P3.182 Friday, Jan. 6 Comparative Morphology of the Musculature in Larviparous Rotifers: Gradual Versus Drastic Metamorphosis HOCHBERG, A.*; HOCHBERG, R.; Univ. of Massachusetts, Lowell Adele_Hochberg@student.uml.edu
Most sessile rotifers secrete protective tubes that they attach to underwater vegetation. The sessile lifestyle is a derived condition within the Rotifera. It is a rare lifestyle among monogonont rotifers, and includes approximately 100 species distributed within the Superorder Gnesiotrocha. Sessile rotifers generally have larviparous lifecycles, possessing free-swimming larvae that are both ecologically and morphologically distinct from the adult. To date, very little is known about rotifer larvae or the process of metamorphosis that leads to the adult body form. In this study, we follow the fate of the muscles in different sessile species to determine how metamorphosis reconfigures muscular architecture, and whether or not species with drastic metamorphosis have significantly different muscular patterns than those that display gradual metamorphosis. A combination of phalloidin stain, CLSM and 3D software are used to reconstruct the muscular systems of species of Collotheca, Floscularia, Ptygura, and Stephanoceros. Preliminary results indicate that species with an infundibulum (i.e., those species that undergo drastic metamorphosis) show greater disparity in muscle architecture relative to species with a more gradual form of metamorphosis.