International Journal of Aquatic Biology
Volume:10 Issue: 2, Apr 2022

Notopterus notopterus (Pallas, 1769), popularly known as bronze featherback, is a commercially important table fish due to its high nutritional resources. It has also been considered as a potent candidate for the ornamental fish industry. It is a predominant species of tropical South-East Asia. Due to overexploitation, habitat destruction, pollution and other anthropogenic stresses, the population of this fish species are under threat and it has been categorized under lower risk near threatened and vulnerable categories in India and Bangladesh, respectively. Conservation of any fish species can be successfully done by a large-scale culture which ensures the supply as well as reduces the pressure on natural stock. The successful culture of a new candidate species needs proper knowledge on its feeding and reproductive biology. This review has been focused to consolidate the information on morphological characteristics, feeding and reproductive biology, and culture of bronze featherback and identifying the scope of future research to support its fishery and conservation. 

This study was conducted to evaluate the health of rainbow trout on three farms in Mazandaran Province using a quantitative analysis of the histopathological alteration method. The fish were sampled within three classes: <100, 300-700, and >1500 g. Ten fish were sampled per size class from each farm. The fish gill, liver, kidney, and intestine pieces were collected, fixed, sectioned, mounted on slides, and stained for histopathological examinations. A quantitative approach was followed to examine the tissues alternation and fish. The results showed that the organ index of the gill in 300-700 and >1500 g fish was significantly higher than <100 g ones. The organ index of the liver in >1500 g fish was significantly higher than in the other two groups. There was no significant difference in the organ index of the kidney and intestine. Organ index within each fish size was as follow: gill> liver> kidney> intestine. Moreover, the total index was calculated based on the organ index in a fish and, accordingly, <100 g fish had the lowest total index than 300-700 and >1500 g fish. In conclusion, the fish gill exhibited more pathological changes due to direct contact with the ambient environment. Moreover, the fish intestines were generally healthy, suggesting suitable diet quality, although vacuolization and hypertrophy of the hepatocytes show that the dietary fat and feeding rate should be controlled.

Looking for effective alternatives, such as secondary microbial metabolites, is needed to restrict the use of antibiotics in farmed fish and their detrimental effects on public health and the environment. Thirty-three water and sediments samples were collected from coastal areas in the Basrah Governorate, southern Iraq, to assess their biological activity against bacterial pathogens isolated from Cyprinus carpio, with enteric red mouth disease. 20 spore-forming bacteria were isolated and identified by VITEK BCL cards and amplifying the gyrA gene. Furthermore, the secondary metabolites produced by the strains were extracted and analyzed by GC-MS. Four pathogenic bacteria were isolated from common carp infected with the enteric red mouth disease. The antibacterial activity of the extracts of the isolated marine strains was examined on bacteria causing enteric red mouth disease and Y. ruckeri and P. aeruginosa. Based on the results, the marine isolates were identified as B. spizizenii and GC-MS analysis revealed that these strains’ extract contained amino acids and their derivatives and esters and hydrocarbons. Also, biochemical identifications showed that the bacteria isolated from fish belonged to the species of Yersinia ruckeri, Aeromonas hydrophila, Streptococcus agalactiae, and Pseudomonas aeruginosa. According to the antibacterial activity assay, the extracts of B. spizizenii strains were considerably active against bacteria involved in enteric red mouth disease, especially Y. ruckeri. These findings indicate marine B. spizizenii can be replaced with antibiotics in the aquaculture industry to combat infections.

This study was carried out in Hor Al-Azim, to determine the concentrations of total petroleum hydrocarbons in water, sediments, and plant and to use Ceratophyllum demersum as a bioindicator to determine the concentrations of polycyclic aromatic hydrocarbons. The study recorded the highest seasonal and local changes in the total hydrocarbons in water, sediment, and aquatic plant, results were as (3.88, 10.99, and 6.74, respectively. The results also showed significant differences in the concentrations of TPHs in C. demersum between the study stations and seasons. The results recorded an increase in the PAHs in C. demersum during the autumn and winter, while the lowest rates in spring and summer. The range was from 5.605 ng/g dry weight in the first station in the summer season and 91.866 ng/g of dry weight at 3rd station in autumn. The ratio of BaA/(BaA+Chr) was 0.000-0.859 during the study seasons, and InP/ (InP + Bghip) between 0.000-0.887 indicating that most of the PAHs sources in this plant are pyrogenic, and few of them petrogenic. The ratio of Flouranthene to most Pyrene compounds is greater than 1, and few are less than 1 indicating that some PAHs sources are petrogenic, and most of them pyrogenic

The effect of feeding aquaculture by-product meal (ABP) to African catfish (Clarias gariepinus) was investigated in a 56-day feeding trial using serum biochemistry, innate immune response, and oxidative stress markers as indices of assessment. Fishmeal protein in control diets was replaced at a rate of 15, 30, 45, and 60% by aquaculture by-product meal protein. Each experimental diet was randomly distributed into triplicate tanks containing catfish fingerlings (n = 15 fingerlings/replicate, 5.58±0.05 g). The primary haematological parameters (haemoglobin, packed cell volume, red blood cell count) and secondary haematological parameters (MCH, MCV, and MCHC) were similar to the control. The white blood cell count and its differential of the fish group fed ABP meal was numerically higher than control but not significant, except in fish fed D30T that had high lymphocyte count. The platelet count in all the dietary groups was similar. There was no significant variation in some of the serum biochemistry parameters: total protein, albumin, globulin and albumin/globulin ratio, urea, HDL-C and LDL-C. Creatinine values of the D60T-fed group were significantly higher than all other dietary treatment groups including the control. Triglyceride level was statistically similar with control up to 30% replacement level, while there were no significant variations in the cholesterol levels of the blood of C. gariepinus fed the different dietary treatments. Except for catalase, there were no significant differences in other oxidative stress biomarkers under study, primarily SOD, GSH, and GPx. Catalase enzyme activities of the fish group fed D30T were statistically higher than other fed groups. Some serum electrolytes, such as calcium and chloride ions of the differently fed fish groups, were not significantly different. Lastly, serum potassium ions were significantly higher among D60T-fed group though statistically similar to D45T-fed group. No stress conditions were recorded among the dietary groups. These results showed that the health status and immunity of African catfish were not degraded by feeding aquaculture by-product meal to the fish.

Ancient Iran is one of the leading civilizations that actively appear to water resources management, especially by the invention of “Qanat”, an artificial underground system/ subterranean tunnel-wells system where the water flows through gravity on a slight slope in arid and semi-arid regions at least 5000 years ago. Qanats were innovated in ancient Iran, spread throughout much of the Middle East, and extended into North Africa, Spain, Italy, and South Asia. Tools preparation, size selection, digging the first and deepest vertical shaft known as “mother-well”, digging several other vertical shafts along a line between the mother-well and Qanat outlet, and constructing a horizontal connection between vertical shafts (known as the main tunnel), which guides the water out through an outlet, are the main steps in Qanat construction. By this innovation, Iranian solved their water-related problems using the basic concepts of Hydraulics. In the same way, water-related infrastructures were built using locally available materials to make a better life for humans and other wonderful well-designed and well-adapted organisms in dry and semi-dry regions, yielding great civilization with a simple, but a fantastic architecture that provides cold water in hot summer and warm water in cold winter. By means of these ancient underground structures, water was funneled from mountainous areas and aquifers to lower lands and thus alluvial fans could be opened up to settlement, and an agrarian civilization developed and evolved. In addition, Qanat provides a continual flow suitable for many aquatic organisms, including crabs, amphipods (gamarids), freshwater shrimps, and fishes. Qantas are home and refugia to about 42 fish species (36 native and 6 exotic species) belonging to 20 genera, 7 families, and 2 orders. The Qanat ichthyofauna is dominated by Cyprinidae with 19 species (45.2 %) followed by Leuciscidae and Nemacheilidae (6 species, 14.28% each), Poeciliidae and Aphaniidae (4 species, 9.52%), and Cobitidae (1 species 2.38%). It is about 14% of the total ichthyofauna of Iran. The Qanat ichthyofauna comprises 36 natives (including 20 endemics) and 6 exotic species. Qanat fauna dominates by species that are generally of small size, are broadcast spawners, nonmigratory, and have a wide tolerance of environmental conditions.

This technical note aims to describe the venipuncture procedure used to collect blood from Southern River terrapins via the subcarapacial venous plexus (SVP) and jugular vein. On uncooperative terrapins, SVP was applied while the jugular vein was reversed. 1.5 ml blood was preserved in 0.5 ml EDTA and stored at -20°C. ReliaPrepTM Blood genomic DNA Miniprep was used to extract DNA. Thermo ScientificTM NanoDrop 2000c was used to determine the concentrations of extracted DNAs. The greatest concentration of DNA is 136.3 g/L, and the highest purity is 1.90. The treatment is safe, minimally invasive, and effective.

Production of live feed for larval development of aquatic species is crucial in the aquaculture industry. The cultivation of cyclopoid copepod, Oithona rigida can enhance the growth performance and nutritional quality of fish and crustacean larvae. Hence this study was conducted to evaluate the different dietary regimes containing swiftlet waste, soybean meal, rice bran and microalgae (Nannochloropsis sp.) on the growth and productivity of O. rigida. The results showed that rice bran and Nannochloropsis sp. additives produced the best outcomes in terms of specific growth rate (0.109±0.002 and 0.104±0.001 day -1) of O. rigida., protein content (66.83±2.25 and 72.08±2.02%), and lipid content (21.98±1.41 and 18.09±1.18%) respectively. A mixture of rice bran and Nannochloropsis sp. (41.62%) as dietary additives also improved the polyunsaturated fatty acids (PUFAs) content of O. rigida as compared with mono diet applied such as rice bran (28.16%) and Nannochloropsis sp. (31.35%). The use of rice bran as food additives for O. rigida has shown a comparable result with the Nannochloropsis sp., in terms of the growth, survival, reproduction and dietary value. Thus, rice bran and Nannochloropsis sp. was marked as the best feeding regime for the cyclopoid copepod, O. rigida as potential characteristics for mass culture in aquaculture hatcheries.

This study was conducted in the Al-Shafi Marsh, north of Basrah City to investigate the effects of succession drought and flooding on the abundance and size spectrum of fish assemblage. Three stations were selected and samples were collected on a monthly basis using various fishing gears such as electrofishing, gill nets, and cast nets. The temperature of the water was 12.50-34.53⁰C, and the salinity fluctuated from 1.64 PSU in May to 4.03 PSU in October. The pH ranged from 7.38 in September to 8.17 in March. The water depth in the low flat areas ranged from 33 cm in October to 71 cm in May, while the average depth in the seasonal flat areas ranged from zero in June, July, August, September, and October to 34cm in April. A total of 19 fish species were collected, representing 17 genera and 11 families. Eight fish species were native, eight exotics, and two marines. Cyprinidae was the most abundant family, with four species. The most abundant species were the Abu mullet, Planiliza abu, Prussian carp, Carassius gibelio, and blue tilapia, Orechromis aureus (28.42, 20.97, and 14.90%, respectively). The D3 dominance index was 64.29%. The length groups of the most important sixth commercial fish species ranged from 5 cm in P. abu to 31 cm in Leuciscus vorax. The diversity index ranged between 1.84 and 2.25, the evenness index 0.74 and 0.88, and the richness index between 1.63 and 2.37. The resident species accounted for 94.82% of the total catch. Seasonal species account 2.76% of all samples. The occasional fish species account for 2.42% of total collected fishes. Based on the results, there was insufficient flood pulsation to stimulate native species to reproduce, combined with overfishing, which resulted in a depletion of the species' biomass, and an increase in the abundance of small medium-sized fish species and small invasive species.

Sewage water contains suspended and dissolved solids, hydrocarbons, many types of organic matter and heavy metals. The reuse of wastewater faces the challenge of removing organic pollutant compounds before discharging them into any natural stream. Therefore, in this study, natural nano-coagulant materials were used and their efficiency in removing turbidity, total organic carbon (TOC), and chemical oxygen demand (COD) from wastewater were investigated. The natural nano-coagulant were synthesized using leaves of Phragmites communis, Schanginia aegyptiaca and Portulaca oleracea. The results showed that 0.5 mg/L of P. oleracea nano-coagulant can remove 96.3% of COD, 86.2% of TOC and 89.5% of turbidity. Also, S. aegyptiaca leaves’ nano-coagulant in the 1 and 0.5 mg/L concentration was removed turbidity, COD and TOC content of the wastewater by 93.1, 89.42, and 81.8%, respectively. Moreover, P. communis leaves removed TOC, COD, and turbidity up to 78.2, 83.48, and 86.18%, respectively. The results showed the efficiency of natural nano-coagulant materials in treating and depositing wastewater pollutants.