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Paralacydoniidae
Description
The prostomium tapers to a blunt tip and bears a pair of
terminal anterior antennae and a pair of ventral palps; the
antennae and palps are of a similar size.
Irregular scattered brown pigment spots are present on the
prostomium and dorsum; eyes are apparently absent. The
pharynx has a terminal ring of papillae; jaws are absent. The peristomium, reduced dorsally, is present
ventrally as lips around the buccal opening; it lacks cirri or
other appendages. The first segment has neuropodia with
neurochaetae and reduced ventral cirri; notopodia and
notochaetae are lacking. All other segments are biramous, with
widely separated parapodial lobes. Notopodia and neuropodia
have small postchaetal and larger prechaetal lobes, and small
dorsal and ventral cirri, respectively. Neuropodia are longer
than notopodia. Aciculae are present in both parapodial lobes. Notochaetae are capillaries, serrated on one
margin, and neurochaetae are compound
spinigers similarly serrated. The pygidium is
bulbous and has a pair of long cirri.
The above description is taken from Wilson (2000), which is based on Rouse & Fauchald
(1997) together with original observations an Australian specimen.
Identification tips
Recognising the family
Paralacydoniids have a
blunt head with four small appendages and well-developed
parapodia. They are most likely to be confused with either Nephtyidae, or with Glyceridae and Goniadidae. The uniramous first segment and compound neurochaetae distinguishes paralacydoniids from nephtyids. The absence of jaws and the presence of more prominent parapodial lobes separates paralacydoniids from glyceridsand goniadids. Paralacydoniids are not common in benthic samples.
Distinguishing species
Currently only a single genus is known with only two species described.
Description |
Identification tips |
Natural History |
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References |
Identification guide
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