Substrate selection and effect of different substrates on survival and growth of juveniles of the freshwater crayfish Cherax quadricarinatus (von Martens 1868) (Decapoda, Parastacidae)

Abstract

Survival and growth of juveniles of the Australian freshwater crayfish Cherax quadricarinatus were evaluated in aquaria with four different substrates covering their bottom. The four substrates were plastic mesh, small stones, fine sand and bare glass without cover (control group). Two size classes of juveniles were evaluated: recently hatched or early (*0.02 g of body weight) and pre-fattening or advanced (*1 g of body weight). A group of twelve early or ten advanced juveniles were placed in each of the 24 aquaria. Each substrate had a total of six aquaria, three containing early juveniles and the other three containing advanced juveniles groups. Each aquarium had an excess small PVC pipes that served as shelters. After 12 weeks, early juveniles raised in small stones or fine sand had a statistically significant heavier body mass than the control group while the advanced juveniles did not show statistically significant differences in body weight. In a second experiment, ten early and ten advanced juveniles were individually placed in a circular glass aquarium divided into four sections each containing one of the same substrates used in the first experiment. Each individual was filmed for 24 h, and the time spent in each compartment was registered. Both sizes of juveniles showed a marked preference for the small stones. This experiment was repeated with animals used in the first experiment and observed the same selection pattern indicating that substrate selection is independent of body mass or previous acclimation to the different substrates.

Contribution of biofilm to water quality, survival and growth of juveniles of the freshwater crayfish Cherax quadricarinatus (Decapoda, Parastacidae)

“…Formulated meal, successfully used in previous studies on C. quadricarinatus (Chaulet et al, 2008;Viau and Rodríguez, 2010) was given every day at a percentage of 10 (early) or 5 (advanced) of juvenile biomass, in specially feeding trays, designed according to Wasielesky et al (2006). Briefly, each tray was composed by a cylindrical plastic base (15 cm de diameter), coupled to a vertical PVC pipe (30 cm long, 1.5 inch diameter) for loading food.…”

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

“…La mortalidad media observada, en este tratamiento, fue de 12% para el experimento 1 y de 25% para el experimento 2. Esta fue similar a la observada por Viau & Rodríguez (2010) para juveniles de igual longitud y mucho menor que la registrada por otros autores para la fase de pre-engorde y con alta densidad de cultivo (Jones, 1995;Karplus et al, 1995;Sagi et al, 1997;Manor et al, 2002).…”

“…Wicki et al (2008) recomiendan, antes de la siembra en estanques, el uso de una fase de pre-engorde (juveniles entre 1 y 10 g), que se desarrolla en tanques externos de cemento, colocados bajo media sombra, donde los individuos adquieren la coloración propia de la especie, antes de transferirlos a la etapa de engorde final en estanques excavados en tierra (300 m 2 ). En la etapa de preengorde, el mejoramiento de los refugios sería una de las estrategias propuestas para obtener mayor crecimiento y minimizar el canibalismo de los juveniles, ya que los protege en el momento de la ecdisis cuando son más vulnerables (Jones, 1995;Jones & Ruscoe, 2001;Molony & Bird, 2005;Viau & Rodríguez, 2010;Ghanawi & Saoud, 2012).…”

Growth Performance and Substrate Preference of Juvenile Mexican Dwarf Orange Crayfish (Cambarellus patzcuarensis) in Different Substrate Types

“…Ten juveniles were placed in each aquarium, similar to densities used previous research carried out by Viau and Rodríguez (2010) with early juveniles of Australian red claw crayfish, C. quadricarinatus. Total length and weight measurements were carried out biweekly during 100-days experiment.…”

“…The global achievement of the freshwater crayfish farming in recent years is based on the selection of species with sufficient characteristics for both cultural and commercial purposes (Viau and Rodríguez 2010). Healthy and peaceful crayfish species are preferred for ornamental purposes by skilled aquarists.…”