Synelmis Chamberlin 1919

Genus Synelmis Chamberlin, 1919

Synelmis Chamberlin, 1919: 177.

Kynephorus Ehlers, 1920: 27.

TYPE SPECIES. — Synelmis simplex Chamberlin, 1919, by original designation. It is a subjective junior synonym of Ancistrosyllis rigida Fauvel, 1919 (see below).

DIAGNOSIS. — Synelminae with three cirriform or fusiform antennae, palps biarticulated with a small ventral papilla associated with palpostyle, eyes lensed, as a single pair, multiple eyes in a row or missing. Two pairs of cirriform or fusiform tentacular cirri. Parapodia with notopodia reduced to dorsal cirri; neuropodia with setal lobe variously developed and ventral cirri in all setigers. Emergent notospines straight, with acute tips. Neurosetae include simple, limbate (laterally spinulose), and furcate setae; without emergent neurospines. Pygidium without anal plate; with two lateral anal cirri. Eversible pharynx without papillae or denticles. Digestive tract straight, without segmental diverticula.

REMARKS

Licher & Westheide (1994: 233) included three traits to define Synelmis, but the only potential autapomorphy is the presence of furcate setae. In fact, they may be homologous to the emergent neurospines that would be, in turn, the autapomorphy for Litocorsa Pearson, 1970; these observations were already done by Fitzhugh & Wolf (1990: 12, 13). However, it should be remembered that furcate setae are both transparent and brittle. Five previous records cannot be accounted for in the key below. Rullier (1963: 181, 182) recorded one specimen of A. rigida, 3 mm in length, from the Marmara Sea; he did not provide specific features or information on where he deposited his specimen. Hartman (1965: 70) recorded A. albini from deep-water in the northwestern Atlantic, and indicated the lack of eyes and the start of notospines in setigers 10- 12. Day (1967: 215) indicated that his specimens of A. rigida have emergent notospines beginning in setigers 12-20 but he failed to detail the position of antennae and the shape of parapodial cirri. Hartman & Fauchald (1971: 51) recorded six other specimens from deepwater in the northwestern Atlantic but without any other data. The record of Synelmis albini which Day (1973) made for North Carolina was re-examined by Gardiner (1976) who found some neuraciculae projecting beyond the setal lobes; this damaged specimen has been examined (USNM 51030) and it resembles Litocorsa antennata Wolf, 1986.

Synelmis albini (Langerhans, 1881) Ancistrosyllis albini Langerhans, 1881: 107, 108, fig. 16a-e.

Synelmis albini – Pettibone 1966: 191. — Glasby 2003: 9-12, fig. 1.

MATERIAL EXAMINED. — Central eastern Atlantic. Canary Islands, Tenerife, La Tejita, mesolitoral, in algae, 4.IV.1976, J. Núñez, 1 posterior fragment with 72 setigers, 14 mm in length, 0.7 mm in width (MCN-PO-178).

DISTRIBUTION. — Kirkegaard (1988: 75) indicated that the species is present in western Africa and, following Pettibone (1966), in the Indian and Pacific oceans. As will be seen below, specimens from these areas have been found to belong to different species. Therefore, S. albini must be regarded as restricted to the eastern subtropical Atlantic Ocean.

REMARKS

Langerhans (1881) described S. albini from a single anterior fragment which was probably alive when he observed it, Augener (1927) noticed this and was later cited by Pettibone (1966), who also suggested that differences between this and other species could be attributed to the effects of preservation. The structures that Langerhans drew could only be seen in living organisms, particularly the elongation of palps, shape of the brain and its posterior lobes (Langerhans 1881: fig. 16a), the transition between stomodeum and muscular tube, and the variation in the width of the latter (Langerhans 1881: fig. 16e). Body transparency might also explain the specific name since one of its acceptions is clear or without color (“farblos” in the description). There is not original type material left; the type locality seems to be Puerto de la Orotava, northern Tenerife, in rocky intertidal bottoms (Langerhans 1881: 95). Recently, Glasby (2003) redescribed the species and proposed a neotype.