A New Subspecies of Common Bottlenose Dolphin Discovered in the Eastern Tropical Pacific.
Eastern Tropical Pacific Bottlenose Dolphin (ETP) – (Photo: SWFSC).
Through the analysis of several specimens, Ana Costa, a marine researcher at the Rosenstiel School of Marine, Atmospheric, and Earth Sciences at the University of Miami (USA), along with her colleagues, discovered a new subspecies that is smaller than other common bottlenose dolphin species.
In a study published in the journal Mammalian Evolution, scientists named the new subspecies Eastern Tropical Pacific Bottlenose Dolphin (ETP), scientifically referred to as Tursiops truncatus nuuanu.
Common bottlenose dolphins are found in temperate, subtropical, and tropical oceans around the world, with an estimated population of about 600,000 globally.
These dolphins are highly intelligent creatures, measuring between 2 to 4 meters in length and weighing over 450 kg. Their name relates to their short, thick snout.
Eastern Tropical Pacific Bottlenose Dolphins prefer deep, offshore waters – (Photo: SWFSC)
The common bottlenose dolphin consists of a single species (Tursiops truncatus). However, in certain locations in the Eastern Pacific, scientists have observed distinct populations. These populations have ecological and habitat preferences different from those of the common dolphins.
In an interview with Newsweek, Ms. Costa indicated that these unique preferences could lead to genetic differences that may result in evolution into separate species.
Ms. Costa, along with Dr. Patricia Rosel from the Southeast Fisheries Science Center (SEFSC) and Dr. Eric Archer from the Southwest Fisheries Science Center (SWFSC), along with the late researcher William Perrin at SWFSC (who passed away in July 2022), conducted a study aimed at better understanding the taxonomy of common bottlenose dolphins in this region.
The researchers examined the skulls of over 130 bottlenose dolphin specimens from both the Eastern Pacific and the Northwest Pacific – off the coast of Japan – preserved in museum collections across the United States. In some cases, the research team also assessed the total body length of these specimens.
Their analysis revealed significant shape differences between bottlenose dolphins from the Pacific.
Bottlenose dolphins found in the tropical Eastern Pacific waters form a distinct cluster and are significantly smaller – based on skull and body length – compared to common bottlenose dolphins.
The new subspecies is limited to the tropical Eastern Pacific and deeper waters offshore between the southern tip of the Baja California Peninsula (Mexico) and the Galápagos Islands (Ecuador).
The findings from the latest research could play a crucial role in the conservation of these marine animals.
