Effect of Density on Growth and Feeding of the CrayfishCambarellus montezumae(Saussure, 1857)

Abstract

The acocil C. montezumae is a freshwater crayfish endemic to the Central Plateau of Mexico, but, in recent years, the natural population of this species has diminished considerably. In this work was investigated growth performance and feeding of this crayfish reared at high densities. A random block experimental design with two repetitions and three treatments (77, 154 and 231 crayfish/m 2 ) was carried out. Organisms were fed every third day with 15% of their total biomass of shrimp commercial food with 25% of crude protein, and individual food consumption (IFC) was calculated. Significant differences (ANOVA, P < 0.05) were detected in final weight, absolute increase, relative rate of increase, instantaneous rate of increase, yield and survival rate between the densities, with those reared at a density of 77 organisms/m 2 reaching the largest sizes. There were no-significant differences (P > 0.05) among treatments in terms of initial weight, specific growth rate and feed conversion l rate.

Effect of density and shelter on growth, physiology, and biochemical composition of the crayfishCambarellus montezumae

“…De Los Santos and Silva (2008) found a significant effect of density on biomass in Macrobrachium michoacanus in which 8 organisms/m 2 performed better than 12 organisms/m 2 . Arredondo et al (2010) suggest that a higher number of shelters offers the opportunity to maintain higher densities. Kozak et al (2000) pointed out that the presence of shelter lowers mortality in the crayfish Pacifastacus leniusculus.…”

“…They concluded that the presence of shelters at an optimal density can minimize stress and mortality, particularly after the molt process. Arredondo et al (2010) found the highest growth and survival rate of C. montezumae at a density of 77 organisms/m 2 . The combination of high density with the use of shelters should maximize growth and survival (Verhoef and Austin 1999).…”

“…Several studies have demonstrated an inverse relationship between population density and growth (Barki et al 2006). Arredondo et al (2010) found that growth and survival of C. montezumae stocked at 77 crayfish/m 2 were significantly higher than at 154 or 231 crayfish/m 2 after 4 months. In addition, Domingues and Alaminos (2008) found a direct correlation between stocking density and the rate of cannibalism.…”

Study of the Reproduction of Cambarellus montezumae (Saussure, 1857) Under Different Sex Relations

“…In this respect [5,11] experimented with three densities in Cambarellus montezumae (77, 154 and 231 crayfish/m 2 ), observing that the best density to breed these organisms is that of 77 organisms/ m 2 since they were the ones that reached the largest sizes. In this work it was found that the highest density condition (28 org/m 2 ) obtained the best indicators of growth in weight and height.…”

“…Economically, in the local markets, it represents a profit of 1 dollar per ration for consumption, food rich in protein, and 1/4 of dollar per unit to be used as live food in aquarium. In particular, due to the overexploitation of these crustaceans in the Valley of Mexico, a decrease in the natural populations of species such as Cambarellus montezumae has been observed [4,5]. Another element that has affected the vulnerability of the species is the overexploitation of water resources in the environments that host them.…”