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Friday, November 21, 2014

Species Fact Profile: Shark Ray (Rhina ancylostoma)

Shark Ray (Bowmouth Guitarfish)

Rhina ancylostoma (Bloch & J.G. Schneider, 1801)

Range: Indian Ocean, Western Pacific ocean
Habitat: Shallow seas with sandy or muddy bottoms, Coral Reefs, Mangroves
Diet: Crustaceans, Mollusks
Social Grouping: Solitary
Reproduction: Fertilized eggs are retained within the female's body, usually 4-5 pups (range 2-11) are born live when they are expelled from the female's uterus, offspring are independent immediately after birth; females are sexually mature at 1.5-1.8 meters, males at 1.8 meters
Lifespan: 7 Years (Captivity)
Conservation Status: IUCN Vulnerable

  • Shark rays can grow to 2.9 meters in length and weigh up to 135 kilograms; females often grow larger than males
  • Named for their supposed intermediary appearance between sharks and rays, shark rays are a cartilaginous fish with broad, blunt heads, large flat pectoral fins, two dorsal fins (the front larger than the back), and a relatively slender tail
  • Coloration changes with age; the young are brown with pale spots and black bars, whereas adults are grey with small white spots and no bars; all ages are pale on their underside
  • The eyes of a shark ray are found on top of the head, and prey is largely found by smell; prey animals are pinned to the sea floor with the large head and eased into the moth, which is full of large flat teeth
  • Known to be preyed upon by tiger sharks; the thorn-like protrusions on the head and back of the shark ray are possible defenses against predators
  • While not considered an especially desirable food fish, shark rays are caught as bycatch by commercial fisheries.  They are also sought for their very large pectoral fins, used to make "shark fin soup", a delicacy in traditional Chinese culture.  Dynamite fishing and loss of coral reefs are also contributing the the decline of the species
  • Rarely displayed in captivity, and only very recently in the Americas; the first captive breeding of this species took place at the Newport Aquarium in 2014, though none of the pups survived

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