shark shark species requiem shark family distributed worldwide tropical subtropical waters migratory shark deep waters edges continental shelf typically found depths night surface shallower water shark plain colored grows length long broad snout prominent nasal skin flaps tall triangular upper teeth pectoral fins long straight ridge dorsal fins hunting close sea floor shark feeds bony fishes cephalopods viviparous meaning embryos sustained term connection females bear litters pups month gestation period despite size shark lives deep pose danger humans caught incidentally commercial fisheries parts range meat fins skin liver oil presently lacks information assess global conservation status species fishing pressures range cause concern given slow reproductive rate declined northwestern atlantic taxonomy phylogeny shark expert described shark issue scientific journal later authors regarded genus synonym specific epithet derived latin deep refers shark habits type specimen immature female long caught reef florida keys april alternate common species shark originally florida fishery workers species described phylogenetic studies published based morphology placed shark group centered shark shark group consists large triangular toothed sharks ridge dorsal fins study based sequences upheld resolved ridge backed group shark found sister species shark forming group branches distribution habitat records world indicate shark probably distribution tropical subtropical waters atlantic_ocean occurs delaware bay brazil mediterranean_sea west_africa indian_ocean known south_africa madagascar red_sea india pacific_ocean recorded china australia hawaii ecuador reportedly common florida bahamas west_indies rare brazil mediterranean shark found near edge continental shelf upper continental slope generally swimming close sea floor depths young sharks venture water shallow night time captures species close surface suggest perform vertical migration moving deep water upwards coast night northwestern atlantic shark conducts poorly documented seasonal migration spending summer east_coast winter gulf_of_mexico caribbean_sea individual sharks recorded traveling distances description heavily built shark long broad blunt snout nostrils preceded developed triangular flaps skin moderately large circular eyes equipped membranes protective mouth broadly curved lacks obvious furrows corners upper teeth number rows tall broad triangular edges erect jaw center increasingly oblique sides lower teeth number rows narrow erect extremely fine pairs gill slits moderately long long wide pectoral fins pointed tips nearly straight margins dorsal fin originates roughly rear pectoral fin bases fairly tall shaped blunt apex long free rear tip second dorsal fin relatively large short free rear tip positioned slightly ahead anal fin high ridge present dorsal fins caudal crescent shaped notch origin upper caudal fin margin caudal fin large lower lobe strong ventral notch near tip upper lobe dermal denticles closely spaced non overlapping skin shows oval horizontal ridges leading marginal teeth coloration gray bronze faint pale stripe flank white green gills tips fins pelvic fins darker obvious young sharks males females grow long respectively species possibly reaches length maximum weight record biology ecology shark feeds mainly dwelling bony fishes including fishes including cephalopods turn juveniles potentially fall prey larger sharks like requiem sharks species viviparous developing embryos exhaust supply yolk depleted yolk sac converted connection mother delivers females bear litters pups seven typical following gestation period approximately months single litter males reported occur august september mediterranean september october madagascar measure long males females mature sexually long respectively average age active individuals years human interactions large dangerous shark seldom comes contact humans preference deep water species deep set fisheries particularly targeting parts range regularly taken cuban waters produce liver oil southeast_asia meat consumed fins shipped shark fin soup shark commercially united_states listed fishery management plan atlantic sharks australia listed shark overall inadequate population fishery monitoring species considered concern given slow faces widespread heavy fishing pressure evidence numbers recently declined furthermore shark occurs international waters single stock affected multiple fisheries listed highly migratory species agreement highly migratory fish stocks far led significant conservation measures iucn assessed shark northwestern atlantic specific data lacking suspected declined commonly shark known decline shark numbers resulting fishing represent decline shark numbers species assessed concern australian waters faces significant threats
Bignose shark