Behzadi Siamak, Ali Salarpouri, Mohammad Darvishi, Gholam Ali Akbarzadeh Chamachaei, Sajjad Pourmozaffar, Mohsen gozari, Mohammad Momni,
Volume 9, Issue 1 (Winter 2020)
Abstract
Aims: Monitoring of the fish biomass is one of the basic principal of fisheries management, but ornamental and reef fish stocks, because of difficulty of estimating their abundance, have been less studied than others. The aim of this study was to estimate the standing biomass of ornamental and reef fishes in Larak Island, in the Strait of Hormuz.
Materials &Methods: Standing biomass of the fish species was assessed seasonally using Underwater Visual Census Method (UVCm) in coral reefs and mesophotic coral reefs in Larak Island throughout 2018 and 2019. Two popular methods in UVCm (belt transect and stationary point) were used based on topography of sea bottom. The confidence interval of estimated standing biomass is calculated using bootstrapping method.
Findings: The standing biomass of ornamental and reef fishes is estimated as 2522.18, 5222.17 and 1325.15(Kg.) in Site 1, Site 2 and Site 3, that are located in 3-15meters depth. The standing biomass at Site 4, was estimated as 884.13kg. The minimum were observed in summer, also the result showed that the standing biomass in summer was significantly lower than other seasons (P <0.05). In addition, the temporal diagnostic test showed that population structure of fish in the spring, autumn, and winter seasons was similar but significantly different from the population structure in summer.
Conclusion: The less of standing biomass in summer season can be affected by seasonal migrations of fish in tropical and subtropical waters to deeper waters, in order to trade of the stresses caused by temperature fluctuations.
Saeedeh Sarhadi, Iman Sourinezhad, Mohsen gozari,
Volume 13, Issue 3 (10-2024)
Abstract
Evaluation of the antimicrobial activity of bacteria in the aquaculture ecosystem is the first stage of probiotic bacteria screening studies. The aim of the present study was to isolate the intestinal bacteria of cultivated Vanammei shrimp with antimicrobial activity against pathogenic bacteria in vitro and in vivo. For this purpose, sampling of shrimp culture sites in South Tiab and North Tiab was done in 3 stages. The results of counting culturable bacteria using Zobell agar culture medium showed that in South Tiab site, the average number of bacteria in shrimp intestine samples was from 3.66 × 106 CFU/gr in the first stage of sampling to 4.63 ×106 CFU/gr in the third stage. With a similar trend, the changes of this amount in the North Tiab site fluctuated from 16.4 ×106 CFU/gr to 16.16 ×106 CFU/gr. Evaluation of the antimicrobial activity of the isolates using the agar diffusion method showed that 9, 6, 4 and 3 isolates respectively compared to V. alginolyticus, V. harveyi, V. parahaemolyticus and P. aeroginosa showed antimicrobial activity.
