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Dorvilleidae
Description
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The prostomium is
generally rounded and has a pair of ventro-lateral, simple to
biarticulated palps and a pair of dorsal, simple or articulated
antennae; both palps and antennae may be
absent. Eyes are present or absent. The peristomium is a
single ring or is subdivided into two rings.
The parapodia are usually sub-biramous); the
notopodium is represented only by a simple to biarticulated
dorsal cirrus with or without an embedded acicula.
Secondarily, the parapodia may be uniramous or absent.
Branchiae are occasionally present. Neuropodia bear typically
supra-acicular simple and furcate chaetae, and subacicular compound falcigers
and/or spinigers. However, some or all chaetal
types may be absent and the inferiormost chaetae may be
simple. Ventral cirri may be present or absent. Pygidial cirri
number two or four, may be absent, or may include an
unpaired pygidial stylus. Dorvilleids, particularly the smaller
species, are often ciliated in the form of ciliary bands around
the prostomium, peristomial rings and trunk segments.
The mandibles are unfused and the maxillae are
not mineralised; both may be reduced or absent. Typically,
maxillae consist of carriers, and paired superior and inferior
basal plates with numerous anterior free denticles. Supplementary rows of spinous denticles may
also be present.
The above description is based on Paxton (2000), which in turn is based on Fauchald & Rouse (1997).
Identification tips
Recognising the family
Representatives of this family range from small interstitial forms to large animals. The arrangement of the antennae is characteristic and the structure of the jaws, with multiple maxillary denticles, is unique to the family. It is the structure of the jaws and the parapodia which are used to separate this family from other members of the Eunicida, although interstitial and symbiotic or parasitic species exhibit varying degrees of loss or reduction of the jaws and parapodia.
Distinguishing species
In benthic samples the two best represented genera are Dorvillea and Schistomeringos which can be distinguished by the presence or absence of furcate chaetae, which are absent in Dorvillea and present in Schistomeringos. The distribution of dorsal cirri, form of the parapodial lobes and ratios of tine lengths of forked chaetae are used to distinguish species.
Description | Identification
tips | Natural History | Diversity
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