Asian Journal of Fisheries and Aquatic Research

This study evaluated biochemical responses of genetically male tilapia after replacing fish oil with plant-based oils in their diets. The sources of oils were coconut, olive, crude palm, sunflower and sesame seed. These oils were incorporated at 7% level and were used to formulate five isonitrogenous (42.5% CP) diets. In the control experiment (sixth diet) fish oil was used. Fish were reared in 1 m x 1 m x 1 m floating net-hapa. Feeing trial lasted for 12 weeks. At the end of the experiment, blood samples were collected and tested for serum protein, electrolytes and tissue lipid peroxidation. Results of the study revealed that the ratio of albumin to globulin was statistically similar (p > 0.05) in all fish group examined. The results of serum electrolyte showed that olive oil treated fish recorded the highest (p < 0.05) level. The amount of malondialdehyde (MDA) formed in fish tissues increased (p < 0.05) in sunflower oil group by 69%, 43%, 20% and 32% in the liver, kidney, gills and heart respectively. This indicated that reactive oxygen species may be associated with the metabolism of sunflower oil leading to peroxidation of membrane lipids of the respective organs. However, this level of MDA deposition had not been associated with any negative effects on fish health. Inferences from this study conclusively support the direct use of these plant oils as total replacement for fish oil in diets of Oreochromis niloticus.

Seagrass beds in Ujung Genteng waters are one of the shallow marine ecosystems that have relatively high biodiversity. Seagrass ecosystem as one of the coastal ecosystems in these waters has a diversity of marine life that is associated with it. The purpose of this study was to establish the association pattern and the correlation of mega zoobenthos to seagrass ecosystem conditions. The method used was a survey method by conducting a survey direct observation of the stations that have been determined.  Three seagrass species were identified, namely: Thallasia hemprichii, Cymodoceae rotundata and Enhalus acoroides. The highest density of seagrass was found in station 2 with the type of seagrass Thallasia hemprichii as much as 207 ind/m². Fifteen mega zoobenthos species were identified representing 3 phyla. Species Mega zoobenthos which is most commonly found in Ujung Genteng waters is Ophiothrix fragilis, Ophiocoma erinaceus, and Diadema setosum. The mega zoobenthos Diversity Index at the observation station is included in the medium category that is 2.33-2.66 and the evenness index is 0.63-0.84. Correlation of seagrass density with mega zoobenthos obtained by 0.92 shows that there is a very strong relationship between seagrass density with mega zoobenthos. The result shows that there are 4 patterns of close association and 2 patterns of very close association. Ophiocoma erinaceus of the ophiuroidea class has a pattern of very close positive associations with seagrass Cymodoceae rotundata and Dendrodoris sp of the order nudibranchia has a pattern of very close negative associations with seagrass Cymodoceae rotundata.

The purpose of this research is to determine the condition of waters in the Citarik River with the periphyton community as a bio indicator. This research was conducted from March-April 2019. The research method used was a survey method at 4 station points, five times sampling with a span of 7 days. The smallest periphyton abundance is in station IV which is 22 ind/cm² and the most is in station I which is 18278 ind/cm². Comparison of species deficit values at each station is different, this is influenced by different physical and chemical parameters. The dominance index value in the waters of the Citarik River ranges from 0.1 to 0.8 and the diversity index value ranges from 0.2 to 0.9. The results showed the Citarik River was in a mildly polluted condition.

Scomberomorus guttatus is a large pelagic fish commodity in Pangandaran Regency. It has the highest amount and production values, therefore it needs to be maximally utilized but remains its sustainability. The purpose of this research is to determine the most selective fishing gear for Scomberomorus guttatus commodities based on the frequency of Scomberomorus guttatus length, the proportion of the main catch and by-catch in Pangandaran Regency for sustainable and environmentally friendly capture fisheries management. The data used in this study are the number of catches, catch weight and length of the Scomberomorus guttatus catches from gillnet, longline, and beach seine. Data used in research collected during November 2018-January 2019 in Pangandaran Regency. Analysis data used in the study is the analysis of the selectivity of the types of catches and the selectivity of the length of the catchable Scomberomorus guttatus from each of fishing gears. The results showed that of the three fishing gears used to catch Scomberomorus guttatus, gillnet is the most selective and productive fishing gear for utilizing Scomberomorus guttatus commodity because it has a 43,2% of main catch, 84,6% of the feasible Scomberomorus guttatus size. Longline is a fishing gear that is only selective to the length size of the Scomberomorus guttatus that has a percentage of decent size catch equal to 86,4%, while beach seine isn't selective fishing gear and unproductive for Scomberomorus guttatus commodities due to it designed to catch a demersal fish.

Fish farming has a long tradition in Central Europe. Aquaculture is highly developed here and even so, freshwater fish meat consumption is still very low. Freshwater fish meat is an important source of n–3 long-chain polyunsaturated fatty acids (PUFA), principally eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which have an indisputable effect on human health and prevent the genesis of human coronary disease. Previous researches revealed many aspects affecting the PUFA quantity. In general, the fatty acid composition of fish lipids affects age, seasonal change, nutrition, sex, reproductive cycle, geographical location, etc. This review represents a step towards the characterization of the fatty acid composition of economically important freshwater fish species from different points of view, including the above-mentioned factors and taking into consideration the way of stunning and differences of lipid composition in individual fish body sections.