New data on the heterobranch gastropods (‘opisthobranchs’) for the Bahamas (tropical western Atlantic Ocean)

Abstract

The Bahamian archipelago is one of the richest regions in the Caribbean province and its importance as a hot spot of biodiversity and potential centre of origination of new species in the tropical western Atlantic has been suggested. In this paper I report on the sea slugs collected during a field trip to Eleuthera Island, the Bahamas. Animals were collected from the intertidal down to five metres deep by direct sampling. Nineteen species of opisthobranchs were found including two new records to the Bahamas (Berghia stephanieae and Gastropteron vespertilium) and three putatively new species of Haminoea. Colour variation was detected on adults of the species Chelidonura hirundinina and Bulla occidentalis, the latter suggesting isolation across a reduced geographical scale. Ontogenetic variation in Philinopsis cf. pusa was found and is here documented. The uniqueness of the Bahamian biodiversity is highlighted.

Identification guide to the heterobranch sea slugs (Mollusca: Gastropoda) from Bocas del Toro, Panama

“…From Mexico to Colombia, Cayman Islands, Cuba, Jamaica, Martinique, Puerto Rico, Bermuda, Bahamas (Valdés et al, 2006;Ornelas-Gatdula et al, 2011;Malaquias, 2014).…”

“…Common on shallow sandy areas as it buries itself in the sand, can be found crawling among seagrass at daytime (Valdés et al, 2006;Malaquias, 2014 (Valdés et al, 2006;Caballer Gutiérrez et al, 2015).…”

“…Martin, St. Lucia, Barbados, St. Vincent and the Grenadines, Grenada, Brazil (Valdés et al, 2006;Malaquias, 2014;Caballer Gutiérrez et al, 2015).…”

A biting commentary: Integrating tooth characters with molecular data doubles known species diversity in a lineage of sea slugs that consume “killer algae”

“…A similarly deep phylogeographic divide, with rare migrant individuals sampled in Florida and the Bahamas, was recently reported for another sacoglossan (Ellingson and Krug, 2016). Biophysical barriers and cycles of transient allopatry during the Pleistocene may have produced both genetically subdivided populations within species, and also a rapid radiation of Atlantic taxa in the O. antillarum-viridis complex, consistent with high Caribbean endemicity across marine heterobranchs (Ornelas-Gatdula and Valdés, 2012; Espinoza et al, 2014; Malaquias, 2014; Krug et al, 2016; Valdés et al, 2016).…”

First record of the Bahamian mollusc Spurilla dupontae (Mollusca: Aeolidiidae) in the Caribbean subprovince

“…These authors pointed out the existence of genetically distinct clades in this subprovince for some groups of molluscs, despite the general faunal homogeneity of the Caribbean. Moreover, Malaquias (2014) remarked the importance of the Bahamas for the biodiversity of the whole tropical western Atlantic region and discussed that the archipelago may "act as a centre of origination of new species". In addition, it seems common in certain families of heterobranchs to observe a distribution pattern comprising an endemic species from the Bahamas that is sister to a widespread western Atlantic species living in the same kind of habitat, suggesting an allopatric speciation process (Carmona et al 2014).…”