Survival and growth studies of Acipenser persicus larvae fed with Artemia nuaplii enriched with two probiotic strains of Lactobacillus delbrukii bulgaris

Objective: Probiotic bacteria are known to improve growth, survival and immune responses in animals including fish and shellfish. Acipenser persicus is one of the endemic species of sturgeon fish living in the Caspian Sea. Many studies have proved the beneficial effects of probiotic bacteria on survival, general health status and growth in many animals including fish. Since restocking of the sturgeon fish depends on production of good quality fingerlings, we studied the use of two human Lactobacillus delbrukii strains L. delbrukii bulgaris (PTCC1332) and L. delbrukii bulgaris (B51-IMB) enriched Artemia nauplii on survival and growth factors of Acipenser persicus larvae. Method & Materials: 300 randomly selected active larvae (initial weight, 39 mg) were transferred into 45 liters polyethylene tanks (5*3). We adopted an open flow through culture system, with water current at the rate of 1: l-min. Five feeding treatments were used in this study to feed the fish larvae: (1) Newly hatched Artemia nauplii enriched with commercial L. delbrukii bulgaris (B51-IMB), (2) Newly hatched Artemia nauplii enriched with L. delbrukii bulgaris (PTCC1332), (3) Newly hatched nauplii, (4) Newly hatched nauplii + commercial feed (50%-50%), (5) Commercial feed. Dead animals in each tank were removed and counted everyday. Results & Conclusion: The results indicated that fish larvae fed on un-enriched newly hatched Artemia nauplii had significantly better growth compared to other feeding groups (P < 0.05). A. persicus larvae fed on commercial feed showed significantly lower survival and growth compared to the rest. Lowest and highest FCR was observed in larvae fed on newly hatched Artemia nauplii and commercial feed, respectively. Survival was very high in all treatments except in the fish larvae fully fed on commercial food. It was concluded that supplementation of the two probiotics used in this study does not significantly affect the survival and growth parameters in A. persicus. Moreover, we found that a 50-50 combination of newly hatched Artemia nauplii and commercial feed could be used as a good combination at the start of feeding for A. persicus larvae. Highest survival was observed in the fish larvae received Artemia nauplii enriched with L. delbrukii bulgaris (PTCC1332), however this was not significant. This indicated that supplementation of this probiotic could have a positive effect on improving health factors resulting in higher survival. Improving general immunity in the fish larvae could be another reason for better survival that needs to be studied in detail.

کلیدواژه ها:

Acipenser persicus ، Artemia ، Lactobacillus ، survival ، growth