Horn Shark (Heterodontus francisci)

Don’t you think sharks with horns would be super cool? They’d reach a whole new level of badassery. Unfortunately, though today’s animal is called the horn shark, it does not actually have horns. People who name animals shouldn’t get my hopes up so much.

Horn sharks like warm waters, hanging around where temperatures are warmer than 20ºC. Their range is restricted to the eastern Pacific Ocean, and are particularly abundant along the coast of California and Mexico. These sharks live at the bottom of shallow waters, around 8-12 meters in depth. During winter they migrate into deeper waters, and can occasionally be found as deep as 200m, but this is rare.

Just because horn sharks don’t have actual horns, it doesn’t mean they don’t look cool. They have blunt noses, and a head that is capped by two ridges above the eyes (this is what gives them the ‘horn’ name). Horn sharks have two dorsal fins, in front of which are some neat and nasty spines. The sharks reach maximum lengths of around one meter, and are grey or brown with black spots covering the body.

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A great picture of a horn shark, illustrating the animal’s ‘horns’. Image credit: Chad King via Wikipedia

Horn sharks are not great swimmers, and usually lie on the ocean floor, pushing themselves along the sand with their pectoral fins. They are nocturnal, coming out at night to feed on molluscs, sea urchins and crustaceans. Feeding on this type of prey can be troublesome; the hard shells of horn sharks’ prey can be quite difficult to break through. Horn sharks, though, have the highest bite force of any shark, relative to size. So chomping down on those shells isn’t too much of an issue for these guys.

The other problem horn sharks have with their diet is that often times molluscs and sea urchins attach themselves to rocks, making them difficult to pry off and eat. Horn sharks get around this with a peculiar method of feeding. They grab onto the prey and hold their head and pectoral fins along the ocean floor, and raise their tail as high as they can. They then bring their tail down, which forces the sharks’ heads up and pries the victim loose. It’s really incredible that horns sharks have figured out how to use themselves as levers.

Mating in horn sharks occurs in the winter, from December to January. Males swim after a female shark until she settles on the ocean floor, signalling her readiness to mate. The female lays eggs from February to April, laying eggs two at a time, for a maximum of 24. Once the eggs have been laid, the female shark grabs the case in her mouth, and places it in a rock crevice for protection. The egg cases of horn sharks are quite remarkable, having a double spiral around the outside to help secure it in these crevices. Young sharks are 15 cm long at hatching, and mature at 56-61 cm in length.

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The egg case of a horn shark. Image credit: Devra via Wikipedia

Though horn sharks have scary spines that can inflict nasty wounds on people who get too close, these guys are pretty shy, and prefer to flee from people rather than bite. They are not usually caught for food purposes, but some divers will catch horn sharks to make jewelry out of their spines. Still, at the moment, horn sharks are not thought to be threatened, as they have little commercial value or threat to people. Seems like a pretty good survival strategy to me.

Cover image credit: Ed Bierman via Wikipedia

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