species family native coastal waters western atlantic_ocean state massachusetts venezuela dwelling species prefers sandy muddy habitats deep migratory northern portion range typically growing characterized pectoral fin disc broadly rounded outer corners angled snout whip like tail upper keel lower fin fold line small middle active night day usually buried sediment predator small benthic invertebrates bony fishes species viviparous young initially yolk later milk produced mother females birth pups gestation period months consists period arrested development tail spine potentially dangerous listed species concern widely distributed common threatened commercial fisheries taxonomy phylogeny french naturalist originally described specimens collected little egg harbor state new_jersey published account volume named new species honor thomas founding members academy species moved genus subsequent authors german erroneously gave specific epithet der typical spelling literature recently push use correct original spelling proposed officially spelling consistency previous usage phylogenetic analysis based morphological characters found basal members genus sister species diamond western pacific_ocean species likely diverged formation panama million years ago distribution habitat found western atlantic_ocean chesapeake_bay southward northern gulf_of_mexico greater lesser antilles rare occasions found far north new_jersey massachusetts far south venezuela far west mexico absent southern gulf_of_mexico caribbean coast central_america reports species brazil argentina likely represent common coastal habitats bays dwelling species usually found depth recorded deep sandy muddy flats preferring water temperature adult seldom found meadows serves habitat young rays east_coast schools migrate long distances northward bays spend summer southern offshore waters winter description diamond shaped pectoral fin disc sixth wider long broadly rounded outer corners leading margins disc nearly straight converge tip snout angle anterior disc shape distinguishes species similar atlantic longer acute snout mouth curved central projection upper jaw fits lower jaw row floor mouth pair smaller set apart upper tooth rows teeth bases arranged pattern flattened surfaces tooth crowns rounded females juveniles males breeding condition triangular pointed pelvic fins triangular rounded tips whip like tail measures half times long disc bears long spines quarter tail length base second spine present replacement periodically grows existing spine spine developed upper lower fin lower fold longer wider upper small found row eyes base tail spine increasing number age adults eyes outer parts disc dorsal coloration grayish reddish greenish brown individuals possess bluish spots darker sides rear thin white disc margin ventral surface whitish dark disc margin dark record french gives maximum disc width species specimen sources maximum disc width females grow larger males biology ecology generally nocturnal habits spends day buried substrate known follow rising tide forage water barely deep cover body species small invertebrates including crustaceans worms bony fishes mainly targets benthic organisms takes free swimming prey delaware bay species feeds predominantly shrimp blood worm overall composition virtually identical shares bay preyed larger fishes bull shark known parasites species include like viviparous embryos initially sustained yolk later development finger like extensions called surround embryo deliver protein rich milk produced mother left adult females functional mating occurs defined period april june peaking males presumably pointed teeth grasp females development stage shortly formation resume approximately months spring following year embryos rapidly mature period weeks period reflect greater availability food spring including extended period gestation period lasts months young born mid late shallow channel virginia large observed repeatedly breaking surface swimming rapidly straight lines tails air seen rising slowly surface hanging minutes rays hooked shock capture caused release near term suggesting activity related aborted young pale small yolk swelling place tail spines females begin new batch eggs immediately giving birth indicating annual reproductive cycle newborn rays measure weigh males mature sexually disc width weight females mature disc width weight human interactions aggressive defend stepped tail spine inflict injury easily pierce leather rubber venom delivered potentially life threatening effects heart respiratory problems subject research species popular divers abundant widespread caught incidentally commercial fisheries operating waters activities threat population captured rays released alive impact fishing southern parts range uncertain unlikely significantly affect species activities occur outside centers distribution result listed concern
Bluntnose stingray