Meeting Abstract

P2.130  Monday, Jan. 5  On the structure and function of larval muscular systems in trematodes (Platyhelminthes: Neodermata): intramolluscan stages from sporocyst to metacercaria. TJIONAS, G*; PATI, A; HOCHBERG, R; Univ. Massachusetts Lowell; Univ. Massachusetts Lowell; Univ. Massachusetts Lowell rick_hochberg@uml.edu

Freshwater molluscs serve as intermediate hosts for trematodes that parasitize amphibians, birds, fish and other vertebrate animals. An individual snail can harbor multiple larval stages of a single trematode species or even multiple species. Different species and ontogenetic stages of intramolluscan trematodes often show characteristic behaviors (movement patterns) that may be correlated with their body shape and the architecture of their muscular systems. Patterns of musculature may also be of systematic relevance. To date, few studies have examined muscle pattern diversity within a clade or even the ontogeny of a single species – from sporocyst to redia to cercaria and metacercaria. To understand how muscle patterns may differ between systematic groups, or even within the ontogeny of a species, we examined multiple larval stages of select trematodes from the pulmonate hosts, Menetus dilatatus and Physa sp., using fluorescent phalloidin stains and confocal laser scanning microscopy. Our results reveal similarities in muscle arrangement among comparable larval stages, and interesting differences between larval stages within a single species. This study underscores the need for greater attention to larval morphology (beyond taxonomic characters) to understand the functional significance of different muscle patterns and their importance for trematode systematics.