Search

Growth parameters and production of the population of D. obesulus at the exposed sandy beach of Sarapampa (100 km south of Lima) were estimated. Monthly samplings were carried out during a year (October 2005-August 2006) in 6 stations distributed throughout the beach. Length- frequency distributions were elaborated and the growth parameters of the Von Bertalanffy growth equation (VBGE) determined by ELEFAN I. Total mortality rate (Z) was estimated by the length- based catch curve method and production of somatic and shell components were estimated by the mass specific growth rate method. Growth parameters were estimated as K= 0.991 and L∞= 33.70 mm and total mortality as Z= 3.28. Mean biomass was calculated using the relation length-shell and free wet mass (SFWM = 0.0003 L3.-61 ) as 54.10 g SFWM.m -2. The average production of this species was calculated in terms of ash free dry weight in 3.76 g AFDW.m-2 .year-1. Individuals ranging from 22 to 23 mm contributed most to the total production (10.3%). Mean annual turnover rate (P/ B̅) was 1.20. Growth and production of this species is compared with other species of the same genus. [ABSTRACT FROM AUTHOR]

This study analyzes and compares the growth and survival of juvenile Argopecten purpuratus cultivated in suspended and bottom systems in Casma, Ancash-Peru. From July 29th to October 21th, 2006 an experiment was installed using pearl nets and yards with individuals of 10mm² (0.067g of soft tissue) at densities of 816, 2450, and 4080 indiv/m . Every two weeks individuals were measured (mm, shell height) and weighted (g, total and tissue weight) and dead scallops counted. Additionally information on production costs was recorded in order to compare profits in both systems. At the end of the experiment height and weight were higher in suspended than in bottom system and showed an inverse relation with density. Growth rates in height and weight in suspended system ranged from 0.07 to 0.43 mm/day and from 0.009 and 0.100 g/day and in bottom system varied between 0.11 and 0.26 mm/day and between 0.007 and 0.045 g/day, respectively. Survival was higher in suspended (96.8%) than in bottom systems (84.8%). The ANOVA showed a significant effect of density and culture system on growth and survival of juvenile scallops (P<0.01). The cost-benefit analysis demonstrated that scallop culture in bottom systems is more profitable than in suspended systems. Maximum profit is reached in bottom systems at a density of 4080 ind/m² and at 816 ind/m² in suspended systems. The feasibility of the adoption of bottom systems for culture of juveniles by enterprises and fisherman is discussed. [ABSTRACT FROM AUTHOR]