Zebra Shark

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Zebra Shark

Looking at an adult zebra shark, it is easy to think the species was misnamed since they have dark spots on a pale tan background, which doesn’t sound zebra-like in any way. However, the juveniles are so different in appearance that one might think they were a different species. Until they are about three feet long, young zebra sharks have light stripes on a dark background, evoking the zebra comparison.


Content List

1. Scientific & Common Names

2. Characteristics

a. Breeding

b. Behavior

3. History

4. Present Status

5. References


Scientific & Common Names

Kingdom - Animalia

Phylum - Chordata

Class - Chondrichthyes

Order - Orectolobiformes

Family - Stegostomatidae

Genus – Stegostoma

Species – S. fasciatum

Common Names - Zebra Shark, Variegated Shark, Leopard Shark (most commonly used for the species Triakis semifasciata or more occasionally the Tiger Shark)


Characteristics

They are a distinctive shark and have a cylindrical body with prominent ridges running horizontally, ridges which are not present in the young. The caudal fin (tail) is very long and makes up almost half the total length of the shark. Their maximum size is 7 ½ feet and their lifespans are believed to be up to thirty years, although there is still much to be learned about their lifecycles.


Breeding

Zebra sharks tend to be solitary, but large groups have been observed, possibly for the purpose of mating. Females lay eggs, which are deposited in crevices and then then left to develop. Like other oviparous sharks, the young are small when they emerge, only about 10-14 inches long. As with all sharks, the young are immediately able to care for themselves and must soon begin to hunt.


Behavior

Zebra sharks are more active at night and they stay in relatively shallow depths, but can be found as deep as 200 feet. Crustaceans, mollusks, and small fish are their primary prey as they remain near reefs and rocky areas. They are slow swimmers and prefer to sift the sand or force their agile bodies through crevices in search of prey. They pose no threat to humans and the International Shark Attack File has only one unprovoked attack listed, and that incident resulted in no injuries


History

Sharks have a 400 million year history, predating even dinosaurs. While there are hundreds of species of shark alive today, the zebra shark is the only species found in the genus Stegostoma. Its closest relative may be the enormous whale shark.


Present status

Although not yet rare, the species is considered at risk due to fishing and habitat loss. The numbers in Australia’s waters, where they are not actively fished, are healthier.


References

Florida Museum of Natural History International Shark Attack File

Sharks, Skates, and Rays: The Biology of Elasmobranch Fishes Edited by William C. Hamlett

Reef Fish Identification - Tropical Pacific by Gerald Allen, Roger Steene, Paul Humann, and Ned DeLoach

Discovering Sharks by Dr. Jeffrey Carrier