Meeting Abstract
Microbiomes are quickly gaining recognition as ubiquitous and integral components of multicellular organisms whose imprints are found in the biology of their hosts. In the sponge genus Ircinia, evolutionary responses to host-microbial symbioses abound as Ircinia holobionts exhibit several hallmarks of metabolic integration including microbial genome streamlining, translocation of nutrients between the microbes and sponges, and heritability of endosymbionts. Thus, microbes in Ircinia hold the potential to influence the evolutionary histories of their hosts. A Caribbean member of this genus, I. felix, is represented by four distinct morphotypes that are regarded as putative lineages. This study tests the hypothesis that these four morphotypes constitute separate species by analyzing microbial 16S and host-derived RADseq data using tests of host-microbe co-diversification and the multispecies coalescent. As the bodies of Ircinia and sponges in many other clades possess few taxonomically informative characters, this approach to species delimitation provides a means to resolve species boundaries where traditional morphology-based taxonomy has fallen short.
