Meeting Abstract
41.1 Friday, Jan. 4 Molecularly Based Re-examination of Subfamily Relationships and Polyphyly in the Pinnotheridae (Decapoda, Brachyura, Pinnotheridae) PALACIOS-THEIL, E*; CUESTA, JA; FELDER, DL; Univ. of Louisiana at Lafayette; ICMAN-CSIC, Spain; Univ. of Louisiana at Lafayette emma@ull.edu
The family Pinnotheridae is presently comprised of 306 described species distributed among 56 genera. Many others remain to be described, a task complicated by the confused state of systematics in the group. Despite a massive taxonomic literature base, illustrations are of limited scope and quality, hampering morphologically based phylogenetic comparisons within the group. Striking post-planktonic changes in ontogeny, related to the unique life histories, can occur among subadults, confusing taxonomy when not all stages are known; different stages of the same species have occasionally been named as separate species. Polyphyly of the Pinnotheridae has been addressed, including some of our own work. Cuesta et al. 2002 clearly supported the polyphyly of the Pinnotheridae in an analysis that combined findings from adult and larval morphology with molecular genetic data. While some issues of polyphyly center at the generic level, there also remains question as to how family and subfamily ranks should be applied to reflect monophyletic clades of recent phylogenetic trees. The molecular component of previous analyses was based only on the mitochondrial large subunit 16S rRNA gene, primarily to examine generic assignments. Here we compare results from analysis of that mitochondrial gene with data based on the 18S rRNA nuclear gene. The 18S gene is established in defining of relationships at decapod family and subfamily levels, but our results show it to vary more extensively than expected within the Pinnotheridae. While variation in this gene is less than in 16S, phylogenetic analyses based on the 18S gene allow us to further clarify definitions of and relationships between some genera (supported under NSF/AToL EF-0531603).
