Amphicteis Grube, 1850

Genus Amphicteis Grube, 1850 View in CoL

Type species

Amphicteis gunneri ( Sars, 1835) View in CoL as Amphitrite View in CoL

Diagnosis

Prostomium with a pair of dorsal longitudinal ridges and a pair of transverse nuchal grooves. Four pairs of branchiae of variable shape (usually cirriform and sometimes foliaceous or pennate). Branchial ridge usually present and with a pair of nephridial pores. Paleae usually present and well developed; absent in some species. Buccal tentacles smooth. Seventeen thoracic chaetigers and 14 thoracic uncinigers. Thoracic notopodia with distal ventral cirrus. Fifteen to twenty abdominal chaetigers with uncinigerous pinnules and rudimentary notopodia. All thoracic neuropodia of thoracic type; all abdominal neuropodia of abdominal type. Thoracic and abdominal uncini with a single vertical row of teeth of similar size, pygidium with a pair of anal cirri.

Remarks

According to Hartman (1959) and Fauchald (1977), the genus Crossostoma Gosse, 1855 was traditionally considered invalid and a synonym of Amphicteis . However, Hartley (1985:309), when re-establishing the validity of A. midas (Gosse, 1855) , the type species of the genus Crossostoma , recognized the interbranchial region as markedly different to that of the group of species close to the genotype Amphicteis gunneri (compare fig. 1 with fig. 3 in Hartley 1985) and therefore suggested that it was necessary to reconsider the status of Crossostoma . This suggestion has not been adopted in later works ( Hartmann-Schröder, 1996), probably because Hartley’s article was not included in Holthe’s papers (1986a:88; 1986b:56), the latter constituting the reference works on the taxonomy of European Terebellomorpha. Only a revision of the genus in European waters could confirm or deny this possibility.

Jirkov (2001:439) considered characters such as the presence or absence of paleal chaetae, number of pairs of gills and number of thoracic uncinigers as of low taxonomic value in generic discrimination in the family Ampharetidae (see also Jirkov 2008:111). Therefore, Jirkov (2001:407) proposed Phyllamphicteis Augener, 1918 (two of four pairs of branchiae lamellate and originally described with 18 thoracic chaetigers, although re-examination of the holotype revealed only 17), Paramphicteis Caullery, 1944 (no paleae) and Pseudoamphicteis Hutchings, 1977 (papillose buccal tentacles and originally described with two pairs of branchiae but actually possessing four as revealed during re-examination of the paratype in London) as junior synonyms of Amphicteis .