Intrahost distribution and trasmission of a new species of cyclopoid copepod endosymbiotic to a freshwater snail, Pomacea canaliculata (Caenogastropoda, Ampullariidae) from Argentina.

Gamarra-Luques CD, Vega IA, Koch E, Castro-Vazquez A.

Laboratory of Physiology (IHEM-CONICET), Department of Morphology and Physiology, School of Medicine, University of Cuyo, Casilla de Correo 33, M5500 Mendoza, Argentina.



A new species of cyclopoid copepod, Ozmana huarpium, is described as a symbiont to Pomacea canaliculata (Lamarck 1822) (Caenogastropoda, Ampullariidae). Rather large numbers (about one hundred copepods per snail) were found, although there was no evidence of harm to the host. To our knowledge, O. haemophila (symbiont to P. maculata), and the currently described species, O. huarpium, are the only copepod species ever recorded as endosymbionts to freshwater invertebrates. While O. haemophila is restricted to the haemocoel of its host, O. huarpium predominate in the penis sheath, the ctenidium and the mantle cavity, figuring in these pallial organs 63-65% of total mature forms. The sex ratio of the symbiont is skewed to the female side in these organs, specially in male hosts. The hypothesis that a special female tropism for the male host's pallial organs might ensure interindividual transmission of the symbiont was tested, with indications that the symbiont is mainly transmitted during copulation.

Biocell. 2004 Aug;28(2):155-64.

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