Morphological and molecular evolution are not linked in Lamellodiscus (Plathyhelminthes, Monogenea).
Lamellodiscus Johnston & Tiegs 1922 (Monogenea, Diplectanidae) is a genus of common parasites on the gills of sparid fishes. Here we show that this genus is probably undergoing a fast molecular diversification, as reflected by the important genetic variability observed within three molecular markers (partial nuclear 18S rDNA, Internal Transcribed Spacer 1, and mitonchondrial Cytochrome Oxidase I). Using an updated phylogeny of this genus, we show that molecular and morphological evolution are weakly correlated, and that most of the morphologically defined taxonomical units are not consistent with the molecular data. We suggest that Lamellodiscus morphology is probably constrained by strong environmental (host-induced) pressure, and discuss why this result can apply to other taxa. Genetic variability within nuclear 18S and mitochondrial COI genes are compared for several monogenean genera, as this measure may reflect the level of diversification within a genus. Overall our results suggest that cryptic speciation events may occur within Lamellodiscus, and discuss the links between morphological and molecular evolution.
UPMC Univ Paris 06, UMR 7232, Biologie Intégrative des Organismes Marins, Observatoire Océanologique, Banyuls-sur-Mer, France. tpoisot@um2.fr
Timothée
T
Poisot
Olivier
O
Verneau
Yves
Y
Desdevises
D000818:Animals; D001499:Bayes Theorem; D004275:DNA, Ribosomal / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D016013:Likelihood Functions; D008969:Molecular Sequence Data; D010802:Phylogeny; D010986:Platyhelminths / Q000033:anatomy & histology* / Q000235:genetics*; D013045:Species Specificity
D004275:DNA, Ribosomal; D003576:Electron Transport Complex IV