Nurse Sharks

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Name: Nurse Shark
Scientific name: Ginglymostoma cirratum
Range
Atlantic--off Cape Hatteras to off the coast of Brazil in the West and off of West Africa and the Cape Verde Islands in the East.  Strays have been found around Rhode Island and Chesapeake Bay. 
Pacific--Gulf of California to Peru, common in shallow waters throughout the West Indies, South Florida, and the Keys.
Habitat: Shallow water, less than ten feet in depth.  Can be found lying motionless in the bottom of the water with a its head in a cave or under coral formations.
Status: Not threatened 
Diet in the wild: invertebrates and small fish--Crabs, shrimp, squid, and sea urchins.
Diet in the zoo: Frozen fish mackerel, smelt, and herring (twice a week).
          Location in the zooJames R. Record Aquarium

 
 

Physical description: 

  • Average Weight is about 330 lbs.(150kg) 
  • Average Length is about 7-10 feet. (believed to reach 14 ft)(230-300cm)
  • Minute teeth.   Numbers for each are as follows: Upper 30-36, Lower 28-31
  • They have groves that connect the nostrils to the mouth 
  •  They are distinct due to their "nasal barbels"(tender) that provide a sense of touch
  •  "The upper surface of the body is yellow-brown to gray-brown.  The remainder of  body is a lighter shade of the same color". 
  • Short snouts with rectangular mouths, small eyes, flattened bodies, 5 gill slits, spiracles present just behind the eye, and multicuspid teeth.
 

General information: 

The nurse shark is an unaggressive creature that in the most part is lazy and peaceful who moves mainly at night.  Their small strong teeth are designed fro cracking the shells of molluscs.  Feeding involves the use of its pharyngeal cavity to create a suction pressure that will suck small prey from between the rocks.  Reproduction for this creature is common among fish.  The young are born alive, hatched from eggs that are retained in the mother's uterus "(ovoviviparous)." 
 
 


Special anatomical, physiological 
or behavioral adaptations:

As you can see here the nurse shark has adapted very well to its environment.   The nurse shark is very nonthreating to divers of the sea until it believes you have invaded its "domain," which at that time it becomes very aggressive. 
 


 
 
Comments about the nurse shark of the Fort Worth Zoo:


The sharks look as if they are very content.  Although the swimming area seems small I think that because they are such an inactive shark, that does not require swimming in order to breathe is an excellent reason to keep such a shark in captivity.

Personal Observations: 

Silence...
Sleeping Shark

I can vouch for the laziness of the nurse shark at the zoo.  This is a special picture of it  sleeping. It seems that it is not quickly motivated nor does it move hardly at all.  In fact, it seems that all it wants to do is lay on the bottom floor "dwelling."  I would imagine that time would go by so much faster if I could have actually been in the water next to this shark, but from the outside of the glass, a few minutes of waiting for movement was all I could stand.  This definitely is a lazy shark.  Perhaps it likes being the center of attention, when people come up to the glass to look and gaze at it.


 
 
Source Materials and Related Links:
  • Sharks on the Web
  • Nurse Shark at the Houston Zoo
  • Nurse Sharks
  • Nurse Sharks:  University of Michigan Animal Diversity Web 

  •  
  • Sharks,  by Lee Server; Cresent Books New York 1989; Crown Publishers Inc.  Page 78
  • The Sharks of North American Waters by Jose I. Castro

  • #5:  The W.L. Moody, Jr., Natural History Series; Texas A&M Univ. Press; College Station 1983; Pages 76-77.
     
    Page author: {short description of image}
    Joyce Creger 

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