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Ginglymostomidae Nurse Sharks Chris Bedore October 2, 2007 Taxonomy and Etymology Order Orectolobiformes Family Ginglymostomidae Genus Ginglymostoma Nebrius Pseudoginglymostoma ginglymostoma= “hinge mouth” Morphology General characteristics • 2 spineless dorsal fins, 1 anal fin •barbels on nostrils, nasoral groove • broad, flat head • small spiracles behind small eyes • ventral caudal lobe small or lacking • small, multicuspid teeth • small gill slits, 4th and 5th almost overlapping Morphology Morphology Distinguishing characteristics •large caudal fin with strong terminal lobe and subterminal notch • coloration- lacks patterns (saddles, stripes, spots) Morphology Morphology Ginglymostoma cirratum** ~300cm TL rounded fins yellow to grey-brown long barbels Nebrius ferrugineus ~315cm TL long barbels angular fins shades of brown Pseudoginglymostoma brevicaudatum ~75cm TL, dark brown short barbels dorsal fins same size Habitat, Distribution, Lifestyle •subtropical and tropical G. cirratum: especially E. Pacific and Atlantic •continental waters •associated with coral and rocky reefs, sandy bottom, lagoons, mangroves <1 to 12m •basically benthic, but do swim around •very common in Gulf of Mexico and FL Keys Behavior • like to hide in caves, under reefs • nocturnal Behavior • docile, not aggressive will bite divers when provoked! Behavior • social, will rest in groups or piles of 20-30 individuals Behavior • although docile, spin on line when hooked (like an alligator) Reproduction • ovoviviparous, large yolk sac Reproduction • 20-30 pups/litter, at different stages due to ovulation • 5-6 month gestation, mating in May-July • Males mature 10-15 years, Females 15-20 years (~150cm TL) Prey/Feeding habits • benthic prey crustaceans, squid, teleosts, stingrays • suction feeders- small mouth, large pharynx • will eat any bait Human Importance • Nuiscance in some places- raid bait traps • Not aggressive (unless provoked) • Economic importance: tourism ex: Shark and Ray Alley, Belize aquarium not sportfish because sluggish, but flesh is edible Conservation Status • abundance has decreased • exhibit site fidelity- anthropogenic activities threaten habitat (esp. mating /nursery grounds) • IUCN Redlist: G. cirratum- data deficient; likely decreasing due to habitat N. ferrugineus- decreasing; bycatch in coastal fisheries P. brevicauda- data deficient, may be decreasing due to bycatch Research Jeff Carrier (Albion College) and Wes Pratt (Mote Marine Lab) http://www.albion.edu/sharklab/default.asp probably most reproduction info of any species known multiple observed matings in FL Keys/Dry Tortugas- model for repro. behavior (see Pratt and Carrier, 2001) seasonal closures of mating grounds in Dry Tortugas (see Carrier and Pratt, 1998) Jose Castro (Mote Marine Lab)- detailed biology of the nurse shark (see Castro, 2000) Research Selected Works Carrier J.C. and H.L. Pratt, Jr. 1998. Habitat management and closure of a nurse shark breeding and nursery ground. Fisheries Research 39:209-213. Castro, J.I. 1983. The sharks of North American waters. Texas A&M Univ. Press, College Station, TX. 180p. Castro JI. 2000. The biology of the nurse shark, Ginglymostoma cirratum, off the Florida east coast and the Bahama Islands. Environ. Biol. Fish. 58: 1-22. Compagno, L., M. Dando, and S. Fowler. 2005. Sharks of the World. Princeton University Press, Princeton, NJ. 368p. Klimley A.P. 1980. Observations of courtship and copulation in the nurse shark, Ginglymostoma cirratum. Copeia 1980(4):878-882. Pratt H.L. and J.C. Carrier. 2001. A review of elasmobranch reproductive behavior with a case study on the nurse shark, Ginglymostoma cirratum. Environmental Biology of Fishes 60:157-188.