Eclysippe Eliason, 1955

Reuscher, Michael G. & Fiege, Dieter, 2016, Ampharetidae (Annelida: Polychaeta) from cold seeps off Pakistan and hydrothermal vents off Taiwan, with the description of three new species, Zootaxa 4139 (2), pp. 197-208 : 200-201

Eclysippe Eliason, 1955

Type species: Lysippe vanelli Fauvel, 1936

Generic diagnosis. Prostomium without glandular ridges. Buccal tentacles smooth. Three pairs of cirriform branchiae. Notochaetae of segment II enlarged as paleae. Twelve thoracic uncinigers. Posterior thoracic uncinigers strongly elongated. Two intermediate uncinigers. Abdominal rudimentary notopodia absent.

Remarks. Curiously, both valid species of the genus, Eclysippe vanelli ( Fauvel, 1936) and E. trilobata ( Hartman, 1969) were originally described with four pairs of branchiae. Eliason (1955) accredited Fauvel’s diagnosis to a misinterpretation of notopodia as bases of the fourth pair of broken branchiae and redescribed the species Lysippe vanelli in the new genus Eclysippe Eliason, 1955 . This new diagnosis of E. vanelli has been widely accepted (e.g. Holthe 1986; Hilbig 2000). E. trilobata , described as Anobothrus by Hartman (1969), was redescribed with three pairs of branchiae by Williams (1987) upon examination of the type specimens and assigned to Eclysippe .

Day (1973) argued that specimens of E. vanelli described by Eliason (1955) were different from specimens reported by Fauvel (1936) and subsequently described a new species, Samythella eliasoni Day, 1973 from North Carolina, which, according to Day, was identical to the Swedish E. vanelli specimens described by Eliason (1955). However, he assigned the species to Samythella because of the uncertainty in the number of branchiae in Eclysippe (see discussion above) and because it fit into the generic diagnosis of Samythella according to his opinion. We do not follow Day’s opinion because the latter genus lacks the elongation of posterior thoracic uncinigers that is characteristic for Eclysippe . Furthermore, Samythella has broad, foliaceus branchiae, whereas Eclysippe has thin cylindrical branchiae. In his description of S. eliasoni Day did not mention the elongation of posterior thoracic uncinigers, which is the most conspicuous character of Eclysippe . Therefore, the generic affiliation of S. eliasoni is uncertain. Day (1963) described another species, Samythella affinis Day, 1963 that bears some resemblance to Eclysippe , even though Day did not mention the elongated posterior thoracic uncinigers and acknowledged that the generic affiliation of this species was uncertain.