Abstract
At least 30 species of cetaceans are known to inhabit the waters of the Wider Caribbean, of which 19 species have been documented in the waters of Trinidad and Tobago.1,2 One such species is the melon-headed whale (Peponocephala electra), which is known to inhabit tropical and subtropical zones worldwide, and appears to be present in most areas of their range year-round.3 At least five melon-headed whales (Peponocephala electra) stranded singly on the beaches of the eastern (Atlantic) coast of the Caribbean island of Trinidad between March 2013 and November 2015. We examined four of the five reported cases. Animals displayed a loss of equilibrium and repeatedly re-stranded following re-flotation attempts. One animal died naturally at the stranding site, while three were euthanised after unsuccessful re-flotation attempts. Eggs and/or adult trematodes (Nasitrema sp.) were identified in the brain of all cases and were generally associated with moderate to severe meningitis or suppurative meningoencephalitis. Peritoneal parasitic (cestode) cysts, gastrointestinal helminthiasis and ulcerative gastritis associated with anisakid nematode infestation were also common findings across specimens. This report confirms that Nasitrema sp.-associated encephalitis is a common cause of melon-headed whale strandings in the south eastern Caribbean. We provide the first documented reports of melon-headed whale strandings in Trinidad and Tobago, and we further report on central nervous system (CNS) lesions that were associated with the presence and/or migration of Nasitrema sp. in all stranded melon-headed whales examined on the island during the period March 2013 to November 2015, the presence and in some cases the severity of which can be associated with ill-thrift, debilitation and ultimately, stranding. To the best of our knowledge, we present the first report of brain lesions associated with this parasite and its eggs in melon-headed whales.
Acknowledgements
The authors wish to thank the Trinidad and Tobago Marine Mammal Stranding Network (TTMMSN) and the numerous volunteers who offer their time and assistance during stranding response activities. We also thank Dr. R. Charles for assisting in verifying the identification and measurements of the adult trematodes and eggs.
* Presenting author
Literature Cited
1. UNEP- The Caribbean Environment Programme, 2015. Marine Mammals. www.cep.unep.org/publications-and-resources/marine-and-coastal-issues-links/marine-mammals (accessed May 10 2016).
2. Cetacean Conservation and Research Organisation, 2013. Cetaceans. www.ccaro.org/m-cetaceans.php (accessed May 10 2016).
3. Jefferson TA, Barros NB. 1997. Peponocephala electra. Mammalian Species. 553:1–6.