Incongruence between molecular phylogeny and morphological classification in amphipod crustaceans: a case study of Antarctic lysianassoids.
In Antarctic waters, the superfamily Lysianassoidea is one of the most important amphipod groups both in terms of species number and abundance. Dominant members of this superfamily are species of the orchomenid complex, found throughout the Southern Ocean. This study presents the first molecular phylogenetic analysis based on a representative subset of the Antarctic species belonging to different orchomenid genera and hence provides a framework for a systematic revision of these taxa. The current classification of the orchomenid genera is mainly based on mouthpart morphology. The validity of these morphological characters was assessed by resolving phylogenetic relationships using nuclear 28S rRNA and mitochondrial cytochrome oxidase subunit I sequences. The molecular data rejected most of the previously proposed taxonomic subdivisions within this complex. The genera Abyssorchomene and Orchomenella as well as the subgenus Orchomenopsis appeared to be non-monophyletic. This implies that the supposed diagnostic characters are likely a result of convergent evolution. Further, our results indicated the necessity of a revision of the family-level systematics.
Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000 Brussels, Belgium; Laboratory of Marine Biology, Place Croix du Sud 3, Catholic University of Louvain, 1348 Louvain-la-Neuve, Belgium. Electronic address: chavermans@naturalsciences.be.
Charlotte
C
Havermans
Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000 Brussels, Belgium. Electronic address: zoltan-tamas.nagy@naturalsciences.be.
Zoltán T
ZT
Nagy
Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000 Brussels, Belgium. Electronic address: gontran.sonet@naturalsciences.be.
Gontran
G
Sonet
Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000 Brussels, Belgium. Electronic address: claude.debroyer@naturalsciences.be.
Claude
C
De Broyer
Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000 Brussels, Belgium. Electronic address: patrick.martin@naturalsciences.be.
Patrick
P
Martin
D033304:Amphipoda / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D000818:Animals; D000864:Antarctic Regions; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D008957:Models, Genetic; D010802:Phylogeny; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D004272:DNA, Mitochondrial; D012339:RNA, Ribosomal, 28S; D003576:Electron Transport Complex IV