Meeting Abstract

33.5  Friday, Jan. 4  Molecular phylogeny of Anomura: is parallel evolution common in Decapoda? TSANG, L.M.*; CHAN, T.Y.; CHU, K.H.; The Chinese University of Hong Kong; National Taiwan Ocean University; The Chinese University of Hong Kong kiryu-sky@i-urban.com.hk

Anomura is morphologically the most diverse group of decapods and the interfamilial relationship has long been controversial. Here we reconstruct the phylogeny of Anomura (as defined by Martin and Davis, 2001) using six DNA markers with a combined data set of over 4000 bp. The monophyly of the infraorder is strongly supported with Hippoidea being basal, but the superfamilies Galatheoidea and Paguroidea appear to be polyphyletic. Aeglidae is the sister group to the monotypic Lomisoidea and the two families show higher affinity to Parapaguridae than to the other galatheoid families. The three families diverge as a separate lineage from the other galatheoids and paguroids. On the other hand, Galatheidae, Chirostylidae and Porcellanidae form a single clade and cluster with Pylochelidae. Thus, Paguroidea is not monophyletic unless Paraguridae and Pylochelidae are excluded. The other four paguroid families are closely related. Diogenidae appears to be paraphyletic with Coenobitdae nested within it. In congruent with previous molecular studies, Lithodidae is considered to be derived from Paguridae. Thus, the separation of Lithoididae into a new superfamily as proposed by McLaughlin et al. (2007) is not supported. The multiple carcinization events of Anomura and Brachyura have been attributed to the adaptive advantages of crab-like phenotypes. Our results suggest that the �hermit crab-like� forms have probably evolved from multiple independent origins within Anomura. Although the selective advantages of the �hermit� life style remain unknown, these results indicate that parallel evolution is more common in decapod evolution than we expect.