Family TRICHOBRANCHIDAE

Trichobranchidae

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Family TRICHOBRANCHIDAE

Compiler and date details

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

8 August 2003

Introduction

Trichobranchids inhabit soft sediments from shallow water to depths of 2700 m; they may be more common in deep and cold waters. In Australia they are common in inshore waters and on the shelf; they may be locally abundant in benthic samples. All trichobranchids are thought to be non-selective deposit-feeders. Trichobranchids tend to have a relatively short, compact body with an extended tentacular membrane and numerous buccal tentacles of two types. Branchiae range from simple filaments to rosettes to a single stout stalk bearing two to five lamellate lobes.

Figures of 4 genera and 10 species were given by Beesley et al. (2000: App. 1) for representation of the family in Australian waters, and 5 genera and 30+ species worldwide.

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

Database Notes

checked against CD, 2003 by RTJ

Diagnosis

General features. Body shape vermiform; segments numerous (more than about 15); segments similar dimensions throughout; regionation present, comprising distinct thorax and abdomen; regions demarcated by absence of abdominal notopodia. Glandular ventral shields absent. Pygidium simple ring or cone. Pygidial appendages absent.
Head & head structures. Head bearing many tentacles (=oral filaments) around mouth. Prostomium projects as a tentacular membrane. Eyes absent. Oral filaments present; arise outside on membrane above mouth. Palps absent. Nuchal organs indistinct paired dorsolateral patches. Peristomial ring absent.
Pharynx & pharyngeal apparatus. Foregut a ventral pharyngeal organ; dorsolateral ciliated folds present (?).
Body segments & parapodia. First segment a smooth ring. First chaetiger with notochaetae only. Parapodia biramous with prominent parapodial lobes; notopodial lobes represented by at least one chaetal lobe; neuropodial lobes low ridges (tori) (over most of body). Dorsal cirri absent. Ventral cirri absent. Branchiae absent, or present; arise from dorsum; occur only on achaetous first segments, or occur on at least some chaetigerous segments; filiform, or lamellate.
Chaetae. Notochaetae present. Aciculae absent. Capillary chaetae hair-like; smooth. Spines absent, or present only in one or a few anterior chaetigers; in neuropodia only; sharply bent (=geniculate) or curved. Hooks present; unprotected; occur in thoracic neuropodia only. Uncini present (abdominal neuropodia); with teeth arranged in transverse series above an enlarged main fang (=crested); arranged in one or two rows.
Tube & burrow. Tube membraneous.

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)