Data from: Prey preference follows phylogeny: evolutionary dietary patterns within the marine gastropod group Cladobranchia (Gastropoda: Heterobranchia: Nudibranchia)

Background: The impact of predator-prey interactions on the evolution of
many marine invertebrates is poorly understood. Since barriers to genetic
exchange are less obvious in the marine realm than in terrestrial or
freshwater systems, non-allopatric divergence may play a fundamental role
in the generation of biodiversity. In this context, shifts between major
prey types could constitute important factors explaining the biodiversity
of marine taxa, particularly in groups with highly specialized diets.
However, the scarcity of marine specialized consumers for which reliable
phylogenies exist hampers attempts to test the role of trophic
specialization in evolution. In this study, RNA-Seq data is used to
produce a phylogeny of Cladobranchia, a group of marine invertebrates that
feed on a diverse array of prey taxa but mostly specialize on cnidarians.
The broad range of prey type preferences allegedly present in two major
groups within Cladobranchia suggest that prey type shifts are relatively
common over evolutionary timescales. Results: In the present study, we
generated a well-supported phylogeny of the major lineages within
Cladobranchia using RNA-Seq data, and used ancestral state reconstruction
analyses to better understand the evolution of prey preference. These
analyses answered several fundamental questions regarding the evolutionary
relationships within Cladobranchia, including support for a clade of
species from Arminidae as sister to Tritoniidae (which both preferentially
prey on Octocorallia). Ancestral state reconstruction analyses supported a
cladobranchian ancestor with a preference for Hydrozoa and show that the
few transitions identified only occur from lineages that prey on Hydrozoa
to those that feed on other types of prey. Conclusions: There is strong
phylogenetic correlation with prey preference within Cladobranchia,
suggesting that prey type specialization within this group has inertia.
Shifts between different types of prey have occurred rarely throughout the
evolution of Cladobranchia, indicating that this may not have been an
important driver of the diversity within this group.