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Aphroditidae
Description
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The prostomium in Aphroditidae is a frontally rounded double lobe, and the
peristomium is reduced to lips around the mouth. A median
antenna is present; lateral antennae are absent.
A facial tubercle is prominent in most taxa. Ventral, tapering,
unarticulated palps are present; they are fused to the anterior
surface of the first pair of parapodia. Nuchal organs are
present. Longitudinal muscles are present in
four bundles; segmentation is distinct. The first
segment is curved around the prostomium and has parapodia
which are similar to those of other body segments. Two pairs of tentacular cirri are present. The
notopodia are always shorter than the neuropodia. Either
dorsal cirri or elytra are on segments throughout; ventral cirri
are present. Elytra are absent in Palmyra. Simple papillae are present on the venter and
parapodia in many taxa. Pygidial cirri have been interpreted as being either present or absent Fauchald & Rouse (1997).
Lateral organs and dorsal cirrus organs have not been
observed. The buccal organ is an eversible muscular axial
pharynx with two pairs of dorso-ventrally arranged jaws
which are poorly developed in some species;
terminal pharyngeal papillae are present. The gular membrane
is absent, and the gut has paired side-branches (caeca) in most
segments. The segmental organs, mixonephridia, are present
in most segments. The circulatory system is closed and the heart body
absent. Aciculae are present. Chaetae are variously
ornamented capillaries and spines.
Notochaetae are spines, capillaries and fine silky fibres,
which form a dorsal felt in many taxa. The silky fibres are
produced by spinning glands.
The above description is based on Hutchings (2000), which in turn is based on Fauchald & Rouse (1997).
Identification tips
Aphroditids are typically large compact bodied worms with iridescent chaetae covering the dorsum, parapodia are not conspicuous from the dorsal surface and neither is segmentation.
Recognising the family
Aphroditids are distinctive, and their short, often ovoid body with felt-like dorsal surface made up of fine, silky, often iridescent chaetae is unlike any other polychaete family. Sometimes sediment is trapped among the chaetae.
Aphroditids are most likely to be confused with one of the other families that also have dorsal rows of scales. The quick guide to scale worms should help separate these 6 families.
Distinguishing species
Complete individuals are required and the head structures must be intact, juvenile specimens cannot be reliably identified as they adult chaetal structures. Species are distinguished by the development of the elytra and the dorsal felt; number of pairs of elytra varies between genera (and, in Laetmonice, between species). The structure of the median antenna is a useful character, as are the presence or absence of nuchal flaps and the development of ocular peduncles or raised ocular areas. The structure of the chaetae and their arrangement along the body is also useful in distinguishing species.
Description | Identification
tips | Natural History | Diversity
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