Intertidal and nearshore Nereididae (Annelida) of the Falkland Islands, southwestern Atlantic, including a new species of Gymnonereis

Abstract

The intertidal and nearshore Nereididae of the Falkland Islands are detailed and a new species of Gymnonereis described. The new species, Gymnonereis tenera sp. n., is the first record of the genus for the Falkland Islands. It is, so far, only known from a few intertidal locations in fine and muddy sands. Main distinguishing characters are: jaw teeth absent (in adults), 3 papillae in Area V–VI, falcigers absent, second ventral cirrus present throughout. Nereis atlantica McIntosh, 1885, known only from the description of a single specimen and one doubtful record from the Falkland Islands, is reviewed and transferred to Perinereis on the basis of the presence of shield-shaped bars in Area VI of the proboscis and the absence of notopodial falcigers. A key to all seven species discussed is provided.

Review of some Perinereis Kinberg, 1865 (Annelida: Nereididae) species of Group 2 sensu Hutchings, Reid & Wilson, 1991 from the Eastern and South-eastern Asian seas

“…(1991) have been followed ever since (e.g. Wilson & Glasby, 1993; de León-González & Goethel, 2013; Darbyshire, 2014).…”

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

“…Nevertheless some authors indicate its presence; Read (1980) for Nereis ovarius (Read), Santos and Lana (2003) for Nereis pseudomoniliformis (Santos and Lana), Chambers and Garwood (1992) for Nereis pelagica (and corroborated by us), and Darbyshire (2014) for Nereis eugeniae (Kinberg, 1865). Also, the three species herein described have postchaetal lobes shorter or subequal than neuroacicular ligules, and in epitoke specimens these lobes carry natatory lamellae; therefore, we considered postchaetal lobes as present in Nereis .…”

A new substance to relax polychaete worms (Annelida) prior to morphological study

“…As a result, different substances have been used to facilitate pharynx eversion. The most frequently used substance, mentioned in scientific papers, is 7–8% Magnesium Chloride (MgCl 2 ) in seawater (MgCl 2 .6H 2 O) (Bonyadi and Rahimian 2009; Darbyshire 2014; Fauchald 1977; Williams and Van Syoc 2007), although Rouse and Fauchald (1997) recommend dilution in fresh water. Time to relaxation is at least 30 minutes on small-sized worms.…”