Lissarca notorcadensis ( Bivalvia : Philobryidae ) living on Notocidaris sp . ( Echinoidea : Cidaridae ) : Poptdation dynamics in limited space
نویسندگان
چکیده
Summ~,ry. Popula t ion dynamics of the epizoic bivalve Lissarca notorcadensis living on spines of cidaroid sea urchins in the Weddell Sea were investigated. Total productior~ (somatic & gonad) of the suspension feeding bivalve ranged between 16.5 and 487.4 mg A F D M y 1 per sea urchin. Annual sedimentation rates are not sufficient to mai~:ttain the product ion of the Lissarca sub-populations carried by the sea urchins, and resuspension of organic; matter is mos t likely to be an impor tant food source. The ratio of the number of freshly settled juveniles to the J:umber of embryos b rooded is between 0.054 and 0.207 aad seems negatively related to the biomass already present, indicating intraspecific competi t ion for space. Intersp:.'cific competi t ion for space is caused by the strong preferel:tce of L. notorcadensis as well as other epizoa (coloni:~.l an thozoans and bryozoans) for the spines located on the aboral hemispere of the sea urchins.
منابع مشابه
Clarifying phylogenetic relationships and the evolutionary history of the bivalve order Arcida (Mollusca: Bivalvia: Pteriomorphia).
The systematics of the bivalve order Arcida constitutes an unresolved conundrum in bivalve systematics. The current definition of Arcida encompasses two superfamilies: Limopsoidea, which includes the recent families Philobryidae and Limopsidae, and Arcoidea, which encompasses the families Arcidae, Cucullaeidae, Noetiidae, Glycymerididae and Parallelodontidae. This classification, however, is co...
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