title: Taxonomic remarks on the genus Ctenodrilus (Annelida: Cirratulidae) including description of a new species from the Pacific Ocean.
abstract: A new species of Ctenodrilus is described based on morphology, anatomy and molecular (COI and 16S) data. Phylogenetic analyses revealed that the newly described Hawaiian species is the sister taxon of the widely distributed C. serratus. Comparisons of K2P distances show distances of at least 10.9 % for 16S and 18.7 % for CO1. Morphology of C. serratus differs from C. pacificus sp. nov. in the shape, number and distribution of multidentate hooks along the body, extent in segments of anterior ventral cilia, and presence of stomach cilia. Ctenodrilus pacificus sp. nov. resembles C. parvulus in terms of the internal anatomy but differs in respect to the shape of multidentate hooks. Asexual reproduction in the new species is described including associated changes in the external morphology and internal anatomy. A revision of the taxonomic characters of Ctenodrilus is also presented in order to provide background information for a better assessment of the widely distributed taxon Ctenodrilus serratus.
authors.affiliation: Department of Biology, University of Hawaii at Manoa, 2538 McCarthy Mall, Honolulu, Hawaii 96822, USA Water Resources Research Center, University of Hawaii at Manoa, 2540 Dole Street, Honolulu, Hawaii 96822, USA; Email: magalhaeswf@gmail.com.
authors.forename: Wagner F
authors.initials: WF
authors.lastname: Magalhães
authors.affiliation: Molecular Evolution & Animal Systematics, Institute of Biology, University of Leipzig, Talstrasse 33, 04103 Leipzig, Germany; Email: unknown.
authors.forename: Michael
authors.initials: M
authors.lastname: Weidhase
authors.affiliation: Department of Marine Biology, Texas A&M University at Galveston, 200 Seawolf Parkway, Galveston, TX 77553, USA; Email: unknown.
authors.forename: Anja
authors.initials: A
authors.lastname: Schulze
authors.affiliation: Department of Biology, University of Hawaii at Manoa, 2538 McCarthy Mall, Honolulu, Hawaii 96822, USA Water Resources Research Center, University of Hawaii at Manoa, 2540 Dole Street, Honolulu, Hawaii 96822, USA; Email: unknown.
authors.forename: Julie H
authors.initials: JH
authors.lastname: Bailey-Brock
mesh_terms: D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D005260:Female; D006254:Hawaii; D008297:Male; D009929:Organ Size; D010140:Pacific Ocean; D010802:Phylogeny; D011077:Polychaeta / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development