NIWA Guide to Polychaeta | Shore polychaetes | Pick shore group | Pick shore family | Shell polychaetes |
Cossuridae | Family Cossuridae (cossurid)
Scolecida (Annelida: Polychaeta) |
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About Family Cossuridae polychaetes in New Zealand. | ||||
How to recognise the family: | The diagnostic family character of cossurids is a unique single elongate cylindrical filament originating from the mid-dorsal of an anterior segment. The pointed prostomium is followed by one narrow 'segment' without chaetae (regarded as part of the prostomium), and the first chaetiger usually has only one group of chaetae. Chaetae are simple capillaries, finely haired and denser in anterior chaetigers, and there are either no parapodial lobes or they are inconspicuous. Mid-body segments become thicker. The pygidium usually has three slender cirri. Cossurids are slender, deposit-feeding worms, once placed within the Cirratulids but, because they lack palps, are not now regarded as closely related. Most species are very similar. The mid-dorsal filament, long called a tentacle and formerly believed to be a food-gathering organ, is most probably used for respiration rather than feeding. Adult size: To 20 mm length by 0.7 mm wide. | |||
How to recognise the New Zealand genera: | Cossura is the only genus in the family. | |||
Quick pick shore species: | The only known New Zealand Cossura is C. consimilis. Its dorsal filament originates from near the anterior margin of chaetiger three, level with the lateral chaetal groups, and extends for a length of 20 or more segments along the body. The worm has similar dimensions to many small Spionidae and Paraonidae, and co-occurs with them in soft substrata, but the lack of a series of segmental gills and the poor parapodial development singles it out, even when the unpaired filament is lost. C. consimilis is a softshore soft sediment species only. | |||
Possible misidentifications: | None | |||
Distributions, lifestyle, and habitat: | Shallow subtidal to continental shelf throughout New Zealand. Cossura consimilis occurs in soft muds in harbours and estuaries and on the inner continental shelf and out to the continental slope (0-2330 m). | |||
Abundance: | Uncommon to localised moderate abundance. | |||
Taxonomic note: | None | |||
References: | (Fournier & Petersen 1991: p63-80, f1), (Tzetlin 1994: p137-143, f4), (Read 2000: p1096-1110, f1-4) (Full citations at Family pages literature cited list.) |
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Species in the guide: | Rock Species: None for this family. | |||
Sand Species: Cossura consimilis | ||||
Shell Species: None for this family. | ||||
Internet sources: |
GOOGLE Search | AlltheWeb Search | CISTI | CBIF BiOSC Gateway | GOBASE Molecular | GenBank | | |||
Family in Ubio Taxonomic Name Server | PubMed | Scirus | Zoological Record | | ||||
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The information provided by this page and by the pages of the "more information" links is held in a structured form for rapid and frequent updating and improvement. Descriptive text is compiled from a number of database fields, some of which may occasionally be empty. Last modified by G. Read, 25/07/2004 (dd/mm/yy) |