Abstract

PRIETO, Antulio; MARCANO, Jesús; VILLEGAS, Liz  and  LODEIROS, César. Population structure of the clam, Asaphis defl orata, in Caurantica, gulf of Paria, Sucre state, Venezuela. Zootecnia Trop. [online]. 2008, vol.26, n.1, pp.55-62. ISSN 0798-7269.

Populations structure and bioecological aspects of the bivalve Asaphis defl orata were evaluated in locality ofCaurantica, northeasthern of Guiria, Gulf of Paria, Sucre state, Venezuela. Samples were collected monthly fromMarch 2005 until February 2006, using a stratifi ed random sampling with a quadrate of 0.25 m2. During sampling water temperature and salinity were measured. In order to test the spatial dispersion, the area was divided into 3 zones parallel to the coast and 4 fringes perpendicular to it, according to the topographical characteristicsof the substrate. The population presented a length interval from 10 until 74 mm, with a predominance of the lengths between 48-54 mm, although since September 2005 there were organisms with lengths smaller than 26 mm incorporated into the population. A aggregated microespatial dispersion was observed in each zone, with an increase of the length of bivalves from of the zone of low to one high tide. Relationships between morphometricparameters were highly signifi cative and length (Lt)-total mass (TM) relationship was represented by the equationTM = 0.0003*Lt2.806 (r²= 0.93). Average biomass and density were 400.33 g/m² and 69.33 ind/m². The biomass presented maximum values in the zone of low tide, whereas the maximum density was observed in zone of high tide. There were not detected signifi cant differences in average biomass and  density among zones, but amongfringes. Condition factor presented its maximum value in May 2005 (36.6%) and minimum in August 2005 (28.8%) 2005. We suggest that salinity variation in the region has infl uence on the physiological condition of the species.

Keywords : Asaphis defl orata; abundance; Caurantica; Gulf of Paria; Venezuela.

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