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The present study was conducted to investigate the interaction of biofloc water supplementations and potential zooplankton abundance and structure in Nile tilapia Oreochromis niloticus -rearing systems on zootechnical performance and biochemical indicators. Nile tilapia juveniles (13.30 g and 9.50 cm) were randomly distributed into 18 fiberglass tanks (500 L/tank with a stocking density of 40 fish/tank) to start the feeding experiment for 60 days. Fish weights were recorded weekly to adjust the feeding rate at 3% of their biomass using a commercial diet. Compared to the control group (T0, zero biofloc water supplementation), the influence of five biofloc supplementation levels was applied as follows: 14.2, 28.4, 42.6, 56.8, and 71 g L−1 (T1, T2, T3, T4, and T5, respectively). The biofloc was prepared in an external fermentor fiberglass tank (300 L) and added to the fish tanks to keep the biofloc levels constant during the experiment. After 30 and 60 days of the experiment, the number of zooplankton was 46,501 and 24,537 Ind. L−1, respectively, which included four families (Rotifera, Copepoda, Cladocera, and free-living nematodes) with the domination of family Rotifera at 81.65% and 93.89%, respectively. The water quality indicated was within the standard values recommended for fish culture. Compared to those of the control group, the values of growth performance, whole-body biochemical composition, and blood biochemical indicators were significantly higher in biofloc groups than in the control group. Group T3 achieved the highest significant growth performance values. In comparison with the control group, T3 achieved the lowest number of cultures and the abundance of small invertebrate prey after 60 days of culture. The fish reared in groups T0 and T1 showed the highest significant urea content and the highest concentrations of liver function enzyme activities. Interestingly, compared to all groups, T3 achieved the best feed conversion ratio (FCR) value (1.68). Principal component analysis (PCA) and Pearson's correlation coefficient confidence (PCCC) clarified a close positive relationship between T0 and T3 with the total individual, Rotifera abundance, and FCR. The highest PCCC value with T0 was in group T3 (0.947). In conclusion, biofloc supplementation (42.6 g L−1) showed a sustainable clean aquadiet strategy and significantly improved Nile tilapia growth and FCR with regard to the culture of small prey invertebrates for 60 days. [ABSTRACT FROM AUTHOR]

Simple Summary: This study assessed the combined effects of dietary yeast and thymol on the growth and health of rainbow trout. The results showed that dietary yeast supplementation improves fish growth, antioxidant and immunological parameters. Dietary thymol supplementation does not improve fish growth but does improve antioxidant and immunological parameters. Dietary yeast and thymol supplementation shows interaction effects on the gut-immune-related transcripts. Based on the results, yeast supplementation was particularly effective in enhancing fish growth performance and non-specific immunity, while thymol supplementation primarily led to improved antioxidant capacity. This study assessed the effects of thymol and yeast Saccharomyces cerevisiae on the growth performance, antioxidant capacity and immunological responses and gut immunological transcripts in rainbow trout, Oncorhynchus mykiss. Two hundred and seventy fish (6.62 ± 0.18 g) were distributed in 18 aquaria (15 fish per aquarium) as a 2 × 3 factorial design. The fish were fed on diets containing 0 and 1 × 108 cfu/g of yeast and 0, 250 and 500 mg/kg of thymol for 60 days. The results showed that dietary yeast supplementation led to significantly improved fish weight gain and feed efficiency (p < 0.05). Thymol and yeast supplementation affected the hepatic antioxidant status, leading to lower lipid peroxidation and higher glutathione reserves (p < 0.05). Thymol and yeast supplementation led to significantly lowered plasma aspartate aminotransferase levels (p < 0.05). Dietary yeast supplementation led to significantly elevated plasma and mucus lysozyme, plasma alternative complement, immunoglobulin and mucus alkaline phosphatase levels. In contrast, thymol supplementation led to significantly increased plasma lysozyme and mucus alkaline phosphatase levels (p < 0.05), whereas it had no significant effects on other immunological parameters. The mucus bactericidal activities were improved by dietary yeast but both supplements enhanced the plasma bactericidal activity (p < 0.05). Thymol and yeast supplementation significantly up-regulated the expression of tumor necrosis factor-alpha, interleukin-1 beta, transforming growth factor-beta, beta-defensin and heat shock protein-70 in the hindgut (p < 0.05). In conclusion, dietary yeast supplementation was particularly effective in enhancing fish growth performance and non-specific immunity, while thymol supplementation primarily led to improved antioxidant capacity. Notably, a dietary dose of 250 mg/kg of thymol alone failed to affect the gut transcription as much as 500 mg/kg; however, the co-supplementation of 250 mg/kg of thymol and yeast led to comparable results. [ABSTRACT FROM AUTHOR]

Catastrophic typhoons with heavy rainfall introduce massive flow and fine sediments into stream channels. In addition, the natural disturbances and engineering practices afterward may strongly alter the fish abundance and their environment. This study compared physical habitat parameters and fish abundance before and after two major typhoons using two sampling period datasets (November 2008–March 2009 and May 2011–March 2012). The study area was in the Cishan Stream, a tributary of the Gaoping River in southern Taiwan. This area experienced two strong typhoons (Morakot and Fanapi) between the two sampling periods, providing an opportunity to compare pre- and post-typhoon conditions. The collected species were Hemimyzon formosanus, Rhinogobius nantaiensis, Onychostoma alticorpus, Candidia barbata, Acrossocheilus paradoxus, and Spinibarbus hollandi. Our results show a decrease in substrate size, fish size, and fish weight after typhoons. The river channel transformed into an unstable condition after the heavy rains, as major habitat types in our sampling stations changed from riffles with coarse substrate to runs with fine substrate. The results of statistical tests indicate the different habitat requirements of three major fish species (H. formosanus, R. nantaiensis, and O. alticorpus) and can indicate whether species' requirements change between the two sampling periods. Water depth and pebbles were critical habitat requirements for the adults of H. formosanus; water depth, pebbles, and sand were critical habitat requirements for the adults of R. nantaiensis; and flow velocity and standard deviation of flow velocity were critical requirements for the juveniles of O. alticorpus. Understanding habitat requirements can provide useful information for post-disaster restoration and contribute to eco-sensitive river engineering. [ABSTRACT FROM AUTHOR]

In the Philippines, nemipterid fishes hold substantial economic importance due to their high market value. However, the local longline fisheries lack specific regulations for managing the capture of these fishes. This study aimed to determine the optimum hook size for increasing catchability in nemipterid fishing while minimizing bycatch, thus promoting sustainable fisheries. We conducted experimental fishing at three depth ranges, using Mustad J-type hooks of 11 different sizes, ranging from #562, the largest, to #572, the smallest. All Mustad J-type hooks utilized medium-sundried Sardinella lemuru as bait. Seven Nemipteridae species and 31 other bycatch species were collected, with Nemipterus nematophorus emerging as the predominant species, constituting 61.96% and 56.99% of the catch by count and weight, respectively. The largest hook size (#562) demonstrated the lowest catch in both fish count and weight, revealing its inefficacy in capturing a wider size variation of fish. However, larger fish were collected with larger hooks, as suggested by the generalized additive model (GAM). In contrast, the generalized additive model suggested that middle-sized hooks (#566 to #568) yielded the highest catches but with an increased bycatch. Thus, these hook sizes, commonly used by many fishermen, were identified as the most exploitative and risky in terms of increasing bycatch. Using large hooks, preferably #562 to #565, would lead to an increase in the individual catch size for nemipterids, to reduce the small-size fish, and to minimize bycatch. These results suggest that regulating hook sizes is essential for sustainable fishing, which can result in a potential short-term reduction in catch rates but offer long-term benefits for nemipterid fisheries management. [ABSTRACT FROM AUTHOR]

Simple Summary: The limited understanding of the fractionation of rare earth elements (REEs) in fish has hindered the effective use of biomonitoring to assess REEs contamination in aquatic environments. Guangzhou City, which faces widespread emissions of REEs, urgently needs biomonitoring of REEs. Therefore, this study took Guangzhou City as a case study and conducted wild fish collections to investigate the bioaccumulation and fractionation of REEs. Additionally, the associated health risks were evaluated to guide fish consuming. This study confirmed the different REEs bioaccumulation and fractionation among 11 fish species. The bioaccumulation of REEs was found to be a process that could mitigate REEs fractionation. The bioaccumulation and fractionation of REEs among fish with feeding behaviors and living habitats were determined to be specific, so that REEs bioaccumulation and fractionation could be used for tracing the environmental behaviors of fish. Food sources should be treated as the critical regulator in varying REEs bioaccumulation and differentiation. The overall low content of REEs in wild fish shows their consumption should not pose a relevant risk. In this study, the total content of REEs ranged from 1.32 to 67.74 μg/kg, with a predominant presence of light REEs. The ΔEu and ΔCe values, which exceeded and approached 1, respectively, indicated positive Eu anomalies and low Ce anomalies. Wild fish were categorized into high-, medium-, and low-REEs-bioaccumulation groups using cluster analysis. Higher LRs/HRs and ΔEu values, coupled with lower ΔCe values, in fish from the high-bioaccumulation group suggested that increased bioaccumulation mitigated fractionation. Omnivorous fish with higher REEs levels and lower LRs/HRs indicated broader feeding sources may enhance REE bioaccumulation and diminish fractionation. Elevated REEs concentrations and LRs/HRs in demersal fish highlighted a preferential accumulation of light REEs in the benthic environment. Smaller fish with higher REEs levels but lower LRs/HRs were likely associated with complex feeding sources. Regression analysis revealed that fish with lengths and weights of less than 18 cm and 130 g, respectively, were more susceptible to REEs bioaccumulation. Despite higher ADI values indicating a greater risk for children and Pelteobagrus fulvidraco, all ADI values within 70 μg/(kg·d) suggested that fish consumption poses no risk. This study confirmed that the fractionation of REEs in fish can be used to trace their bioconversion. [ABSTRACT FROM AUTHOR]

The latest strain of Oreochromis niloticus is an altered ecological adaptation for sustainable aquaculture and is necessary to sustain stocking density and reduce physiological stress of the new strain. The present study aimed to determine the optimum stocking density, biological performance, and economic efficiency of the Nile tilapia. The 14,000 healthy seeds and uniform weight (40 ± 2.4 g) sex‐reversed Oreochromis niloticus were stocked in four cages, which are cage (1) 20 fish/m3, cage (2) 30 fish/m3, cage (3) 40 fish/m3, and cage (4) 50 fish/m3. The fish were fed 30% dietary protein and feeding frequency three times per day and the feeding rate adjusted according to the fish body weight. Results showed a significantly higher growth, weight gain, and specific growth rate in Nile tilapia stocking density on cage (1), 20 fish/m3 and cage (2), 30 fish/m3 compared to cage (3), 40 fish/m3 and cage (4), 50 fish/m3 (p < .05). The survival and growth rate showed an inverse relationship with stocking density. The feed conversion ratio (FCR) is the lowest in cage (1) and cage (2), which is significantly different from those of other cages (p < .05). The profit index (%) was significantly higher at low density. There was no significant variation in the HSI, VSI and CF. The digestive enzymes such as lipase and amylase were secreted highly in the cages (3) and (4) but high protease was secreted in cage (1). The lipid, ash, and protein of the whole fish were reduced to a lower density, but the moisture levels in the fish bodies raised significantly (p < .05) with increasing stocking density. The phenomenal regression indicates that 25–35 fish/m3 are optimum stocking density for Nile tilapia in the cage culture system. The current study has made significant step toward optimizing the stocking density of a new strain and developing cage culture in Pakistan. [ABSTRACT FROM AUTHOR]

Body length and weight are key parameters measured to provide information about the growth and condition of larval, juvenile, and adult fishes from both the wild and aquaculture. The goal of this study was to evaluate the effects of preservation in formalin and alcohol on juvenile rainbow trout, Oncorhynchus mykiss (Walbaum) standard body length (SL) and weight changes. Standard length (19.43–32.98 mm SL) decreased after 60 days of preservation by an average of 2.98% in 96% alcohol and 2.26% in 10% formalin. In contrast, fish body weight (0.094–0.63 g) decreased in alcohol (31.22%) but increased in formalin (11.65%). These percentage values can be used as correction factors, with the exception of fish body weight in alcohol since the size of individuals affected the magnitude of change. Accordingly, a correction formula accounting for fish weight must be applied (fresh weight (g) = -0.0363 + 1.667 × preserved length). Changes in fish length and body weight in different preservatives resulted in significant differences in the Fulton condition factor, with underestimation in alcohol (fresh F = 1.58; preserved F = 1.20) and overestimation in formalin (fresh F = 1.60; preserved F = 1.92). [ABSTRACT FROM AUTHOR]

This study analyzed the length–weight relations and condition factors of 13 species belonging to three highly endemic genera: Oxynoemacheilus (6), Seminemacheilus (2) and Cobitis (5). Fish were sampled in several streams and lakes using a backpack electroshocker. Analyses were based on a total number of individuals, which was n = 304. A linear regression model was applied to determine the relationship between fish length and weight. The coefficient of determination (R2) ranged from 0.950 to 0.980 for all populations (p < 0.05). Allometric coefficient 'b' values ranged from 2.498 to 3.201 for Oxynoemacheilus, from 2.970 to 2.127 for Seminemacheilus, and from 2.111 to 3.076 for Cobitis populations. Fulton's condition factor for Oxynoemacheilus, Seminemacheilus and Cobitis ranged from 0.391 to 3.080. This study addresses gaps in LWR and CF information for a number of ecologically important freshwater fish species. It is expected that the results of this research provide baseline data for further fisheries management studies and may support conservation studies of related species. [ABSTRACT FROM AUTHOR]

The number of artisanal fishers and consequently their catch in the Sava River have been declining significantly for years. The aim of this study is therefore to examine how this affects the average weight of the most important fish species caught. The average weight increased significantly for bream Abramis brama (P < 0.01), pike-perch Sander lucioperca (P < 0.01) and wels catfish Silurus glanis (P < 0.05), while this was not the case for common carp Cyprinus carpio and pike Esox lucius (P > 0.05). Although recreational anglers also catch fish in the same waters, together with the two groups of fishermen from Bosnia and Herzegovina from the other bank of the river, it is expected that the average weight of the main fish caught will not decrease under the current circumstances. [ABSTRACT FROM AUTHOR]

Six 0.1‐ha earthen ponds with 45 kW/ha of aeration capacity were stocked with hybrid catfish (Ictalurus punctatus x I. furcatus) ranging from 15,000 to 90,000 fish ha−1 in 15,000 fish ha−1 increments to analyze the effect of nitrogen loading on ammonia accumulation and fish production. Minimum dissolved oxygen (DO) concentration was maintained above 3.0 mg O2 L−1 to prevent hypoxia‐induced appetite reduction. Stocking density did not impact survival but decreased average fish harvest weight and increased food conversion ratio (FCR). Gross production increased with stocking density and ranged from 7249 to 35,674 kg ha−1. Average total (TAN) and un‐ionized ammonia (NH3) were not different among stocking densities despite greater nitrogen inputs in ponds with higher feeding rates. Nitrite (NO2−) and nitrate (NO3−) concentrations were significantly higher in ponds with higher stocking densities, suggesting that nitrification increased with nitrogen loading. Phytoplankton assimilation of ammonia is the primary ammonia removal process in traditional catfish ponds with modest fish densities and feeding rates. However, in intensively aerated ponds with high feeding rates, nitrification can become an important process for ammonia removal. These data indicate that small earthen hybrid catfish ponds with high aeration capacities can increase catfish production without ammonia accumulating. [ABSTRACT FROM AUTHOR]

This research evaluated the suitability of commercially available larval feeds, Otohime B2 (OB2), Aller Infa (AI), and Aqua Start (AS), and one Experimental Feed (EF), for the weaning of largemouth bass (Micropterus salmoides), LMB. Feeds were presented with various ?-3 fatty acid levels/bioavailability (high in OB2 and AI), fat percentage (high in OB2 and AS), free amino acid and short peptide (FAA + SP) levels (high in OB2), and various soluble protein (SPR) levels (high in AS and EF). Fish were co-fed Artemia plus OB2 from the 19th to 22nd day post-hatching (DPH), then Artemia in addition to one of the four above diets for seven days, with complete Artemia removal on the 30th DPH. Fish were sampled on the 32nd DPH. Morphometry, digestive enzyme activities, hormonal status, skeleton, muscle development, and potentially pathogenic Flavobacterium spp. levels were estimated. Survival was high (96% or more) in all the weaning regimes. Weaning to OB2 was linked to a fast fish growth rate (14.29%/day), while both OB2 and AI supported the skeleton development. Weight gain correlated with total fat, ash levels, free amino acids, and short peptide levels in the diet. Larvae weaned to soluble proteinrich AS and EF showed the lowest fish weight gain and skeleton development, and lower growth of potentially pathogenic Flavobacterium spp. This research suggests that the weaning diets for largemouth bass should have a balanced protein content and quality while allowing for the inclusion of fewer marine ingredients. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study evaluated the effect of four different feeding regimes on the growth, health, economic effiency and perception of aquaculturists regarding Oreochromis sp. in the Guayas Province, Ecuador. Four treatments based on different feeding regimes were established: T1, once a day with a daily interval; T2, once a day with an interval every two days; T3, twice a day with a daily interval; and T4, twice a day with an interval every two days. Growth parameters such as total fish weight gain, average daily weight gain, daily feed intake, expected weight gain for each daily feed intake, feed conversion ratio, protein efficiency, and protein productive value were measured. Health parameters included serum total protein content, albumin, serum globulins, cholesterol, triglycerides, and glucose levels. Economic efficiency parameters such as feed cost and feed cost per kilogram of weight gain were also assessed. Additionally, surveys were conducted with aquaculturists to assess the perception of aquaculture farmers regarding the importance of growth factors, fish health, and economic efficiency in the selection of feeding regimes for Oreochromis sp. The results indicated that treatment T3 was the most effective in maximizing growth; treatment T1 excelled in fish health; and treatment T2 was the most economically efficient. In conclusion, the choice of feeding regime will depend on the farmers' priorities, with a general trend, according to the survey, toward economic efficiency and growth, while fish health, although relevant, is a secondary priority. [ABSTRACT FROM AUTHOR]

Sillago muktijoddhai is a marine fish found along the Bay of Bengal in Bangladesh and the coast of India. However, detailed information on its reproductive biology, length-weight relationship, and feeding habits is lacking. To fill this gap in literature, a research was conducted from August 2022 to October 2023, during which 444 individuals were collected from the Cox's Bazar coast of the Bay of Bengal, Bangladesh. The total length and weight of the fish ranged from 51.23 to 200.5mm and 2.47 to 71.73g, respectively. Analysis of the sex ratio revealed a dominance of males over females, with a ratio of 1.36:1 (X² = 10.41, P< 0.05). The condition factors indicated that males exhibited a better growth pattern than females. The gonadosomatic index suggested that the peak breeding season occurs in November. Histological observations identified four distinct stages of gonadal development for males: immature, maturing, ripe, and spent. For females, the stages were immature, maturing, mature, and ripe. The absolute fecundity ranged from 6,164 to 30,555 eggs per ovary, with a mean value of 12,176 ± 1,050. The regression coefficient (b) for the length-weight relationship was 3.213, indicating a positive allometric growth pattern. Morphometric analysis of the mouth and relative gut length revealed that S. muktijoddhai is a bottom feeder with carnivorous habits. Gut content analysis showed that crustaceans formed the major component of its diet, although zooplankton, gastropods, bivalves, and sand were also present. [ABSTRACT FROM AUTHOR]

Background: Sexual function is one of the most important aspects of life and is likely to be affected by the side effects of antihypertensive drugs. This study aimed to evaluate the effect of propranolol and prazosin on the sexual performance of female three-spot gourami. Methods: In this study, 84 female three-spot gourami were randomly divided into seven groups, including a control and six experimental groups. The experimental groups were injected with prazosin or propranolol at doses of 1, 2, and 4 mg/kg for twenty days. Finally, the histological morphology of the ovaries and sex hormone levels in the experimental groups were examined. Results: Our experiments showed changes in the oocyte stages, progressing to the cortical and vitellogenesis stages in the treated groups. Additionally, sex hormone levels increased in the groups exposed to that of propranolol and prazosin compared to the controls. The gonadosomatic index (GSI) exhibited a trend similar to the hormonal changes. The weight and length of the fish remained unchanged across the different groups. Conclusion: Our findings indicated that propranolol and prazosin, at the mentioned doses and treatment duration, had a positive effect on the sexual function of female three-spot gourami. [ABSTRACT FROM AUTHOR]

Copyright of Marine Fisheries: Jurnal Teknologi & Manajemen Perikanan Laut is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aeromonas hydrophila causes motile Aeromonas septicemia (MAS), a disease with a high mortality rate in tilapia culture. Feed-based vaccines with the incorporation of inactivated whole-cell bacteria into the feed offer promising tools to control MAS. Currently, the incorporation of genome-free bacteria as bacterial vaccine through the implementation of SimCells® technology into the feed has become a particular interest. Background/Objectives: This study investigates the efficacy of a feed-based vaccine incorporating genome-free A. hydrophila (FBV-GFAH) against MAS infection in red tilapia. Methods: The vaccine was prepared and delivered at 5% fish body weight for three consecutive days in weeks 0 (prime vaccination) and 2 (first booster vaccination), orally. Throughout a five-week experimental period, the immune-related genes (IL-1β, MHC-II, CD4, IgT, and IgM) expression in the hindgut and head kidney of the fish was determined using RT-qPCR assay. Lysozyme (serum) and overall IgM (serum, gut lavage, and skin mucus) productions were also detected. Results: Fish vaccinated with FBV-GFAH showed a significant (p ≤ 0.05) improvement in relative percent survival compared with unvaccinated fish following bacterial challenge. FBV-GFAH induced the expression of immune-related genes in the hindgut and head kidney, especially after booster vaccination. Furthermore, serum lysozyme activity and overall IgM production in serum, skin mucus, and gut lavage were also significantly (p ≤ 0.05) improved in the FBV-GFAH vaccinated fish than the unvaccinated fish. Conclusions: This study showed that FBV-GFAH is a promising feed-based vaccine technology to control MAS in cultured tilapia. [ABSTRACT FROM AUTHOR]

Microplastics are emerging pollutants of global concern, and their presence in the aquatic environment poses a serious risk for aquatic biota. While many studies have been conducted on the presence of microplastics in marine habitats, little research has been done in freshwater African reservoirs on microplastic pollution and their impacts on fish within the subtropical regions. To bridge this gap, the current study investigated microplastic abundances and distribution in freshwater fish within Nandoni reservoir, South Africa, across two seasons (i.e., hot–wet, cool–dry). Fish were randomly sampled using seine and gill nets from seven sites within the reservoir. In the laboratory, fish were then sorted according to taxa before dissecting them to remove the gills and the gastrointestinal tract (GIT). The organs were digested using hot hydrochloric acid and hydrogen peroxide, and the microplastics were classified according to their colours and shapes. Among the 94 fishes (i.e., 8 species) examined, microplastics were detected in 86.6% of the eight species caught. Microplastics were dominant in the gills and GIT during the cool–dry and hot–wet seasons, respectively. High microplastic abundances were found in the gills of Micropterus salmoides and the GIT of Coptodon rendalli, where fibres and the transparent colour were the most dominant. The results further showed high microplastic abundances in benthopelagic feeders highlighting that habitat influences fish consumption of microplastics whether directly or indirectly. Significant differences were observed in the feeding zone and season for all microplastic types. Microplastic sources in the reservoirs could be due to anthropogenic activities such as illegal dumping, fishing, and agriculture. Thus, there is a need for further investigation into the relation of fish weight, fish sex and body in relation to microplastic pollution. The highlighted ecological factors should be taken into consideration for future research and management actions aimed at mitigating and protecting the negative impacts of microplastic pollution on environmental and human health. [ABSTRACT FROM AUTHOR]

Simple Summary: Glycerol monolaurate, known for its strong antimicrobial properties, is a chemical compound formed by the combination of lauric acid and glycerol. This research focused on how glycerol monolaurate affects the growth, digestive enzyme activity, immune system, blood antioxidant level, and intestinal structure of black sea bream. This research could contribute to raising healthier aquatic animals, potentially reducing both the costs and environmental impact associated with aquaculture. These findings suggest that glycerol monolaurate may be the most suitable dietary supplement for fish; however, further research on its effect on the gut microbiota and gene expression is still required. An eight-week feeding trial was conducted to examine the impact of dietary supplementation with glycerol monolaurate (GML) on juvenile black sea bream. A basal diet was formulated containing 24% fish meal, while five additional diets were prepared, each supplemented with varying levels of GML: GML1 (0.01%), GML2 (0.02%), GML3 (0.04%), GML4 (0.08%), and GML5 (0.16%). Triplicate tanks were randomly allocated to each diet, each containing 20 fish with an initial weight of 1.55 ± 0.05 g. By the trial's end, the GML3 group displayed a notably higher final body weight (FBW), weight gain (WG), specific growth rate (SGR), and protein efficiency ratio (PER) compared to the other groups (p < 0.05), but the FCR was significantly higher in the control group. However, no significant differences were observed in the MFI, PPV, CF, HSI, IPF, VSI, or SR among the groups (p > 0.05). Regarding the proximate compositions of the dorsal muscle and whole body, no substantial differences were observed across the groups (p > 0.05). Additionally, there were no significant variations in digestive enzyme activity (p > 0.05), serum immune, or biochemical parameters in the midgut and hindgut among the treatment groups. But in the serum immune response IgM, C3 and C4 were significantly higher in the GML3 group as compared to the other groups (p < 0.05). However, the GML3 group exhibited significantly greater fore-intestinal villus height, crypt depth, villus height per crypt depth, and the number of goblet cells per villus compared to the other groups (p < 0.05). Overall, GML supplementation, particularly GML3, significantly improved growth indicators like the final body weight and intestinal morphology. While certain parameters remained unaffected, these findings suggest GML's potential as a beneficial dietary supplement in fish diets. [ABSTRACT FROM AUTHOR]

Purpose. Substantiation of the prospects for replacing fish meal in the composition of carp feeds with black soldier fly meal (Hermetia illucens) based on the analysis of studies of productive and individual functional parameters of the body of experimental groups of fish. Methodology. The first stage of the study lasted 30 days and was conducted in laboratory conditions at the Institute of Fisheries of the NAAS: a control and three experimental groups of age-1+ carp were formed, which were reared under identical optimal conditions. The control group of fish received a basic diet; in Experiment 1 black soldier fly meal was added to the feed to replace 100% of soybean meal, in Experiment 2 – to replace 100% of fish meal, in Experiment 3 – to replace 50% of fish meal. The second stage lasted 20 days and was conducted at the Lviv Experimental Station of the Institute of Fisheries of the NAAS in net cages placed in ponds. The control group of age-1+ carp was fed feed without supplements, while the experimental group was fed with black soldier fly meal to replace 100% of fish meal. During the study, the state of the main physicochemical parameters of the rearing environment was monitored. The results were analyzed using methods generally accepted in fish farming. The productive, morphological, hematological and antioxidant parameters of the fish body of experimental and control groups were determined. Findings. During both stages of the study, the temperature, oxygen, and hydrochemical conditions did not differ significantly between the experimental and control variants and met fish farming standards. Laboratory studies of fish sizes and weights showed the highest results compared to the Control were obtained in Experiment 3: body length to height ratio (l/H) – 2.64, body length to girth ratio (l/G) – 1.20, relative weight gain (RWG) – 18.5% against 16.1% in Control. In the carp muscles of all experimental groups, SOD activity was lower compared to the Control with a significant decrease of 49% in Experiments 1 and 2 (p < 0.001), in the hepatopancreas the difference was insignificant. Catalase activity in the hepatopancreas was higher in all experimental groups relative to the control group with the highest value in Experiment 2 (p < 0.01). Reverse trends were found for the content of LPO products (diene conjugates and TBC products) in muscles and hepatopancreas. In general, no significant changes in the activity of the antioxidant protection system were found in the investigated tissues; however, the obtained patterns require additional study for an objective assessment. Studies in cages showed that after complete replacement of fish meal with black lionfish meal in carp feeding, the weight of fish caught was 6.9% lower than in the Control. At the same time, a tendency for an increase in hemoglobin content and the count of erythrocytes in the blood of the experimental group compared to the control group was recorded. Originality. For the first time, the effectiveness of full or partial replacement of fish meal in carp feeds with black soldier fly meal was investigated according to a comprehensive analysis of productive, individual physiological and biochemical parameters of the fish body in the experimental groups. Practical value. The results of the study will allow determining the effectiveness and evaluating the potential of using insect protein in carp feeding on the example of black soldier fly meal. The application of the knowledge gained in fish farming practice will provide an opportunity to replace traditional feed components with an alternative cheap, affordable and environmentally friendly source of animal protein. [ABSTRACT FROM AUTHOR]

The present study aimed to isolate vibrio species from fresh and marine water fish responsible for summer mortality syndrome affecting Cage- cultured grouper species fish (Epinephelus aneus; Epinephelus guaza; Epinephelus alexandrines and Epinephelus caninus) and Lout fish (Argyrosomus regius) farms in Egypt. A total of 250 fish of each species of grouper species fish (E.aneus; E.guaza; E.alexandrines and E.caninus) and Lout fish (Argyrosomus regius) were collected at different times. The fish samples were collected at summer and autumn seasons. The fish samples were 25 from each species in each season. Clinically diseased fish were collected live then rinsed with sterile water and packed in a sterile polystyrene bag. Collected samples were immediately transported in an icebox to the private fish diseases Lab, Alexandria branch. Grouper fish weight between (500 - 1000) g and Lout fish weight (4 - 4.5) Kg. The collected fish samples were submitted directly to the lab for clinical and bacteriological examination. The results cleared that, after the clonical signs, post-mortem examination, isolation and identification on different media and molecular identification (PCR) of the isolated bacteria the main bacteria isolated from Grouper and lout were V. alginolyticus and V. parahaemolyticus. This study concluded that, the Multi stress factors are responsible for summer mortality syndrome affecting cultured grouper species fish (Epinephelus aneus; Epinephelus guaza; Epinephelus alexandrines and Epinephelus caninus) and Lout fish (Argyrosomus regius) in Egypt; thermal stress associated with heatwaves is the main predisposing factor. Co-infections are very common in nature and occur when Cagecultured grouper species fish (E.aneus; E.guaza; E.alexandrines and E.caninus) and Lout fish (A. regius) are infected by two or more different pathogens either by simultaneous or secondary infections. [ABSTRACT FROM AUTHOR]

In contemporary markets, fish are frequently wrapped in cling film, necessitating consumers' reliance on visual cues to assess freshness. This study explores whether common Japanese consumers can accurately discern fish freshness based solely on visual information. We conducted an online experiment with 529 randomly selected participants in Japan by asking them to select the freshest fish from photographs of horse mackerel with varying freshness levels. In order to elucidate the mechanism of freshness detection, we conducted principal component analysis on the quantified body color and shape data. Additionally, we measured physical characteristics such as lipid contents, gloss, length, and weight of the fish. This study examines the correlation between these visual cues and consumers' judgments, revealing the accuracy of visual indicators used by consumers in daily assessments of fish freshness. These findings suggest that a portion of Japanese consumers can correctly identify the freshness of fish based on appearance. They primarily rely on the brightness of the fish's eyes and specific color combinations of the body to judge freshness, with the shape of the fish having less impact. Comparing the selection frequency between high- and low-accuracy participants, we observed that a low accuracy in freshness detection was not solely due to a lack of sensitivity to signals from photographs, but may also result from a misinterpretation of these signals by consumers. [ABSTRACT FROM AUTHOR]

In recirculating aquaculture systems (RAS), off‐flavours accumulated in fish muscle tissue can be problematic in terms of consumer acceptance and the reputation of farmed fish products. Off‐flavours often give fish earthy, muddy, or other undesirable flavours. Typically, off‐flavours are removed during a depuration period in which fish are fasted and held in clean water. Unfortunately, this causes additional costs and delayed sales, while fish lose weight and show a decrease in lipid content. First, we studied fish growth in a partial RAS (PRAS) where the conditions are very similar to those in depuration with a water exchange rate of 4000 L kg−1 feed, compared to RAS with a 650‐L water kg−1 feed. Rainbow trout (Oncorhynchus mykiss) was reared in both systems. Our aim was to combine the benefits of a higher water exchange rate: the lack of need for biofilters and a lower accumulation of off‐flavours while obtaining stable rearing conditions. Additionally, we studied the effects of moderate feeding and H2O2 addition during depuration. The fish grew faster in a PRAS than in a RAS when fed ad libitum. Thirteen off‐flavour compounds were found in the fish flesh and 11 in the circulating water. The H2O2 addition led to decreased levels of off‐flavours in the tank water and in fish muscle. The results showed no significant differences in off‐flavours between the fed and not‐fed systems, showing that moderate feeding did not prevent a good depuration result. However, the lipid content and the overall fish weight were higher in the fed systems, which suggests more effective depuration. Increased depuration efficiency can be an important tool when considering ways to improve the profitability of production. [ABSTRACT FROM AUTHOR]

This study evaluated how feeding the common carp (Cyprinus carpio) at multiple protein levels affected their growth and body composition during the winter season. Four experimental diets with varying protein levels were tested, with protein levels of 30% (T1), 28% (T2), 26% (T3), and 35% (T4), respectively. Fish were obtained and kept in a water culture pond with dimensions of 4x4x3 meters. Fish average weight was 148.7± 5.76g, while its length measurements were recorded at 24.33± 2.45cm, fork length at 21.15± 2.34cm, and standard length at 18.96± 1.66cm. The fish were purchased from a hatchery farm in Mosul City, northern Iraq. For 90 days, the fish were fed experimental feed once daily until they reached satiation. Compared to other treatments, fish fed T2 (28% protein) showed higher daily weight gain, total weight gain, weight growth rate, relative growth rate, metabolic growth rate, and specific growth rate. The feed diet T2 had the highest Fulton and modified condition factor, reaching 4.84± 0.14; 2.81± 0.03, whereas the highest condition factor was recorded (3.34± 0.16; 2.1± 0.03) for feed treatment T3. Feeding indicators in the feed treatment T2, such as total feed intake, daily feed consumption, and total protein productivity, were greater. The protein efficiency ratios of the fish groups fed formulations T2, T1, and T3 were recorded at 1.32± 0.004, 1.34b± 0.004, and 1.425c± 0.007%, respectively. In comparison, a significant difference was detected for the fish group consuming feed T4, with a value of 1.058d± 0.009%. For the length-weight relationships, an isometric growth (26, 35%) was recorded for T3, an allometric positive growth for T2, and a negative growth for T1. [ABSTRACT FROM AUTHOR]

The roll damping coefficient is essential when considering the viscous effect in the potential-based hydrodynamic analysis of fishing vessels; it is an important factor in the roll motion response. The present study performs free roll decay simulations, altering weight variables using Computational Fluid Dynamics (CFD) to investigate the correlation between the roll damping coefficient and the weight variation of a fishing vessel. The time series of roll amplitude and roll damping coefficient are compared, for varying vertical and longitudinal centres of gravity and radii of gyration in roll motion. As the vertical centre of gravity increases, both the roll decay period and the roll damping coefficient also increase. The roll decay period tends to increase with the increase in the radius of gyration during roll motion, while the roll damping coefficient exhibits a decrease. A longitudinal centre of gravity has a limited effect on free roll decay characteristics. The roll damping coefficients between the maximum and minimum combinations of weight variables show significant differences. The findings of the present study could enhance the understanding of the safety of fishing vessels based on their loading conditions. Consequently, future research could further improve the results obtained in the present study by considering various hull shapes and speeds. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Aquatic Ecology is the property of University of Hormozgan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plastic pollution is a global problem affecting all ecosystems, and it represents most of the marine litter. Offshore aquaculture is a sector particularly vulnerable to this issue. To investigate this concern, the present study employed videography to monitor macroplastics at an offshore fish farm on Madeira Island (Portugal) and analysis of fish gut content to evaluate macroplastic ingestion by farmed sea bream Sparus aurata. Our analysis revealed that the majority of identified plastic debris originated from domestic use (66.66%) and fisheries/aquaculture activities (24.99%). While the number of dead fish suitable for sampling was limited (1.05% of the total mortality), macroplastic debris ingestion was identified in 5.15% of the total mortalities and reported for the first time in species in offshore farming conditions. Fish ingested fragmented plastic sheets, with the amount positively correlated with fish weight (r = 0.621, p = 0.031, n = 12). Notably, the stretched length of these fragments exceeded 50% of the standard length of most fish. Inconsistencies were observed in the number of samples collected per cage and per week. To ensure robust results, these discrepancies should be rectified in future studies. Additionally, extending the sampling period to encompass all seasons would be beneficial for a more comprehensive understanding of seasonal variations in plastic occurrence. [ABSTRACT FROM AUTHOR]

Nile Tilapia (Oreochromis niloticus) management procedures are directly linked to the final quality of the product. The aim of this study was to evaluate the effect of pre-slaughter density and different stunning methods on biochemical, respiratory and muscle injury parameters associated with quality and sensory characteristics of Nile tilapia fillets. Fish with an average weight of 762±105 g were used, first collected called the control group. The experiment was conducted in a 2 × 2 factorial scheme, with two densities (50 and 300 kg of live weight m−3) and two stunning methods thus totaling four treatments, with 15 repetitions per treatment totaling 75 fish sampled. Blood gas analysis, evaluation of biochemical parameters, analysis of meat quality and sensory analysis were carried out. For blood gas, biochemical and enzymatic parameters, the highest values were obtained for the density of 300 kg m−3 and asphyxia method: partial pressures of CO2; glucose and lactate, the highest values presented were 268.98 and 11.33 mg dL−1 respectively. As well as enzymatic activities, Creatinine kinase (CPK); Creatinine kinase isoenzyme (CKMB) showed higher values (768.93 and 1078.98 mg dL−1 respectively) in the higher density and asphyxia method. Conversely, when evaluating the quality parameters, the highest values were observed for lower density and thermonarcosis. High depuration density (300 kg m−3), combined with the asphyxiation stunning method, promotes changes in respiratory dynamics and provides greater stress, less firm fillet texture and greater weight loss due to cooking, as well as changes in creatine kinase (CK) and its CK-MB isoenzyme, demonstrating greater muscle damage. On the other hand, the density of 50 kg m−3 during pre-slaughter, combined with the method of stunning by thermonarcosis, provide a longer period of permanence in pre rigor mortis, which will result in fillets with a better sensory profile. [ABSTRACT FROM AUTHOR]

The interplay between environmental, biological, and physical factors often leads to the deterioration of dead fish in marine cages prior to their removal. Depending on the weight of the dead fish and the frequency of their removal, deterioration can progress to a stage where visual identification by divers becomes challenging, thereby disrupting accurate counting of dead fish. This study presents a practical precision tool for monitoring the number of dead fish during the pregrowth and growth phases of caged European sea bass (Dicentrarchus labrax). To improve the assessment of collected mortality, experiments were conducted in farming cages with various fish weights. Identifiable fish rates (I, %) were calculated every 24 hr and classified into four weight classes: WC1 (4–15 g), WC2 (15–30 g), WC3 (30–80 g), and WC4 (>80 g). The corrected number of dead fish (M) was calculated by dividing the collected number (C) by a correction factor (McR), which was determined based on the adopted removal frequency. The possible mortality removal frequencies per week (Fn) included operations such as F7 (daily), F3 (3 times), F2 (2 times), and F1 (once). The smallest correction denominator was 22% for WC1 at a frequency of once per week, whereas the maximum was 100% for WC3 and WC4 daily. The results revealed a high negative significant correlation between Fn and uncollected degraded fish rate (UR) (r = –0.841, p < 0.05). Applying corrections to mortality collected in three finished batches (B2, B3, and B7) led to an increase in the mortality rate by 3.9% ± 1.5%, 5.5% ± 0.7%, and 5.0% ± 0.5%, respectively. This explained 16.8% ± 4.7%, 65.5% ± 26.7%, and 30.3% ± 3.7% of fish disappearances in B2, B3, and B7, respectively. The significance of this study lies in its practical applicability to fish farms as a precise tool for monitoring fish raised in marine cages. [ABSTRACT FROM AUTHOR]

This study aims to identify the characteristics of skin, bones, and scales as a biomaterial byproduct of snakehead fish, Channa striata (Bloch, 1793) before and after the extraction process into gelatin, based on 36 fresh snakehead fish samples. The biomaterials were identified, including their proximate composition (by weight of protein, fat, moisture, ash) collagen, amino acids. The physicochemical properties of gelatin in terms of yield, gel strength, viscosity pH, and functional groups were determined for scales, skin and bones. Combined, these biomaterials made up about 47.74 % of the total byproduct by weight of snakehead fish that would usually be discarded. Moisture and protein content of the skin was higher than that of scales and bone (P < 0.05), and fat content was higher in bone than in skin and scales (P < 0.05). The lowest ash content was in skin (<1 %), compared to scales and bone (P < 0.05). The collagen content of scales was higher than that of skin and bone (P < 0.05). Glycine and proline in the three biomaterials were nearly equal and highest in skin, scale, and bone, respectively. There were significant differences in viscosity and gel strength of the three types of gelatin (P < 0.05), the highest viscosity was in skin gelatin while the best gel strength was in scale gelatin, while pH was not significantly different (P > 0.05). The application of the same method and solvent can produce different properties and characteristics of gelatin, and the presence of functional groups helps determine the occurrence of changes in the secondary structure of gelatin from the three biomaterials. [ABSTRACT FROM AUTHOR]

Chaunax abei Le Danois, 1978, is a bottom-dwelling species caught by bottom trawls in Suruga Bay. In the present study, we assessed the age and growth pattern of C. abei from Suruga Bay during the period of 2021-2022 for the first time. The total length (TL) of the population ranged from 37.4-268.8 mm (mean ± SD: 124.7 ± 3.64 mm), and the fish weight (W) between 1.11-491.75 g (mean ± SD: 58.40 ± 7.25 g). The length-weight relationship was estimated as 𝑊𝑊 = (2.07 × 10-5)𝑇𝑇𝑇𝑇2.996 (r² = 0.937). Age determination was based on annual growth ring counts of transverse sections of the sagittal otoliths and age ranged from 1 to 12 years, with the majority of fish aged 4 (32.79 %) years old. The von Bertalanffy growth function was used to model the growth, and the parameters were found as: TL∞ = 468.1 mm, K = 0.056 year-1, t0 = -0.402 year. This research provides the first results on the growth of C. abei and enriches the regional fisheries biology database. Furthermore, it presents the primary population data on the growth patterns of one of the chaunacid species. [ABSTRACT FROM AUTHOR]

The study examined Xenentodon cancila (Hamilton) breeding biology, reproduction, and larval rearing. In this study, gonadosomatic index (GSI) and fecundity were measured for breeding biology every 15 days. Nine doses of common carp pituitary gland (CPG), human chorionic gonadotropin (HCG), and Ovaprim for breeding were administered, except in the control treatment that was without hormones. Mustard oil cake (D1), powdered feed (D2), and one-day-old live tilapia (Oreochromis sp.) larvae (D3) were used to determine larval survival after 28 days. From the end of May to mid-July, the mean GSI value exceeded 15 ± 0.72%, peaking at 16.02 ± 1.28% in June. Mean fecundity ranged from 110 ± 13.34 to 2961 ± 318.57, peaking at the end of June 2019, which indicated that this was the peak breeding season for X. cancila. The best spawning was with CPG at 20 mg kg−1 fish body weight (BW) and Ovaprim at 1.0 ml kg−1 BW, but the control group (B) and the group administered 500 IU kg-1 HCG (H1) did not spawn. Latency and hatching periods were 19-21 and 260-288 h, respectively. The highest fertilization, hatching, and survival rates were 92 ± 4.63%, 69 ± 5.52%, and 66 ± 4.11% with 20 mg kg−1 CPG (C2), while the next closest value was recorded with 1.0 ml kg−1 Ovaprim (O2). After 28 days, D3 had the highest survival rate (47.5 ± 4.62%), followed by D2 (31 ± 2.42%), and D1 (18 ± 1.54%). The findings will be useful for hatcheries, fish farmers, the ornamental fish sector, and biodiversity protection. [ABSTRACT FROM AUTHOR]

In a 56-day experiment, the effects of selenium-enriched yeast (SeY) on the growth, enzymatic activity of the gastrointestinal tract, oxidative stress parameters, and selected immunological parameters of sterlet, Acipenser ruthenus (L.), were analyzed. The concentration of selenomethionine (SeMet) from SeY in the feed was 0 mg kg−1 (C), 0.7 mg kg−1 feed (S1), 1.4 mg kg−1 feed (S2), and 2.1 mg kg−1 feed (S3). Statistically significant differences were found in the final fish body weight between the control and groups S1 and S3. A significant increase in lipase activity was found in the initial section of the small intestine of fish from group S3. The highest activity of the antioxidant enzymes glutathione peroxidase and superoxide dismutase was recorded in the liver of fish from group S2. Analyses of non-specific humoral response parameters showed an increase in ceruloplasmin activity in group S1. The lowest active dose of SeMet derived from yeast tested in this study that stimulated humoral immunity and fish growth was 0.7 mg kg−1 feed (S1). [ABSTRACT FROM AUTHOR]

The silver pomfret fish Pampus candidus (Previously known as Pampus argenteus Euphrasen) was collected from Iraqi marine waters in the northwest Persian Gulf between April and December 2021, using gillnet and demersal trawling. The lengths and weights of fish were recorded, along with data on the initial maturity length, sex ratio, gonadosomatic index (GSI), Dobriyal index, gonad maturation, development cycle, and absolute fecundity rate. The forked length of female individuals varied from 248 to 281mm, whereas that of male individuals ranged from 124 to 194mm. In July, young fish began to appear. Male individuals had a somehow shorter period of sexual maturity compared to female counterparts. Furthermore, it is noted that males tend to be generally less in size compared to females. The length at first maturity female and male was recorded as 203 and 115mm, respectively. The sex ratio tends to increase for males, and there were two peaks in the rise of the gonadosomatic index and Dobriyal's index, which indicate two periods of spawning activity during June and September. Six stages of fish maturity have been identified, with differences in the size of the eggs. They had a long and continuous breeding season that lasted from May to November, and they spawned by releasing eggs in batches. Notably, they have two distinct reproductive periods: The first during May and June and the second during October and November. The relationship of fecundity with weight was found to be more representative than with length. The document mentions that the silver pomfret spawning and nursery areas are adjacent to the Shatt al-Arab discharge area. [ABSTRACT FROM AUTHOR]

Vermicompost is the product of organic waste digestion by earthworms besides aerobic decomposition at ambient temperature. It is a rich composition containing plant nutrients and beneficial microorganisms. Some fishes, especially predatory species such as rainbow trout, need nutritive feed so that they can be healthy; a useful and cheaper additive such as vermicompost can supply this aim. In this study, the effect of different percentages of vermicompost in the diet of rainbow trout was investigated. For this purpose, 100 rainbow trout with an average weight of 120±3 g were distributed in 5 groups in concrete tanks. Their nutrition and physical and chemical water parameters were determined according to the standard. Vermicompost with confirmable analysis was added to their daily feed (2, 4, 6, and 10%). After 2 months, the feed conversion ratio and survival rate were examined. The results showed that there was a significant relationship between the performance of the control group and the treatment groups (p<0.05). The data obtained from this experiment indicated that the 10% of vermicompost in the diet was more effective. Therefore, the use of vermicompost supplements can be recommended for the cultivation of rainbow trout. [ABSTRACT FROM AUTHOR]

In 2022-2023 specimens of A. fallax are recorded for the first time in approximately 17 years in Szczecin Lagoon. We collected 11 specimens of juveniles, 9 premature and mature females, and 9 premature and mature males (20.3-40.7 cm of total length, aged from 1+ to 4+). The 2+ aged fish was slightly dominated (34.5% of the whole sample). Females in the Szczecin Lagoon were ready to spawn in the age of 3+ and 4+ years, while males partly in 2+, and in the age of 3+ and 4+. Fulton's condition factor of this fish was 0.93±0.14 and Clark's 0.78±0.14. Analysis of correlations between the total length and individual weight of fish revealed that the growth of A. fallax was allometric (b < 3.0). The range of gonadosomatic index (GSI) was 0.12-26.59%, while the mean of the absolute and relative fecundity was 58,756 eggs per female and 139,650 eggs per kilogram of body weight. The obtained results indicate the occurrence of an anadromous population of Alosa fallax in the studied water areas. However, there is still a need to obtain detailed information on the population status and the biology of A. fallax in these areas in order to designate special conservation areas (SACs) for their protection, especially taking into account spawning habitats. [ABSTRACT FROM AUTHOR]

Copyright of Al-Anbar Journal of Veterinary Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Monopterus albus is one of China's renowned and superior aquaculture species, with its seedlings mainly sourced from wild capture. One of the bottlenecks in M. albus aquaculture is the high mortality rate and low feeding initiation rate from stocking wild fry to the initiation of feeding. In production, trash fish is commonly used to wean M. albus juveniles onto feeding. In this study, we introduced three other natural feeds, earthworms (EW), yellow mealworms (YMW), and fly maggots (FM), with frozen trash fish (TF) serving as the control group, to evaluate the effects of these four natural feeds on the survival rate, feeding initiation, antioxidant enzymes activity, and body composition of M. albus juveniles under recirculating water aquaculture conditions. The experiment comprised four treatments, each with three replicates. Each replicate consisted of stocking 150 M. albus juveniles weighing 10.02 ± 0.89 g in size, raised for 5 weeks. The survival rate of the YMW group was 73.33%-85.33%, which was significantly higher than that of the other three bait groups (p < 0.05). The four bait groups showed no significant differences in final body weight and specific growth rate (SGR) (p > 0.05). The EW group showed the highest final body weight, with an average SGR of 2.73, whereas the YMW group had an average SGR of 1.87. The average daily feeding amount was significantly higher in EW and YMW groups than in the other two groups (p < 0.05). The percentage of feeding amount to fish weight in the EW group reached 7.3% in the fifth week. After 5 weeks of cultivation, NO2--N content was significantly higher in the waters of the TF and EW groups than in the waters of the FM and YMW groups (p < 0.05), there was no significant difference in TAN content among the treatment groups (p > 0.05). Liver malondialdehyde content was significantly higher in the TF group than in the other bait groups (p < 0.05). GSH-Px activity was significantly higher in the EW group than in the FM group and YMW group. No significant differences in SOD and CAT activity and T-AOC were observed among the bait groups (p > 0.05). The increase in crude protein content was significantly higher in the TF group than in the FM group, but the increase in crude ash content was significantly lower in the TFgroup. In conclusion, Tenebrio molitor could potentially serve as one of the alternative feeds during the initial stages of M. albus juveniles stocking. [ABSTRACT FROM AUTHOR]

The study tested the effect of daily feed ration (DFR: 0.5%, 0.75%, 1.0%, 1.25%, and 1.5% of fish biomass) on juvenile pikeperch (Sander lucioperca) with an initial body weight of 21.5 ± 5.1 g and total length of 144.5 ± 8.5 mm. The pikeperch were fed floating feed at 8-hour intervals for a duration of 84 days. By the end of the experiment, the group fed DFR of 1.5% exhibited the highest body weight (51.5 ± 16.1 g) and total length (188.2 ± 17.8 mm). The weight heterogeneity, measured as the coefficient of variation (CV), ranged between 30.29 and 33.24%. The specific heterogeneity rate (SHR) ranged from 304.44 to 334.94‰/day. The group with DFR of 1.0% exhibited the highest degree of heterogeneity. Minor fin erosion was observed in the caudal fin by the end of the experiment. No significant differences were revealed in selected biochemical parameters indicating the liver, spleen, and intestinal function. All the fish tested were adequately fed, being provided sufficient nutrients for the proper growth of pikeperch. The DFR of 1.5% was evaluated as the most favourable. This amount of feed supported a higher number of values for Fulton's coefficient (FC), specific growth rate (SGR), thermal growth rate (TGR), fish weight heterogeneity, growth of total fish biomass (BG), and optimum level of biochemical parameters in blood plasma. [ABSTRACT FROM AUTHOR]

This study aimed to identify a new feed for Catla catla post larvae. There is no suitable feed in Sri Lanka for post-larvae of Indian carp. A complete randomized design was used. Two feeds were formulated using different nutrient compositions with 32 % and 25 % of the fish meal separately. The formulated feeds were used as treatment one and treatment two. Commercial feed was used as the control. Catla catla post-larvae were stocked at a density of 300 post larvae per m2 in nine cement tanks. Growth parameters were measured every two other days. Feeds were formulated according to the nutrient requirement of Catla catla post larvae. Water quality parameters were measured daily to maintain the water quality at the proper level. T-test preformed in Mini tab 16.0. Total body weight and length were significantly different (p

Clarias batrachus is a commercially important food fish. In the present study, effect of varying dietary protein levels was evaluated on the survival, growth parameters and proximate composition of C. batrachus. Diets comprising 25%, 30%, 35%, 40%, 45%, and 50% crude protein (CP) were supplied to fish in T1, T2, T3, T4, T5, and T6, respectively, at the rate of 5% of fish body weight for the entire 90 days, twice daily. Size of each stocked C. batrachus was recorded after 15 days. Results revealed 100% survival rate of C. batrachus in all treatments. Significantly highest (P<0.001) mean value of weight gain (g/fish), percent weight gain, daily growth rate, specific growth rate and protein efficiency ratio (PER) in C. batrachus were recorded, reared in T4 by feeding 40% CP in diet. The best FCR value (1.90±0.02) for C. batrachus was obtained in T4 by feeding 40%CP in diet. Mean value of water, ash, fat and protein contents (wet mass) were ranged 74.10–79.23%, 3.12–4.68%, 3.90–4.43% and 13.09–16.79% for C. batrachus in the studied treatment groups. Water content (%) was found significantly (P<0.05) higher in the body of C. batrachus for T1, T2, T3 and T6 than for T4 and T5. Ash was found significantly (P<0.05) higher in the fish reared in T4 and T5. Fat content in the wet body mass of C. batrachus was found significantly higher in T4 and T1. While, significant higher (P<0.05) values of mean protein content was noted in C. batrachus reared in T4 and T5. Body composition of C. batrachus was also categorically affected by body size, however, condition factor showed non-significant correlation in most of the relationships in the present study. Overall, results indicated that feeding appropriate diet (containing 40% CP) to the fish resulted good growth performance, lower FCR and higher protein content in the fish. Present study provides valuable knowledge of optimal dietary protein level in C. batrachus which will help in commercial success of aquaculture. [ABSTRACT FROM AUTHOR]

The current study's objectives were to investigate the growth parameters, mortality, and yield per recruit of the bogue fish, Boops boops (Linneaus, 1758), in North Sinai, Egypt (Mediterranean coast) from January to December 2022. A total of 868 specimens of the bogue were monthly collected from the main landing site of El Arish Fisheries. The length and weight of the sampled fish ranged from 8.4 to 23.1cm and 6.1 to 138.2g, respectively, with an average total length of 13.57cm and body weight of 29.84g. The length-weight relationship was expressed using the equation W=0.0097L3.0433The von Bertalanffy growth equations were calculated giving L∞ = 24.15cm, k = 0.34 year-1 and t0 = -1.2916 year. The growth performance index (Φ') was calculated as 2.2973. The length at first capture was estimated to be 11.37cm. The total mortality rate, natural mortality rate, fishing mortality rate and exploitation rate were 2.19 year-1, 0.86 year-1, 1.33 year-1 and 0.61 year-1, respectively. The relative yield per recruit analysis (Y'/R) revealed that the current level of exploitation is much higher than E0.5 (0.362), indicating that the population is overexploited and subject to fishing pressure. To ensure sustainable management of this resource, the existing extraction rate should be reduced by 40% (i.e. from 0.610 to 0.362). [ABSTRACT FROM AUTHOR]

Background: When pesticides are introduced into wetlands by agriculture, fish quickly absorb them through their gills. Pesticides reduce hatchability, impede growth, and antioxidant response, killing fish. Therefore, it's crucial to find effective pesticide mitigation methods for fish. Objective: In this study, the effects of garlic (Allium sativum) oil on the growth, haematology, biochemistry and histopathology parameters of Nile tilapia (Oreochromis niloticus) exposed to cypermethrin toxicity were investigated. Methods: In the research, cypermethrin was added to the water of the experimental groups at a rate of 1:20 of the LC50 value, and 1.00% garlic oil was added to the fish feed. Fish with an initial weight of 30.26 ± 0.26 g were fed for 45 days. Results: At the end of feeding, the final weights were determined as 69.39 ± 0.41 (G1), 61.81 ± 0.65 (G2), 82.25 ± 0.36 (G3), and 75.04 ± 0.68 (G4) grams, respectively. Histopathological examinations revealed serious lesions in the gill, liver, brain, and muscle tissues in the cypermethrin group, whereas these lesions were minimal or absent in the garlic oil group. Conclusions: Garlic oil supplementation had positive effects on growth, haematology, blood biochemistry, hepatosomatic index and histopathological parameters. These findings suggest that garlic oil is a potential protective agent against cypermethrin toxicity. [ABSTRACT FROM AUTHOR]

This study aimed to identify a new feed for Catla catla post larvae. There is no suitable feed in Sri Lanka for post-larvae of Indian carp. A complete randomized design was used. Two feeds were formulated using different nutrient compositions with 32 % and 25 % of the fish meal separately. The formulated feeds were used as treatment one and treatment two. Commercial feed was used as the control. Catla catla post-larvae were stocked at a density of 300 post larvae per m2 in nine cement tanks. Growth parameters were measured every two other days. Feeds were formulated according to the nutrient requirement of Catla catla post larvae. Water quality parameters were measured daily to maintain the water quality at the proper level. T-test preformed in Mini tab 16.0. Total body weight and length were significantly different (p<0.05). The survival percentage was higher in T1. Treatment feeds were not affected by the water quality parameters. Catla catla post-larvae show a maximum increase in length, survival percentage and weight in T1. It was concluded that T1 has a good combination of fish meal for Catla catla post-larvae. This study will help in future feed formulation for post-larvae feeds in developing nations. [ABSTRACT FROM AUTHOR]

The biologger is a widely used tool in biotelemetry for investigating marine fish. However, studies reported that the attachment of biologgers has a negative effect on the target organisms. We assessed the health status of spotted sea bass with attached biologgers by analyzing changes in their serum biochemistry and biomarker gene expression at varying biologger/fish body weight ratios. Especially, the assessment of the health status using biomarker genes offers the rapid evaluation of the condition of an individual. The genes bax, hsp70-2, and Cx32.7, associated with apoptosis, stress, and immunity, were selected as biomarker genes to assess the fish stress levels and overall health. The experimental groups included a control group without the biologger (C) and biologger-equipped groups, each carrying a biologger whose weight was 2.0–3.0% (W2), 5.0–6.0% (W5), and 10.0–12.0% (W10) of the fish body weight. Blood samples were collected on days 0, 1, 7, 14, and 21 post-attachment. The expression of bax, hsp70-2, and Cx32.7 was analyzed in the liver and muscle on day 21. The W10 group showed significantly higher levels of superoxide dismutase on day 1 and of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase on day 7 than the other groups. On day 21 post-attachment, regardless of the biologger/fish body weight ratio, the liver and muscle tissues from groups W2, W5, and W10 showed significantly higher expression of bax, hsp70-2, and Cx32.7 than those from group C, respectively. However, there was no significant change in blood parameters depending on the weight of the attached biologger on day 21 post-attachment. These results indicate that the spotted sea bass gradually adapted to the attached biologgers of weights up to 10–12% of their body weight under our experimental conditions, providing clues to determine the timing of biologger release for biotelemetry studies. [ABSTRACT FROM AUTHOR]

China is a major player in the marine fish trade. The price prediction of marine fish is of great significance to socio-economic development and the fisheries industry. However, due to the complexity and uncertainty of the marine fish market, traditional forecasting methods often struggle to accurately predict price fluctuations. Therefore, this study adopts an intelligent combination model to enhance the accuracy of food product price prediction. Firstly, three decomposition methods, namely empirical wavelet transform, singular spectrum analysis, and variational mode decomposition, are applied to decompose complex original price series. Secondly, a combination of bidirectional long short-term memory artificial neural network, extreme learning machine, and exponential smoothing prediction methods are applied to the decomposed results for cross-prediction. Subsequently, the predicted results are input into the PSO–CS intelligence algorithm for weight allocation and to generate combined prediction results. Empirical analysis is conducted using data illustrating the daily sea purchase price of larimichthys crocea in Ningde City, Fujian Province, China. The combination prediction accuracy with PSO–CS weight allocation is found to be higher than that of single model predictions, yielding superior results. With the implementation of weight allocation intelligent combinatorial modelling, the prediction of marine fish prices demonstrates higher accuracy and stability, enabling better adaptation to market changes and price fluctuations. [ABSTRACT FROM AUTHOR]

Sex, size and age structure, growth, mortality, and some of the morphological parameters of the otoliths of the black scorpionfish, Scorpaena porcus collected in the south-western Black Sea waters of the Crimea were analyzed. A total of 500 S. porcus specimens were examined. The total sex ratio differed (1.00:0.67) with the predominance of females. The maximum total length and age of females were estimated to be 26.9 cm and 12 years old, respectively; for males, they were 21.3 cm and 11 years. The growth rate was determined to be sex-specific. The values of the parameters of the Bertalanffy equation were calculated. For females, the asymptotic total length was estimated to be 28.9, weight - 519.7 g, parameter k = 0.10 year-1, to = -2.90; for males, the asymptotic total length was estimated to be 23.2 cm, weight, 226 g, parameter k = 0.16 year-1, to = -2.13. The total, natural, and fishing mortality coefficients for females amount to 0.67, 0.45, and 0.26 year-1, respectively; for males, they are 0.46, 0.30, and 0.13 year-1. The exploitation ratio for females is 0.38, and for males, it is 0.28, corresponding to the low fishing pressure. The relationship between the fish length and the otolith length is isometric, but the relationship between the fish weight and the otolith weight is positively allometric. The Black Sea black scorpionfish differs from the Mediterranean population by their bigger maximum sizes, low growth rate, longer lifespan, and more evident sexual dimorphism. [ABSTRACT FROM AUTHOR]

The research assessed the inclusion of MRD-Pro®, a bacterial-derived single-cell protein (SCP), in the diets of Nile tilapia (Oreochromis niloticus) fry with an initial weight of 0.12 grams. Using a diet composed of 45% crude protein and 14% crude fat, with an initial fishmeal content of 8.0% (designated as Diet 0.00% SCP, the control), SCP replaced 50% and 100% of the fishmeal on a protein basis, incorporated at levels of 4.25% and 8.50%, respectively. In addition, two more diets were prepared with higher levels of SCP, 14.50% and 21.00%. All diets were isoproteic and isolipidic. Weight gains of fish fed with the control diet (27.26 g) and the 4.25% SCP diet (21.61 g) were statistically comparable among themselves but were significantly greater than those of fish fed the 8.50% SCP (10.45 g), 14.50% SCP (11.54 g), or 21.00% SCP (7.28 g) diets, a trend observed across all growth and feed utilization indices. Increasing dietary SCP significantly reduced the crude fat and dry matter content in fish muscle tissue, while minimal changes in the amino acid profile of fish muscle tissue were observed. The bacterial-based SCP MRD-Pro® is a nutritious feed additive that can be effectively incorporated, within limits, into the diet of tilapia fry. [ABSTRACT FROM AUTHOR]

Ballan wrasse (Labrus bergylta) are commonly used as cleaner fish in salmon farms as a biological treatment to mitigate sea lice infestation. Improved welfare for cleaner fish both during production of these fish and when in sea-cages with salmon is crucial for the industry's development. A common operational procedure in ballan wrasse production is transporting juveniles from one landbased farm to another for further on-growing. Episodes of increased mortality have been reported after such transportations. In this study, the relationship between transport stress and post-transport mortality at the on-growing facility was examined. It was also investigated if light sedation with AQUI-S® can mitigate stress during transport. Stress was quantified by measuring cortisol release rate to the tank water during transport. This was investigated in 10 commercial live carrier truck transports (6 without AQUI-S® sedation and 4 with sedation during loading and transport). The total time of transport varied between 12 and 21h. In general, mortality was significantly higher (1.0± 0.6% day-1) the first five days posttransport compared to 15-20days post transport (0.5% day-1). There was also a strong relationship between fish weight at transport and post-transport mortality, where higher mean weight at transport reduced mortality. In contrast to what was expected, AQUI-S® treatment during transport procedures increased cortisol excretion rate, suggesting a stimulating effect of AQUI-S® on the stress axis in ballan wrasse. Considering these results, the value of using AQUI-S® to reduce stress during transport of juvenile ballan wrasse might be questioned. However, there was no relationship between cortisol release rate during transport and post-transport mortality. Furthermore, this study emphasizes that water cortisol measurements can be used as a none-invasive tool for monitoring stress and can be integrated into the welfare evaluation during commercial fish transports. [ABSTRACT FROM AUTHOR]