Fish Body Weight Research Articles

Ektobakteri Pada Ikan Nila (Oreocromis niloticus) Di Desa Lihung Kecamatan Karang Intan Kabupaten Banjar Propinsi Kalimantan Selatan

Intensive cultivation often risks the emergence of disease, this is because in intensive cultivation tilapia are kept with high stocking densities and intensive use of feed, which causes a decrease in water quality which in turn can trigger the emergence of disease. Fish diseases arise due to an imbalance between fish as gills of pathogens/microorganisms that carry disease, and the environment. The fish's defense system can be disrupted due to environmental changes and the development of pathogens in a cultivation container. This research aims to find out whether there are ectobacteria in tilapia fish in fish farming ponds in Lihung Village. The results of the research will make it easier to provide information about sick fish and how to deal with disease in the environment of fish cultivating ponds that are attacked by ectobacteria. The research was carried out for 10 days, 4–14 March 2023 at the KIPM Banjarmasin Laboratory, starting from taking test fish samples, necropsy, microscopic examination, as well as the types of ectobacteria found in tilapia seeds taken from fish farming ponds. Necropsy activities are carried out by weighing the weight of the test fish, checking the completeness of the fish's body organs and checking the body of the fish that will be observed. All samples of the test fish are weighed according to the required standard of at least 10 grams with a fish body weight of 50 grams, for completeness. body organs of all test fish samples are complete. From the sample results, it was found that there were 2 bacteria that attacked Tilapia fish in Lihung Village, namely Aeromonas sp. and Proteus sp bacteria

Fully automatic system for fish biomass estimation based on deep neural network

The approach for estimating biomass in non-contact, free-swimming fish has encountered difficulties such as fish body occlusion, bending, non-orthogonal angles, and low efficiency. To address these issues, this study had combined fish posture recognition (using deep learning technology) with biomass estimation (utilizing stereo vision technology) for the first time, and developed a fast, precise, and fully automatic fish biomass estimation system. The improved single-stage target detection algorithm significantly improved the direct detection and extraction of high-quality images of moving fish in real-time, eliminating the need for manual processing of images that may have imperfect posture. Fish body length and height were measured in the real world using binocular stereo vision technology. Finally, the fish body weight can be estimated by considering the relationship among their body length, height, and weight. The experiment confirmed that the system had successfully avoided influencing factors that could affect fully automatic estimation. The results demonstrated a strong linear relationship between the estimated and measured fish body weights, with a mean relative error (MRE) of 2.87%. There were no significant differences between the estimated and measured weights (p = 0.94). The MRE of the multi-factor model was much lower than that of the single-factor model (length-weight of 8.86% and height-weight of 7.41%). The results indicate that the system developed is a highly effective approach to fully automated biomass estimation. This can be used to guide actual production and further study of the mechanism of fish growth.

Chitosan- hypothalamic hormonal analogue nanoconjugates enhanced the reproductive performance in Indian major carp, Labeo rohita

The current study reports the potential of chitosan nanoparticles for the efficient delivery of hypothalamic hormonal analogue in Labeo rohita, aiming to improve reproductive performance. Here salmon gonadotropin-releasing hormone analogue (sGnRH-a) was conjugated with chitosan nanoparticles (ChN-sGnRH-a) to evaluate its efficiency in enhancing the reproductive gene expression, hormones as well as the overall reproductive output in L. rohita. A total of 54 pairs of brooders were selected and divided into six treatments viz; C0: Negative Control (fish injected with bare chitosan nanoparticles), C: Positive Control (fish injected with Gonopro-FH®, a commercially available inducing hormone, at a dose of 0.2 ml/kg body weight of fish), T1: fish injected with ChN-sGnRH-a at a dose of 0.2 ml/kg, T2: T1 + 10 mg/ml domperidone, T3: fish injected with ChN-sGnRH-a at a dose of 0.1 ml/kg, T4: T3 + 10 mg/ml domperidone. In T2 and T4 treatments, serum hormones, Testosterone (T); Estradiol (E2); Vitellogenin (Vtg); and 17α, 20β-dihydroxyprogesterone (17α, 20β-DHP) showed the sustained elevation. The means of reproductive traits like fecundity, fertilization rate, pseudo-gonadosomatic index and spawning rate were significantly (P<0.05) higher in T2 treatment, while no significant difference was found between C and T4 treatment. The mRNA expression level of follicle-stimulating hormone (fshβ), luteinizing hormone (lhβ) and their cognate receptors was significantly better in T2 treatment, while no significant difference was found between T4 and C treatments. Further, the histological analysis of ovaries showed increased post-ovulatory follicles in C, T2 and T4 treatments. The results indicate that ChN-sGnRH-a could help in reducing the recommended dose of sGnRH-a without affecting the reproductive performance in L. rohita females. The sustained releasing mechanism of this formulation may be used as an induced breeding strategy in female L. rohita broodstock.

Effect of florfenicol administered through feed on Atlantic salmon (Salmo salar) gut and its microbiome

Although concerns about the impacts of antibiotics in aquatic organisms are reported worldwide, the potential adverse effects on fish gut microbial communities and fish health are still not well known. In this study, we investigated the effects of florfenicol (FFC) on the gut microbiome and gastrointestinal (GIT) gene expression in juvenile Atlantic salmon (Salmo salar). Three doses of FFC were used to coat experimental feed at 10, 20 and 30 mg/kg/ fish body weight (bw). The feed was administered for 18 days, followed by a 10-day recovery period. The metatranscriptome analysis revealed that 10 and 30 mg/kg bw of FFC led to the downregulation of genes involved in the transcription of NADH-ubiquinone oxidoreductase chain-1, suggesting that the antibiotic targets bacterial respiratory metabolism. The 30 mg/kg bw FFC treatment upregulated genes that encode glycolytic enzymes, such as phosphoglycerate kinase, indicating a disruption of energy metabolism in the microbiome. Analysis of the fish host transcriptome showed that the FFC treatment affected cellular processes in the GIT system of fish, including pathways related to apoptosis and DNA metabolism. The 30 mg/kg bw FFC treatment specifically activated pathways related to cellular regulation, including LXR/RXR activation, FXR/RXR activation, and protein ubiquitination. At the end of the recovery phase, the 30 mg/kg bw FFC treated group altered pathways related to EIF2 signaling and lysine degradation.This study identified molecular-level effects of FFC treatment on the gut microbiome and the GIT of juvenile Atlantic salmon, although phenotypic changes in growth or condition were not observed. Most of the observed changes were reversible and receded at the end of the recovery period, apart from the highest treatment group. These findings emphasize the importance of understanding the molecular mechanisms that underlie the potential effects of antibiotics in order to optimize antibiotic treatments in aquaculture.

Microplastics in commercial fish digestive tracts from freshwater habitats in Northern Thailand

Microplastics (MPs) contamination in fish species was one of the emerging environmental issues as a result of the widespread presence of plastic pollution in the environment. The presence of MPs in Thailand's freshwater was scant, and in contrast to other countries, little was known about the presence of this contaminant in freshwater fish. Hence, the purpose of this study was to examine the abundance, characteristics, and variation of MPs in various Thai commercial freshwater fish species. In order to compare the differences in MP ingestion rates across different feeding zones, 166 fish representing 24 species from various feeding zones were collected. MPs were found in the gastrointestinal tracts (GIT) of all fish samples tested, which was a substantially larger number than previously reported in other locations. Of all the fish species, Anabas testudineus, Labeo rohita, and Oreochromis mossambicus had the highest concentration of MPs (34.90 ± 21.43, 34.50 ± 7.78, 34.10 ± 11.15 items/individuals). Microscopical examinations showed that the majority of MPs were fiber-shaped and blue in color. Fourier transform infrared analysis (FTIR) showed that the polymers found in fish GIT were polyethylene, polypropylene, polyethylene terephthalate, polyvinyl acetate, poly (methyl vinyl ether), poly (methyl vinyl ether), polybutadiene, poly (ethylene-co-propylene), poly (ethylene glycol) tetrahydrofurfuryl ether, poly (methyl phenyl siloxane), poly (styrene-co-divinylbenzene), and polyvinylidene fluoride. The results of this study demonstrate that demersal fish had a higher concentration of MPs than benthopelagic and pelagic fish, indicating that plastic ingestion in fish may be related to the feeding habitat. However, it was not discovered that differences in the fish's body weight and length affected the MPs' ingestion. Our findings will help people in Thailand understand which freshwater fish and fish from which feeding zones are more contaminated with MPs for human consumption.

Biofloc technology application in Nile tilapia (Oreochromis niloticus, L.) hatcheries: effect on the reproductive performance, offspring quality, growth performance, and physiological parameters of fry

ABSTRACT This study evaluated the potential of applying biofloc technology (BFT) in Nile tilapia (Oreochromis niloticus) hatcheries. The first experiment was conducted to determine the effect of maintaining tilapia broodstock in BFT system in terms of reproductive performance and offspring quality as compared with the conventional clear-water system. A total of 45-tilapia broodstock were reared for 2 months in each treatment. Females at advanced maturation were transferred to four spawning tanks (800 L) at a density of eight individuals per tank (3:1 female:male sex ratio). Two tanks were assigned to each of the two treatments (BFT and control). Reproduction took place over the course of 2 months, with all females being inspected weekly to verify the presence of eggs. The second trial (43 days) analyzed the effect of BFT system on growth performance, feed utilization, digestive enzymes activity, and antioxidant status in the early fry stages. A total of 540 larvae (8.7 ± 0.7 mg) were assigned to six glass aquariums (60 L capacity). One experimental group was reared using a BFT system with daily sugar addition at a C/N ratio of 15/1, in comparison to a control group reared in clear water. Fish were fed commercial pellets three times a day at various feeding ratios (6–9% of the fish body weight). The fecundity of tilapia, hatching rate, egg and larval size, and larval resistance to stress tests presented no significant differences among treatments (P > .05). After 20 days of larval rearing, the daily weight gain was 29% higher in BFT fish as compared to the control treatment. The BFT system had better feed conversion ratio than control treatment. The larvae reared in BFT system had significantly higher alpha-amylase and catalase activities than control (P < .05). Overall, these results suggest that the BFT system can be used in tilapia hatcheries for broodstock rearing without negative effects on reproductive performance. The better growth performances of larvae reared in BFT treatment justified the application of this system during nursery phase.

Evaluating the viability of the use of T‐bar and radiotelemetry tags on prespawn Arctic Lampreys

AbstractObjectiveArctic Lampreys Lethenteron camtschaticum are harvested by subsistence and commercial fisheries in the Yukon–Kuskokwim River region of Alaska; however, baseline population data are deficient. For mark–recapture and telemetry studies to be effectively implemented to assess Arctic Lamprey abundance, migratory and dispersal patterns, and spawning locations, tags must not impact fish survival, physiology, or behavior.MethodsFor this laboratory evaluation, we examined survival, tag retention, swim endurance at short‐term (1 day posttreatment) and long‐term (43 days [~6 weeks] posttreatment) intervals, and incision healing for T‐bar‐tagged and radio‐tagged prespawn Yukon River Arctic Lampreys (N = 216). Six treatment groups were evaluated: control; sham surgery; external T‐bar anchor tag; and small (0.30 g; 0.1–0.4% tag burden [ratio of tag weight to fish body weight]), medium (0.57 g; 0.2–0.8% tag burden), and large (1.50 g; 0.6–1.9% tag burden) internal dummy radio transmitter tags.ResultAlthough all lampreys survived tagging and surgical procedures through the first 4 weeks of the experiment, a higher tag burden was associated with an increased mortality hazard up to 35 weeks postsurgery. Over the 14‐week experimental period, one T‐bar tag and one small radio tag were shed by lampreys. Although treatment was not a significant predictor of swim endurance, a higher tag burden led to reductions in swim endurance at 1 day posttreatment but not at 43 days posttreatment. Healing did not differ among surgical treatment groups, but persistent inflammation was observed at incision sites and skin erosion was observed at antenna protrusion locations.ConclusionThese results indicate that T‐bar anchor tags and internal radio tags are acceptable for Arctic Lamprey tagging studies if the radio tag burden is ≤1.3% for short‐term (≤14‐week) studies and ≤0.5% for long‐term (≥14‐week) studies.

Effects of dietary hydrolysate supplementation on growth, body composition, hematological responses, and liver histology of juvenile giant trevally (Caranx ignobilis Forsskal, 1775).

A feeding study was conducted to investigate how fish protein hydrolysate (FPH) supplementation affected the growth, feed utilization, body composition, and hematology of juvenile giant trevally (Caranx ignobilis Forsskal, 1775). Seven isonitrogenous (52% protein) and isocaloric diets (10% lipid) were formulated, wherein shrimp hydrolysate (SH) and tuna hydrolysate (TH) were used to replace fishmeal at inclusion levels of 0 (control), 30, 60, and 90 g/kg and labeled as control, SH30, SH60, SH90, TH30, TH60, and TH90, respectively. Each diet was fed to triplicate groups of juvenile giant trevally for 8 weeks. The results showed higher final body weight and specific growth rate in fish fed SH30, SH60, TH30, and TH60 than fed control diet. No difference was observed in feed intake, but reduced feed conversion ratio (FCR) was found in fish fed SH30, SH60, TH30, and TH60, demonstrating these diets improved feed utilization. TH90 caused deposition of lipid droplet in the hepatocyte, a sign of liver damage. Total monounsaturated fatty acids, polyunsaturated fatty acids (PUFA), and highly unsaturated fatty acids in fish were not affected by FPH supplementation. Fish fed TH30 showed lower ∑n - 3 PUFA than the fish fed remaining dietary treatments. The elevated serum protein was seen in fish fed control, SH30, SH60, and TH30, demonstrating that these diets were beneficial for the innate immune response in giant trevally. The results indicate that TH and SH could be incorporated into diets of giant trevally at 30-60 g/kg, replacing 7%-13% fishmeal with enhanced growth and health benefits.

Growth performance and physiological responses of striped catfish (Pangasianodon hypophthalmus) under different carbohydrates supplemented biofloc aquaculture systems

Biofloc technology is booming in inland aquaculture sector across the world especially in the places where water scarcity is high and land cost is expensive. Currently, the lack of appropriate selection and application feasibility of suitable carbohydrate in water quality management and fish health in biofloc aquaculture system are the major concern for wider adaptability of the technology. Therefore, the present experiment investigated the effect of different carbohydrate sources on overall wellbeing of striped catfish (Pangasianodon hypophthalmus) fingerlings. The experiment was randomly designed in four treatments (T1, T2, T3 and T4) and one control in triplicates in indoor tanks (1.0 m3). T1, T2, T3 and T4 groups supplemented with tapioca flour, sugarcane bagasse, molasses and jaggery, respectively under biofloc system at C:N ratio of 15:1, whereas the control group was not supplemented with carbohydrate source. Pre-acclimatized 525 fingerlings (7.2 ± 0.03 cm, 7.4 ± 0.003 g) were randomly stocked (35 nos. m−3) in the tanks and reared for 90 days. Overall, better water quality, fish performance and health status were observed in all the carbohydrates supplemented treatments than the control. Higher abundance of heterotrophic bacteria (5.88–118.18%) and biofloc associated microorganisms in jaggery supplemented biofloc, significantly (P ≤ 0.05) reduced total ammonia nitrogen, nitrite‑nitrogen, and increased nitrate‑nitrogen concentrations than other treatments. In the T4 treatment, jaggery supplementation enhanced biofloc volume, which influenced enhancement of fish body weight gain, specific growth rate, and improvement of feed conversion ratio than other biofloc treatments. Enhanced gut microbial population and digestive enzymes activity in fish significantly enhanced protein efficiency ratio, apparent net protein utilization, and flesh protein content in the T4 treatment. Fish showed significantly (P ≤ 0.05) higher haematological, immunological, and improved antioxidative responses in the T4 treatment than other treatments. Consumption of biofloc significantly (P ≤ 0.05) improved intestinal villi microarchitecture as higher villi surface area, width and height were detected in the T4 treatment. Collectively, the findings suggested that jaggery was the suitable carbohydrate source in terms of overall improvement of the culture system including growth performance and health status of P. hypophthalmus, if applied appropriately in biofloc aquaculture system. The present study comprehensively addressed carbohydrate sources, biofloc formation, total ammonia nitrogen management, fish growth and health resulting in better adoptability of biofloc technology by farmers in aquaculture.

Bioecology Study of Brackish Pond Waters for Saline Tilapia in Petta Barat Village Sangihe Archipelago District

Problems that often arise in the fisheries sector, especially in the development of saline tilapia aquaculture, are always related to constraints in feed supply. Therefore, feed management involving the use of immunostimulants is required as an effort to improve the growth and survival of saline tilapia. Thus, the objective of this study was to identify the relationship between the use of immunostimulant yeast derived from natural extracts of cucumber fruit on the relative growth rate of saline tilapia and its relationship with ecological characteristics and water quality in saline tilapia ponds in Petta Barat Village, Sangihe Regency. This study applied a completely randomized experimental design (CRED) with four treatment groups and repeated it three times. The treatment groups were A (no addition of natural yeast in feed), B (10 ml natural yeast/kg feed), C (20 ml natural yeast/kg feed), and D (30 ml natural yeast/kg feed). Feeding was done twice a day, with the amount of feed given as 5% of the fish body weight. The findings of this study indicated that variations in the addition of natural yeast of cucumber fruit extract to the feed did not result in a significant impact on the relative growth rate of saline tilapia. In addition, water quality parameters such as temperature, pH, dissolved oxygen (DO), salinity, nitrate, nitrite, and ammonia remained within appropriate ranges and supported the survival of saline tilapia.

Biological observations of Salmostoma novacula fishery of a protected reservoir in India

Feeding and breeding biology of a prominent indigenous fishery of Peechi Reservoir(protected reservoir) was assessed using 300 specimens in this study. Catch compositionstudies identified Salmostoma sp. as the major species contributing to the reservoir fishery.With the help of mitochondrial CO1 gene, the species was identified as Salmostomanovacula. The feeding biology of the fishes was studied using index of preponderance(IOP), gastro-somatic index (GaSI) and relative gut length (RGL). IOP of S. novacula revealedthat zooplankton dominated the gut of the species to the tune of nearly 70.82%. The meanRGL and GaSI of S. novacula was estimated at 1.42 (1.42±0.25) and 4.22 respectively. Theindices used for reproductive study were size at first maturity, sex ratio, gonado-somaticindices and fecundity. The size at first maturity for S. novacula was found to be 13.0 cm. Thesex ratio and relative fecundity were estimated at 1.2:1.0 and 8500-8833 nos. per gram bodyweight of fish. The study indicated that the fishes mature during March to August and exhibitspawning activity in September. The paper emphasises a need for enforcing minimum legalsize and restricted monsoon fishing for sustained fisheries in this reservoir. Keywords:CO1 gene, Feeding biology, Fisheries management,Reproductive biology, Salmostoma novacula

Stocking density optimisation of pangasius (Pangasianodon hypophthalmus) fingerlings with basil (Ocimum basilicum L.) in nutrient film technique (NFT) based aquaponics

An experiment for 90 days was performed to optimise the stocking density of pangasius(Pangasianodon hypophthalmus) with basil (Ocimum basilicum L.) in a nutrient film technique(NFT) based aquaponics. The experiment had four treatments with different stockingdensities of pangasius as T1 (2.5 kg m-3), T2 (2.75 kg m-3), T3 (3.0 kg m-3) and T4 (3.25 kg m-3)with a constant plant density of 24 plants m-2 and control viz., C (2.5 kg m-3 withoutplants). Significant (p&lt;0.05) difference in final body weight of fish was found among thetreatments and control. The highest fish biomass was recorded in T3 (10.29±4.41 kg m-3)followed by T4, T2, T1 and C. The highest plant yield was found in T4 (510.90±6.25 g);however, no significant difference was found between T4 and T3. No significant (p&gt;0.05)difference in macro and micronutrient content of basil leaves was recorded in T4 and T3.The physiological parameters (hematological, serum biochemical and anti-oxidant stressenzymes) were found to be within the acceptable range. Considering the water qualityparameters, fish growth, total biomass of fish, fish physiological responses, basil yield andnutrient content, the stocking density of 3.00 kg m-3 (pangasius) with 24 plants m-2 of basilcould be recommended for basil-pangasius aquaponics. Keywords:Aquaponics, Aquaculture wastewater, Basil,Nutrient film technique, Pangasius

Comparison of Controlled Nursery Rearing of Hybrid Tilapia Seeds in Different Culture System

The experiment was conducted to find out the best rearing system for hybrid tilapia young fry. Rearing of hybrid tilapia young fry (Red strain) was undertaken in two types of rearing systems for 21 days. Young fry of hybrid tilapia (0.12 ± 0.019 g average body weight) was stocked in hapa at a stocking density of 87 fish/lit and in 3 aquarium tanks at a stocking density of 88 fish/lit. Fry were fed with crumble feed having 30% CP @7 times a day in the first week, 6 times in the second week and 5 times in the third week in both hapa and tank. The physico-chemical parameters ofhapa and aquarium tank were taken every day. The DO, pH, TDS, alkalinity and temperature were higher in the hapa than in the tank water. And ammonia was found to be higher (0.5-1 mg/L) in the aquarium tank system. After 21 days of trial, hapa stocked fishes had a weight gain of 3.48 g, while the fishes in aquarium tank had weight gain of 2.58 g. The survival rate in hapa and aquarium was 97% and 85% respectively. The hapa rearing resulted in 74% more growth than in the glass aquarium tank. The final average body weight of fishes reared in hapa was 3.6 g while that of aquarium tanks was 2.7 g. The body colour of the fishes in hapa was brighter than the tank of fishes. To conclude it was found that rearing of red tilapia fry was comparatively better in hapa as compared to glass aquarium.

Gut microbiota related response of Oryzias melastigma to combined exposure of polystyrene microplastics and tetracycline

The co-existence of microplastics (MPs) and antibiotics in the coastal environment poses a combined ecological risk. Single toxic effects of MPs or antibiotics on aquatic organisms have been verified, however, the exploration of their combined toxic effects remains limited. Here, foodborne polystyrene microplastics (PS-MPs, 10 μm, 0.1 % w/w in food) and waterborne tetracyclines (TC, 50 μg/L) were used to expose an estuarine fish Oryzias melastigma for four weeks. We found that the aqueous availability of TC was not significantly altered coexisting with MPs. The fish body weight gain was significantly slower in TC alone or combined groups than the control group, consistent with the lower lipid content in livers. The body length gain was significantly inhibited by the combined presence compared to the single exposure. Both exposures led to a shift of gut microbiota composition and diversity. TC and the combined group possessed similar gut microbiota which is distinct from PS-MPs and the control group. The Firmicutes/Bacteroidetes (F/B) ratio in the TC and combined groups were significantly lower compared to the control, while the PS-MPs group showed no significant impact. Metabolomic analysis of the fish liver confirmed the shift of metabolites in specific pathways after different exposures. More, a number of gut microbiota-related metabolites on lipid metabolism was perturbed, which were annotated in arachidonic acid metabolism and linoleic acid metabolism. In all, TC modulates bacterial composition in the fish gut and disturbs their liver metabolites via the gut-liver axis, which led to the slower growth of O. melastigma. More, the adverse impact was aggravated by the co-exposure to foodborne PS-MPs.

Supplementation of potassium in aquaculture wastewater and its effect on growth performance of basil (Ocimum basilicum L) and pangasius (Pangasianodon hypophthalmus) in NFT-based aquaponics

An experiment was conducted for 120 days to optimize the potassium dose and investigate its effects on the growth performance of basil and pangasius in a nutrient film technique-based aquaponics. Potassium was supplemented as four different dosages assigned as T1 (90 mg/L), T2 (120 mg/L), T3 (150 mg/L), and T4 (180 mg/L) were compared to an unsupplemented control (C). Basil and pangasius were stocked at 24 plants/m² and 3.00 kg/m³, respectively. The highest basil yield occurred during the 3rd harvest in T4 (390.50 ± 4.25 g), followed by T3, T2, T1, and control. No significant difference in plant yield was observed between T4 and T3. Similarly, highest plant height, leaf length, leaf width, SFW, SDW, RFW, and RDW was recorded in T4 and T3 compared to control and other treatments. Potassium supplementation resulted in increased uptake of macro-micro nutrients viz., phosphorous, nitrogen, sulfur, potassium, copper, iron, zinc, and manganese in basil. The physico-chemical parameters and nutrient profile of culture water were found to be within the permissible limits for aquaponics. The body weight of fish didn't show any significant difference in control, T1, T2 and T3 while significantly lower body weight was recorded in T4. Significantly higher serum cortisol and glucose levels were found in T4. Considering the basil yield, nutrient and chlorophyll content of basil plant, water quality, body weight of fish, and fish stress parameters, supplementation of 150 mg/L (T3) of potassium was found to be the optimum dose for basil and pangasius culture in NFT-based aquaponic system.

Utilisation of Sun Dried Azolla Caroliniana in Substituting Groundnut Oil Cake in the Conventional Carp Feed

Sun- dried and powdered Azolla caroliniana substituting 20, 40, 60 and 63.6% of the protein supplement (groundnut oil cake) of the conventional diet (at 10, 29.2, 60 and 63.6% incorporation in diet, respectively) of Indian major carp was fed to Labeo rohita fingerlings for a period of 90 days. Substitution of groundnut oil cake up to 40% in the protein supplement resulted in 115.48±4.20% and 24.85±4.22% increment in the fish body weight and length, as against compared to 100.40±4.53% and 23.38±1.05% in the control, respectively. There was no significant (P &lt; 0.05) variation in the muscle protein and moisture contents. Feeding on a diet with increased substitution of groundnut oil cake by Azolla (60% or more in protein supplement) resulted in lower body weight and length increment as well as lower muscle protein content, with no significant difference in moisture content as compared to the control diet.

Food Preponderance Index and Feeding Habit of Macrognathus pancalus, (Hamilton, 1822) from Kotpally Reservoir Vikarabad District, Telangana State, India

The striped spiny eel, Macrognathus pancalus is a widely distributed species of fish in the Mastacembelidae family found in Asia. This study article discusses with the natural diet of M. pancalus as a first step towards understanding its feeding and nutrition, emphasising periodic dietary fluctuations and the link between fish size and diet. The study demonstrates that M. pancalus feeding strategy is more sophisticated than previous reports. GaSI provides details on the conditions around fish feeding. Prior to dissection, the fish's body weight was measured, and a weighing scale was used to determine the weight of the alimentary canal in order to determine the gastrosomatic index of the fish. The 'index of preponderance method was used to determine the relative importance of each dietary item. In the present study, 392fish species of M. pancalus relative lengths of the gut (RLG) was measured during the study period from February 22 to January 23. The study revealed minimal variation in the different sizes and lengths of fish species. The lowest value was 0.55± 0.11 in the 19–21 cm group, while the highest value was 0.68 ± 0.14 in the 6–8 cm group In general, the RLG value was higher in the younger size groups of the species. Monthly fluctuations in feeding percentage intensities of the gut were determined to be 8.38% with full gut, 23.20% with 3/4th full gut, 31.84% with 1/2th full gut, 23.79% with 1/4th full gut 7.61% with full gut, and 12.43% empty. In the present investigation, the fullness of gut in different maturity stages showed that higher active feeding (22.91% with 3/4full &amp; 9.37% with full gut 23.52% with 1/2 full) were found in maturing stage; moderate (1/2 full with 23.52%) were found in immature stage; highest percentage of poor feeding (51.21% with empty and nearly empty29.26%) were recorded in ripe stage. More empty stomachs (16.67%) and ½ full with 26.19% were found in spent stage. The preponderance index values of M. pancalus showed that the insect larvae were the most favored food item (65.26%) for this species, followed by zooplankton (14.33%), digested food (13.76%), crustaceans (3.12%), sand and mud (2.71%), annelids (0.62%), molluscans (0.16%), and fish scales (0.007%).

Microplastic Pollution in the Gastrointestinal Tract and Gills of Some Teleost and Sturgeon Fish from the Caspian Sea, Northern Iran.

The increasing microplastic pollution in the marine environment has raised global concern. The main risk of microplastics in aquatic ecosystem is their bioaccumulation in aquatic organisms. A few studies have reported microplastic pollution in the digestive system of Caspian Sea fish species, but there is no research on sturgeon species, nor on fish gills. We investigated the occurrence of microplastics in the gastrointestinal tract (GIT) and gills of 62 specimens belonging to four species including three teleosts (Cyprinus carpio, Rutilus kutum, and Chelon aurata) and one sturgeon (Acipenser persicus, a valuable endangered species) from the Caspian Sea between January and March 2022. Fish tissues were removed, exposed for 24 h to 10% KOH, and then dried on filter paper. Particles were observed under a stereomicroscope and analyzed by Raman microspectrometry, scanning electron microscopy, and energy-dispersive spectroscopy. A total of 91 microplastics were detected in the GIT (average of 1.46 ± 1.17 items/individual) and 63 microplastics in the gills (average of 1.01 ± 0.62 items/individual). A significant correlation was not found between the number of microplastics found in both tissues and fish body length, body weight, GIT weight, and gill weight (p > 0.05), except between microplastics isolated from gills and gill weight in C. carpio (rs = 0.707, p = 0.022). The abundance of microplastics in fish followed the order of A. persicus > C. aurata > R. kutum > C. carpio. The microplastics were in the size range of 45 to 5000 µm, with particles of 300 to 1000 µm being the most prevalent; 74.68% of the particles were shaped like fibers, 30.53% were red, and 70.6% were composed of nylon polymer. Environ Toxicol Chem 2023;42:2453-2465. © 2023 SETAC.

Development of dynamic growth and body composition models for Nile Tilapia (Oreochromis niloticus): An exploratory approach to protein and energy metabolism

The aquaculture sector has been steadily growing and thus there is an increasing need to develop mathematical models that allow the estimation of production-related parameters. Prediction of fish growth, feed requirements and waste outputs, are essential in order to ensure the profitability and sustainability of the production activities. Bioenergetic models have been widely used to estimate growth based on energy budgets, but they have some limitations by not explicitly considering the mass-balance of the main macronutrients (e.g., protein). In turn, nutrient-based models are more explanatory, as they consider both energy and nutrient inputs, and estimate fish growth by simulating nutrient accumulation in the fish body. Although some bioenergetic and nutrient-base models for predicting Nile tilapia growth exist in the literature, their suitability is not entirely clear, since their development is often based on uncertain or suboptimal criteria (e.g., relying solely on calibration goodness-of-fit measures).In this work, Nile tilapia growth datasets covering a wide range of rearing conditions and feed compositions were collected from the scientific literature. An exploratory analysis of the collected data was performed to clarify the relationships between energy/protein intake and gain. In this analysis, a direct relationship was observed between digestible energy intake and energy gain, as well as between digestible protein intake and protein gain. Protein gain showed better efficiency than energy gain, even at higher intake levels and without clear evidence of a saturation effect. While digestible energy intake negatively affects energy retention efficiency, digestible protein intake does not significantly impact protein retention efficiency. Furthermore, while energy retention efficiency varies with fish body weight, the same effect was not observed for protein retention efficiency. Finally, though DP/DE ratio has no apparent effect on energy retention efficiency, it seems to negatively affect protein retention efficiency. Considering these observations, plausible growth models with different levels of complexity were developed and calibrated under a diverse set of assumptions. Additionally, two growth models already published for Nile tilapia were calibrated using the same datasets, and their performance was compared with the models developed in the present study. The exploratory analysis of the data suggests a direct relationship between digestible energy intake and energy gain, and between digestible protein intake and protein gain. Furthermore, fish body weight seems to affect the energy retention efficiency. The results of model evaluation showed that energy-protein flux models (EP models) have lower errors in predicting fish growth than pure bioenergetic models (MAPEbw ∼ 9% against ∼13%, respectively), showing the importance of considering protein intake when estimating Nile tilapia growth. Furthermore, assuming the fixed standard metabolic body weight exponents of 0.80 and 0.70 (for energy and protein, respectively), rather than estimating them from the data, seemingly improved the predictive ability of the models. This approach demonstrates the benefits of coupling bioenergetics with nutrient-based models to predict growth and body composition of Nile tilapia along time.

Carp-Based Small Indigenous Species (SIS) Fish Farming in Fattening Pond Under Barind Area in Rajshahi, Bangladesh

The present study was conducted on four experimental ponds (T1, T2, T3, T4) each with three replications (R1, R2, R3) in Tanore upazila (sub-district) of Rajshahi district, Bangladesh for a period of six months. Four treatments were assigned for this study as T1 ( silver carp-742/ha, catla-990/ha, rui-1485/ha, mrigel-990/ha and shing 5,000/ha), T2 ( silver carp-742/ha, catla-990/ha, rui-1485/ha, mrigel-990/ha and magur 5,000/ha), T3 (silver carp-742/ha, catla-990/ha, rui-1485/ha, mrigel-990/ha and pabda 5,000/ha) and T4 (silver carp-742/ha, catla-1235/ha, rui-1729/ha and mrigel-1235/ha) each with three replications. The initial average weight of fish was silver carp (H. molitrix)-252.53g, catla (G. catla) - 270g, rui (L. rohita)-245g, mrigel (C. mrigala)-235g, shing (H. fossilis)-2.03g, magur (C. batrachus) -3.28g, pabda (O. pabda)- 1.51g respectively. Supplementary feeds were applied at an average rate of 5% of the body weight of fish. During the study period, it was found that the water quality parameters were within the acceptable ranges for carp-based small indigenous species fish farming in the study area. In case of growth performances, Treatment T2 showed the highest Yield followed by T1, T3 and T4.