Asian Journal of Fisheries and Aquatic Research

Partial and Total Replacement of Soya Bean Meal with Rhynchophorus phoenicis (African Palm Weevil) Larvae Meal in the Diet of Oreochromis niloticus

Oladunni Sakeenah Alli, Adetutu Nifemi Adebayo, Olajumoke Olamiposi Omosowone — Sat, 04 Apr 2026 00:00:00 +0000

Growth efficiency of fingerlings of Oreochromis niloticus fed different replacement levels of soybean meal with larvae of African palm weevil Rhynchophorus phoenicis (RP) meal was assessed in the present study. Oreochromis niloticus of the initial weight of 6.0 ± 0.05g was evaluated over 74 days. Five different inclusion levels of Rhynchophorus phoenicis meal RP1 – RP5 were combined to formulate five experimental diets: 0% (control), 25%, 50%, 75%, and 100%, where RP1 is the control. All diets were iso-nitrogenous, and there were three replicates of each treatment.

At the end of the feeding trials and statistical analyses, it was concluded that O. niloticus fed with 100 % inclusion of RP performed best in the growth indices. They consumed the most feed, gained the most weight, and had the best feed conversion ratio. The blood parameters of O. niloticus were not adversely affected by the addition of RP to their diet. Red blood cells increased as the RP meal increased, indicating that the RP meal had no detrimental effects on red blood cells, while white blood cells decreased as the RP meal increased, which might be due to experimental stress. In the carcass composition, crude protein was highest in the fish fed with 100% inclusion of RP meal. It was also concluded that there was no adverse effect on the culture media and water parameters when O. niloticus was fed an RP meal. Therefore, the present study suggests that Rhynchophorus phoenicis meal may serve as a 100% substitute for soybean meal in the diet of O. niloticus fingerlings to increase the growth performance

Community Structure and Spatial Pattern of Coral Reef Fishes in Nipah Bay, North Lombok Regency

Lalang Setiawan Hamsy, Nurliah Buhari, Edwin Jefri — Mon, 06 Apr 2026 00:00:00 +0000

Reef fishes are key indicators of reef condition and play an important role in linking benthic and pelagic processes. This study aimed to quantify the community structure and spatial variation of reef fishes in Nipah Bay, North Lombok. Surveys were conducted in July 2025 at three stations and two depths (3 m and 7 m) using underwater visual census along 70 × 5 m belt transects. All observed fishes were identified to species level, and total length was recorded to estimate biomass using family-specific length–weight relationships. Environmental parameters, including temperature, salinity, pH, current velocity, and total suspended solids (TSS), were measured concurrently. A total of 1,884 individuals belonging to 55 species, 32 genera, and 15 families were recorded. The assemblage was dominated by Pomacentridae, followed by Labridae and Acanthuridae, while Chaetodontidae were relatively scarce. Diversity indices indicated moderate to high diversity (H' = 2.13–3.02), high evenness (E = 0.67–0.86), and low dominance (D = 0.06–0.19). Descriptive analysis of community composition suggested variation in reef fish assemblages among stations, with relatively higher similarity between T1 and T2 compared to T3. Total fish biomass reached 58.07 g m⁻², with Acanthuridae contributing the largest proportion. Spatial variation in reef fish assemblages was likely influenced by benthic habitat characteristics, including structural complexity, substrate composition, and live coral cover, while water quality parameters were relatively homogeneous across sites. These findings provide baseline information on reef fish community structure and support future reef management and long-term monitoring in Nipah Bay.

Fish Assemblage Structure and Biodiversity in the Han and Cu De Rivers, Central Vietnam

Nguyen Thi Tuong Vi, Phan Minh-Thu, Le Thi Thu Thao — Thu, 09 Apr 2026 00:00:00 +0000

Estuarine ecosystems are among the most biodiverse yet increasingly threatened environments worldwide, particularly in tropical coastal regions where river and marine systems interact. This study investigated the structure, species composition, and seasonal variation of fish assemblages in the Han and Cu De Rivers in Da Nang City, central Vietnam. Field surveys were conducted during the rainy season (September–December 2024) and dry season (March–June 2025) at major fish landing sites and aquatic product collection points along the two river basins. A total of 957 specimens were collected and analyzed using standard morphological taxonomy, and community patterns were analyzed using Bray–Curtis similarity and Principal Component Analysis (PCA). Overall, 166 fish species belonging to 122 genera, 64 families, and 21 orders were recorded. Species richness differed between rivers, with 109 species in the Han River and 99 in the Cu De River, and only 42 shared species, indicating clear spatial differentiation. The Han River assemblage was dominated by estuarine and marine-associated taxa (e.g., Acanthuriformes and Carangiformes), whereas the Cu De River was characterized by freshwater taxa, particularly Cypriniformes (28.3%). Seasonal variation was pronounced, with 121 species recorded in the dry season compared to 75 in the rainy season. These findings demonstrate that the study area functions as an estuarine transition zone with strong environmental gradients shaping fish communities. The results provide essential baseline data for biodiversity conservation and fisheries management, while highlighting the importance of hydrological connectivity and seasonal dynamics in coastal river ecosystems.

Nano-enabled Delivery of a Polyherbal Formulation from Tridax procumbens, Boerhavia diffusa and Tinospora cordifolia to Enhance Growth, Immunity and Disease Resistance in Pangasius pangasius Fingerlings

Sachin Ghate, Shivaji G. Jetithor, Datta Ashok Nalle — Sat, 11 Apr 2026 00:00:00 +0000

The present study evaluated improved growth performance, immunity, and disease resistance in Pangasius pangasius fingerlings (initial weight: 9.1 ± 0.3 g), the current study assessed a nano-enabled delivery system for a polyherbal formulation consisting of Tridax procumbens, Boerhavia diffusa, and Tinospora cordifolia (TP:BD:TC = 1:1:1). Chitosan–tripolyphosphate (CS–TPP) ionic gelation was used to nanoencapsulate a combination of hydroethanolic extract. Four experimental diets were given to fish for 60 days: control (C0), polyherbal (PH 1%), nano-polyherbal (NPH0.5), and nano-polyherbal (NPH1.0).

In comparison to the control group, NPH1.0 considerably (p < 0.05) increased weight gain (20.75 g), specific growth rate (1.82% day⁻¹), and feed conversion ratio (1.34). Lysozyme activity (30.8 U/mL), respiratory burst activity (NBT: 0.46), and alternative complement activity (ACH50: 162 U/mL) were among the immune markers that showed a substantial increase. Additionally, the nano-treated groups showed decreased lipid peroxidation and increased antioxidant enzyme activity. The NPH1.0 group had the highest survival rate (81.1%) and relative percent survival (RPS: 66.7%) after the Aeromonas hydrophila challenge.

Overall, nano-polyherbal supplementation demonstrated superior efficacy over free herbal inclusion, likely due to improved bioavailability and controlled release of bioactive compounds. These findings suggest that nano-encapsulated polyherbal formulations can serve as a promising, eco-friendly alternative to antibiotics for sustainable health management in aquaculture.

Proximate Composition, pH and Mineral Element Analysis of Some Selected Indigenous Dried Freshwater Fish Species from Assam, India

Jayanta Deka — Sat, 11 Apr 2026 00:00:00 +0000

Because of the high quality of the protein it contains, fish is an exceptional animal food source for a large portion of the global population. Fish and aquatic foods contain a potent combination of micronutrients, amino acids, vitamins, and protein, all of which contribute to a multitude of daily health benefits across the globe. The present study aimed to explore the proximate Composition, pH and Mineral Element Analysis of Some Selected Indigenous Dried Freshwater Fish Species from Assam, India. A total of seven samples of dry fish were analyzed from Assam, India. Fish samples used were of the following species: Labeo catla, Chanda nama, Rasbora daniconius, Channa punctata, Puntius sophore, Amblypharyngodon mola and Anabas testudineus. Biochemical analyses, including moisture, fat, ash, and pH, were performed according to standard method. The moisture content of dry fish samples ranged from 2.87% to 6.92 %, while protein levels ranged from 37.45% to 58.24 %. Lipids were found to be between 13.27% and 18.75 %, while ash varied from 13.18% to 32.21%. Using X-Ray Diffraction (XRD), it was determined that the dry fish contained elements: Na, K, Ca, Mg, Mn, Zn, Fe & P. The pH of all samples ranged between 6.16 and 8.29, and all experiments were done in triplicate. The variation in mineral composition may be influenced by environmental conditions, feeding habits, physiological characteristics, and drying techniques. Overall, the findings confirm that dried freshwater fish represents a nutrient-dense and affordable food resource, capable of contributing significantly to dietary protein and mineral intake, particularly in developing countries where fish forms an integral part of traditional diets.

Seasonal Availability, Proximate Composition and Mineral Analysis of Edible Cephalopods at Digha Coast, West Bengal, India

Indrani Banerjee, Sahali Chakraborty, Sumana Saha — Wed, 15 Apr 2026 00:00:00 +0000

The present study investigates the seasonal availability, proximate composition, and mineral content of edible cephalopods from the Digha coast, West Bengal, India. Cephalopods, including species like squids, cuttlefish, and octopuses, are economically and nutritionally important seafood, contributing significantly to the local fisheries and export markets. Sampling was conducted across different seasons to assess fluctuations in species abundance and biochemical properties. The proximate analysis revealed that cephalopods are rich sources of protein (ranging from 15-17%) with less amount of lipid content, making them a healthy dietary option. Seasonal variations influenced the moisture content (70-80%) and carbohydrate levels, reflecting metabolic changes and reproductive cycles. Mineral analysis showed that these species are high in essential elements such as calcium, phosphorus, and iron highlighting their nutritional significance. Seasonal availability patterns indicated peak landings during the post-monsoon i.e. winter months, corresponding to favorable environmental conditions and spawning activities. The study underscores the importance of sustainable harvesting practices to maintain the ecological balance and long-term productivity of cephalopod resources in this region. These findings contribute to understanding the nutritional potential of cephalopods and support their effective utilization in the food industry.

Effect of Carbon-to-Nitrogen(C/N) Ratio Manipulation on the Growth Performance, Nutrient Utilization and Body Composition of Clarias gariepinus in a Wheat Bran Based Biofloc System

A. A. Kolawole, D. M. Umar — Thu, 16 Apr 2026 00:00:00 +0000

Biofloc Technology (BFT) can be effectively implemented using a range of organic carbon sources; however, carbohydrate-based inputs are generally regarded as most suitable. The selection of an appropriate carbon source depends on several factors, including cost-effectiveness, biodegradability, local availability, and the efficiency of bacterial assimilation. A 10-week outdoor culture experiment was conducted to evaluate the effects of varying carbon-to-nitrogen (C/N) ratios on growth performance, nutrient utilisation, and body composition of African catfish (Clarias gariepinus) reared in a biofloc system. Biofloc-based treatments were established at three C/N ratios (10, 15, and 20) through the addition of wheat bran, while a freshwater system with regular water exchange and no supplementary carbon source served as the control (C). The experimental design comprised 12 plastic tanks (100 L capacity), with each treatment conducted in triplicate. Each tank was stocked with 20 fingerlings and the fish were fed a commercial diet containing 40% crude protein throughout the study period. The water quality parameters (EC, pH, temperature, total ammonia nitrogen, nitrite nitrogen, dissolved oxygen, and total dissolved solids) were monitored throughout the experiment. There was no significant (p > 0.05) difference among the treatments in the case of EC, TDS and temperature. The pH, total ammonia nitrogen, and DO showed significant differences. Survival rate improved with increasing C:N ratio up to 15:1 (83.33 ± 1.22%), followed by a slight decline at 20:1 (80.00 ± 2.89%). Final mean weight (FMW) and mean weight gain (MWG) increased significantly (p < 0.05) from 41.80 ± 0.69 g (control) to 52.73 ± 1.15 g at C:N 15, but declined slightly at C:N 20 (43.80 ± 0.64 g). Feed conversion ratio (FCR) improved markedly from 2.08 ± 0.05 (control) to 1.26 ± 0.12 at C:N 15, demonstrating better feed utilization due to microbial protein supplementation and nutrient recycling. Protein efficiency ratio (PER) and protein productive value (PPV) were also significantly affected by C:N ratio, peaking at C:N 15 (PER = 17.65 ± 1.15; PPV = 33.85 ± 1.35%). Crude protein increased significantly from 18.45 ± 1.23 % in the control to 27.60 ± 1.22 % at C:N 20. Fat content followed a similar pattern, rising from 3.24 ± 0.06 % (control) to 6.14 ± 0.44 % at C:N 20. All data collected were subjected to one-way ANOVA. However, the growth production and feed utilization results indicate that a C:N ratio of 15:1 in wheat bran–based biofloc systems provides the best performance thereby it is recommended for fish farmers. The proximate profiles reveal that moderate to high C:N ratios enhance nutrient deposition and metabolic efficiency in C. gariepinus.

Impact of Temperature Stress on Adaptive Mechanisms in Zebra Fish (Danio rerio)

Thu, 16 Apr 2026 00:00:00 +0000

Environmental temperature plays a crucial role in regulating physiological and biochemical processes in ectothermic organisms such as Zebra fish (Danio rerio). Thermal stress can disrupt homeostasis by elevating reactive oxygen species (ROS), leading to oxidative damage in vital tissues. The present study investigates the impact of gradual temperature stress on antioxidant and metabolic enzyme responses in Zebra fish, with a focus on key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and metabolic markers such as acid phosphatase (ACP), alkaline phosphatase (ALP), Β amylase, and Acetylcholinesterase (AChE) along with the lipid peroxidation marker malonaldehyde (MDA). Results demonstrated a significant increase in oxidative stress markers, with MDA levels rising by approximately 6.20-fold at 32°C and 6.48-fold at 38°C relative to control, indicating enhanced lipid peroxidation. Antioxidant responses were markedly elevated, with SOD activity increasing by 1.87-fold and 2.43-fold, CAT by 1.97-fold and 2.41-fold, and GSH by 1.97-fold and 2.02-fold at 32°C and 38°C, respectively compare to control. Metabolic enzymes exhibited temperature-dependent upregulation, with ALP increasing by 1.63-fold and 2.09-fold at 32°C and 38°C, respectively compare to control, ACP by 1.57-fold and 1.66-fold at 32°C and 38°C, respectively, and β-amylase by 1.20-fold and 1.70-fold at 32°C and 38°C, respectively as compare to control, suggesting enhanced metabolic turnover and energy mobilization. AChE activity also increased moderately (1.18-fold and 1.56-fold at 32°C and 38°C, respectively, indicating altered neurophysiological dynamics under thermal stress. These findings highlight the sensitivity of Zebra fish antioxidant systems to temperature fluctuations and underscore the importance of rate and duration of thermal exposure. This study contributes to understanding how climate-induced temperature changes can affect aquatic vertebrate physiology at the molecular and biochemical levels.