Utilización de organismos vivos como primera alimentación de larvas de yaque (Leiarius marmoratus) bajo condiciones de laboratorio

to evaluate the effect of living organisms as a first feeding of yaque (leiarius marmoratus) larvae, an evaluation of the morphological development of larval was done based on the absorption of the yolk sac and the mouth opening. to evaluate the effects of different living organisms in the diet on some productive variables, larvae were subjected to laboratory conditions at a density of 10 larvae/l for 12 days of rearing, providing them four different daily rations of live food as follows: newly hatched brine shrimp nauplii (t1), cladocerans of the genus diaphanosome (t2), copepods of the genus diaptomus (t3), cladocerans + copepods (t4) and newly hatched larvae cachama blanca (piaractus brachypomus) (t5). a total of 3000 larvae of 50 hours post-hatching (hph) with an initial weight of 0.81 ± 0.02 mg and 3.68 ± 0.04 mm total length were used. the time of mouth opening was observed at 10 hph with a mouth opening size of 72.6 ± 5.7 μm. at the end of observation period (50 hph), the larvae reached a maximum opening of the mouth of 532.6 ± 7.8 μm with a 95 % yolk sac resorption. the best performance were observed in t5 in terms of weight and length gain with a value of 17.4 ± 0.5 mm and 116.1 ± 3.7 mg, respectively; however, a lower survival than the other treatments was observed. the highest survival percentage was observed in t1 (55.3 ± 6.5 %) followed by t2 (18.6 ± 3.8 %). under the conditions of the present study it is possible to conclude that larvae fed with brine shrimp nauplii or cladocerans showed the best results, the cladocerans becoming an important alternative source of food during the larviculture of this species.