Family SPINTHERIDAE

Spinther sp.

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Family SPINTHERIDAE

Compiler and date details

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

7 August 2003

Introduction

Spintherids are either ectoparasites feeding directly on the sponge or feed commensally on the epibionts associated with the host. They attach themselves using their strongly curved compound neurochaetae. Some species have been reported as living on hydrozoans. Spintherids are inconspicuous as they are the same colour as their host. They are characterised by their distinctive oval shaped flattened body, the absence of dorsal cirri and long transverse notopodial ridges which carry spines.

Figures of 1 genus and 1 species were given by Beesley et al. (2000: App. 1) for representation of the family in Australian waters, and 1 genus and 12 species worldwide.

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

Database Notes

proof read against Day & Hutchings 1979 by RW; no subsequent records added
checked against DELTA CD, 2003 by RTJ

Diagnosis

General features. Body shape ovate to rounded; 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; level with or posterior to the first segment. Prostomium rounded to oval (anteriorly truncate). Eyes absent, or present; two pairs; situated on prostomium; without lenses. Prostomial antennae present; single arising anteromedially; smooth. Palps absent. Nuchal organs absent. Peristomial ring absent.
Pharynx & pharyngeal apparatus. Foregut a ventral pharyngeal organ.
Body segments & parapodia. First segment chaetigerous. First chaetiger with both notochaetae and neurochaetae; anteriorly directed and wrapping around head. Parapodia biramous with prominent parapodial lobes; notopodial lobes long dorsal ridges; neuropodial lobes represented by at least one chaetal lobe. Dorsal cirri absent. Ventral cirri absent. Branchiae absent.
Chaetae. Notochaetae present. Aciculae present; in ventral position (=neuroaciculae). Capillary chaetae absent. Spines present in most or all chaetigers; in notopodia only; slightly curved and more-or-less smooth (bifid distally). Hooks absent. Compound chaetae present; appendage distally curved (=falcate); appendage not canaliculated; appendage without hoods or guards; joint more-or-less symmetrical (=homogomph; includes also hemigomph and sesquigomph); joint effected by fold in external sheath of chaeta; shaft tapering slightly or evenly thick from emergence to joint; shaft without distinct core. Compound falcigers present in most or all chaetigers.

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)