
Meeting Abstract
Sea cucumbers are the most apomorphic echinoderms: bilaterally symmetrical worms with a reduced skeleton. They have evolved bizarre specializations such as anal suspension feeding, evisceration, sticky Cuvierian tubules that entangle attackers, and a “melting” body wall. They are abundant, ubiquitous in the benthos, from poles to equator, intertidal to the deepest trenches, and include >1700 species in 25 families. They are among the most conspicuous mobile invertebrates on reefs and the deep sea and constitute the largest invertebrate fishery on Pacific islands, with stocks fully depleted throughout the tropics. A recent six gene molecular phylogeny showed substantial conflict with previous morphological-based relationships. Here, we present a phylogenomic analysis of Holothuroidea using 9 unpublished and 11 published transcriptomes. Our data pipeline includes transcriptome-assembly with Trinity, orthology assignment with OrthoFinder, and alignment construction using MAFFT and Gblocks. We conduct both concatenated and coalescent-based phylogenomic reconstruction. In addition, we use our sea cucumber orthogroups and our recently published draft Australostichopus mollis genome to design a set of target-enrichment baits for Holothuroidea. The combination of a backbone phylogeny built with hundreds of genes and high-quality baits for target enrichment, will help bring phylogenetic resolution to this fascinating group of animals and provide an important set of resources for systematists to conduct low-cost phylogenetic and population sampling.