Structural patterns of fisheries communities with relation to ecological condition in subtropical coastal waters of the northern Bay of Bengal, Bangladesh

1720-1732Fisheries assemblages with notes on the ecological conditions in coastal waters of the northern Bay of Bengal, Bangladesh, were investigated based on beach seine fishing net data form a one-year cycle (2015-2016) data collected by beach seine net. A total of 75 species comprising of 61 finfishes, 7 shrimps, 2 cephalopods, 2 lobsters and 3 crab species were identified. Among them, 58 species were commonly distributed in all four seasons, while 16 species were found dominant to the total communities. The species number, richness, evenness, and species diversity peaked in the monsoon and fell in the winter. Multivariate analysis of CAP and dbRDA revealed that there were clear temporal and spatial variations in fisheries assemblages in the Kohelia channel. RELATE analysis showed a significant correlation between fisheries communities with environmental variables. Furthermore, best matching analysis (BEST/BIOENV) confirmed that these temporal and spatial variations were driven by changing salinity, transparency and nutrients either alone or combined with soil nutrients. Thus, these findings suggest that fisheries community structure is shaped by the ecological condition in this marine channel system

Sustainable Treatment of Aquaculture Effluents in Future-A Review

There is a growing contamination of soil and irrigation water by intensive agricultural use and environmentally-unfriendly activity, which is due to the need to generate ever greater quantities of food to meet the demands of the growing population throughout the world. Many aquaculture systems produce high amounts of wastewater containing compounds such as suspended solids, total nitrogen (N) and total phosphorus (P). However, the load of waste is directly proportional to the fish production. Therefore, it is necessary to develop more intensive fish culture with efficient management for wastewater treatment. A number of physical, chemical and biological methods used in conventional wastewater treatment have been applied in aquaculture systems. This review gives an overview about possibilities to avoid the pollution of water resources; it focuses initially on the use of systems combining aquaculture and plants with a historical review of aquaculture and the treatment of its effluents. It discusses the present state, taking into account the load of pollutants in wastewater such as nitrates and phosphates, and finishes with recommendations to prevent or at least reduce the pollution of water resources in the future. All aspects of water treatment play a vital role in intensive fish production, because the control and monitoring of water quality is of significant importance to the success or failure of the aquaculture venture and its production. It is therefore necessary to develop new research applications focused on minimizing or at least reducing the negative impacts of aquaculture effluents on the environment. This review aims at giving an overview about aquaculture systems developed in historical times which could still be valuable for the future generation, about the present problems, and about innovative ideas, especially with respect to the integration of halophytic plants as bio-filter in saline aquaculture systems

DNA Barcoding of Stone Fish Uranoscopus Oligolepis: Intra Species Delineation and Hypothetical Protein Analysis

The present study addresses this issue by examining the patterning of Cytochrome Oxidase I diversity in the stone fish Uranoscopus oligolepis the structurally diverse group of Family Uranoscopidae. The sequences were analyzed for their species identification using BOLD’s identification engine. The COI sequences of U. oligolepis from different geographical regions were extracted from NCBI for intra species variation analysis. All sequences were aligned using Clustal W. The sequences were trimmed using software and phylogenetic tree was constructed with bootstrap test. The results showed that the cytosine content was high (31%). The least molar concentration was observed in guanine (19.5%) and Adenine (19.6%). Thymine was the second predominant in molar concentration next to thymine which is followed by adenine. The G+C content was found to be 49.6% and A+T content was 50.4%. Leucine and Alanine content was high in the amino acid composition. From the study it is assumed that the mitochondrial gene COI can be the potential barcoding region to identify an organism up to the species level

Food and feeding Biology of Fish Epinephelus malabaricus of Palk Bay and Gulf of Mannar coastal waters

The present study addresses this issue by examining the patterning of Cytochrome Oxidase I diversity in the stone fish Uranoscopus oligolepis the structurally diverse group of Family Uranoscopidae. The sequences were analyzed for their species identification using BOLD’s identification engine. The COI sequences of U. oligolepis from different geographical regions were extracted from NCBI for intra species variation analysis. All sequences were aligned using Clustal W. The sequences were trimmed using software and phylogenetic tree was constructed with bootstrap test. The results showed that the cytosine content was high (31%). The least molar concentration was observed in guanine (19.5%) and Adenine (19.6%). Thymine was the second predominant in molar concentration next to thymine which is followed by adenine. The G+C content was found to be 49.6% and A+T content was 50.4%. Leucine and Alanine content was high in the amino acid composition. From the study it is assumed that the mitochondrial gene COI can be the potential barcoding region to identify an organism up to the species level

Sedimentary Nutrient Dynamics in Homestead Fishpond Systems from a Subtropical Coastal Area

Homestead ponds are small seasonal ponds that are rarely utilized for fish farming. Culturing fish in these small ponds can boost household fish consumption and cash inflow. The availability of nutrients in the water and sediment, however, plays a significant role in the pond’s natural productivity. This study was conducted to assess nutrient contents and some key physical parameters in the bottom sediments of 30 homestead ponds from the central coast along the Northern Bay of Bengal. Analyses of results showed the average values (±SD) of temperature, pH, electrical conductivity, organic matter (OM), organic carbon (°C), nitrogen (N), phosphorus (P) and sulphur (S) were 17.8 ± 1.12 °C, 7.29 ± 0.11, 0.41 ± 0.09 mS/cm, 29,615.48 ± 10,528.9 mg kg−1, 11,958 ± 6107 mg kg−1, 1030.6 ± 252 mg kg−1, 17.1 ± 13.5 mg kg−1 and 32.6 ± 19.7 mg kg−1 during winter and 27.2 ± 1.81 °C, 6.73 ± 0.12, 0.38 ± 0.17 mS/cm, 19,100.01 ± 13,739.07 mg kg−1, 11,079 ± 7969 mg kg−1, 955 ± 229.4 mg kg−1, 26.6 ± 20.2 mg kg−1 and 23.4 ± 15.9 mg kg−1 during pre-monsoon, respectively. One-way ANOVA revealed no significant differences in the mean value of sediment quality parameters among the selected ponds (p > 0.05) except for phosphorus in the winter season (p p < 0.05). Based on Cluster Analysis (CA), two major associations among the nutrients were attained at a 15% similarity level: C, OM, and N in one cluster and P and S in another. The findings showed that the parameters were within the preferable range for aquaculture, and the homestead ponds are average productive ponds