AVIS-IBIS

Birds of Indian Subcontinent

Molecular phylogeny of leeches: Congruence of nuclear and mitochondrial rDNA data sets and the origin of bloodsucking

Publication Type:Journal Article
Year of Publication:1999
Authors:Trontelj, P, Sket, B, Steinbrück, G
Journal:Journal of Zoological Systematics and Evolutionary Research
Volume:37
Issue:3
Date Published:1999
ISBN Number:1439-0469
Keywords:bloodsucking, congruence, Evolution, Hirudinea, Hirundinidae, Hirundo, Hirundo rustica, leeches, molecular systematics, phylogeny, rRNA
Abstract:Complete 18S rDNA sequences and sequences of domain III of mitochondrial 12S rDNA were obtained to assess phylogenetic relationships among major suprageneric taxa of leeches and the possibly closely related clitellate taxa Branchiobdellida and Acanthobdellida. The monophyly of the families Erpobdellidae, Piscicolidae, and Glossiphoniidae, the suborders Erpobdelliformes and Hirudiniformes, and the order Arhynchobdellida have been confirmed by parsimony and maximum likelihood phylogenetic analysis of separate and combined data sets. Both the nuclear 18S rDNA sequences and the mitochondrial 12S rDNA sequences were consistent in not supporting a monophyletic order Rhynchobdellida, represented by the families Piscicolidae and Glossiphoniidae. A topology with the Piscicolidae as the first branch in the leech tree followed by the Glossiphoniidae received the highest support in terms of taxonomic, character, and outgroup congruence. According to this topology, the putative apomorphies of the Rhynchobdellidae (e.g. the proboscis) can be parsimoniously explained as plesiomorphies already present in the ancestral leech. This common ancestor was probably a bloodsucking leech with a proboscis rather than an unspecialized ectocommensal, as suggested by previous hypotheses. During the course of leech evolution, a reduction of the proboscis could have taken place in predatory arhynchobdellid ancestors to enable swallowing of larger prey. A second gain of sanguivory by the jawed Hirudiniformes could have been facilitated by pre-adaptations to ectoparasitic blood feeding. The 18S rDNA analysis further indicates a close relationship between the clitellate groups Branchiobdellida and Acanthobdellida, although this relationship is not strongly supported.
URL:http://dx.doi.org/10.1111/j.1439-0469.1999.00114.x
Short Title:Journal of Zoological Systematics and Evolutionary Research
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith