Aquaculture Research最新文献

Although medicinal plants can be used to reduce stress caused by transportation and handling and to prevent and treat certain diseases in fish, evaluating their safety for fish is essential before their use. This study aimed to evaluate the pharmacological effects and determine the safe dose of the Tanacetum parthenium (known as feverfew) extract (TPE) on blood biochemical parameters and the oxidative stress liver biomarker of common carp (Cyprinus carpio). In this study, fish were fed with doses of 0.0%, 0.5%, 1%, 2%, 5%, and 10% TPE per kg feed for 28 days. Next, blood biochemical parameters and hepatic oxidative biomarkers were measured to determine safe doses of the extract. The activities of aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase significantly increased (p < 0.05) after feeding fish with 10% TPE. Conversely, there was a notable decrease (p < 0.05) in alanine aminotransferase activity in the plasma of fish given 10% TPE. Furthermore, lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activities in the plasma were significantly higher (p < 0.05) in fish fed with either 5% or 10% TPE compared to the control group. Increasing doses of the extract significantly elevated plasma cholesterol, triglycerides, creatinine, and glucose levels; however, it did not significantly affect total protein, albumin, and globulin levels. Oxidative stress biomarkers indicated that 0.5%, 1%, and 2% doses were safe, while 5% and 10% extracts induced oxidative stress in fish. In conclusion, lower doses (0.5%–2%) of TPE are recommended for evaluating its therapeutic properties, as they offer safe and effective treatment for common carp without causing oxidative stress.

This study investigated the effectiveness of adopting a fed-batch culture mode with intermittent feeding of culture media to enhance the biomass production of Chaetoceros calcitrans. Three experimental runs were undertaken, each comprising four cycles. The nutritional composition of the C. calcitrans biomass produced was evaluated. The experiment yielded a consistent production of C. calcitrans dry biomass, with outputs of 257.01, 251.88, and 252.41 g obtained in a cultivation period of 28 days per cycle. The initial inoculum concentrations for each run were high, measuring 4.2 × 10⁷, 4.2 × 10⁷, and 4.4 × 10⁷ cells mL⁻¹, respectively. A consistent increase in cell density and dry biomass was observed across all cycles. The cell density at the harvesting point was between 7.3 × 10⁷ and 1.10 × 10⁸ cells mL⁻¹. The nutritional analysis of the C. calcitrans biomass revealed that protein comprised the largest proportion of the total biomass at 41.8 ± 0.7%, followed by carbohydrates at 27.2 ± 0.1% and lipids at 11.3 ± 0.6%. The biomass contained a total of 17 amino acids, comprising 43.2% essential amino acids and 56.7% non-essential amino acids, with the highest concentration observed for glutamic acid (17.6 ± 0.1%). The fatty acid composition of C. calcitrans was recorded with predominant polyunsaturated fatty acids (PUFAs) (44.6 ± 0.2%). The results suggest a possible cost-saving mechanism, as the culture mode adopted yielded higher microalgal biomass production while retaining a good range of nutritional profiles of C. calcitrans biomass.

Pesticide pollution in aquatic ecosystems poses a prevalent and pressing concern, with a particular emphasis on developing nations. The effect of cypermethrin (CP), a synthetic type II pyrethroid pesticide, on phenotypic traits, enzyme activities, and biochemical nutrients in freshwater, mrigal fish (Cirrhinus mrigala) was investigated in this study. Fingerlings (average weight: 118.29 ± 46.21 mg; average total length (TL): 0.182 ± 0.234 cm) were exposed to CP concentrations of 0.0065, 0.013, and 0.026 ppm to determine the median lethal concentration (LC₅₀) for 32 h and subsequently, three sublethal concentrations of 0.0026, 0.0013, and 0.00065 ppm were employed to analyze the chronic toxicity stress for 6 weeks. Fish fingerlings tolerated well at lower concentrations (0.0065 ppm) of CP over exposure times, while 50% mortality occurred at 0.013 and 0.026 ppm after 32 h and 4 h of exposure, respectively. In the present investigation, growth and eye diameter showed marked differences among treatments, while remaining TL, standard length (SL), head length (HL), tail length, head width (HW), body depth (BD), body area (BA), and dressing percentage (DP) were found similar among treatments. This study revealed that the amylase and protease activities decreased significantly at increasing concentrations of CP. On the other hand, biochemical nutrients (protein, lipid, moisture, and ash) among the treatments were similar. This study proves that short-time exposure to CP has a negative impact on fish growth and enzymatic activities; however, further studies, such as metabolomic approaches, are required to fully explore the effect of CP during sublethal exposures.

The use of marine collagen for regenerative applications is rapidly expanding. Tilapia (Oreochromis niloticus) skin is an emerging byproduct of food industry and a valuable biomaterial known for its pro-regenerative properties. Enhancing its intrinsic composition through nutritional strategies could further improve its clinical potential. This study investigates the impact of a hydrolyzed collagen-enriched diet on the skin properties of aquaponically farmed Tilapia, with the aim of enhancing collagen content while preserving tissue homeostasis. The results showed a modulation of key amino acids and fatty acids, suggesting a favorable shift toward anti-inflammatory and pro-regenerative properties. A measurable increase in skin thickness and hydration was registered, as well as an ECM remodeling. No detrimental effects on mineral content or mechanical integrity were observed. These findings demonstrate that dietary supplementation with collagen can be an effective, non-invasive, approach to improving the biomedical quality of fish-derived skin products.

Fish seed production in private hatcheries is rapidly increasing in Bangladesh as aquaculture expands. However, a clear forecast of fish seed production trends, including major carps, exotic carps, pangas, and other key species, remains lacking. This study aimed to develop a dynamic time series model that accurately predicts future fish seed production scenarios at the private hatchery level, facilitating effective planning and management strategies for sustainable growth. Data from 2007 to 2024 were obtained from the Department of Fisheries (DoF), Bangladesh, which reports seed production as total biomass (kg) rather than seed count. The study identified ARIMA (2, 0, 2) as the most suitable model for predicting fish seed production based on its lowest Bayesian information criterion (BIC) value, along with comparatively lower error metric values, and supported by graphical assessments of the autocorrelation function (ACF) and partial ACF (PACF) plots. According to the autoregressive integrated moving average (ARIMA) (2, 0, 2) model, fish seed production at the private hatchery level is projected to continue increasing, reaching 740,983 kg by 2030, representing an estimated 14% increase from 2024. This projected growth highlights the expanding potential and opportunities for fish seed production in private hatcheries across Bangladesh. The findings of this study provide valuable insights for researchers, policymakers, academics, and aquaculture stakeholders in formulating strategies for the future development and management of private hatchery-based fish seed production in Bangladesh.

Diatoms are a group of unicellular microalgae with a very attractive biochemical composition for biotechnology and aquaculture. This study aimed to characterize the morphometry and compare the biochemistry of eight diatom strains—Amphora sp., Entomoneis sp., Nanofrustulum shiloi, Navicula salinicola, Navicula sp., Nitzschia inconspicua, Psammodictyon panduriforme, and Odontella aurita—isolated from coastal areas of Baja California Sur, México. Morphometric analyses revealed cell volumes ranging from 16.2 to 794.0 µm³ and specific growth rates between 0.3 and 0.4 days⁻¹. Ash content ranged from 13.6% to 25.9% dry weight. Biochemical composition varied among strains, with protein (27.1–42.0%), carbohydrates (5.8–26.4%), and lipids (19.4–42.3%). Pigments included chlorophyll a (1.6–5.3%), chlorophyll c (0.4–1.0%), and total carotenoids (1.3–3.5%). Fatty acids were dominated by C14:0, C16:0, C16:1n7, and eicosapentaenoic acid (EPA; 20:5n-3), with arachidonic acid (ARA; 20:4n6) present in most strains except Entomoneis sp. These isolates’ morphometric and biochemical traits were comparable to those of diatom species widely used in aquaculture, suggesting their potential as alternative live feeds. Although direct feeding or toxicity assays were not performed, these comparative analyses provide a robust basis for proposing potential applications in aquaculture and biotechnology.

This study compared the impacts of three aquaculture systems, a biofloc tank system (BTS) without sludge removal, a clear water (non-biofloc) tank system (CTS), and an earthen pond system (EPS), on the zootechnical, biochemical, haematological, and enzymatic activities of Nile tilapia (Oreochromis niloticus). Monosex (male) fish (initial weight: 22.01 ± 0.33 g) of Nile tilapia were reared in triplicate under these systems for 90 days, with feeding rates of 3%–2% for BTS and 6%–4% for CTS and EPS. All systems maintained optimal water quality parameters throughout the rearing period. The fish reared in EPS performed the best (p < 0.05) in terms of all the indices of growth, morphometrics, and flesh yield. Principal component analysis (PCA) confirmed distinct morphometric clustering in EPS fish, whereas BTS and CTS overlapped. However, the BTS-reared fish performed better in terms of feed (feed conversion ratio and protein efficiency ratio and resource (water and space) use efficiency (p < 0.05). Although there were no significant differences (p > 0.05) in crude protein content, significantly higher lipid and ash levels (p < 0.05) were determined in the muscle of BTS-reared fish. Additionally, BTS-reared fish presented increased protease and hepatic enzyme activities (p < 0.05) and improved haemato-biochemical parameters, particularly a significant increase in white blood cells (WBCs; p < 0.05). In summary, while EPS supports superior growth and body dimensions, BTS without sludge management ensures efficient feed and resource (water and space) utilization while improving the nutritional composition, enzymatic activity, and health of Nile tilapia. These results highlight the potential of the BTS as a sustainable alternative for small-scale urban aqua entrepreneurs.

High temperatures (>34°C) of water in aquaculture production systems potentially generate oxidative stress in white shrimp (Penaeus vannamei), which could result in high mortality rates and/or poor production performance of organisms. Protein hydrolysates elaborated with fishery byproducts have shown high nutritional and antioxidant potential, which can be used as functional ingredients in the formulation of nutraceutical feeds for shrimp. In the present study, two protein hydrolysates made with tuna dark muscle (TDM) protein (Thunnus albacares) (TDM hydrolysate (TPH)) at 10% and 20% degree of hydrolysis (DH) were supplemented on two shrimp feeds, FH10 and FH20, respectively. A total of 180 juvenile whiteleg shrimp (P. vannamei) were fed for 5 weeks with the experimental feeds. The best results in productive performance (final weight; weight increment; protein efficiency ratio [PER]; feed conversion ratio [FCR]; specific growth rate [SGR%/days] and survival %) were obtained with FH20, being these organisms subjected to an acute thermal stress by high temperature (35°C) for 12 and 24 h of exposure. The results indicated that the organisms fed with FH20 obtained a better enzymatic response of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the first 12 h of exposure to thermal stress, compared to a control feed (CF) without TPH.

The New Zealand green-lipped mussel, Perna canaliculus, is a key aquaculture species often used in bacterial exposure experiments to better understand infection mechanisms resulting in decreased health and survival. The route of bacterial exposure in an experimental setting has largely been standardised, yet corresponding data on mussels’ physiological response would be beneficial to larger experimental designs. In this study, two bacterial exposure methods, namely, injection and immersion, were implemented to assess their effects on haemolymph parameters and metabolite profiles in mussels following exposure to the bacterium, Photobacterium swingsii. As expected, when injecting bacteria into the mussels’ adductor muscle, higher bacterial colony-forming units were detected in the haemolymph, compared to mussels under immersion, showing the effectiveness of injection as a bacterial delivery method. Alongside this, haemocyte profiles showed decreased haemocyte viability and increased total haemocyte counts following injection. Moreover, immersion resulted in moderate shifts in haemocyte subtypes, particularly increases in hyalinocytes and mixed granulocytes. Metabolomics analyses revealed decreases in amino acids and fatty acids in bacterial-infected groups (irrespective of administration method). This indicates a shift in energy metabolism associated with physiological stress or immune-related processes. Additionally, metabolites linked to antioxidant pathways, such as glutathione and methionine, were significantly reduced in the infected mussels, highlighting the increased demand for countering oxidative stress post-bacterial exposure. Collectively, these results underscore the importance of bacterial exposure method selection in mussel trials and provide physiological and metabolic information for future studies aiming to monitor haemolymph immune dynamics and metabolic changes under controlled experimental conditions.

Farmed Atlantic salmon are increasingly being challenged by rising sea surface temperature. For salmon aquaculture in Australia, the water often exceeds the thermal tolerance limit during summer, causing reduced feeding, intestinal inflammation and increased susceptibility to disease. Dietary inclusion of crystalline L-arginine can improve gut epithelium function under heat stress in other animals, including pigs and rodents. Here, we conducted a feed trial to determine if an additional 1.5% dietary arginine above base diet requirements can improve gut function in chronically heat-stressed Atlantic salmon. Two diets, termed ‘control’ and ‘arginine’, were fed to Atlantic salmon smolt during a 9-week trial. After 1 week at 15°C, both treatments were ramped to 19.5°C over 5 weeks and then held at 19.5°C for 3 weeks. Following the trial, growth performance was evaluated, and the distal intestine was assessed for the effect of arginine supplementation on histopathology, intestinal permeability and tight junction gene expression. Growth performance, intestinal inflammation markers and intestinal permeability were not significantly improved by supplemental arginine in heat-stressed Atlantic salmon. However, the distal intestine simple fold length increased, and there was a trend towards a higher daily feed intake (p = 0.053) in salmon fed with supplemental arginine. While additional arginine did not appear to greatly improve intestinal function in heat-stressed Atlantic salmon smolt, the results do not rule out a benefit for elevated L-arginine for improved health.