Aquaculture Research最新文献

Spiny lobsters (Panulirus spp.) hold great ecological and economic importance in many tropical and subtropical regions, supporting coastal livelihoods and high-value seafood markets worldwide. Countries such as Vietnam, Indonesia, India, and Australia have advanced aquaculture and hatchery research for these species, showing that commercial culture is possible with scientific guidance and institutional support. In Bangladesh, where suitable coastal conditions exist, this potential remains largely untapped. This review presents global scientific knowledge on spiny lobster biology, larval development, seed collection, hatchery production, nursing aspects, culture systems, feeding practices, and disease management. It draws insights from international aquaculture experiences to inform the establishment of a sustainable lobster farming industry in Bangladesh. It also highlights opportunities for site selection and pilot-scale aquaculture in the waters of Cox’s Bazar and the Teknaf coast of the Bay of Bengal. Long larval cycle, low hatchery survival, lack of formulated diets, disease outbreaks, dependance on wild broodstock and seed, high operational costs, environmental risks, weak policy support, limited technical expertise, and inadequate infrastructure are some of the major challenges identified. A strategic management framework is proposed that integrates research and development, seed supply systems, aquaculture operations, and policy coordination. This framework emphasizes participatory governance, capacity building, and environmental stewardship as core pillars of sustainable development. Future research should focus on larval nutrition, broodstock domestication, biosecure hatchery and nursery systems, and climate-resilient farming models. By connecting global experience with local ecological and social realities, Bangladesh can build a viable spiny lobster aquaculture sector that enhances food security, supports community livelihoods, and contributes meaningfully to the national blue economy.

To address key issues in the breeding and aquaculture of Cherax quadricarinatus, two experiments were conducted based on existing research. The first experiment investigated the effects of four disinfection methods on the microbial community and diversity indices on the surface of isolated embryos, with three replicates per group. Previous studies were summarized to establish a protocol for artificial incubation. Results showed that treatments with essential oil-based solutions and formaldehyde achieved the best disinfection effects, effectively reducing harmful bacteria while maintaining higher microbial diversity. Using the established artificial incubation protocol, a total of 550 egg-holding crayfish were used, and a total of 90,142 juveniles were hatched, with a hatching rate of 91.04 ± 1.91% and a survival rate of 60.65 ± 6.77%. The second experiment examined the cultivation of large-sized juveniles in a pond greenhouse, focusing on release modes, densities, and culture areas, with three replicates per group. Survival rates did not differ significantly between the staged culture mode (66.69 ± 8.84%) and the direct free-range mode (62.71 ± 14.15%). However, the survival rate at a density of 10,000 tail/667 m² group was significantly higher than that at 20,000 tail/667 m² group. The smaller-area group (133 m²) had a survival rate of 62.71%–66.69%, whereas the larger-area group (400 m²) had a survival rate of only 48.43%–58.86%. In conclusion, essential oil-based solutions or formaldehyde are recommended as disinfectants, while cultivation area (133 m²) and lower stocking density are important for improving juvenile survival. These findings can contribute to the development of breeding and aquaculture of C. quadricarinatus.

This study investigated the effects of cadmium (Cd), microplastics (MPs), and pectin (Pec) supplementation on biochemical, oxidative, and immunological parameters in crayfish (Astacus leptodactylus). Four hundred fifty crayfish were acclimatized under controlled laboratory conditions and distributed into 15 experimental groups using a definitive screening design (DSD) approach. The groups were exposed to varying combinations of Cd (0, 20, and 40 µg/L), MP (0, 50, and 100 mg/L), and Pec-supplemented diets (0%, 0.25%, and 0.5% per kg feed) for 45 days. The findings showed that Pec supplementation increased superoxide dismutase (SOD) and glutathione (GSH) peroxidase (GPx) activities but did not affect catalase (CAT) activity. Cd and MPs reduced SOD, CAT, and GPx activities, with Pec partially restoring CAT activity. Exposure to Cd and MPs elevated alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, triglycerides, cholesterol, creatinine, and glucose levels, while gamma-glutamyl transpeptidase, lysozyme, total protein, and albumin decreased. Pec normalized triglyceride and alkaline phosphatase (ALP) activity but showed limited protective effects on GPx, cholesterol, creatinine, and glucose regulation. The results indicated that because crayfish were directly exposed to MPs and Cd, oral administration of the Pec supplement failed to restore some biochemical parameters to normal levels. These findings indicate Pec’s selective efficacy in mitigating Cd- and MP-induced stress in crayfish.

Understanding species-specific physiological flexibility in Indian major carps (IMCs) is crucial for enhancing thermal resilience, safeguarding health, and sustaining year-round productivity in climate-sensitive freshwater systems. This study examined the seasonal physiological adaptability of three Indian main carps (Labeo rohita, Gibelion catla, and Cirrhinus cirrhosus) by measuring growth performance, proximate composition, and hematological profiles in both overwintering and summer aquaculture environments. It was hypothesized that seasonal heat changes would cause species-specific metabolic and immunological responses, indicating varying tolerance to environmental stress. All IMC species exhibited enhanced growth during the summer season, for example, G. catla exhibited the highest specific growth rate (SGR) of 1.26 ± 0.13%/day and average daily growth (ADG) of 2.56 ± 0.32 g than the other species. Moisture dominated the proximate composition, while protein and lipid contents declined in winter. Hematological analysis manifested seasonal and species-specific physiological responses to environmental stressors. Increased concentrations of white blood cells (WBCs), monocytes, glucose, and mean corpuscular volume (MCV) in fish blood denoted that higher temperature in summer attributes to increased metabolic activities and improved immune responses. Conversely, reduction in hematocrit (HCT) levels during winter in G. catla (32.53  ±  0.54%) and C. cirrhosus (33.14  ± 1.35%) suggests a physiological adaptation to lower oxygen availability, potentially reflecting a seasonal modulation of erythropoiesis and oxygen-carrying capacity under cold-induced hypoxic stress. Furthermore, the elevation in serum creatinine levels in all experimented IMCs during winter suggested potential changes in renal activity due to fish physiological adjustments in winter. The findings highlight the importance of better aeration, water exchange, and ammonia control in summer and careful stocking with minimal handling in winter to reduce stress in overwintering ponds.

This study assessed the effect of different feeding levels on the growth performance of Nile tilapia (Oreochromis niloticus) as well as on the stability of the biofloc system over a 9-week experimental period. Three feeding levels were tested: BFT100 (100% of a complete ration), BFT75 (75% of a complete ration), and BFT50 (50% of a complete ration). A flow-through system group (control) was feed 100% ration, while biofloc groups received 100% (BFT100), 75% (BFT75), or 50% (BFT50) of that ration. Each treatment was replicated 3 times, and the fish were reared in subsquare tanks (130 L) at a stocking density of 6.2 kg.m⁻³ per experimental unit (70 fish per tank). Growth performance was recorded at 14-day intervals. All fish were counted and weighed to determine the total biomass. A sample of 30 fish per unit was measured and weighed individually to assess variability. Growth performance was significantly affected by feeding level (p  < 0.05), whereas survival remained high and did not differ among treatments (92.9%–98.6%). The highest specific growth rate (SGR) was observed in the flow-through control (2.72% day⁻¹), followed by BFT75 (1.92% day⁻¹) and BFT100 (1.70% day⁻¹), while BFT50 exhibited the lowest SGR (1.21% day⁻¹). A moderate level of feed reduction (BFT75) resulted in improved water quality and maintained feed efficiency, with a feed conversion rate (FCR) (0.89) similar (p  > 0.05) to that of the control (0.75). In contrast, higher FCR values were recorded in BFT100 (1.09) and BFT50 (1.13), indicating reduced feeding efficiency under full feeding and excessive feed restriction, respectively. Notably, the BFT100 treatment was characterized by signs of organic overload under full-feeding conditions, including floc disruption, increased nitrogenous waste levels, microbial imbalance, and mortalities. Accordingly, this study concludes that the biofloc system can withstand a 25% feed reduction without adverse effects on FCR when environmental stability is maintained. Resource optimization and progressive system management are likely the most effective approaches to enhance the sustainability of biofloc technology (BFT)–based tilapia rearing.

Barnacle aquaculture is a developing area of production that is currently limited by the reliance on capturing naturally produced larvae. The solution to this limitation would be the development of hatcheries for culturing barnacle larvae and juveniles (Juvs). The giant barnacle Austromegabalanus psittacus (Molina 1788) is an edible species and, thus, of economic importance in Chile. Extensive cultures and hatcheries on an experimental scale have been developed for this species. In this study, a dynamic model, based on data from previously published studies, was developed to evaluate the larval development of A. psittacus over a range of temperatures and salinities in order to identify the optimal culture conditions for obtaining Juvs. The larval development time, survival, physiological, and biochemical responses of A. psittacus larvae were evaluated. The conceptual model representing the dynamic hypothesis, and the simulations, were carried out using Vensim PLE and Stella Architect, respectively. The best production performance under hatchery conditions was obtained at 18°C/32 PSU. Under these conditions, the survival during the development of the nauplius (Nau) stages was 90%, and the development time was 7.5 days. The recently molted cyprids (Cyps) had an accumulated energy of 24.42 J/mg dry weight (dw). At the Cyp stage, the development time was 6 days and the survival was 54%, while the energy of the Juv was 12.02 J/mg dw. Increasing the initial energy of Nau I (NI) resulted in higher survival and energy in the Cyp and Juv stages. These simulations demonstrate the usefulness of these dynamic models in designing and evaluating hatchery protocols that optimize the performance of A. psittacus larvae and may allow scaling to mass cultivation.

With the development of the aquaculture industry, the issue of aquaculture wastewater has become increasingly severe, and wastewater treatment and resource utilization have become critical research directions. This study explores the effects of fermentation temperature on the fermentation aroma, nitrogen, and phosphorus nutrient levels, and their relationships with key microorganisms in aquaculture wastewater fermentation. Using sensory evaluations, water quality testing, and high-throughput sequencing, the study analyzes the changes in water quality indicators, and the microbial community structure of aquaculture wastewater fermentation broths. The results indicated that fermentation temperature significantly impacts both the aroma and nitrogen/phosphorus nutrient levels in the fermentation broth. Moreover, the dominant microbial genera differ under different fermentation temperatures. At 15°C, the genus Debaryomyces was the most dominant, comprising 68.72%, while Sporolactobacillus dominated at 30°C (57.50%) and 40°C (61.82%). These findings reveal the impact of varying temperatures on the dominant microorganisms in aquaculture wastewater fermentation and provide a preliminary analysis of the correlations between dominant microorganisms, fermentation aroma, and nitrogen/phosphorus nutrient levels. This study offers valuable insights for improving aquaculture wastewater fermentation technology, and the screening of fermentation microorganisms.

Egg yolks derived from various avian species have been widely applied as cryoprotective additives in mammalian sperm preservation; however, their efficacy in fish sperm cryopreservation remains poorly understood. Therefore, this study evaluated the cryoprotective effects of quail (Coturnix coturnix), chicken (Gallus gallus domesticus), and turkey (Meleagris gallopavo) egg yolks incorporated at a 10% concentration into a Tris-based extender for Nile tilapia (Oreochromis niloticus) sperm cryopreservation. In addition, the extender was supplemented with 10% concentrations of different permeating cryoprotectants (CPAs)—dimethyl sulfoxide (DMSO), methanol (MeOH), and glycerol—to assess their effects on post-thaw sperm quality and fertilization capacity. The results indicated that a 10% concentration of DMSO, when combined with each egg yolk type separately, provided the most effective cryoprotective effect, significantly enhancing motility, motility duration, and viability (p < 0.05) compared to MeOH and glycerol. The highest mean fertilization rates of 48.2% ± 1.5% and 52.6% ± 1.7% were achieved using the Tris-based extender with 10% DMSO and 10% chicken egg yolk in 0.25-mL and 0.50-mL straws, respectively (p < 0.05). According to the results of this study, the extender containing chicken egg yolk showed significantly better (p < 0.05) post-thaw quality parameters and fertility results for the Nile tilapia sperm compared to those of quail and turkey.

This study assessed the influence of salinity and element composition of rearing seawater on unfed Japanese eel (Anguilla japonica) larvae at 5 days after hatching (DAH). First, no significant differences in larval survival were found between natural and artificial seawater across various container materials and sizes (50mL–20 L). Subsequently, 10 to 15 larvae were housed in 100m L polypropylene (PP) bottles with seawater of different elemental compositions. Analyses of mean lethal DAH, survival activity index (SAI), and survival rate on the mean lethal DAH demonstrated that Na, Mg, K, and Ca are essential, while S and Cl also appear highly required. Next, optimal salinity (1–34 psu) was investigated by rearing individual larvae in 48-well microplates, revealing that SAI peaked at 13–16 psu. Formulated seawater containing these six key elements at 13 psu significantly enhanced larval survival. These findings confirm that specific salinity and elemental composition are conducive to Japanese eel larval survival and offer insights for optimizing hatchery protocols.

Limited information is available about the digestive tract morphology and function in some marine fish species. Using anatomical methods, this study compared the morphological characteristics of the digestive tract among 11 marine fish species of different taxonomic status, feeding habits and ecological niches. Except for black scraper (Thamnacomus modestus), a omnivores fish, the rest of fish species involved in this study, are carnivorous fish. Three replicate fish of each species were used. The relative intestine length (RIL) of black scraper (T. modestus) was the highest among all species investigated, while skate (Raja kenojei) had the lowest RIL. The hepatosomatic index (HSI) was the highest in tiger puffer (Takifugu rubripes) and the lowest in Japanese Spanish mackerel (Scomberomorus niphonius). The highest viscerosomatic index (VSI) was found in black scraper and the lowest value was found in Japanese Spanish mackerel. In terms of stomach morphology, black scraper, tiger puffer, turbot (Scophthalmus maximus), javelin goby (Synechogobius hasta) and skate had ‘I’-shaped stomach; greenling (Hexagrammos otakii), rockfish (Sebastes schlegelii) and hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) had ‘V’-shaped stomach; while Japanese Spanish mackerel, Chinese seabass (Lateolabrax maculatus) and conger eel (Conger myriaster) had ‘Y’-shaped stomach. Besides, the pyloric caeca were found in turbot (S. maximus), greenling (H. otakii), rockfish (S. schlegelii), hybrid grouper (E. fuscoguttatus♀ × E. lanceolatus♂), Japanese Spanish mackerel (S. niphonius) and Chinese seabass (L. maculatus). The oropharyngeal morphology of fish provided clues to fish feeding pattern. In conclusion, for the 11 marine fish species, the morphological structure of stomach and oropharyngeal cavity, and the RIL had high correlation with their body shape, oropharyngeal capacity and feeding habit.