Eucrossorhinus

Eucrossorhinus is a genus of catsharks in the family Scyliorhinidae, containing two known species, the swell shark (E. falcatus) and the Japanese swell shark (E. spinosus). Both species are found in the western Pacific Ocean, with the swell shark inhabiting waters off the coast of Australia, and the Japanese swell shark found off the coast of Japan, Taiwan, and the Korean peninsula. They are characterized by their stout bodies, short, broad heads, and a pair of large, distinct dorsal fins.

Tasselled wobbegong – Eucrossorhinus dasypogon

Common Names

The common name "swell shark" refers to the genus Eucrossorhinus as a whole, while the two species are also referred to by their specific common names: swell shark (E. falcatus) and Japanese swell shark (E. spinosus). Other names that may be used include "false catshark," "smooth-hound shark," and "swell-bodied catshark."

Characteristics

Eucrossorhinus sharks are generally small to medium-sized, with adults reaching lengths of around 1.2 meters (4 feet) in the swell shark and 1 meter (3.3 feet) in the Japanese swell shark. They have a stout body, with a short, broad head and a flattened snout. Their eyes are relatively small and located on the sides of the head. Their mouth is wide and located at the tip of the snout, with small, pointed teeth. Their dorsal fins are large and distinct, with the first dorsal fin positioned far forward on the back, and the second dorsal fin located closer to the tail. Their pectoral fins are broad and rounded, and their pelvic fins are small and located close to the anal fin. The most notable feature of these sharks is their ability to inflate their bodies with water when threatened, making themselves appear larger and more formidable to predators.

Environment

Eucrossorhinus sharks inhabit a variety of habitats, including coastal waters, rocky reefs, and sand flats. They are typically found at depths of up to 200 meters (650 feet). They are nocturnal and feed primarily on smaller fish, squid, and crustaceans. They are ovoviviparous, meaning that the embryos develop inside the mother's body, but are nourished by a yolk sac rather than a placenta. The swell shark typically gives birth to 4-12 pups, while the Japanese swell shark gives birth to 2-8 pups.

References

  • Compagno, L.J.V. (2001). Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date. FAO Species Catalogue for Fishery Purposes. No. 1, vol. 2. Rome, Italy: Food and Agriculture Organization of the United Nations. pp. 1–265.
  • Last, P.R.; Stevens, J.D. (2009). Sharks and Rays of Australia. CSIRO Publishing. pp. 384–385. ISBN 978-0-643-09924-1.
  • FishBase: Eucrossorhinus falcatus
  • FishBase: Eucrossorhinus spinosus