Triakis semifasciata, Leopard Shark [+]
Kingdom Animalia
Phylum Chordata
Class Elasmobranchii
Order Carcharhiniformes
Family Triakidae
Genus Triakis
species: Triakis semifasciata [+ITIS +WoRMS]
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Description & Behavior
The leopard shark, Triakis semifasciata (Girard, 1855), is a member of the Houndsharks Family, Triakidae. The zebra shark, Stegostoma fasciatum, is commonly confused with the leopard shark and shares the same common name in Australia and SE Asia. The leopard shark has a short, broadly-rounded snout, the first dorsal fin is moderately large and its origin is over the pectoral fin inner margins. The second dorsal fin is nearly as large as the first one (height approximately 3/4 of the first dorsal fin). Anal fin is much smaller than the second dorsal fin. Pectoral fins broadly triangular. Very conspicuous dark saddles and dots. Gray to bronze-gray upper body with light ventral surface. Average size between 1.2-1.5 m, maximum total length about 1.8 m. Can weigh up to 18.4 kg and live as long as 30 years.
World Range & Habitat
Eastern Pacific: Oregon to Gulf of California, Mexico. An abundant species of cool and warm-temperate waters. Found inshore and offshore in continental littoral waters. Most common on or near the bottom in shallow water, between 4-90 m. Prefers sandy or muddy bays. An active, strong swimming species. They form large schools that seem to be nomadic. The swimming motion of this species is undulating. Often seen together with brown smooth-hound, Mustelus henlei, and gray smooth-hound, Mustelus californicus or the piked dogfish, Squalus acanthias.
Feeding Behavior (Ecology)
The leopard shark, Triakis semifasciata, feeds primarily on bottom-living invertebrates. Small sharks have been found in their stomachs. Diet seems to change with season and size.
Life History
Leopard sharks are aplacental viviparous (ovoviviparous). Between 4-29 pups per litter. Size at birth about 20 cm. Slow growth. They reach maturity at an age of about 10 years, males at a size between 0.7-1.2 m, females at approximately 1.1-1.3 m, respectively.
Ovoviviparous: eggs are retained within the body of the female in a brood chamber where the embryo develops, receiving nourishment from a yolk sac. This is the method of reproduction for the "live-bearing" fishes where pups hatch from egg capsules inside the mother's uterus and are born soon afterward. Also known as aplacental viviparous.
Conservation Status/Additional Comments
Leopard sharks are harmless to humans. Utilized fresh or frozen for human consumption. This mid-sized coastal shark is fairly common in bays and estuaries of the eastern North Pacific from California, USA, to the northern Gulf of California, Mexico. It is taken both commercially and by recreational anglers.
Although a slow-growing, late-maturing shark with low productivity, management introduced in recent decades has reportedly protected the core of the population in California and Oregon waters from overfishing. Little is known of the stock status in Mexico.
The leopard shark, Triakis semifasciata, is listed as Lower Risk/conservation dependent on the IUCN Red List of Threatened Species:
LOWER RISK/conservation dependent (LR/cd) - A taxon is Lower Risk when it has been evaluated, does not satisfy the criteria for any of the categories Critically Endangered, Endangered or Vulnerable. Taxa included in the Lower Risk category can be separated into three subcategories:
1. Conservation Dependent (cd). Taxa which are the focus of a continuing taxon-specific or habitat-specific conservation programme targeted towards the taxon in question, the cessation of which would result in the taxon qualifying for one of the threatened categories above within a period of five years.
2. Near Threatened (nt). Taxa which do not qualify for Conservation Dependent, but which are close to qualifying for Vulnerable.
3. Least Concern (lc). Taxa which do not qualify for Conservation Dependent or Near Threatened.
References & Further Research
BioOne ~ CITES ~ Discover Life ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList ~ MarineBio Network ~ NCBI ~ SCIRIS ~ SIRIS ~ Tree of Life Web Project ~ Wikipedia
Leopard shark (Triakis semifasciata) - Shark Foundation
Search the Web for Leopard Shark » ARKive ~ Ask.com ~ Ask Jeeves ~ bing ~ deviantART ~ dmoz ~ Dogpile ~ Google Images ~ MySpace Images ~ OceanFootage ~ Picsearch ~ StumbleUpon ~ Yahoo! Images ~ YouTube
