borneo shark borneo shark species requiem shark family extremely rare known waters northwestern borneo widely distributed small gray shark reaching length species member genus row enlarged pores corners mouth slender body long pointed snout low second dorsal fin placed posterior anal fin origin known natural history borneo shark viviparous like requiem sharks females bear litters pups gestation connection assessed species endangered time seen extant population found borneo shark continues merit conservation concern given highly limited range heavily waters taxonomy phylogeny dutch originally described borneo shark issue scientific journal based account newborn male long caught western borneo later authors recognized species belonging genus specimens borneo shark known immature collected april researchers discovered number additional specimens surveying fishery resources evolutionary relationships borneo shark uncertain morphological study place close member genus tentatively grouped shark shark shark creek shark shark shark borneo shark resembles sharks certain traits example enlarged pores mouth aspects morphology firmly place description borneo shark slim bodied long pointed snout oblique like nostrils preceded narrow shaped flaps skin eyes large circular equipped membranes corners sizable mouth bear short indistinct furrows immediately series enlarged pores unique genus upper lower tooth rows upper teeth single narrow oblique strongly edges large trailing lower teeth similar tend slender finely pairs gill slits short pectoral fins short pointed shaped pelvic fins small triangular nearly straight trailing margin dorsal fin fairly large triangular blunt apex sloping trailing margin origin lies free rear tips pectoral fins second dorsal fin small low originates middle anal fin base ridge dorsal fins caudal bears deep crescent shaped pit origin upper caudal fin lobe caudal fin developed lower lobe longer narrow upper lobe strong ventral notch near tip dermal denticles small overlapping horizontal ridges leading marginal teeth species slate gray tips dorsal fins upper caudal fin lobe specimens irregular rows small white artifact handling underside white extends flanks vague pale band faint lighter edges pectoral pelvic anal fin trailing margins largest known specimen measures long distribution habitat recent specimens borneo shark collected solely fishery landing sites despite thorough surveys rest borneo including locality type specimen range restricted shallow waters northwestern borneo earlier specimens came borneo china wider historical distribution species recorded philippines java records subsequent sightings areas biology ecology bony fishes probably main food borneo shark viviparous like requiem sharks developing embryos mother connection formed depleted yolk sac litter size pups born close long available specimens length sexual maturity males females human interactions assessed borneo shark endangered based data include recent specimens previously fishery surveys supposed historical range failed find borneo shark conservation status remains given small range waters subjected intensive commercial fishing caught line gear meat minimal commercial significance
Borneo shark