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Sabellidae
Description
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Prostomium fused to peristomium and forming a prostomial branchial crown. Peristomium ring shaped; usually with an anterior collar and an anteriorly projecting section around terminal mouth. Anterior appendages brachial crown and extensions of dorsal loops. Nuchal organs present. Longitudinal muscles grouped in bundles; segmentation distinct. First segment similar to next following segment; but with notopodial chaetae only. Parapodia biramous; anterior notopodia cylincrical or tapering and anterior neuropodia tori; posterior notopodia tori and posterior neuropodia short cylinders. Dorsal and ventral cirri absent. Gills, epidermal papillae and pygidial cirri absent. Lateral organ and dorsal cirrus organs not observed. Stomodaeum without buccal organ. Gular membrane absent; gut a straight tube. Segmental organs mixonephridia; first pair excretory, posterior ones gonoducts. Circulatory system closed; heart body absent. Aciculae absent; chaetal inversion present. Chaetae variously modified capillaries, dentate hooks without hoods and uncini.
The above description is taken from Fauchald & Rouse 1997.
Identification tips
Recognising the family
Sabellids are most likely to be confused with the Serpulidae which also have a tentacular crown of pinnate feeding tentacles. The mucous/sediment tube constructed by sabellids easily distinguishes them from Serpulidae, which have hard calcareous tubes. [Calcisabella piloseta Perkins 1991 is apparently unique among sabellids in constructing a tube of calcareous matrix with sediment particles incorporated.] The absence of a thoracic membrane (which is always present in Serpulidae) immediately distinguishes members of the Sabellidae.
Distinguishing species
Important characters are the type of thoracic neurochetae present, the degree of fusion of branchial radioles and their ornamentation and numbers of pairs present. The structure of notochaetae is also important. Considerable differences may occur between thoracic and abdominal chaetae.
Description | Identification
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