Revista Chilena de Historia Natural (Sep 2001)
Sobrevivencia y crecimiento de post-larvas de Argopecten purpuratus (Lamarck, 1819) en Bahía Inglesa, Chile: efectos del origen, distribución en la bahía y bacterioflora larval Postlarval survival and growth of Argopecten purpuratus (Lamarck,1819) in Bahia Inglesa, Chile: effects of origin, distribution in the bay and larval bacterioflora
Abstract
Argopecten purpuratus es uno de los recursos marinos de mayor importancia comercial en Chile. Una de las etapas críticas en el cultivo de esta especie, es el traspaso de las post-larvas al medio natural, ya que durante este período se produce un significativo descenso en el número de post-larvas. Los factores que provocan estas bajas sobrevivencias pueden ser diversos, pero aún son desconocidos. En el presente estudio se evaluó la incidencia en la sobrevivencia y crecimiento de las variables origen de las larvas, distribución de los colectores en diferentes estaciones de Bahía Inglesa, III región (27° 03' 24" S, 70° 51' 30" O) y los cambios en la bacterioflora asociadas a las post-larvas. Los organismos utilizados en el estudio fueron obtenidas desde los "hatcheries" de Cultivos Marinos Internacionales (III región) y Cultivos Guayacán (IV región). Los resultados del estudio indican claramente que la ubicación y origen de las post-larvas en la bahía incide en la sobrevivencia de éstas. Sin embargo, el crecimiento no es afectado por las variables estudiadas (P Argopecten purpuratus is one of the most commercially important marine resources in Chile. One of the most critical steps in the massive culture of this species is the transference of postlarvae from hatchery production to the sea where significant mortality regularly occurs. The factors behind this low survival rate are probably diverse, and are as yet unknown. In the present study, postlarval survival and growth was observed as a function of origin of postlarvae, distribution of postlarvae in the bay, and microbial loading of the postlarvae. Survival rates were measured for different sites in Bahia Inglesa, Chile (27° 03' 24" S, 70° 51' 30" W) as well as changes in the bacterioflora of the postlarvae. Postlarvae utilized in the study were obtained from Cultivos Marinos Internacionales (III Región) and Cultivos Guayacan (IV Región). Results of the study clearly indicated that survival in culture of the postlarvae was related to their location in the bay and the origin of the postlarvae. However, the growth of the post-larvae is not affected (P < 0.05). Microbiologically, it was observed that Vibrio spp. were the bacterial component most represented among strains isolated from the postlarvae (53.36 %) from both populations studied. Principal component analysis revealed no differences between cultivable vibrios from both cultures. However, microflora from the Guayacan group were less susceptible to increases in bacteria originating in their surrounding environment
