ASPECTS OF THE POPULATION-DYNAMICS OF 6 BIVALVE SPECIES FROM SOUTHERNCHILE - RESULTS OF THE HENSEN,VICTOR CRUISE TO THE MAGELLAN STRAIT AND THE BEAGLE CHANNEL IN OCTOBER NOVEMBER 1994/

Growth, mortality and production of six bivalve species from southern Chile (53 degrees S) were determined from data obtained during the cru ise of the research vessel 'Victor Hensen' to the Magellan Strait in O ctober/November 1994. The six species were Mulinia edulis (Ring and Br oderip, 1832), Eurhomalea exalbida, (Dillwyn, 1817), Venus antiqua (Ki ng and Broderip, 1835), Tawera gayi (Hupe, 1854), Gaimardia trapesina (Lamarck, 1819) and Chlamys patagonica (King and Broderip, 1832). To s tudy the effect of latitude dependent environmental factors, data from the literature were compared with data obtained in this study: P/(B) over bar values for different bivalve species and populations studied along the Peruvian-Chilean coast decrease from the equator towards the Antarctic. A linear regression was established between the growth per formance index phi prime (Phi') and mean latitude of the distribution range as well as latitude of the study area. Growth decreases towards the Antarctic. For Phi' and the mean of the distribution range r(2) = 0.43 was obtained, for Phi' and the latitude of the study area r(2) = 0.67.