Abstract
Nereis falsa de Quatrefages, 1866 has been regarded as a cosmopolitan species, and several species described from different localities have been regarded as junior synonyms of N. falsa. The present study is an attempt to resolve the taxonomic confusion in N. falsa, which seems to contain several distinct species due to previous inappropriate synonymy, widely distributed in the Atlantic and eastern Pacific Oceans. For this purpose, the authors first propose the resurrection of the synonymy of N. falsa with Hediste diversicolor that was concluded during the 19th century but disregarded later. After the fixation of the identity of N. falsa sensu stricto, the authors re-evaluate the proper taxonomic status of species which have previously been confused with N. falsa. Type, topotype and non-type specimens were examined; most species are redescribed, and others are reinstated. Nereis splendida Grube, 1840 is a valid Mediterranean species, and a neotype is proposed; it includes the Mediterranean populations of what is currently regarded as N. falsa. Consequently, N. falsa is transferred to Hediste Malmgren, 1867, and some taxonomic comments are added for the latter genus and a key to species is also included. Nereis callaona Grube & Kröyer in Grube, 1857, N. marginata Grube & Örsted in Grube, 1857 and N. riisei Grube & Örsted in Grube, 1857 are restricted to tropical American shores and are all redescribed. Nereis pelagica lunulata Ehlers, 1901, formerly regarded as a junior synonym of N. falsa by Fauvel (1941), is redescribed and elevated in rank to species level. Nereis lucipeta Ehlers, 1908, formerly regarded as a junior synonym of N. splendida by Ehlers (1913) and of N. falsa by Fauvel (1919), is reinstated. Nereis occidentalis Hartman, 1945 is also redescribed. Furthermore, N. ambigua Treadwell, 1937, formerly regarded as a junior synonym of N. riisei by Monro (1933), deserves to be reinstated. Western Africa specimens recorded as N. falsa are newly described as N. mezianei sp. nov.
Highlights
Nereis falsa de Quatrefages, 1866 has been regarded as a cosmopolitan species (Salazar-Vallejo et al 2017)
The widespread confusion regarding what Nereis falsa de Quatrefages, 1866 is can be partially solved if it is regarded as belonging in Hediste Malmgren, 1867, and probably as a junior synonym of H. diversicolor (Müller, 1776)
With the indication of a distinct species in the Black Sea, the name N. falsa would be available for it once it is accepted as a valid species
Summary
Nereis falsa de Quatrefages, 1866 has been regarded as a cosmopolitan species (Salazar-Vallejo et al 2017). It has been indicated that N. falsa might include several distinct species from different localities all over the world (Salazar-Vallejo et al 2017), such that it could be regarded as a species complex. Fauvel was relying on morphological resemblances when accumulating some species group names under N. falsa, but in case differences in some fine diagnostic features are found, the included species cannot be regarded as phylogenetically related. To clarify this problematic group, a revision of type or topotype specimens under a standardized approach, together with an improved understanding of the supposed affinities, might suffice to clarify the differences, if some morphological ones can be noted
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
