sand tiger sand tiger extremely rare species shark family possible worldwide distribution large species reaching length sand tiger long snout large orange eyes membranes mouth narrow teeth prominently exposed distinguished similar sand tiger teeth lateral uniformly dark brown color inhabiting continental margins oceanic waters depths sand tiger vertical horizontal migratory movements feeds bony fishes squid sizable eyes dark coloration suggest spend time zone reproduction probably viviparous embryos like shark species shark caught incidentally commercial fisheries determine conservation status taxonomy phylogeny known sand tiger female long caught april set black specimen mounted later formed basis scientific description authored german article named species honor late director assigned new species genus time members sand tiger shark family came recognized valid genus separate sand tiger reassigned given resemblance sand tiger specimens examined 1980s authors speculated species represented extreme variant sand tiger names shark include black sand tiger oceanic sand tiger ragged tooth shark sand tigers belong family similar sand tiger shark debated morphological studies giving inconsistent results molecular phylogenetic analysis based mitochondrial dna supported sister species relationship clade consisting instead found closer shark suggesting placed separate families description body conical snout large mouth filled protruding teeth sand tiger looks like better known sand tiger shark large eyes lack membranes small corner mouth extends level eyes jaws highly upper lower tooth rows include zero rows small teeth upper jaw rows lower half upper jaw teeth second rows large fourth rows small rows large tooth narrow like central flanked smaller contrasts sand tiger lateral pairs gill slits pectoral fins medium sized broad rounded tips large dorsal fin rounded apex positioned closer pectoral pelvic fins second dorsal fin half size originates rear tips pelvic fins pelvic fins large dorsal fin anal fin smaller second dorsal fin positioned caudal crescent shaped notch dorsal origin caudal fin lower lobe caudal fin short distinct upper lobe long deep notch trailing margin near tip skin covered overlapping dermal denticles horizontal ridges leading marginal teeth species plain dark reddish brown chocolate brown black trailing margins fins white tipped dorsal fin eyes dark orange vertically oval green pupils black patches inside mouth jaws floor mouth gill arches largest male female specimens measured long respectively distribution habitat extremely rare sand tiger reported scattered locations world suggesting wide possibly global distribution tropical warm temperate oceanic waters known specimens come atlantic found southern brazil texas eastern florida evidence presence indian_ocean set jaws originated possibility existence species pacific_ocean suspected teeth recovered sediments confirmed decade later captures hawaii sand tiger caught depths recorded continental shelves near sea floor mid water parts open ocean deep swimming upper levels water column nighttime captures relatively shallow depths suggest species vertical migration rising zone zone night feed brazilian waters sand tigers captured spring type seasonal migratory movement biology ecology account sand tiger caught alive noted behaved aggressively snapping violently water large eyes uniformly dark coloration characteristic traits fish sand tiger feeds bony fishes squid reproduction little known probably similar sharks viviparous embryos feed eggs gestation adult females single functional right functional males mature sexually long females mature long information available growth aging human interactions sand tiger encountered commercial importance caught incidentally purse captures suggest lives waters deep commercial fisheries listed species citing lack biological population data prohibited taking species united_states waters
Bigeye sand tiger