Aquaculture Research最新文献

The introduction of the non-native North African catfish (Clarias gariepinus) and its hybrids with Thailand’s native bighead catfish (Clarias macrocephalus) has been a turning point in Thailand’s aquaculture sector, affecting sustainable food production and economic growth. Although the global production of these species has significantly increased, a decline in catfish production has been observed in Thailand. This shift has raised concerns regarding the ecological impacts, disease transmission and resource competition with native species, leading to potential biodiversity loss. This review examined the implications of North African catfish and hybrid aquaculture on local ecosystems and socioeconomic conditions. The rapid growth and environmental adaptability of these fish pose threats to native species through competition and hybridisation. Effective management strategies, including the evaluation of market dynamics, biosecurity measures and the promotion of socially integrated entrepreneurship, are essential for addressing these challenges. Current aquaculture practices that prioritise short-term gains over long-term sustainability were scrutinised, emphasising the need for a One Health approach that integrates the health of ecosystems, humans and animals. Sustainable practices, such as integrated multi-trophic aquaculture (IMTA) and the use of high-quality feed, are recommended to minimise ecological degradation. Finally, this review calls for the establishment of robust regulatory frameworks to ensure the long-term viability of the aquaculture sector and promote equitable economic benefits. By addressing the challenges and opportunities presented by the introduction of North African catfish, Thailand’s aquaculture industry can be enhanced for sustainability, contributing to food security while preserving ecological integrity.

High feed costs driven by reliance on imported ingredients hinder aquaculture development in Zambia. Locally available animal protein alternatives offer a promising solution, but their digestibility remains underexplored. This study evaluated the apparent digestibility coefficients (ADCs) of two local caterpillars: mopane caterpillar or vinkubala (Gonimbrasia belina) and silkmoth caterpillar or tukanja (G. zambesina), as well as three small fish species, namely kapenta (Limnothrissa miodon), kakeya (assorted fish), and chisense (Potamothrissa acutirostris), for potential inclusion in juvenile GIFT tilapia (Oreochromis niloticus) diets. A reference diet with yttrium oxide (Y₂O₃) as a digestibility marker and test diets (70% reference diet, 30% test ingredient) were used. Fish were fed at 90% satiation for 6 weeks, with feces collected in the last 2 weeks. The ADC of the test diet ranged from 98% to 99% for dry matter (p  > 0.05), while crude protein (80%–92%), crude lipid (90%–97%), and energy (78%–89%) were significantly different (p  < 0.05), reflecting the effective utilization of these ingredients in the diet. The ADCs of the tested ingredients showed numerical differences, but high variability in standard deviations resulted in no statistical significance (p  > 0.05). ADC of dry matter ranged from 54% to 62% in caterpillars and 67%–81% in fish, crude protein from 62% to 65% and 68%–82%, crude lipid from 66% to 74% and 68%–83%, and ash from 60% to 69% and 74%–83%, respectively. These findings highlight the potential of locally available Zambian ingredients to support sustainable and cost-effective aquafeeds for tilapia. However, the variability in digestibility values indicates the need for further investigation to optimize their inclusion in diets.

The application of fish protein hydrolysates (FPHs) in aquaculture has achieved encouraging outcomes due to its growth and health promoting properties. This trial was carried out to detemine the effects of various alcalase-derived fish protein hydrolysate (FPH) supplementation on growth, feed utilization, proximate composition, liver and gut histology of juvenile giant trevally fed low fishmeal diets. Four tested diets (52% protein and 10% lipid) were produced, in which fishmeal and poultry meal (PM) were the main protein sources in the basal diet. 50 g/kg of each shrimp hydrolysate (SH), squid hydrolysate (SHH), and tuna hydrolysates (THs) were supplemented into the basal diet, namely SH, SHH, and TH, respectively. Fish were fed experimental diets in 56 days with four replicates per dietary group. The results reported that giant trevally fed SH, SHH and TH achieved higher growth than those fed the control. Feed intake (FI) didn’t alter, but lower feed conversion ratio (FCR) was seen in fish fed SH compared to the control, demonstrating that SH improved feed utilization. Protein and ash contents were increased in fish fed SH, SHH, and TH supplemented diets, whereas increased whole-body lipid was obtained in those fed TH. Dietary SH, SHH, and TH supplementations contributed to higher whole-body isoleucine, and higher lysine was seen in fish fed SH and TH. Total intestinal aerobic microbiota increased in fish fed SH, whereas Vibrio spp. density was relatively low among treatments. The goblet cells also increased in the intestine of the fish fed SH, indicating that SH could enhance intestinal health. The results indicated that all fish hydrolysates had beneficial effects of growth performance of juvenile giant trevally, in which SH showed more bioavailable than others, by improving feed efficiency and intestinal health.

Aquaculture techniques for marine ornamental fish have advanced rapidly but remain in their early stages, with challenges in providing suitable food for larvae. This study investigated using inorganic fertilization to raise Cirrhitichthys falco larvae. The fertilized group (F group) received inorganic nitrogen and phosphorus (N: 700 µg L⁻¹, P: 100 µg L⁻¹) without supplemental feeding, while the control group (C group) was fed the ciliate Euplotes sp. without fertilization. Key measurements included nutrients, water conditions, chlorophyl a, zooplankton density and diversity, and larval survival. Results showed higher phosphorus, nitrogen, dissolved oxygen (DO), pH, chlorophyl a, and zooplankton density in the F group (p  < 0.05), with zooplankton mainly composed of Strombidium spp. The F group also had significantly higher larval survival rates and growth compared to the C group (p  < 0.05). This suggests that inorganic fertilization stimulates natural prey production, enhancing survival and growth, and reducing the need for specific feeding strategies in marine fish larviculture.

Environmental enrichment refers to the addition of stimuli or modifications to captive environments that promote the expression of natural behaviors and enhance animal welfare. While enrichment has the potential to enhance welfare, its effects on fish immune function remain unclear. This study examined whether enrichment modulates the immune system beyond welfare benefits. Growth (length, weight, and Fulton’s body condition factor [K]), immune parameters (leukocyte counts and respiratory burst activity), and serum markers (cortisol, myeloperoxidase, antiprotease, and lysozyme) were assessed in rainbow trout (Oncorhynchus mykiss, n = 240). Trout (20 per aquarium, initial weight: 9.84 ± 0.77 g) were reared for 48 days in four conditions: horizontal (H, gravel), vertical (V, rubber cords), combined (VH), or a control (C, no enrichment) in 60 L glass aquaria (40 cm × 40 cm × 40 cm). Immune cell counts, including monocytes and lymphocytes, were significantly lower in enrichment setups compared to the C setup (p < 0.05), whereas spontaneous respiratory burst activity, although higher in enrichment setups, did not differ significantly. Growth and organ weights were unaffected by enrichment, except for a lower hepatosomatic index (HSI) in VH. No differences in serum markers were detected between setups. In conclusion, the V setup acts as an immunomodulator by reducing immune cell counts in rainbow trout but not affecting its respiratory burst activity. Disease resistance experiments are necessary to determine whether these immune changes affect susceptibility to infections, which is critical for assessing practical implications of V setup in aquaculture and research.

Being a key ecological and economic fish species, migratory salmon typically hatch in freshwater rivers, migrate to the ocean for maturation, and return to their natal streams to spawn. This life cycle necessitates physiological adjustments to manage fluctuating salinity levels, particularly in estuaries—critical transitional zones for smoltification. Concurrently, climate warming may directly impact the metabolic efficiency and growth rates of migrating salmon. Understanding the adaptive demands of salmon is essential, as the ability of anadromous fish to cope with salinity and thermal variability determines their resilience in a rapidly changing environment. This study employed masu salmon (Oncorhynchus masou), a nationally protected endangered salmonid species with anadromous and resident phenotypes during their life history, as an object of study to evaluate the combined effects of acute salinity stress (0, 15, and 30 ppt) and elevated temperature (10°C vs. 14°C) on osmoregulation, ion concentration, hormone levels, and immune regulations. The results revealed that exposure to seawater adversely affected the physiological and immune parameters of masu salmon, which was exacerbated under high-temperature conditions. Furthermore, anadromous individuals exhibited greater sensitivity to rapid changes in salinity compared to resident individuals. Our findings highlight the impact of climate warming on water salinity during masu salmon migration and provide evidence of the distinct physiological and immune strategies employed by anadromous and resident fish in response to the combined influences of temperature and salinity.

Liaodong Bay is an important aquaculture base in the northernmost part of China’s sea area. With the rapid development of aquaculture and the rapid expansion of aquaculture ponds, the ecological environment of many aquaculture areas has been deteriorating, which has brought about a series of ecological and environmental problems, so it is necessary to carry out rapid, accurate, and sustained monitoring of the near-coastal aquaculture areas. In this study, we utilized the Google Earth Engine (GEE) platform to extract the spatial distribution and temporal distribution information of aquaculture ponds in Liaodong Bay in a long-term time series from 1985 to 2020 using Landsat image data, which was validated by accuracy assessment, and then analyzed the distribution, area change, and spatial and temporal evolution of aquaculture ponds. The results showed that the spatial distribution of aquaculture ponds in Liaodong Bay was uneven, with hotspots mainly located in Linghai, Jinzhou; Gaizhou, Yingkou; Suizhong, Huludao; Changxingdao, Dalian; and part of Panjin. The process of change in the area of aquaculture ponds in Liaodong Bay is divided into three phases: the fluctuation period of 1985–1995, the rapid expansion period of 1995–2010, and the stabilization period of 2010–2020, and the aquaculture ponds in Liaodong Bay show a shift from continuous expansion to sustainable development, from quantitative growth to quality and efficiency, and from single-emphasis on production to energy-saving and environmentally friendly modes. The results of the study are expected to reveal the current situation, dynamics and development pressure of aquaculture ponds in the coastal area of Liaodong Bay, and to provide information support and decision support for scientific planning of aquaculture in Liaodong Bay.

In this study, the effects of antibiotics on antioxidant enzyme activities, tissue damage, and the intestinal microbiome of Opsariichthys bidens were preclinically investigated by detecting the liver’s enzymatic activities, observing hepatointestinal tissue sections, and high-throughput sequencing technology. Doxycycline hydrochloride (DH), neomycin sulfate (NM), and sulfamethoxazole (SD) were selected as representatives of three classes of antibacterial agents and used for testing. The findings indicate that administering treatment doses of DH, NM, and SD for 7 days each led to alterations in the total antioxidant capacity (T-AOC) of O. bidens and triggered oxidative stress, with SD causing a decrease in the activity of superoxide dismutase (SOD). Histological analysis revealed that the three antimicrobials could cause tissue damage; for example, liver cell swelling, infiltration of inflammatory cells, and significant congestion in severe instances. The number of goblet cells in the intestinal mucosal layer increased significantly, the microvilli fell off, and the muscle layer dissolved into bubbles. High-throughput sequencing technology was used to analyze the gut microbiota of O. bidens fed with antibiotics for 14 days, and the three antimicrobials had different observed effects on the abundance and diversity of the intestinal microbiota. NM increased the abundance and diversity of the microbiota, while DH and SD reduced the abundance and increased the diversity of the microbiota. In addition to inhibiting the growth of pathogenic bacteria, these antimicrobials can also promote the growth of abnormal intestinal microbiota (other pathogenic bacteria), therefore, destroying intestinal homeostasis. In conclusion, dietary supplementation with therapeutic doses of antibiotics for O. bidens can cause tissue damage, oxidative stress, and alterations in the abundance and diversity of the intestinal microbiome. This study provides a reference for the scientific use of antibiotics in O. bidens and establishes an important theoretical framework for preventing intestinal homeostatic imbalances.

With aquaculture playing an increasingly important role in global food systems, there is a pressing need for feed innovations that can support industry growth without exacerbating overfishing or environmental degradation. The white worm, Enchytraeus albidus, is a promising substitute live feed candidate capable of growing on a variety of organic waste materials. This study explores the effects of agri-food waste products on the biomass yield, juvenile production, and nutritional composition of E. albidus. Using a nutritional landscape approach, we found that white worm cultures fed baking yeast and oatmeal yielded the highest biomass, while cultures fed fat-reduced oatmeal, spent brewer’s grain, and oatmeal produced the most juveniles. This approach proved valuable for identifying optimal nutrient combinations and visualizing how dietary trade-offs shape growth and reproduction across diverse feed inputs. Diets containing 10%–75% protein, 30%–85% carbohydrate, and 0%–40% lipid, respectively, optimized biomass production, with protein and carbohydrate content serving as critical limiting factors. Juvenile production was primarily influenced by carbohydrate content, with at least 50% carbohydrate needed to achieve more than 85% of the reproduction observed in the control. Feed treatments significantly affected the macronutrient composition of the worms, with high-lipid diets, such as coffee grind and rape seed oil, increasing total fatty acid content. These findings demonstrate the potential of utilizing no- or low-cost feedstock to optimize E. albidus cultivation, providing a cost-effective and sustainable fish feed alternative that could help reduce reliance on marine-derived resources in aquaculture.