Abstract

A subset of Indo-Pacific bottlenose dolphins (T. aduncus) presented with consistent low total white blood cell counts approximately six months after transport from Subic Bay, Philippines to Dolphin Bay at Resorts World Sentosa (RWS), Singapore in November 2012. Neural-immune testing was carried out on this subset of dolphins as well as their counterparts who presented with normal white blood counts. The following tests were performed in two rounds: immunophenotyping (MHC II+ cells, T cells, T helper cells, B cells), lymphocyte proliferation, phagocytosis and respiratory burst, hormone analysis (ACTH, cortisol), and catecholamines (epinephrine, norepinephrine, dopamine). No significant differences were determined for any of the neural-immune measurements between the two groups (p<0.05). Interestingly, the immunophenotyping tests that had been conducted on the same animals from 2011 to 2012, while they were housed in sea holdings in the Philippines, revealed a significant decline in the absolute number of B lymphocytes after being at RWS for approximately six months (p=0.001). This may be a reflection of response to the greater number and diversity of microbes and antigens in the ocean vs. lesser immune challenge with filtered disinfected water in their habitat at the oceanarium. This is the first report of T. aduncus hormone levels, catecholamines, and immune function that we know of. Future investigations will include testing these dolphins again using the same neural-immune parameters to assess the status of their immune system over several additional years under professional care and with the inclusion of newborns that were never exposed to the natural habitat.

*Presenting author