Parasitic castration of a marine snail by larval trematodes.

ALDA, MARIA DEL PILAR; MARTORELLI SERGIO R

Buenos Aires

Congreso; 45th. Annual Meeting of the Society for Invertebrate Pathology- International Congress on Invertebrate Pathology; 2012

Society for Invertebrate Pathology

In a two year survey, we collected and dissected 7,504 specimens of Heleobia australis(Mollusca: Cochliopidae) from Bahía Blanca estuary, Argentina. We fixed some infected specimens in Bouin?s fluid and used standard histological techniques to locate the site of infection of larval trematodes within the snail.The remaining individualswere necropsied to sexthehost(bythepresenceofpenisinmales),classifyfemales inmatureorimmature(bythepresenceorabsenceofoocytes), and examine the presence of parasites.We found40% of the snails infected with 15 species of trematodes: Microphallidae (4), Echinostomatidae (2), Lepocreadioidea (1), Heterophyidae (1),Cryptogonimidae(1),Psilostomidae(1),Sanguinicolidae(1), Notocotylidae (1),Haploporidae (1),Renicolidae (1),andother (1).Microphallussimillimus,amicrophallidwithanabbreviated life cycle,was the most prevalent trematode(32%).Except for the sporocyst sof Renicola sp.that grow thin the mantle tissues and a metacercaria of an undetermined family that encyst in the head of snails, we found that all the parasites were occupying the digestive gland and the gonad of snails. Females were more abundant and infected than males and infected mature females were fewer than uninfected mature females. We suggest that parasites could be affecting the development of the penis in males or causing higher mortalities in males than in females. Our results allow us to support the idea that larval trematodes consume the host energy for their own reproduction, blocking host reproduction.