title: A comparative study of populations of Ectopleura crocea and Ectopleura ralphi (Hydrozoa, Tubulariidae) from the Southwestern Atlantic Ocean.
abstract: Ectopleura crocea (L. Agassiz, 1862) and Ectopleura ralphi (Bale, 1884) are two of the nominal tubulariid species recorded for the Southwestern Atlantic Ocean (SWAO), presumably with wide but disjunct geographical ranges and similar morphologies. Our goal is to bring together data from morphology, histology, morphometry, cnidome, and molecules (COI and ITS1+5.8S) to assess the taxonomic identity of two populations of these nominal species in the SWAO. We have observed no significant difference or distributional patterns between the so-called Brazilian E. ralphi and Argentine E. crocea for both morphological and molecular data. Therefore, SWAO populations of Ectopleura belong to the same species. In a broader view, it is difficult to find decisive character distinguishing E. crocea from E. ralphi, and both species have indeed recently been synonymized, with the binomen E. crocea having nomenclatural priority. Geographically broader genetic analysis should be carried out in order to test the validity of this synonymy because taxonomical procedures such as studying type specimens and documenting broad phenotypic variability have not yet been conducted.
authors.affiliation: Departamento de Zoologia, Instituto de Biociências, USP, CEP 05508-090 São Paulo, SP, Brazil.; Email: marques@ib.usp.br.
authors.forename: Maurício Antunes
authors.initials: MA
authors.lastname: Imazu
authors.affiliation: Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, USP, CEP 05508-090 São Paulo, SP, Brazil; Email: unknown.
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Ale
authors.affiliation: Estación Costera Nágera, Departamento de Ciencias Marinas, Facultad de Ciencias Exactas y Naturales, Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata, Mar del Plata - CONICET, Argentina.; Email: genzano@mdp.edu.ar.
authors.forename: Gabriel Nestor
authors.initials: GN
authors.lastname: Genzano
mesh_terms: D000818:Animals; D001118:Argentina; D001267:Atlantic Ocean; D001938:Brazil; D005260:Female; D037402:Hydrozoa / Q000033:anatomy & histology* / Q000145:classification* / Q000254:growth & development / Q000648:ultrastructure; D007814:Larva / Q000033:anatomy & histology / Q000145:classification / Q000254:growth & development / Q000648:ultrastructure; D008297:Male; D008855:Microscopy, Electron, Scanning