Age, growth and mortality of the cortes geoduck, Panopea globosa (Bivalvia: Hiatellidae) in the central Gulf of California, Mexico

摘要

For the first time, this paper describes the age, growth and mortality of the cortes geoduck Panopea globosa in the Gulf of California. This study was motivated because of the limited knowledge regarding biological aspects of this species in Mexico. Commercial catches of geoduck Panopea generosa and P. globosa started along the Baja California coast in 2002, nowadays catches are 1200 ton, similar to those in Washington, USA and British Columbia, Canada, when fisheries started in 1970 and 1976, respectively. The objective of this study was to know the age, growth and mortality of P. globosa. Geoducks were collected from November 2008 through to February 2010, in the central eastern coast of the Gulf of California (Bahia del Sol, Sonora, Mexico). Age was established using the 'acetate peel' method and von Bertalanffy growth parameter was estimated as L-infinity = 122.86 mm, k = 0.33 and t(o) = -0.2. Mortality according to each method ranged from 0.79 to 0.546. Ages varied from 2 to 27 years old but the mode was 10 y. Average size (+/- IC alpha 0,05) was 109.8 +/- 3 mm shell length. The growth parameter and mortality rates are similar to those found in young organisms of congener species. For these reasons the conclusion is that according to our findings, this stock is a recently established population in response to a favorable environmental event.