Cookie Cutter Sharks of the "Deep Sea"

The Cookiecutter Shark is a mesopelagic shark, ranging from the surface at night to almost 12,000 feet during the day, and is found in all the major oceans. Adult males are 12-14.5 inches, while females reach 15-17 inches (www.elasmo-research.org). Its long body contains a gigantic liver, which accounts for nearly 35% of the shark’s total weight. This energy-saving liver is “perfused with low-density oils which render the shark nearly neutrally buoyant over a wide range of depths” (www.elasmo-research.org).


The Cookiecutter has huge eyes, which it uses to spot unsuspecting prey. It then gets sneaky, slowly closing in on the luscious meal. When nearby, the Cookiecutter turns on the fire. Photophores abound on the shark’s body, particularly on its underside. This creates for counter-shading, making our dude more or less invisible to fish below. However, the Cookiemonster takes it one step further. On a special favor from Dios, he has no photophores in between his gills on his throat. This dark spot baffles “upward-looking pelagic predators” (www.elasmo-research.org), making them think the Cookiecutter is a small fish aka brunch. Boom---before you know it, the Cookiemonster busts out his “short, broad caudal fin that is ideal for rapid bursts of acceleration over short distances” (www.elasmo-research.org) and the diner has become dinner!

So what do these guys eat? Mad stuff---squid, mesopelagic teleost fish, crustaceans, pelagic teleosts, cetaceans, other sharks (a bit cannibalistic), and even humans on the rare occasion (he is not picky at all). The Cookiecutter is defined as a parasite because it eats its prey one small bite at a time---and it has pretty much dabbled in every available food the ocean has to offer. Now, how do they eat? Funny you should ask, because it’s pretty strange. Using its “unique suctorial lips that glom onto and help create a good seal against the body surface of its prey,” he chomps on “neatly sliced out circular plugs of flesh” (www.elasmo-research.org). Good day!