Meeting Abstract

2.2  Tuesday, Jan. 4  Evolutionary dynamics of boxfish carapace I: phylogenetic diversity MARCROFT, T.A.*; MODLIN, J; SANTINI, F; MCPEEK, M.A.; ALFARO, M.E.; Univ. of California, Los Angeles; Univ. of California, Los Angeles; Univ. of California, Los Angeles; Dartmouth College; Univ. of California, Los Angeles tmarcroft@gmail.com

Boxfishes–order Tetraodontiformes, families Ostraciidae and Aracanidae–are characterized by having a unique hard carapace that is believed to function in hydrodynamic stabilization and protection from predation. Substantial morphological diversity is found in the 37 reef-dwelling or demersal species; however, neither the extent of carapace diversity, nor its influence on performance, are well understood. Using 3D laser scan models we have created, we quantify carapace shape using spherical harmonics (SPHARM). The primary axis of shape variation ranges from a general box shape with major lateral keels to discs with major dorsoventral keels. The secondary axis ranges from tall, flat, deep prisms to short boxes. Projection of boxfish phylogeny to create a phylomorphospace indicates that Aracanidae appear to have split from the rest of the boxfishes early and that Ostraciid genera Lactophrys and Acanthostracion occupy their own distinct areas of the morphospace. Lactoria, Tetrosomus, and Ostracion cluster together in their own portion of the morphospace. Ancestral state reconstructions also shed light on the tempo of morphological evolution of the carapace.