Growth and fisheries of the black ark anadara tuberculosa, a bivalve mollusk, in bahía magdalena, baja california sur, Mexico

To determine trends in landings and growth of the pustulose ark or black ark Anadara tuberculosa, a bivalve mollusk in the Bahía Magdalena-Bahía Almejas region along the southwestern coast of the Baja California Peninsula, Mexico, catch statistics recorded by artisan or small-scale fishermen from 1992 to 2002 and size frequency distributions of samples from commercial catches (November 1998-December 2000) were analyzed. Catch data revealed considerable fluctuations and a trend toward decline. No defined seasonal exploitation pattern was observed; however, on average, the months with the highest catches coincided with the highest reproductive activity. There was evidence of a decrease in black ark density, which might be accounted for by the fishery. Parameters derived from the von Bertalanffy growth equation confirm that individuals reach the minimum catch size of 60 mm in a little more than 1 year. Catch sizes ranged between 40 and 80 mm.