A Comparison of Proximate Composition And Fatty Acid Profile of Indus River Fish Species

Effects of different stocking densities on growth, nutritional quality, stress and antioxidant response in Labeo rohita; cultured in in-pond raceway system

A 171-day long experimental trial was undertaken to study intricate physiological response of rohu (Labeo rohita) under stress caused by high stocking density in In-pond raceways system (IPRS). Fingerlings of rohu (initial body weight: 250 ± 1.20 g) were cultured at three different stocking densities; low density (LD) (2.27 kg/m3), medium density (MD) (3.79 kg/m3) and high density (HD) (5.30 kg/m3) in raceways of IPRS production system. Each treatment was in triplicate. Fish growth exhibited a decline in HD treatment statistically as its average weight gain/fish/day was 4.21 g as compared to MD (4.82 g) and LD (4.74 g). Nutritional profile of rohu indicated by the content of crude protein, fatty acids, and profile of amino acids was up to the set dietary benchmarks. Survival rate of fish in all the treatment groups was greater than 99%. The elevated cortisol levels observed in the HD treatment in contrast to the other treatments suggested the presence of stress. The levels of superoxide dismutase, catalase and glutathione peroxidase were also higher in HD as compared to other treatments. However, there were no difference in the level of MDA between the three treatments. Activity of amylase, protease was significantly different in treatment whereas the difference in lipase activity was found to be insignificant. It can be concluded that medium stocking density i.e. 3.79 kg/m3 outperformed the high density (5.30 kg/m3) in different aspects of this study. Nevertheless, additional research is imperative to ascertain whether any intermediate stocking density between medium (3.79 kg/m3) and high (5.30 kg/m3) such as 4 kg/m3, 4.5 kg/m3, or 5 kg/m3, could potentially serve as suitable options for rohu. It is also suggested that brood stock of rohu should be genetically improved to obtain stress resilient fingerlings which will perform better at high stocking density at large scale production level.

Investigating the optimum stocking density of tilapia (Oreochromis niloticus) for intensive production focused to in-pond raceway system

The primary objective of this trial was to study the effects of stress caused by stocking density in tilapia (Oreochromis niloticus) cultured in the in-pond raceway system (IPRS). Fingerlings (Initial body weight = 30.00 ± 1.20 g) were reared at different stocking densities i.e. low stocking density (n = 13,000; 1.77 kg/m3), medium stocking density (MSD) (n = 17,000; 2.32 kg/m3), and high stocking density (HSD) (n = 21,000; 2.86 kg/m3), all confined within the raceways of the IPRS. Each group was studied in triplicates. The observed growth revealed a regression in the HSD treatment, evident in its reduced weight gain per fish per day, in contrast to other treatments. Survival rate across all treatments was above 99%. Notably, the HSD treatment exhibited an elevated level of cortisol; however, this intensified crowding stress did not significantly undermine the nutritional value of the fish in HSD and other experimental treatments. Furthermore, an elevation in the levels of superoxide dismutase, catalase, and glutathione peroxidase was noted within the HSD treatment in comparison to the other treatments to reduce the damage caused by reactive oxygen species. As the trial proceeded, functions of digestive enzymes like amylase, protease, and lipase diminished consistently across all treatments. This could possibly signify a deliberate redirection of energy resources toward stress alleviation rather than the usual digestive processes. In summation, it can be reasonably deduced that a stocking density of approximately 2.32 kg/m3 (MSD) emerges as the optimal threshold for effectively cultivating tilapia within an intensive aquaculture framework.

Nutritional profiling of some selected commercially important freshwater and marine water fishes of Bangladesh

The purpose of the study was to investigate the proximate composition and mineral content of Bangladesh's economically important freshwater and marine water fish. Proximate composition and mineral content was determined according to the Association of Official Agricultural Chemists (AOAC) standard method. All of the factors had a substantial variation (p < 0.05), according to the findings. The maximum protein content was observed in Lates calcarifer (18.673%) and minimum in Pangasius pangasius (15.616%). The content of lipid among the species varied from 0.316% to 13.396%, with Mugil cephalus having the highest lipid content and Channa striata having the lowest. The moisture content ranges from 68.343% to 81.160%. All the fishes have an average ash content of 0.850%–4.350%. The energy content is also significantly higher in marine water fishes. The mineral content was highly variable. Calcium content was lowest in Pangasius pangasius (0.555%) and highest in Setipinna phasa (3.495%). The magnesium content ranged between 0.281% and 1.885%. Phosphorus was lowest in Lepturacanthus savala (0.826%) and highest in Setipinna phasa (2.114%). The amount of sodium, potassium, and sulfur was relatively less for all fish species but there were substantial differences across the twelve samples. The PCA biplot's for proximate composition analyses has demonstrated positive affinity only between Lates calcarifer and Mugil cephalus in case of ash, lipid, and carbohydrate whereas Setipina phasa, Mugil cephalus, Lutjanus lutjanus, and Oreochromis mossambicus were grouped together with magnesium, phosphorus, calcium, and sulfur in the case of mineral content. Overall, the marine water fishes can be a good food item in terms of nutrition which could provide better health benefits for human.

Muscle proximate composition of various food fish species and their nutritional significance: A review

Today, there is a growing awareness about the importance of eating nutritious foods and fish is gaining momentum as a result of its unique nutritional benefits. Fish are considered as nutritionally valuable part of the human diet because of the presence of both macronutrients (proteins, lipids and ash) and micronutrients (vitamins and minerals). These nutrients are indispensable in human nutrition and have proven to be involved in several metabolic functions. The nutritional content can be used to rank different fish species based on their nutritional and functional benefits, allowing consumers to make better decisions according to their requirements. Proximate composition of fish includes determination of moisture, protein, fat and ash contents, which constitutes about 96%-98% of the total constituents of the fish body. The study of these components gives us a clear understanding in assessing the energy value of the fishes. In the present study, an attempt has been made to provide a concise review about the proximate composition of various fish species from different parts of the world in order to evaluate the high-protein, low-fat food with excellent nutritional values and to enlighten the different exogenous and endogenous factors that are actually responsible for their variation. The review also provides an insight into the characteristics of the chemical composition of various fish species, which are gaining importance for the sector involving fish and fishery products for domestic and foreign trade and for appreciating as animal feed all over the world.

An Overview of the Biological Features, Distribution, and Conservation of a Critically Endangered Riverine Catfish, Bagarius bagarius (Hamilton, 1822), in the Natural Waters of Bangladesh

Bagarius bagarius (Hamilton, 1822) is widely distributed in South and Southeast Asian countries, including Bangladesh. This species is economically important as a game and food fish. The abundance of this fish is declining around the world, especially in Bangladesh, due to a variety of meteorological and mostly anthropogenic factors, which is potentially generating concern among the conservationists. Therefore, this species has already been declared a critically endangered species by IUCN Bangladesh. Although there is no specific conservation initiative for B. bagarius in Bangladesh, various measures are there to conserve fisheries resources, which may have an impact on conserving B. bagarius in this country. This study reviews the biology and ecology with its distribution throughout the country as well as the world, threats, conservation measures, and finds out the gaps in research on this fish. Moreover, this review suggests a suitable conservation framework to improve the conservation strategy for this critically endangered fish that can be replicated in other countries for the same purpose.

Analysis of the growth performance, stress, profile of fatty acids and amino acids and cortisol in Tilapia (Oreochromis niloticus), cultured at high stocking density using in-pond raceway system

In-pond raceway system technology (IPRS) was introduced in Pakistan in 2019 as solution for sustainable aquaculture approach by effectively increasing production, reducing pollution and facilitating feed and pond management. Fingerlings of GIFT Tilapia (Oreochromis niloticus) (n = 16,500 in each raceway, initial weight = 32.00 ± 1.26 g) were stocked in June 2019 in two IPRS raceways (area of each raceway = 220 m3) for 171 days until harvested on November 30, 2019. Fingerlings stocked in traditional earthen ponds (area of each pond = 6167 m3) were studied as control (n = 3000 in each pond, initial weight = 32.00 ± 1.26 g). Average harvested biomass from raceways was 57.33 kg/m3 with an average daily weight gain per fish of 4.47 g per day. On the other hand, average harvested biomass from control ponds was 0.38 kg/m3 with an average daily weight gain per fish of 4.60 g per day. Average feed conversion ratio (FCR) in both raceways and control ponds was recorded as 1.25 and 1.24, respectively. Overall survival rate in both raceways and control ponds was above 99%. No sign of any disease was noted at any stage in both study groups. Crude protein and fats contents did not reduce in any raceway despite of high stocking density and sharp seasonal changes. Profile of essential and non-essential amino acids were found to be upto nutritional requirements of adult human. High levels of n-3 and n-6 fatty acids in fish collected from raceways as compared to those in traditional earthen pond show that muscle quality was not compromised due to high stocking density in small area. Return on investment excluding capital cost was 47.05 which implies that IPRS technology can be economically feasible with further modifications.