ABSTRACT
The octopus Octopus cf. vulgaris is a potential species to diversify aquaculture. Due to absence of balanced commercial diet, growth of the O. cf. vulgaris is based on natural diet with local and low-cost inputs. In Brazil, studies on experimental octopus ongrowing are recent and there is little available data. We evaluated the performance, survival and food consumption of O. vulgaris fed on mussel Perna perna for 20 days. Six octopuses with initial weight of 415±12.73g (mean±standard deviation) were divided into two groups (n=3 octopuses/group) according to the diet: MC Group (frozen mussels) and MV Group (live mussels). The Weight Gain of octopuses was 273.33±94.52g and 340.00±26.46g; the Absolute Growth Rate was 13.67±4.73 and 17.00±1.32g.dia-1 and the Specific Growth Rate of 2.95±0.58 and 2.64±0.37%.day-1 to MC and MV groups, respectively. There was no significant difference in performance between groups and the survival rate was 100%. Octopuses well accepted both diets and despite the amount of frozen mussels (129±31) was higher than in live mussels (100±19), there was no significant difference regarding the consumption between groups. Our results demonstrate that the mussel Perna perna can be used frozen or live as monodiet in O. cf. vulgaris ongrowing.(AU)
Subject(s)
Animals , Diet/veterinary , Perna , Octopodiformes/growth & development , Aquaculture/methodsABSTRACT
Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from length frequency distribution analysis, illustrated by case studies of three tropical species from different aquatic environments: tilapia (Oreochromis aureus),red octopus (Octopus maya)and the Caribbean spiny lobster (Panulirus argus).The analysis undertaken compared the size distribution of males and females of a given cohort through modal progression analysis. The technique used proved to be useful for highlighting the differences in growth between females and males of a specific cohort. The potential effect of extrinsic and intrinsic factors on the organism's development as reflected in the size distribution of the cohorts is discussed.
Los parámetros de crecimiento son un componente importante para la evaluación de las poblaciones de especies acuáticas explotadas. Sin embargo, es complicado aplicar métodos directos para estimar el crecimiento y analizar las diferencias entre machos y hembras particularmente en zonas tropicales. El objetivo de este estudio fue analizar el crecimiento entre cohortes de tres recursos tropicales y discutir las posibles implicaciones en el manejo pesquero. Se utilizó un método simple para comparar las curvas de crecimiento individual obtenidas a través del análisis de distribución de frecuencias de longitudes, para ello se usaron tres casos de estudio de especies tropicales provenientes de diferentes ambientes acuáticos: tilapia (Oreochromis aureus),pulpo rojo (Octopus maya)y la langosta del caribe (Panulirus argus).El análisis consistió en comparar la distribución de longitudes de hembras y machos obtenidas del análisis de progresión modal. Esta técnica puede ser utilizada para resaltar las diferencias en el crecimiento entre hembras y machos de una cohorte específica. En este documento se discute el efecto potencial de los factores intrínsecos y extrínsecos en el desarrollo de los organismos como se refleja en la distribución de tallas de las cohortes.