Do Dolphins’ Teeth Help Them Hear Underwater?

While the average somebody has 32 teeth , some species of dolphin own as many as 240 . Why so many ? Not all species are quite so prosperous – Risso ’s dolphins only have four to 14 in their lower jaw . However , scientists have suspect mahimahi ’ tooth are for more than just munching for some fourth dimension . Now , newfangled enquiry suggest it may have something to do withecholocationand may even help dolphinfish hear underwater .

A team of Nipponese researcher inquire the structure and function of the tissues that surround theteethof different species ofdolphin , include bottlenose and striped dolphins , and compared them to those of other brute . The findings reveal a set of differences that pose the dental structures of dolphinfish apart from those of other mammalian . For example , the osseous tissue that hold in the teeth ( bed as the alveolar os ) is spongier than those found in other animal . What ’s more , the socket contain the tooth in dolphin are remarkably large and the teeth are loose .

The researchers also found that dolphins own a unique ligament structure – like other mammal , fibers in the inside layer spread out from the solution of the tooth ; however , unlike other mammals , fibers in the forbidden layer penetrate the spongy bone in a complex way of life . In between the two layers , there were thick bundles of long nerve fibers that are again unequaled to dolphins . Interestingly , some fibers stop in structures that count like sensorial receptors and allow electrochemical signal to travel through the fibers at a quicker pace .

take together , these morphological feature evoke dolphins ’ tooth serve a sensorial intent , start the animals to detect changes in their environment – in a similar mode towhiskerson a hombre . Ryo Kodera from Tsurumi University in Japan toldNew Scientistthe prospicient fibers show “ meaning tooth mobility ” and the duncical nerve bundles point “ heightened sensitivity to tooth drift . ”

While the finding do not conclusively say what sense these physiologic differences might affect , Kodera suggest it could help dolphinfish hear better underwater . He say New Scientist , “ Our findings underpin the hypothesis that dolphins utilize their teeth as part of an innovative wakeless reception system . ”

submerged hearing is not the only great power dolphin possess – late research suggests bottlenose mahimahi have a " seventh signified " andcan detect electrical currentsbetter than duckbill ( though not quite on the stage ofsharksandrays ! ) .

The subject field is print in the journalThe Anatomical Record .