TY - JOUR

T1 - The Phylogeny of Rhizocephalan Parasites of the Genus Heterosaccus Using Molecular and Larval Data (Cirripedia: Rhizocephala; Sacculinidae)

AU - Glenner, H.

AU - Thomsen, Philip Francis

AU - Rybakov, A.V.

AU - Galil, B.S.

AU - Høeg, Jens Thorvald

N1 - Keywords: phylogeny, parasitology, larval biology, SEM, marine immigrant

PY - 2008

Y1 - 2008

N2 - Within parasitic barnacles of the family Sacculinidae, the genus Heterosaccus is the third largest, with 12 species infesting various brachyuran hosts throughout the world. As part of an effort to reconstruct rhizocephalan phylogeny we performed an analysis of four species of Heterosaccus and of selected sacculinid and non-sacculinid rhizocephalans. We used both molecular sequence data (16s rDNA and 18s rDNA ) and morphological characters from an SEM analysis of the cypris larvae. Using, Bayesian methods we obtained a highly Supported tree in which the lour species of Heterosaccus form a monophylum, whereas both the genus Sacculina and the family Sacculinidae are polyphyletic. The sister-roup to Heterosaccus is a Glade consisting of the sacculinids Loxothylacus panopaei and the "classical" rhizocephalan Sacculina carcini. The molecular results found support ill cypris morphology where we identified two distinct synapomorphies for Heterasaccus, both present in male cyprids only: A large flap extending posteriorly from the third antennular segment, and the male-specific aesthetasc on the third segment being reduced to a rudiment or lacking completely. Female cyprids didn't show,generic level apomorphies but resembled those of other sacculinid Species. No morphological synapomorphies were identified between Heterosaccus. L. panopaei and S. carcini. While larval characters proved to be informative. we conclude that future studies on rhizocephalan taxonomy must rely primarily on molecular data. both to provide an overall phylogenetic framework and to assure an accurate identification of species for biogeographical and other biological purposes

AB - Within parasitic barnacles of the family Sacculinidae, the genus Heterosaccus is the third largest, with 12 species infesting various brachyuran hosts throughout the world. As part of an effort to reconstruct rhizocephalan phylogeny we performed an analysis of four species of Heterosaccus and of selected sacculinid and non-sacculinid rhizocephalans. We used both molecular sequence data (16s rDNA and 18s rDNA ) and morphological characters from an SEM analysis of the cypris larvae. Using, Bayesian methods we obtained a highly Supported tree in which the lour species of Heterosaccus form a monophylum, whereas both the genus Sacculina and the family Sacculinidae are polyphyletic. The sister-roup to Heterosaccus is a Glade consisting of the sacculinids Loxothylacus panopaei and the "classical" rhizocephalan Sacculina carcini. The molecular results found support ill cypris morphology where we identified two distinct synapomorphies for Heterasaccus, both present in male cyprids only: A large flap extending posteriorly from the third antennular segment, and the male-specific aesthetasc on the third segment being reduced to a rudiment or lacking completely. Female cyprids didn't show,generic level apomorphies but resembled those of other sacculinid Species. No morphological synapomorphies were identified between Heterosaccus. L. panopaei and S. carcini. While larval characters proved to be informative. we conclude that future studies on rhizocephalan taxonomy must rely primarily on molecular data. both to provide an overall phylogenetic framework and to assure an accurate identification of species for biogeographical and other biological purposes

M3 - Journal article

VL - 54

SP - 223

EP - 238

JO - Israel Journal of Ecology & Evolution

JF - Israel Journal of Ecology & Evolution

SN - 1565-9801

IS - 2

ER -