Reestablishment of Notopygos megalops McIntosh, description of N. caribea sp. n. from the Greater Caribbean and barcoding of “amphiamerican” Notopygos species (Annelida, Amphinomidae)

Abstract

The species of the genus Notopygos Grube, 1855 are characterized by an ovate body, a prominent caruncle with three lobes, dendritic branchiae, and double dorsal cirri. Twenty-two species belonging to Notopygos have been described, mostly from the Indo-Pacific region. In America, few species are frequently recorded: Notopygos crinita Grube, 1855 from St. Helena Island (Atlantic) and Notopygos ornata Grube and Ørsted in Grube 1857 from Costa Rica (Pacific). Notopygos crinita is a widely distributed species in the Western Atlantic with additional reports in the Mediterranean Sea (as a questionable alien species) and in the Pacific Ocean. However, only the genus features have been considered, consequently some records could be misidentifications. During a revision of materials from collections and the barcode project, ‘Mexican Barcode of Life, MEXBOL’, we found specimens of Notopygos megalops and an undescribed species from reef zones in the Caribbean; the former had been considered a junior synonym of Notopygos crinita. Herein, Notopygos megalops is reestablished and Notopygos caribea sp. n. is described. A morphological and DNA barcode approach was used to explain the records of Notopygos ornata in the Atlantic and to show the differences with the new species, since both species share features such as complex pigmentation patterns, and circular projections in the median lobe of the caruncle.

Polychaetes of Greece: an updated and annotated checklist

“…This re-description of Notopygos megalops differs from the description by Fauvel (1923) (which was probably used for the identification of the Greek specimens) in the following characters: Branchiae from chaetiger 6 (Yáñez-Rivera and Carrera-Parra 2012) instead of chaetiger 7 (Fauvel 1923); anterior branchiae with main stem and seven branchial filaments, in median chaetigers branching into four stems with five to seven filaments each (Yáñez-Rivera and Carrera-Parra 2012) vs. small tufts of 2–4 filaments anteriorly and only a single papilliform filament anteriorly Fauvel (1923). Yáñez-Rivera and Carrera-Parra (2012) define the start of the branchiae on chaetiger 6 as characteristic for the species; this seems to be invariable in juvenile individuals, too (McIntosh 1895). Thus, the species described by Fauvel (1923) and any specimens identified based on his description probably belong to a different species.…”

“…Notopygos megalops was originally described based on a juvenile specimen from the Caribbean Sea and used to be considered a synonym of Notopygos crinita (Grube, 1855) before it was re-described by Yáñez-Rivera and Carrera-Parra (2012) from the Caribbean Sea based on adult characters. This re-description of Notopygos megalops differs from the description by Fauvel (1923) (which was probably used for the identification of the Greek specimens) in the following characters: Branchiae from chaetiger 6 (Yáñez-Rivera and Carrera-Parra 2012) instead of chaetiger 7 (Fauvel 1923); anterior branchiae with main stem and seven branchial filaments, in median chaetigers branching into four stems with five to seven filaments each (Yáñez-Rivera and Carrera-Parra 2012) vs. small tufts of 2–4 filaments anteriorly and only a single papilliform filament anteriorly Fauvel (1923). Yáñez-Rivera and Carrera-Parra (2012) define the start of the branchiae on chaetiger 6 as characteristic for the species; this seems to be invariable in juvenile individuals, too (McIntosh 1895).…”

Redescriptions of Nereis oligohalina (Rioja, 1946) and N. garwoodi González-Escalante & Salazar-Vallejo, 2003 and description of N. confusa sp. n. (Annelida, Nereididae)

“…However, other amphiamerican species have been shown to be restricted to one coast or the other, often resulting in description of new taxa (e.g. Carrera-Parra and Salazar-Vallejo 2011; Yáñez-Rivera and Carrera-Parra 2012). On the other hand, the Caribbean species Namanereis garwoodi González-Escalante & Salazar-Vallejo, 2003 could be confused with Namanereis oligohalina , and without an updated description of the latter, a synonymy can be anticipated.…”