[CINC] New Tursiops Dolphin Species - Burrunan

[Bernardo Alps]

Hi Marty.
 
The bottlenose dolphin is a cosmopolitan species that occurs in diverse habitats in tropical and temperate latitudes around the world. Scientists have long been aware of many different "populations" or morphological variants and they have been considered different species in the past, but all were consolidated into Tursiops truncatus until 1999 when the Indo-Pacific bottlenose dolphin, T. aduncus, became a separate species. T. aduncus has a fairly extensive range along the entire east coast of Africa and south coast of Asia up to Korea and the entire Indonesian archipelago and northern Australia; while T. australis has a fairly limited range in southern and south-eastern Australia. 

Locally, we have two forms of bottlenose dolphins, coastal and offshore, but they are officially still considered to both be T. truncatus. The California population of nearshore T. truncatus has been pretty well studied and is estimated at 350 to 450 individuals, while the offshore populations is estimated at 3,500 and probably many more. They are considered separate stocks by NMFS and managed as such. There are significant morphological and genetic differences between the two ecotypes, showing that they diverged quite a while ago. There is an interesting paper by Perrin et al., the abstract can be found at http://onlinelibrary.wiley.com/doi/10.1111/j.1748-7692.2010.00442.x/abstract, if anyone is interested, email me and I can send you a PDF of the entire paper. 

Basically, splitting a species is not easy and so far no one has decided to tackle this one. Researchers are aware of the differences and do for the most part keep careful track of which ecotype they are recording, but at this time both forms that we see here in the Southern California Bight are still considered the same species.

I would like to thank Maddlena Bearzi of the Ocean Conservation Society and Dave Weller of NOAA for their incredibly fast and complete responses to my RFI on this matter that allowed me to put together this brief synopsis. Hope this helps.

Take care,

Bernardo
  
-----Original Message----- 
From: Marty Flam 
Sent: Sep 15, 2011 10:08 AM 
To: CINC Rainlist 
Subject: [CINC] New Tursiops Dolphin Species - Burrunan 



Hi fellow CINC Cetacean Watchers,
 
I've heard we have more than one bottle-nose population in our local bight, but classified as only one species.  Same with Orcas. I often wonder if really true and if so, why or why not separated scientifically like this newbie, scientifically speaking.  
 
Marty
 
(Sept. 14, 2011) Burrunan Dolphin Tursiops australis sp. nov., 
 
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0024047
 
...the macro-morphological, colouration and cranial characters of these animals, assess the available and new genetic data, and conclude that multiple lines of evidence clearly indicate a new species of dolphin.
 
...detailed DNA studies and analysis of skulls in museums showed ...a new species
 
http://www.bbc.co.uk/news/science-environment-14921665