Spawn, diet and imposex phenomenon in the zigzag volutid Odontocymbiola magellanica (Gmelin, 1791) (Mollusca: Gastropoda) in Golfo Nuevo, Patagonia, Argentina.

GREGORIO BIGATTI & PABLO E. PENCHASZADEH.

Vigo, ESPAÑA

Congreso; II CONGRESO de las SOCIEDADES MALACOLOGICAS EUROPEAS; 2002

Odontocymbiola magellanica is a volutid snail from Patagonian shallow waters. Itis a volutid snail from Patagonian shallow waters. It has a high economic potential as a natural resource. Two years of sampling by scuba diving in depths of 6-10 m were performed between 2000/2002 in Golfo Nuevo in order .. to study the spawning seasons, diet and the imposex occurrence. 0. magellanica females spawn white, spherical, calcareous egg capsules attached to small rocks and hard flat surfaces from July to November. Egg capsules in different stages of embryos development were found in the field from July to January. External calcium layer of the egg capsule is presumably secreted by a calcareous gland in the snail's foot.magellanica females spawn white, spherical, calcareous egg capsules attached to small rocks and hard flat surfaces from July to November. Egg capsules in different stages of embryos development were found in the field from July to January. External calcium layer of the egg capsule is presumably secreted by a calcareous gland in the snail's foot. Odontocymbiola magellanica is a specialized predator on several bivalves, notably the veneridae Venus antiqua and Eurhomalea exalbida in depths of 6-10m. Other bivalves eaten are Aulacomya ater and Chlamys madrynensis. Gastropods represent lower relevance and the most common are Tegula patagonica, Natica isabelleana and Trophon geversianus. I n a single case we found cannibalism (a large 0. magellanica eating ais a specialized predator on several bivalves, notably the veneridae Venus antiqua and Eurhomalea exalbida in depths of 6-10m. Other bivalves eaten are Aulacomya ater and Chlamys madrynensis. Gastropods represent lower relevance and the most common are Tegula patagonica, Natica isabelleana and Trophon geversianus. I n a single case we found cannibalism (a large 0. magellanica eating aVenus antiqua and Eurhomalea exalbida in depths of 6-10m. Other bivalves eaten are Aulacomya ater and Chlamys madrynensis. Gastropods represent lower relevance and the most common are Tegula patagonica, Natica isabelleana and Trophon geversianus. I n a single case we found cannibalism (a large 0. magellanica eating aAulacomya ater and Chlamys madrynensis. Gastropods represent lower relevance and the most common are Tegula patagonica, Natica isabelleana and Trophon geversianus. I n a single case we found cannibalism (a large 0. magellanica eating aTegula patagonica, Natica isabelleana and Trophon geversianus. I n a single case we found cannibalism (a large 0. magellanica eating aI n a single case we found cannibalism (a large 0. magellanica eating a smaller individual of the same species)