Effect of Stocking Density on the Culture of the Mexican Axolotl (Ambystoma mexicanum)

The Mexican axolotl is an aquatic species endemic to Mexico that has recently attracted increasing interest in both aquaculture and conservation; however, Information on the Mexican axolotl Ambystoma mexicanum remains limited, this study evaluated the effect of three stocking densities on growth, survival, Fulton’s condition factor (K), and proximate composition of A. mexicanum. Juveniles (28.7 ± 0.31 g initial wet weight) were assigned to three densities: D3 (3 individuals/40 L), D6 (6 individuals/40 L), and D9 (9 individuals/40 L), The experiment lasted seven weeks at 19 °C, using a commercial diet containing 55% protein. Final length, wet weight, specific growth rate (SGR), Fulton’s condition factor, size heterogeneity, coefficient of variation, and proximate composition were evaluated. No significant differences were detected among treatments in final length, Fulton’s K, size heterogeneity, coefficient of variation, protein, lipid, or moisture content. In contrast, final weight and SGR differed significantly among densities. Individuals at D3 achieved the highest final weight and SGR, whereas those at D9 showed lower values. Although D9 allows a greater number of individuals to be reared per unit volume, its lower growth performance does not support considering it the most efficient production alternative based on the variables evaluated. Nevertheless, rearing juvenile A. mexicanum at nine individuals per 40 L may offer an option for improving space utilization in captive production and ex situ conservation under the conditions evaluated.