Meeting Abstract

66-3  Friday, Jan. 6 14:00 - 14:15  Size and shape in independent evolutions of cleaning in the Labridae and Gobiidae BALIGA, VB*; MEHTA, RS; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz

Both body shape and size affect the locomotor behavior of organisms, but how these relate to other functional systems such as feeding requires an approach where independent origins of a trophic specialization can be examined. We use the evolution of cleaning behavior in clades within two marine fish families, Gobiidae and Labridae, to explore the extent to which specialization in this tropic strategy is associated with phenotypic evolution. While inference of how and when cleaning evolved in the Labridae has been established previously, we use similar methods to infer the temporal and topological trends of cleaning evolution in the Gobiidae. Through fitting evolutionary models, we explore the extent to which the evolution of cleaning has affected body size in these families, and find that certain smaller-bodied lineages within these families may have been historically “pre-adapted” to clean. We also infer a phylogeny for both families to generate a combined phylomorphospace of body shape using geometric morphometrics. Obligate cleaners exhibit significant morphological convergence in this phylomorphospace, while facultative and juvenile cleaner taxa show more varied patterns. Overall, the evolution of cleaning is associated with not just small body size but a reduction in body depth, elongation of the head, and a more terminal orientation of the mouth. These traits are presumed to enhance a cleaner’s ability to remove ectoparasites that inhabit tightly-confined places such as the gills and oral cavity of their clientele.