The Japanese Tropical Pacific bottlenose dolphin (Tursiops truncatus nuuanu) prefers the deep waters off southern Baja California, the Pacific coast of Central America and Colombia and Ecuador, out to roughly 120º W; the northern vary restrict of this subspecies is between Magdalena Bay on the Pacific facet of Baja California, and Santa Catalina Island, Mexico inside the Gulf of California, whereas its southern restrict would possibly lengthen to not less than the Galapagos Islands.
The Japanese Tropical Pacific bottlenose dolphin (Tursiops truncatus nuuanu). Picture credit score: NOAA / NMFS / SWFSC.
“Bottlenose dolphins are usually sighted all through the japanese Pacific (from Canada to Chile) and the Gulf of California,” mentioned College of Miami marine mammalogist Ana Costa and her colleagues.
“Presently, just one species, the frequent bottlenose dolphin (Tursiops truncatus), is believed to happen all through this geographic space.”
“Within the japanese Pacific Ocean, three distinct types of the species have been recognized, with recommendations they could be totally different species: a southern California/Mexico coastal type, a northern temperate offshore type, and an japanese tropical Pacific offshore type.”
Of their new research, the authors examined complete physique size and cranium morphology of the three kinds with an try to make clear their taxonomic standing and distribution.
They used multivariate and clustering analyses to look at the extent of differentiation among the many bottlenose dolphin populations.
They discovered that the brand new subspecies, referred to as the Japanese Tropical Pacific bottlenose dolphin (Tursiops truncatus nuuanu), is smaller than different frequent bottlenose dolphins.
“We discovered two distinct morphological clusters: the brand new subspecies discovered within the japanese tropical Pacific and the frequent bottlenose dolphins discovered primarily within the japanese and western North Pacific waters,” Dr. Costa mentioned.
“The Japanese Tropical Pacific bottlenose dolphins is likely to be differentiating as a result of distinct environmental situations in these waters, equivalent to oxygen and salinity ranges and temperature situations.”
“A better understanding of marine mammal populations is important for preserving and defending totally different species and subspecies at a time of world warming,”
“The conservation and administration of marine life must be a global precedence.”
The crew’s paper was revealed within the Journal of Mammalian Evolution.
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A.P.B. Costa et al. Tursiops truncatus nuuanu, a brand new subspecies of the frequent bottlenose dolphin from the japanese tropical Pacific. J Mammal Evol, revealed on-line December 10, 2022; doi: 10.1007/s10914-022-09641-5
