Ridiculous as that image might seem at first, such a creature once swam through Earth’s seas. James Miller (author), University of Michigan-Ann Arbor.Imagine a great white shark with a set of sawtoothed scissors for a mouth. Shark copulation is still very much a mystery and has never been observed in the wild (Compagno 1984, Stoakely 1997) Contributors The cookie-cutter shark often swallows and digests its teeth, which is thought to aid in calcification of the skeleton. Because of its small size, and deep water habitat, this species is of little or no danger to swimmers and divers. The attacks on submarines are considered at most a nuisance. They have a potential negative impact on fisheries, as they prey on commercially important fish, but damage is slight. It may use this light to attract the attention of potential victims (Compagno 1984, Roesch 1997). It is bioluminescent, able to emit a greenish light from its belly. It preys on deep water organisms, including crustaceans, squid, large bony fishes, cetaceans, and even large sharks. Detaching, it swims away to enjoy its meal. It then uses its hook-like upper teeth to hold the plug, while the lower teeth scoop the plug out. It attaches itself to its prey with its strong sucking mouth, and then twists about, using its sharp lower teeth to slice out a plug of flesh, which can sometimes be twice as deep as its diameter. Like many sharks, the cookie-cutter shark is a carnivore. This species is known to attack submarines, evidently mistaking them for prey. Their skeleton, though still cartilaginous, is calcified, perhaps to aid in their deep water forays for food. The oily liver of this species (the super-equivalent to a swim bladder in bony fishes) is larger than that of most similar sharks, and it is thought to allow them to swim to greater depths. They are often found near islands, but it is uncertain whether this is because of a greater concentration of prey or in order to mate. It is unknown exactly how deep they swim during the day, but their depth is thought to exceed two miles. Even during the night, however, they stay at least 300 feet below the surface. They follow a diel cycle of movement, coming closer to the surface at night, when they are more likely to be caught in fishing nets. BehaviorĬookie-cutter sharks are essentially a solitary species, coming together only to mate. Males mature at approximately 14 inches and grow to a size of 16 inches, while females mature at 16 inches and reach up to 20 inches (Stoakely 1997). When the young emerge, they are fully developed and capable of hunting for themselves. Hatching can take place after 12 to 22 months. Like other small sharks, this shark is oviparous, and the female coats her eggs in a horny casing before attaching them to rocks and seaweed. Fertilization is accomplished by his insertion of one of his claspers into the female's cloaca. The male has instead two 'claspers' (pterygopodes), located on his underside in the rear. Reproduction of the cookie-cutter shark is accomplished through internal fertilization. Females are larger than males, reaching perhaps 20 inches at full size. Coloration is medium grey to grey-brown, with a dark collar marking its throat. It has suctorial lips, small upper teeth, and large, triangular cusped lower teeth in 25 to 32 rows. The cookie-cutter shark is a typical member of the dogfish order it has no anal fin, a thin, cigar shaped body, and short snout. They tend to be found closer to islands, but they have been caught in open sea, as well. It is a deep-water fish, and wide-ranging, often found near islands.Ĭookie-cutter sharks are wide-ranging creatures, found in tropical oceanic climates all across the world. Pelagic: The cookie-cutter shark is found in seas as far north as Japan and south to Southern Australia.
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