Influencia de la disposicion espacial y la superficie de refugios sobre la supervivencia y crecimiento de juveniles de Cherax quadricarinatus (Parastacidae) y su aplicacion al cultivo intensivo

Abstract

RESUMEN.Cherax quadricarinatus es una especie de elevado interés para la acuicultura y de gran tolerancia a las altas densidades, lo que la hace propicia para el cultivo en sistemas intensivos. El objetivo de este trabajo es determinar el diseño más adecuado de disposición espacial y la superficie de "red cebollera", usualmente utilizada como refugio de juveniles en cultivo, que permita disminuir la mortalidad y mejorar el crecimiento en condiciones de alta densidad. Se realizaron dos experimentos, poniéndose a prueba la disposición espacial (redes paralelas en posición vertical, horizontal y sin ordenamiento) y la superficie de red cebollera (0,612 m 2 , 1,224 m 2 y 1,836 m 2 ) en cultivo con alta densidad de juveniles (41,7 juveniles de 1 g m -2 ). A los 60 días se registró el número y peso de juveniles, y se calculó la mortalidad y biomasa. En el segundo experimento se contabilizó también la cantidad de quelas faltantes y juveniles con todos sus apéndices, para estimar las interacciones agonísticas. La mortalidad resultó menor en el tratamiento sin ordenamiento y en el tratamiento con menor superficie de redes (P < 0,05). Por cada m 2 de fondo, 2,55 m 2 de red cebollera colocada en forma aleatoria sería suficiente como refugio para una densidad alta de juveniles. La biomasa y las interacciones agonísticas fueron similares en todos los casos. Se determinó que la colocación de la red al azar es la disposición más adecuada y económica para los juveniles de C. quadricarinatus, y que su exceso podría perjudicar la supervivencia en cultivo. Palabras clave: Cherax quadricarinatus, refugios, juveniles, supervivencia, cultivo intensivo.Influence of spatial distribution and shelter area upon survival and growth of Cherax quadricarinatus (Parastacidae) juveniles, and its application to intensive culture ABSTRACT. Cherax quadricarinatus is an interesting species for aquaculture and is more tolerant to high densities than other species of commercially important crustaceans, making it suitable for intensive culture. The purpose of this study is to determine the most adequate spatial arrangement and area of onion bag mesh, commonly used as shelter in juvenile culture, to decrease mortality and improve growth under high-density conditions. Two experiments were conducted to evaluate the optimum onion bag mesh spatial distribution (parallel pieces of mesh arranged in a vertical and horizontal position, and mesh with a random arrangement), and area (0.612 m 2 , 1.224 m 2 and 1.836 m 2 ) under high-juvenile density conditions (41.7 one-gram juveniles per m 2 ). The weight and number of juveniles were recorded, and mortality and biomass were calculated at day 60. In the second experiment, the number of missing chelae and juveniles with all their walking legs were counted to estimate agonistic interactions. Mortality was lower in the treatment consisting in randomly arranged onion bag mesh and that with the smallest area. A mesh surface of 2.55 m 2 per m 2 of ground would be sufficient as shelter for juveniles stocked at high dens...

Early and late effects of feed restriction on survival, growth and hepatopancreas structure in juveniles of the red claw crayfish Cherax quadricarinatus

“…The treatments were selected on the basis of previous results. These data indicate that one-gram juveniles of C. quadricarinatus require more than 5 days of initial feeding to molt and that the proportion of molting juveniles which were fed for 15 days is similar to that of continuously fed juveniles (Calvo et al, 2009).…”

Effect of background color and shelters on female pigmentation in the ornamental red cherry shrimp Neocaridina davidi (Caridea, Atyidae)

“…There are several studies about the presence, availability, and different types of shelters affecting variables such as growth, survival, aggression, cannibalism, and so on in several crustacean species (Calvo, Tomas, & López Greco, 2013;James, Tong, & Paewai, 2001;Jones & Ruscoe, 2001;Marshall, Warburton, Paterson, & Mann, 2005;Mintz, Lipcius, Eggleston, & Seebo, 1994;Savolainen, Ruohonen, & Tulonen, 2003), but no data has been reported yet on whether the presence of shelters influences body color in shrimp. In our study, we expected greater body pigmentation in N. davidi females raised without shelters because of the higher exposure to extrinsic parameters such as UV radiation, high light intensities and predation.…”