Scallop-Holoturian Relationship in the Middle-Deep (100m) Argentinian Shelf (Zygochlamys patagonioca and Psolus patagonicus)

PABLO E. PENCHASZADEH Y JULIANA GIMÉNEZ

St. Petersburg, Florida. USA

Workshop; 14Th Internacional Pectinid Workshop.; 2003

Psolus patagonicrrs (Ekrnan 1925) is an abundant holothuroid, living only on the top shell of live Zjgochlamyspatagonica (King and Broderip 1832), in depths of 100-1 10m off the Province of Bucnos Aircs, Argentina, among other invertebrates such as Foraminifera, Sponges, Anthozoans, Bryozoans, Ophiurans. Polychacts, Cirripcdians, bised Bivalvia and Gastropoda. Claractcristically thc family Psolidae have a flattened sole they utilize to attach to hard substrata and an armored dorsum of large calcareous plates. McEuen (1986) and McEuen and Chia (199 1) have summarized most published information on the biology and particularly the reproduction and development of members of the family. Of the approximately 85 species contained in the Psolidae (Pawson 1982) there now exists.at least partial information on the development of 15 species, and 11 species of the 15 are believed to be brooders, but only three are properly documented (McEuen & Chia 1991). There are several types of brooding described in Psolidae: coelomic, in dorsal depressions, in folds of sole, under the sole, in 5 interradial pouches, in chambers underneath dorsal plates, in interradial pouches surrounding the tentacular crown. Psolus patagoniclts incubates the eggs and embryos under the body, between thc sole and the ZigochIamys shell; the complcte development process takes seven months. The smallest recorded incubating female was 17 mm in length and the maximum size recorded was 23 mm. The setting of the eggs under the sole is realized in the months of February - March (uncleaved egg)