Animal food sources provide human beings with minerals considerably in adequate quantities. Fish is an indispensable reliable source of nutrients, as aquaculture is a sector that is fast growing and which provides 50% of the world's fish production. However, fish production is hampered by the increasing costs of feeds due to the ever rising cost of fish meal, an integral component of fish feeds. Substituting fish meal with cheap, yet highly nutritious ingredients in fish feeds is therefore paramount. This study investigated the effects of substituting fish meal with adult cricket meal (ACM) and black soldier fly meal (BSFM) on minerals content of extruded fish feeds, where four levels of substitution (0, 25, 50 and 75%) were used. The effect of feed moisture content on minerals was also studied where 20 and 30% feed moisture levels were used. Leaching effects of the pellets were studied as well. The results showed a significant increase (P \ 0.05) in the levels of phosphorus and potassium as the level of fish meal substitution increased from 0 to 75%. On the other hand, iron and sodium levels reduced significantly (P \ 0.05) as the level of fish meal substitution increased. Magnesium content increased with increasing level of substitution with BSFM, but decreased with increasing level of substitution with ACM. Copper, zinc and manganese were not greatly influenced by levels of fish meal substitution. Diets that had zero substitution showed higher leaching effect for most minerals than diets that were substituted with 75% ACM or BSFM. This study found that both ACM and BSFM can be used to substitute fish meal in fish feeds and obtain adequate mineral profile and low leaching effect.
Incorporation of polyunsaturated fatty acids (PUFAs) as biofunctional compounds with feed is an effective way for gonadal maturation without any hazardous effects on animal health, and thus it is possible to save the vulnerable species from the danger of extinction. In the present study sperm quality, level of Ca(2+) concentration in serum, histological structure of the liver and developmental stages of ovary of an endangered fish species, Nandus nandus were investigated for the confirmation of the positive effects of PUFAs in reproduction and gonadal maturation. Fishes were collected from Brahmaputra River, Mymensingh, Bangladesh. Treated group was fed 1% squid extracted phospholipid supplemented diet that was mixed with silver carp fish muscle where as controlled group was fed the same except phospholipid. For histology of liver and gonads, samples were dehydrated, cleaned and infiltrated, embedded in paraffin wax and sectioned. After that, the samples were stained with hematoxylin and eosin. The photomicrographs of the stained samples were taken by using light microscope. In comparison with the control group, treated group exhibited higher gonadal maturation which resulted in spontaneous spawning. Treated female demonstrated advanced gonadal developmental stages in comparison with the controlled female during different months. During spawning season, lipid granules and normal morphological alteration were observed in case of treated fish liver, whereas less lipid granules with more histological alteration of liver were observed in control group. Serum Ca(2+) concentration in treated female was found significantly higher (P < 0.01) in contrast to the controlled female during the breeding season which was an indicator of the augment of estrogen secretion during ovarian maturation. Better sperm quality, early maturation of oocytes, less histological alteration of liver hepatocytes and spontaneous spawning performances of PUFA-treated fish were as a result of the efficiency of PUFAs in enhancing maturation. The experiment suggests that supplementation of dietary PUFAs improve the spawning performances of fish.
Background: Freshwater fish in Bangladesh are adversely affected by the washed off pesticides, used in agriculture. The aim of this study was to evaluate the impacts of a commonly used organophosphate pesticide on freshwater stinging catfish, Heteropneustes fossilis, which envisioned that the possible threats might occur by this organophosphate group to other species in the wild. Methodology: To study the potential hazards of Envoy 50 SC on H. fossilis, fry of the fish were exposed to the acute toxicity tests. Changes in the hematological parameters, organ-specific histomorphologies, and brain acetylcholinesterase (AChE) activities were determined by treating the fish with agricultural recommended dose and below that dose of 0.015 and 0.0075 ppm, respectively. Results: LC 50 of Envoy 50 SC for the fish was determined as 0.151 (0.014-0.198) ppm. Pesticide abruptly altered the normal tissue structures of the gill, liver, and kidney. The major alterations included were the gill lamellae missing, gill clubbing, hyperplasia, nuclear hypertrophy, vacuolation, glomerular expansion, increasing diameter of the renal tubules, hemorrhage, necrosis, and pyknosis. In blood cells, changes observed in the peripheral nuclear erythrocyte were large lymphocyte, dead cell, fusion of the cells, binucleated cells, tear-shaped cells, ghost cells, senile cells, and abnormal structures of the cells. Significantly lower (P < 0.05) red blood cell (RBC) count and AChE activities in fish brain due to the pesticide exposure suggested the reasons of abrupt behavior, increased oxygen consumption, and fish mortality at higher concentration of this organophosphate pesticide. Conclusion: The presence of pesticides, even at low concentrations, caused deleterious effects on the earlier life stages of a comparatively harder and robust fish, suggesting a wider range effect on the more sensitive wild life, in particular decrease in survival in their native environment. Therefore, measures should be taken to minimize the risk of contamination of the aquatic environment by such toxic chemicals.
Agricultural pesticides, eventually find their ways to aquatic ecosystems by different routes adversely affect the aquatic biota. To determine its potential hazards, acute toxicity tests (LC50) of three commonly used organophosphate pesticides, Envoy 50SC, Samcup 50EC and Dursban 20EC on Labeo rohita and Barbonymus gonionotus were performed. The LC50 (P<0.05) of these pesticides were estimated at 0.110 (0.060-0.199), 0.217 (0.204-0.231) and 0.079 (0.073-0.084) ppm for L. rohita and 0.471 (0.440-0.500), 0.789 (0.754-0.824) and 0.273 (0.260-0.286) ppm for B. gonionotus, respectively. Pesticides abruptly altered the normal structures in various fish organs like gills, kidney and liver. The major alterations included missing gill lamellae, gill clubbing, fungal granuloma, fatty degeneration, lipid droplet formation, degenerating glomeruli and kidney tubules, hyperplasia, hemorrhage, pyknosis, increased number of vacuoles, and necrosis. Envoy 50SC, Samcup 20EC and Dursban 20EC showed significant inhibition on L. rohita AChE activity at 216.7±11.0, 207.3±5.0 and 146.7±5.5 nmol/min/mg protein, respectively. In B. gonionotus, Samcup 20EC and Dursban 20EC showed significant inhibition (P<0.05), which were recorded as 242.0±6.6 and 221.7±60.3 nmol/min/mg protein, respectively. Furthermore, pesticide treated L. rohita showed higher enzymatic inhibition (51.49%) than B. gonionotus (19.60%).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.