Detección de parásitos protozoarios y hermintos en el molusco bivalvo Geukensia demissa (Dillwyn, 1817) presente en el sector de Nararét del Municipio Mara, Estado Zulia, Venezuela

in order to detect protozoa and metazoa parasites in geukensia demissa, a mitilido that has invaded the main estuarine of venezuela (maracaibo lake) and which has a high aquaculture potential, there were collected four hundred live microorganisms in the nazareth community of the mara municipality, zulia state, venezuela. the collection was done during two seasons of the year, dry (january to may) and rainy (june to october). the microorganisms were subjected to a dissection for the extraction of the intestine tube, as well as the gonads, siphons and gills tissues. the parasitological study was done by microscopy examinations of the intestinal content using a temporary dye of lugol and fixed dyes of ferric hematoxiline and kinyoun. the tissues were evaluated histological with the dye of hematoxiline-eosine. from the total amount of mussels collected 42% were parasitized in the intestinal content, with species of clinical concern for the human being like the following protozoa: complex entamoeba histolytica/dispar, entamoeba coli, entamoeba hartmanni, giardia lamblia, iodamoeba spp., blastocystis spp. and cryptosporidium spp. the cystic stage was dominant in those species. strongyloides stercoralis was recovered among the helminths. in regard to the season of the year, it was observed a higher presence of parasites in mussels collected during the dry season (50%) while in the rainy season was 34%. the species entamoeba histolytica/dispar and entamoeba coli were the most abundant, 45 and 30% (dry season) and 26% and 19% (rainy season), respectively. the presence of these parasites responsible for some gastrointestinal illness in a fish product with a high demand represents a warning for the governmental entities about its pathogenic potential and a worry for its sanitary control.