![]() The Living Marine Resources of the Western Central Pacific. ![]() An annotated and illustrated catalogue of shark species known to date. Iso-luminance counterillumination drove bioluminescent shark radiation. Claes, J.M., Nilsson, D.-E., Straube, N., Collin, S.P.Identifying the “demon whale-biter”: Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp. Distribution and frequencies of shark-inflicted injuries to the endangered Hawaiian monk seal Isistius brasiliensis (Quoy & Gaimard 1824) References Scymnus brasiliensis Quoy & Gaimard 1824, Voyage autour du Monde 1: 198. The Largetooth Cookiecutter Shark also lacks the dark coloured band around the body and dark tips on the caudal fin. The Largetooth Cookiecutter Shark, Isistius plutodus, differs in having fewer and larger teeth, and the second dorsal-fin base more than twice the length of the first dorsal-fin base. The cookiecutter shark has reportedly attacked the rubber sonar dome of a submarine. Cookiecutter sharks have their teeth interconnected at the bases, and they replace the whole set of teeth as a single unit. Most shark species replace their teeth singly as they get damaged or lost. ![]() Of no interest to fisheries, although occasionally taken as bycatch in commercial trawl, but usually too small to be caught. Males mature at about 38 cm TL, females at about 40 cm TL. and even a human swimmer in Hawaii.Ĭookiecutter sharks are live-bearers (aplacental viviparous), and females give birth to litters of at least 9 pups that develop inside egg cases and hatch within the uterus. Victims include whales, dolphins, seals, pelagic bony fishes such as tunas, snake mackerels, billfishes, sharks, rays and marine turtles. The use their fleshy lips and specialized muscles in the mouth and throat to suck onto their victims - then twist off a plug of flesh with their large serrated lower teeth and small hook-like upper teeth.Ĭookicutter sharks usually prey on large epi- and mesopelagic fishes and marine mammals, creating circular concave wounds. Cookiecutter sharks are considered to be ectoparasites by some researchers. Widder (1998) suggests that the dark patch works as a lure to attract fast-swimming animals such as tunas, swordfish and dolphins.Ĭarnivore - feeds by removing plugs of flesh from unwary prey (usually sharks, rays, bony fishes and marine mammals). The lower surface, except for the brown collar, is densely covered in minute photophores - so that the shark is counterilluminated. Ventral surface (excluding the dark collar) covered in a network of tiny photophores that produce a greenish bioluminescent glow on the underside.ĭark brown above, paler below, with a prominent brown collar-like band around the gill area fin-tips with lighter or translucent posterior margins caudal-fin lobes dark with a pale or translucent margin. Two spineless nearly equal-sized dorsal fins, the first set far back on the body, originating just before pelvic-fin origin caudal fin large, almost symmetrical. Lower jaw teeth very large, erect, bladelike, symmetrically triangular with smooth to slightly serrate edges. Mouth with expanded sectorial lips teeth strongly differentiated between upper and lower jaws upper jaw teeth slender, thorn-shaped, smooth-edged, without lateral cusps, curved outward near corners of mouth. The species is counter-illuminated, and undertakes vertical migrations towards surface waters at night.īody slender, cigarshaped, abdomen lon snout short, bulbously conical, preoral length 6–7% TL. The Smalltooth Cookiecutter Shark usually occurs off continental and insular slopes at deep to midwater depths between m. Widespread in tropical to temperate waters worldwide, from surface waters to well below 1000 metres. Isistius brasiliensis (Quoy & Gaimard 1824) More Info
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