Horn shark

 

  

The Life of Animals | Horn shark | The horn shark inhabits the continental shelf of the eastern Pacific Ocean, occurring off the coasts of California and Baja California from Monterey Bay southward, and in the Gulf of California. Juvenile sharks horn the between 35-48 cm (1:15 to 1:57 ft) long prefer sandy flats with low vertical relief, in water 40-150 m (130-490 ft) deep. The relative abundances of the horn shark and the swellshark (Centroscyllim ventriosum), the which shares the same habitat, are negatively correlated, horn sharks Because favor water over 20 ° C (70 ° F) while swellsharks are more tolerant of cold. At Santa Catalina Island, a 20-year warming trend has resulted in an increase of population in the horn shark and a Decrease in the swellshark population. Horn sharks are less common than swellsharks in the northern Channel Islands, where the water is cooler.

Like other Bullhead sharks, the horn shark has a short, wide head with a blunt snout and prominent supraorbital ridges over the eyes. The horn shark's supraorbital ridges are low and terminate abruptly; the space the between Them on top of the head is Deeply concave. The inflow openings are encircled by a groove, while another groove connects the outflow openings to the mouth. There are 19-26 tooth rows in the upper jaw and 18-29 tooth rows in the lower jaw.

The fin spines of the reef-dwelling sharks are shorter than the horn Those living in algal habitats, as worn Become Their spines down on rocks from the sharks' movements. The first dorsal fin originates over the bases of the large pectoral fins, while the second dorsal fin originates slightly anterior to the free rear tips of the pelvic fins. The horn shark's dermal denticles are small and smooth, numbering some 200/cm2 on the back in adults The dorsal coloration consists of Various shades of gray or brown with many small dark spots, though these may be absent in older sharks; the Underside is Yellowish .

Under normal circumstances, the horn sharks are harmless to Humans and can readily be approached underwater. The horn shark has no commercial value in California, where it is unintentionally captured in traps and trawls and by recreational anglers. The shark's hardiness ensures That Often it can be returned to the water alive. This species benefits from the general restrictions placed on coastal fishing gear by the State of California. At present, the International Union for Conservation of Nature (IUCN) does not have sufficient information to assess the overall conservation status of this species; its status in United States waters is Likely Least Concern.