Role of Phytobiotics in Modulating Transcriptomic Profile in Carps: A Mini-Review.

Carp is a key aquaculture species worldwide. The intensification of carp farming, aimed at meeting the high demand for protein sources for human consumption, has resulted in adverse effects such as poor water quality, increased stress, and disease outbreaks. While antibiotics have been utilized to mitigate these issues, their use poses risks to both public health and the environment. As a result, alternative and more sustainable practices have been adopted to manage the health of farmed carp, including the use of probiotics, prebiotics, phytobiotics, and vaccines to prevent disease outbreaks. Phytobiotics, being both cost-effective and abundant, have gained widespread acceptance. They offer various benefits in carp farming, such as improved growth performance, enhanced immune system, increased antioxidant capacity, stress alleviation from abiotic factors, and enhanced disease resistance. Currently, a focal point of research involves employing molecular approaches to assess the impacts of phytobiotics in aquatic animals. Gene expression, the process by which genetic information encoded is translated into function, along with transcription profiling, serves as a crucial tool for detecting changes in gene expression within cells. These changes provide valuable insights into the growth rate, immune system, and flesh quality of aquatic animals. This review delves into the positive impacts of phytobiotics on immune responses, growth, antioxidant capabilities, and flesh quality, all discerned through gene expression changes in carp species. Furthermore, this paper explores existing research gaps and outlines future prospects for the utilization of phytobiotics in aquaculture.

Resveratrol impacts on aquatic animals: a review.

Aquaculture has intensified tremendously with the increasing demand for protein sources as the global population grows. However, this industry is plagued with major challenges such as poor growth performance, the lack of a proper environment, and immune system impairment, thus creating stress for the aquaculture species and risking disease outbreaks. Currently, prophylactics such as antibiotics, vaccines, prebiotics, probiotics, and phytobiotics are utilized to minimize the negative impacts of high-density farming. One of the promising prophylactic agents incorporated in fish feed is resveratrol, a commercial phytophenol derived via the methanol extraction method. Recent studies have revealed many beneficial effects of resveratrol in aquatic animals. Therefore, this review discusses and summarizes the roles of resveratrol in improving growth performance, flesh quality, immune system, antioxidant capacity, disease resistance, stress mitigation, and potential combination with other prophylactic agents for aquatic animals.

Assessment of dietary polyvinylchloride, polypropylene and polyethylene terephthalate exposure in Nile tilapia, Oreochromis niloticus: Bioaccumulation, and effects on behaviour, growth, hematology and histology.

Microplastics (MPs) have been recognized as emerging aquatic pollutants receiving major concern due to their detrimental effects on aquatic life. Nile Tilapia, Oreochromis niloticus is a model species considered in toxicological studies to address the effects of pollutants in freshwater animals. However, comprehensive knowledge comparing the impacts on fish across various MPs polymers is scarce. Therefore, the overarching aim of the current study was to examine the bioconcentration of MPs polymers: polyvinylchloride (PVC), polypropylene (PP), and polyethylene terephthalate (PET), and their toxic effects on growth, and behavioral responses, hematology, and histology of gills, liver, and intestine in O. niloticus. Fishes were subjected to a 21-day dietary exposure to MPs by assigning them into six treatment groups: T1 (4% of PVC), T2 (4% of PP), T3 (4% of PET), T4 (8% of PVC), T5 (8% of PP), T6 (8% of PET), and control (0% of MPs), to assess the effects on fish across the polymers and dosage. Results showed several abnormalities in anatomical and behavioral parameters, lower growth, and high mortality in MPs-exposed fish, indicating a dose-dependent relationship. The elevated dosage of polymers raised the bioavailability of PVC, PP, and PET in gills and gut tissues. Noteworthy erythrocyte degeneration referred to cytotoxicity and stress imposed by MPs, whereas the alterations in hematological parameters were possibly due to blood cell damage, also indicating mechanisms of defense against MPs toxicity. Histopathological changes in the gills, liver, and intestine confirmed the degree of toxicity and associated dysfunctions in fish. A higher sensitivity of O. niloticus to PET-MPs compared to other polymers is likely due to its chemical properties and species-specific morphological and physiological characteristics. Overall, the present study reveals valuable insights into the emerging threat of MPs toxicity in freshwater species, which could be supportive of future toxicological research.

The Potential of Fish Protein Hydrolysate Supplementation in Nile Tilapia Diets: Effects on Growth and Health Performance, Disease Resistance, and Farm Economic Analysis.

Fish protein hydrolysate (FPH) has shown immense potential as a dietary protein supplement and immunostimulant in aquaculture, especially in Nile tilapia production. Four isoproteic diets (30% crude protein) were prepared by including FPH at varying percentages (0%, 0.5%, 1%, and 2%). Nile tilapia fed with FPH diets for 90 days, and their growth performance, feed utilization, blood biochemistry, liver and gut morphology, and resistance against Streptococcus iniae were investigated. The findings revealed that diets physical attributes such as pellet durability index and water stability were remarkably (p < 0.05) varied between experimental diet groups. Furthermore, the test diets were more palatable when FPH was included at 1% and 2%. Fish that were fed with a 2% FPH-treated diet had significantly (p < 0.05) greater growth indices than other treatments. Additionally, their feed utilization was significantly (p < 0.05) improved. The experimental diets and intestinal total bacteria count (TBC) exhibited a rising trend with FPH levels, where the 2% FPH-treated diet recorded the highest TBC. Neutrophil (109/L), lymphocyte (109/L), eosinophil (109/L), and red blood cell(1012/L) counts were significantly (p < 0.05) higher in the 2% FPH-treated group, while the white blood cell (109/L), and basophil (109/L) counts were not influenced by the FPH inclusion. Moreover, the FPH-treated groups displayed lower creatinine, bilirubin, and urea levels than the control. The histological examination demonstrated that themid-intestine of 2% FPH-fed Nile tilapia had an unbroken epithelial wall, more villi with frequent distribution of goblet cells, wider tunica muscularis, and stronger stratum compactum bonding than other treatments. Additionally, this group exhibited more nuclei and erythrocytes and less vacuolar cytoplasm in liver than their counterparts. Nile tilapia that were given a diet containing 2% FPH had significantly (p < 0.05) higher resistance (83.33%) to S. iniae during the bacterial challenge test. A significant (p < 0.05) enhancement in farm economic efficiency was observed in the higher inclusion of FPH in diets. In summary, 2% FPH supplementation in Nile tilapia diets improved their growth performance, feed utilization, health status, disease resistance, and farm economic efficiency.

Comparative analysis of biometrical and reproductive indices, proximate composition, and hemato-biochemical variables of cuchia eel Monopterus cuchia (Hamilton, 1822) from six different localities of Bangladesh.

Cuchia eel (Monopterus cuchia) is among the most sought-after freshwater fish, owing to its exceptional nutritional profile and high consumer demand. The current research aimed to establish baseline data by comparing the proximate composition, hematological, and plasma biochemical indices of Cuchia eel populations across six different geographical locations in Bangladesh: Bogra, Haluaghat, Jamalpur, Moktagacha, Sylhet, and Tangail. By examining these parameters, we aim to gain valuable insights into the nutritional benefits, physiological responses, and potential adaptations of this species to varying environments. The statistical analysis revealed no significant (P > 0.05) variances in the whole-body proximate composition of the fish captured from distinct areas. However, it was observed that different geographical regions had remarkable impacts on the variations of the majority of the hematological parameters, except for some cases. Additionally, there was a notable (P < 0.05) increase or decrease in most of the serum biochemical contents in certain localities as compared to others in this study. Light microscopic examination of Cuchia eel blood smears exhibited lower numbers but larger sizes of RBCs. The findings of this study lead to the conclusion that different localities had significant impacts on the hematology and blood biochemical indices of Cuchia eel, even though the whole-body proximate composition showed no significant variations. This research contributes to a deeper understanding of the physiological aspects of Cuchia eel.

The Potential of Fermented Water Spinach Meal as a Fish Meal Replacement and the Impacts on Growth Performance, Reproduction, Blood Biochemistry and Gut Morphology of Female Stinging Catfish (Heteropneustes fossilis).

The identification and development of a new plant-based feed ingredient as an alternative protein source to FM have gained the interest of the aquafeed industrial players. Therefore, this study aimed to investigate the physical, biochemical, and bacteriological properties of dietary FWM and the impacts on the growth and reproductive performances of farmed female stinging catfish, H. fossilis broodstock. Five experimental diets were formulated with different FWM inclusion (0, 25, 50, 75, and 100%). Fatty acid profiles such as 4:0, 10:0, 20:0, 21:0, 22:0, 24:0, 20:1n9, 18:3n6, 20:3n6, 20:4n6, and 22:6n3 were found in higher levels in FWM compared to the water spinach meal (WM). Meanwhile, there were no significant differences in the physical properties of the FWM experimental diets (p > 0.05). Furthermore, the experimental feed with 0%, 25%, 50%, and 75% FWM were more palatable to the broodstock than 100% FWM. The number of total bacteria (TB) and lactic acid bacteria (LAB) in catfish diets exhibited a rising trend with an increase in FWM, while 50% of FWM-fed fish intestines had a significantly (p < 0.05) higher TB and LAB than other treatment groups. The growth, feed utilization, and reproductive variables of H. fossilis were significantly (p < 0.05) influenced by FWM inclusion at various levels. Moreover, the significantly (p < 0.05) highest oocytes weight, fertilization, egg ripeness, and ovipositor diameter were observed in the treatment of 50% FWM diet treatment group. In addition, the spawning response was 100% in all treatments except for the control group (66.67%). Significant differences (p < 0.05) were found in the hematological and serum biochemical indices in most treatment groups. In addition, the histological analysis of H. fossilis midintestinal tissue indicated that the fish fed with a 50% FWM diet had an unbroken epithelial barrier with more goblet cell arrangements and a well-organized villi structure and tunica muscularis compared to other treatment groups. These outcomes suggested that FWM at 50% inclusion is an adequate protein supplement for fish feed, resulting in better growth, reproductive performance, and health of H. fossilis broodstock development.

Exploring the roles of phytobiotics in relieving the impacts of Edwardsiella tarda infection on fish: a mini-review.

Edwardsiellosis caused by Edwardsiella tarda resulted in significant economic losses in aquaculture operations worldwide. This disease could infect a wide range of hosts, including freshwater, brackish water, and marine aquatic animals. Currently, antibiotics and vaccines are being used as prophylactic agents to overcome Edwardsiellosis in aquaculture. However, application of antibiotics has led to antibiotic resistance among pathogenic bacteria, and the antibiotic residues pose a threat to public health. Meanwhile, the use of vaccines to combat Edwardsiellosis requires intensive labor work and high costs. Thus, phytobiotics were attempted to be used as antimicrobial agents to minimize the impact of Edwardsiellosis in aquaculture. These phytobiotics may also provide farmers with new options to manage aquaculture species' health. The impact of Edwardsiellosis in aquaculture worldwide was elaborated on and highlighted in this review study, as well as the recent application of phytobiotics in aquaculture and the status of vaccines to combat Edwardsiellosis. This review also focuses on the potential of phytobiotics in improving aquatic animal growth performance, enhancing immune system function, and stimulating disease resistance.

Comparative study of ovarian development in wild and captive-reared long-whiskered Sperata aor (Hamilton, 1822).

Long-whiskered catfish Sperata aor is a freshwater catfish known for its supreme flesh quality and fast growth, whose captive-reared broodstock denotes a difficult challenge for aquaculture. The reproductive dysfunctions in long-whiskered catfish raised in tank conditions were observed by comparing tissue biochemical composition and ovarian histology of wild female broodstock. Sixty (60) female broodstocks were used in the current study, consisting of 30 reared at sandy-muddy soil tank bottoms in captive conditions and 30 wild individuals collected from the haor basin during the breeding season. The fish reproductive state was investigated using the biometric and reproductive parameters, biochemical composition and levels of amino acids in the different tissues, and histological analysis of ovarian development. Results revealed that the biometrical parameters of wild and captive female broodstocks exhibited no remarkable difference (p > 0.05). Nevertheless, the wild fish had remarkably higher (p < 0.05) GSI (8.73%), oocyte weight (0.45 mg/egg), and ripeness (27.08%) in comparison with captive-reared broodstock. The total length and body weight, body weight and ovary weight, ovipositor diameter and ovary weight, and GSI and HSI displayed a positive relationship with R2 = 1, R2 = 1, R2 = 0.993, and R2 = 0.973, respectively, for wild broodstock, while R2 = 0.994, R2 = 0.806, R2 = 0.804, and R2 = 0.896, respectively, for captive broodstock. Additionally, the proximate composition in oocytes and liver tissues in both broodstocks did not differ significantly (p > 0.05). However, two essential amino acids (EAA), i.e., lysine and phenylalanine, and two non-essential amino acids, i.e., glutamic acid and glycine, were highly significant differences (p < 0.05) in the oocytes and liver of wild broodstock compared to the captive-reared broodstock. On the other hand, the EAA, e.g., isoleucine, threonine, leucine, and arginine, were highly dominated in both wild and captive female brood oocytes and liver. The ovarian histological slides from each fish group showed three oocytes developmental stages that indicated the asynchronous-reproductive ovarian oocytes of this fish. This study may be useful to fully understand the factors affecting the spawning and reproduction of S. aor broodstock, crucial for management in captive conditions as well as conservation and protection for sustainable aquaculture management of S. aor.

The Roles of Polysaccharides in Carp Farming: A Review.

Carp is an important aquaculture species globally, and the production is expected to increase with the growing market demands. Despite that, disease outbreaks remain a major challenge, impeding the development of sustainable carp farming. Moreover, the application of antibiotics, a common prophylactic agent, can adversely impact public health and the environment. Therefore, polysaccharide has been recognized as a novel prophylactic agent in the health management of carp farming, as well as gaining consumers' confidence in carp farming products. In this review, the definition, sources, and main roles of polysaccharides in improving growth performance, stimulating the immune system, enhancing disease resistance, and alleviating abiotic stresses in carp farming are discussed and summarized. In addition, the use of polysaccharides in combination with other prophylactic agents to improve carp farming production is also highlighted. This review aims to highlight the roles of polysaccharides and provide valuable information on the benefits of polysaccharides in carp farming.

The roles of soybean lecithin in aquafeed: a crucial need and update.

Soybean lecithin is extensively used as the dietary supplementation of phospholipids in animal production. Soybean lecithin plays significant roles in aquafeed as growth promoter, feed enhancer, immunity modulator and antioxidant activity stimulator for aquaculture species. Besides, soybean lecithin is also reported to help aquaculture species being resilient to physical and chemical stressors. In this review, common sources, chemical structure and mode of action of lecithin, with highlight on soybean lecithin application in aquaculture over four-decadal studies published between 1983 and 2023, were evaluated and summarized. By far, soybean lecithin is best-known for its beneficial effects, availability yet cost-effective for aquafeed formulation. Findings from this review also demonstrate that although nutritional profile of long-chain polyunsaturated fatty acids and phosphatidylcholine from egg yolk and marine sources are superior to those from plant sources such as soybean, it is rather costly for sustainable application in aquafeed formulation. Moreover, commercially available products that incorporate soybean lecithin with other feed additives are promising to boost aquaculture production. Overall, effects of soybean lecithin supplementation are well-recognized on larval and juvenile of aquaculture species which having limited ability to biosynthesis phospholipids de novo, and correspondingly attribute to phospholipid, a primary component of soybean lecithin, that is essential for rapid growth during early stages development. In addition, soybean lecithin supplementation plays a distinguish role in stimulating maturation of gonadal development in the adults, especially for crustaceans.

Fermented Soybean Meal (FSBM) in African Catfish (Clarias gariepinus) Diets: Effects on Growth Performance, Fish Gut Microbiota Analysis, Blood Haematology, and Liver Morphology.

The study revealed the potential of fermented soybean meal (FSBM) as a fish meal (FM) replacement in African catfish (Clarias gariepinus) feed formulation. Five isonitrogenous diets (32% crude protein) were prepared with five different levels of FSBM as FM replacement, namely 0% FSBM (T1), 40% FSBM (T2), 50% FSBM (T3), 60% FSBM (T4), and 70% (T5). The experimental fish was given the formulated diet for eight consecutive weeks. At the end of the feeding trial, the fish were subjected to growth performance, blood parameters, blood chemical, liver histology, and gut microbiota assessment. The study findings demonstrated that the experimental fish that received the T2 diet exhibited significantly higher (p < 0.05) growth performance. Experimental fish that received diet T2 had significantly higher (p < 0.05) white blood cell (WBC) and significantly lower (p < 0.05) in terms of cholesterol (CHOL), albumin (ALB), globulin (GLOB), and total protein (TP). The replacement of FSBM to FM significantly affected liver morphology on the sinusoid, vacuole, nucleus, and erythrocytes. Gut microbiota composition analysis showed a significantly high abundance (p < 0.05) of Akkermansia muciniphila in the experimental fish that received the T2 diet. The gut microbiota indicates that the experimental fish is in a healthy condition. In conclusion, replacing 40% FSBM with FM in aquafeed could enhance C. gariepinus growth performance and health conditions.