Shell composition of Zygochlamys patagonica (King & Broderip, 1832) along a latitudinal gradient.

ZELAYA D.; SCHEJTER L.

Coquimbo, Chile

Workshop; 13th. International Pectinid Workshop; 2001

The objective of this work is to compare the microstructure in valves of Z. patagonica, analizing not only the latitudinal variation, but also the variation between different size ranges. The existence of a latitudinal gradient in the conquiliological composition is also discussed. Scallops of different size ranges from Reclutas bed (39ºS- 55º56’W), Ushuaia and San José and San Jorge Gulfs were studied. Cuts of the left (upper) valve separated 1 cm from the edge were studied and pictured under scanning electronic microscope. Three different calcium carbonate layers were always found, while the thickness of the valves displayed latitudinal variation. These results are discussed considering environmental variables.