Family EULEPETHIDAE Chamberlin, 1919

Grubeulepis geayi

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Family EULEPETHIDAE Chamberlin, 1919

Scale Worm

Compiler and date details

Jan 2011 - P. Hutchings & M. Yerman, Australian Museum, Sydney, New South Wales, Australia

Eulepinidae Darboux, J.G. 1900. Recherches sur les Aphroditiens. Bulletin Scientifique de la France et de la Belgique 33: 1-274.
Pareulepidae Hartman, O. 1939. Polychaetous annelids. Part I. Aphroditidae to Pisionidae. Allan Hancock Pacific Expeditions 7: 1-154.

Introduction

Eulepethids are long-bodied scale worms which burrow in soft sediments; they have robust bodies which are nearly quadrangular in cross section. Eulepethids can be distinguished from other scale-worms by the characteristic neuropodia which are truncate distally supported by narrow, sclerotinised ridges. The neuroaciculae of eulepethids are also unique: they are elongated, and are shaped like an axehead or hammer.They have simple chaetae exclusively, hence resemble the polynoids, acoetids and aphroditids.

Eulepethids are known from coastal regions of the Pacific, Indian and Atlantic oceans but mainly from equatorial latitudes. The most northerly record is from Japan, and the most southern record is from southeastern Australia. Eulepethids also have restricted bathymetric distributions: only four species have maximum depths in the range 400-800 m, the remainder occurring at depths of 80 m or shallower. Six genera and 21 species occur word-wide. Four species, and four of the six known genera of Eulepethidae are now known from Australian waters.

See Hutchings (2000) for detailed treatment of the family.

Diagnosis

General features. Body shape vermiform; dorsoventrally flattened; segments numerous (more than about 15); regionation absent. Pygidium simple ring or cone. Pygidial appendages present; one pair of cirri.
Head & head structures. Head discrete and compact, dorsal to mouth. Prostomium rounded to oval (anteriorly truncate). Eyes present; two pairs; situated on prostomium; compound with lenses. Prostomial antennae present; include paired anterolateral ones and single medial one; consist of basal ceratophore and distal ceratostyle. Palps paired; unarticulated; ventrolateral. Nuchal organs club-shaped. Peristomial ring absent.
Pharynx & pharyngeal apparatus. Foregut a muscular axial pharynx; with two pairs of jaws; plate-like; distal ring of papillae present.
Body segments & parapodia. First segment chaetigerous (dorsal and ventral cirri enlarged and elongated). First chaetiger with neurochaetae only, or with both notochaetae and neurochaetae; anteriorly directed and wrapping around head. Parapodia biramous with prominent parapodial lobes; notopodial lobes represented by at least one chaetal lobe; neuropodial lobes represented by at least one chaetal lobe (very wide, distally truncate with distal edges supported by narrow sclerotinised ridges). Dorsal cirri modified as elytra (may include cirriform ones as well). Elytra smooth or ornamented, without concentric rings; occur on alternate chaetigers anteriorly, present on all chaetigers or absent posteriorly. Ventral cirri present, cirriform or tapering. Branchiae absent, or present; arise from dorsum; occur on at least some chaetigerous segments; digitiform.
Chaetae. Notochaetae present. Aciculae present; in both dorsal and ventral positions (=noto- and neuroaciculae). Neuroaciculae with elongated, axehead-shaped distal structure. Capillary chaetae hair-like; smooth, or spinose. Spines present in most or all chaetigers; in both notopodia and neuropodia; sharply bent (=geniculate) or curved. Hooks absent.
Tube & burrow. Tube absent or unconsolidated. Burrow traces absent.

The above description was generated from: 'C.J. Glasby & K. Fauchald (2002 onwards). POLiKEY. An information system for polychaete families and higher taxa: Version 1: September 2002.'