Comparative study on bacterial flora of the intestine in Persian sturgeon (Acipenser persicus) fingerlings reared in fiberglass tanks and earthen ponds

In this study, random sampling conducted and 90 individuals of Persian sturgeon having 3-5g weight, collected by trawling in 3 earthen ponds and 15 individuals having 10-20g weight, collected by small net in 3 fiberglass Vans. After recording of biometrical characteristics, the intestine and rearing water were cultured on TSA medium. Gram staining and complementary tests were conducted. In order to identify the bacterial species, various biochemical experiments and diagnosis kit of API 20E (special for gram negative bacteria) applied. According to biometrical recording, in earthen ponds, the mean weight and length of juveniles were 5.59±3.18 and 11.4±2.9, respectively. The results showed that the mean facultative aerobic and anaerobic bacterial counts in intestine were 5.59±0.92 (log CFU g-1) and 6.67±0.34 (log CFU Ml-1) in Acipenser persicus juveniles and rearing water, respectively. Furthermore, the following bacteria determined in intestine of Persian sturgeon: Aeromonas sp., A.sorbia, A.hydrophyla, Entrobacteriaceae and Corynebacterium. The bacteria in the rearing water were Aeromonas sp. and A.soberia. According to biometrical recording, in fiberglass Vans, the mean weight and length of juveniles were 12.13±2.51g and 15.11±1.13 cm, respectively. The results showed that the mean facultative aerobic and anaerobic bacterial counts in intestine were 4.77±0.04 (Log CFU g-1) and 4.81±1 (Log CFU mL-1) in A. persicus juveniles and rearing water, respectively. Furthermore, the following bacteria determined in intestine of Persian sturgeon: Aeromonas sp., Micrococcus, Staphylococcus. The bacteria in the rearing water were Aeromonas soberia, Acinetobacter,Moraxella, Micrococcus and Staphylococcus