Larvicultura de Rhamdia quelen (Pisces, Pimelodidae) con proteína vegetal y animal, suplementadas con plancton

Abstract

Objective: To determine the effect on larval growth and survival of Rhamdia quelen of diets containing different proportions of animal and plant protein supplemented with plankton. Materials and methods: Two experimental diets were formulated, Diet-1 with 70% vegetable protein (soybean meal) and diet-2 with 70% animal protein (beef heart and fish meal); four feeding treatments (T) were studied: T1) 70% vegetable protein + filtering plankton sieve of 50-200 microns, T2) 70% vegetable protein + filtering plankton sieve of 50-200 microns, T3) 70% vegetable protein, T4) 70% animal protein. Larvae were handled at a density of 20 animals L-1 offering food daily to apparent satiation at 07:00, 11:00, 16:00 and 21:00 hours; supplementation with plankton was made at 11:00 and 21:00 hours. Results: There were no differences between T1 and T2 (p>0.05) in final weight (21.89±15.17mg vs 20.37±10.37mg), total length (13.41±2.34mm vs 13.39±1.99 mm), condition factor (K) (0.80±0.13 vs 0.78±0.13) and survival (46.6±2.68% vs 36.0±7.41%); between T3 and T4 the differences for these variables were not significant (3.35±1.40 mg vs 2.98±1.48 mg, 7.54±0.91mm vs 7.33±0.96mm, 0.75±0.13 vs 0.71±0.12, 33.6±24.8±9.07% vs 6.76%, respectively). In addition, significant differences were observed between the groups supplemented with plankton (T1 and T2) vs groups that received only vegetable or animal protein (T3 and T4) (p<0.05). Conclusions: Plankton supplementation was more effective than offering vegetable or animal ration. The inclusion of 62.9% of soybean meal in the formulation (T1), apparently did not affect growth or survival.