O.E. Ebbesson, Lennart Heimer. Projections of the olfactory tract fibers in the nurse shark (Ginglymostoma cirratum). Brain Research Volume 17, Issue 1, 6 January 1970, Pages 47–55
This study looked at the olfactory system of five nurse sharks. They found that the distribution of olfactory tract fibers is entirely ipsilateral to the lesion, with the majority terminating near the attachment of the olfactory peduncle to the hemisphere. Their results indicate that the distribution of olfactory bulb fibers in the shark is much more restricted than had been suggested by most earlier descriptions based on studies of normal material.
Contributed by Cody Keegan - 2014