Developmental trade-offs in Southern Ocean mollusc kleptoparasitic species

Connectivity is a key factor in determining the genetic structure of marine populations, and type and duration of the larval phase strongly affect dispersal abilities of species. In Antarctica, invertebrates show a higher proportion of species with limited pelagic dispersal, and any exception to this pattern is worthy of attention. Capulidae is a family of kleptoparasitic gastropods, with two larval strategies. Most species have a peculiar planktotrophic larva, the ‘echinospira’, which enables a long pelagic dispersal; a minority of species undergo lecithotrophic development. We provide the first molecular phylogenetic framework for the family and define the Antarctic species based on molecular data. Based on this information, and on larval shell morphology, we tested the hypothesis that capulid species with high dispersal capacities via planktotrophic larvae display high genetic connectivity over long distances. Our data showed that whilst larval planktotrophy is the predominant larval strategy of the family worldwide, the vast majority of Antarctic species exhibit non-planktotrophic development. The unique exception, Capulus subcompressus, showed high genetic connectivity between the Ross Sea and Weddell Sea-Antarctic Peninsula. In all other Antarctic species, environmental constraints selected towards intracapsular metamorphosis, despite the associated limits of dispersal and finding a host. © 2015, Springer International Publishing Switzerland.},