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Identification guide



The number of segments varies from about 10 to more than 50, with mature individuals of many species having a fixed number of segments. The first and/or last few segments are often shorter than the middle ones. The body surface is smooth and shiny, or minutely papillated resulting in a rugose or dull appearance. Prostomium small, of variable shape (square, subglobular, pyriform), which may be medially invaginated, and is usually retracted between the first chaetiger; eyespots are rarely present. A pair of large ciliated nuchal organs lie dorso-laterally on the posterior prostomium. The peristomium is a single annulus and includes ventrally a pair of lateral lips (sometimes also a ventral lip) around the mouth. Fauchald & Rouse (1997) interpreted these as palps, but other studies suggest that palps are absent (Hartman 1978; Riser 1987). Rouse & Pleijel (2001) suggest that there is little evidence to support this and larval studies are needed to establish the true nature of the head. The pharynx is looped dorso-ventrally from the mouth to the septum of chaetiger 2/3 (resembles a ventral buccal organ) and opens to a ventral mouth; the gut is ciliated throughout its length and lacks a sphincter. Parapodia are biramous, with low papillate rami; the interramal papillae vary in size and shape (conical, subspherical, clavate) between species. Few simple chaetae are present in each rami, including spines (which may be more or less curved) and longer capillary chaetae. The thickness of both the spines and capillaries typically varies slightly along the body, and intermediate forms are sometimes present. Chaetal spines of the last parapodium sometimes form a cage around the pygidium. The pygidium is terminal and may be surrounded by papillate anal cirri and/or may be retracted within the last few segments.

The above description is based on Glasby (2000), which in turn is based on Fauchald & Rouse (1997).

Identification tips

Recognising the family
Fauveliopsids are small, grub-like worms which are characterised by the presence of inter-ramal papillae in each parapodium. Some members of the Flabelligeridae also have interramal papillae, but flabelligerids only have spines in neuropodia, whereas fauveliopsids have spines in both notopodia and neuropodia.

Distinguishing species
Two distinct morphs occur in the family. Some fauveliopsids are short-bodied, cylindrical, indistinctly segmented, truncate at each end, and preserved specimens are usually stiff and arched dorsally. The other body form in fauveliopsids is longer, inflated anteriorly and/or posteriorly and with more distinct segmentation.


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