Family SIGALIONIDAE

Sigalionidae

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Family SIGALIONIDAE

Scale Worm

Compiler and date details

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

7 August 2003

Introduction

Sigalionids are found throughout the globe in soft sediments, from estuaries and fully marine intertidal zones to the deep sea. However, they are not often abundant in benthic samples. Sigalionids are presumed to be predators, using their jaws to capture prey. However, one species has been found to consume detritus, and few studies have documented sigalionid feeding. Sigalionids are also referred to as scale-worms. However, they have much longer bodies than polynoids. The dorsum of sigalionids is covered to a varying extent by elytra; in some species the elytra are covered in sand grains. They have a well-developed head with many appendages, numerous segments and well-developed parapodia and chaetae.

Figures of 10 genera and 20 species were given by Beesley et al. (2000: App. 1) for representation of the family in Australian waters, and 18 genera and 180 species worldwide. This database includes 18 species from 8 genera. Hutchings & McRae have a revision of selected genera of the Sigalionidae from Australia in press. In this paper 12 new species are described, but as this paper has not been published as of August 2003, these new species have not been included.

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

Database Notes

Hutchings & McRae have a revision of selected genera of the Sigalionidae from Australia in press. In this paper 12 new species are described, but as this paper has not been published as of Aug 2003, these new species have not been included.
checked against DELTA CD, 2003 by RTJ

Diagnosis

General features. Body shape vermiform; not 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). Facial tubercle present. Eyes absent, or present; two pairs; situated on prostomium; compound with lenses. Prostomial antennae present; include paired anterolateral ones and single medial one; smooth (though median one may have lateral auricles at base). Palps paired; unarticulated; ventrolateral. Nuchal organs absent. Peristomial ring absent.
Pharynx & pharyngeal apparatus. Foregut a muscular axial pharynx; with two pairs of jaws; fang-like; distal ring of papillae present.
Body segments & parapodia. First segment chaetigerous (dorsal and ventral cirri enlarged and elongated). First chaetiger with notochaetae only; 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. 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 present; arise from parapodia (on elytrophores or dorsal tubercles); occur on at least some chaetigerous segments; digitiform.
Chaetae. Notochaetae present. Aciculae present; in both dorsal and ventral positions (=noto- and neuroaciculae). Capillary chaetae hair-like; spinose, or corn-eared. Spines absent. Hooks absent. Compound chaetae present; appendage distally tapering to slender tips (=spinigerous), or distally curved (=falcate); appendage not canaliculated, or canaliculated; appendage without hoods or guards; joint distinctly asymmetrical (=heterogomph), or flat or pseudocompound; joint effected by ligament(s); shaft tapering slightly or evenly thick from emergence to joint; shaft without distinct core. Compound falcigers present in most or all chaetigers.
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.'
(See ABRS website: Online Resources: Polikey, for Version 2, released June 2003)