Iranian Journal of Fisheries Sciences
Volume:25 Issue: 1, Jan 2026

Artificial habitats, human-made structures designed to mimic natural habitats, have emerged as an integral approach in fisheries management to mitigate habitat degradation in aquatic ecosystems. This study evaluates the effectiveness of bamboo-based artificial habitat in enhancing prawn community abundance as part of the efforts to replenish and restore the prawn community in Petagas River. We assessed species richness, diversity, and distribution of prawn communities in areas with and without bamboo structures. A total of 111 individuals from five species—Macrobrachium mammillodactylus, M. equidens, M. rosenbergii, Caridina gracilipes, and M. idae—from two families were recorded. Phylogenetic analysis of the Cytochrome Oxidase I (COI) gene revealed two distinct clusters representing the genera Macrobrachium and Caridina, with bootstrap support ranging from 39% to 100%. M. mammillodactylus was the most dominant species (35%), followed by M. equidens (22%), M. rosenbergii (20%), C. gracilipes (19%), and M. idae (4%). Sites with bamboo structures exhibited higher prawn abundance and greater species diversity than control sites. The habitat complexity introduced by these structures provided various microhabitats, promoting species resilience and ecological stability. These findings underscore the potential of low-cost, nature-based solutions like bamboo structures to support aquatic biodiversity and prawn stock recovery. This study provides the first genetic and ecological assessment of bamboo artificial habitats in Sabah, offering valuable baseline data for future habitat-based restoration initiatives.

Studies on the ecotoxicological effects of bisphenol analogues, such as bisphenol Z (BPZ) and Bisphenol A Diglycidyl Ether (BADGE) are still sparse. These compounds can still be widely found in the environment due to it recalcitrance, lipophilicity, and bioaccumulation. This study aimed to investigate the ecotoxicological and cytotoxic effects of BPZ and BADGE on P. tricornutum and M. galloprovincialis to compare the produced effects with the sum of the effects caused by each substance.  We also intend to establish a positive correlation between the results obtained from the P. tricornutum and Mytilus assays for each tested compound, also sharing information regarding the cell replicates exposed to the toxicants. The experimental data will allow the estimation of harm caused by these toxicants in the M. galloprovincialis earlier life stage, contributing to an environmentally safe future application of these compounds. Comprehending these intricate effects is crucial for a comprehensive ecological risk assessment and necessitates further investigation into the mechanisms behind the detrimental effects of BPZ and BADGE on marine ecosystems.

This study aimed to optimise the growth conditions of Arthrospira platensis by modifying the ionic composition of the standard Zarrouk medium using a seawater-based medium (MK1B). The optimisation process involved three stages: adjusting the ionic composition, optimizing iron concentration, and comparing different iron sources. The final mass concentrations for the control, G1, and G2 were 1.25, 1.1, and 1.15 g. L-1, respectively, with no significant differences (p>0.05). The specific growth rate of the control group was significantly higher than G2 and G1. Carbohydrate content was higher in G1 and G2 compared to the control, while the protein content was lower in G1 and G2 compared to the control. In the semi-industrial phase, A. platensis cultivated in MK1B medium showed a productivity of 27.066 mg. L-1 per day and a total biomass of 0.862 g. L-1 after 30 days. The average chlorophyll content was 7.82 mg. g-1, beta-carotene 1.9 mg. g-1, protein 57.96%, lipid 9.35%, and carbohydrate 26.52%. The microbial load of A. platensis in MK1B medium met USP43 and ISIRI11166 safety standards, confirming its suitability for food and pigment applications. Finally, using seawater for the sustainable production of Spirulina microalgae, with potential applications in food supplements and natural pigment resources is feasible.

A six-week investigation was conducted to examine the interactive influences of dietary lipid sources and soybean lecithin (SBL) levels on some physiological responses of Asian seabass (Lates calcarifer) juveniles (50.2±2.3 g). A research design containing three SL levels, including 0, 2 and 4%, and four lipid sources, including fish oil (FO), vegetable oils (VO, canola and soybean oils; 1:1), rendered animal fats (RAF, lamb and poultry oil; 1:1), and their mixture (MIX) (FO, VO, and RAF; 1:1:1). Based on this twelve experimental groups were designed as follow, 1) FO (FO without SBL), 2) FO+2 (FO+2% SBL), 3) FO+4 (FO+4% SBL), 4) VO (VO without SBL), 5) VO+2 (VO+2% SBL), 6) VO+4 (VO+4% SBL), 7) RAF (RAF without SBL), 8) RAF+2 (RAF+2% SBL), 9) RAF+4 (RAF+4% SL), 10) MIX (MIX without SBL), 11) MIX+2 (MIX+2% SBL) and 12) MIX+4 (MIX+4% SBL). Asian seabass juveniles were distributed into thirty-six 300-L container (15 fish in each replicate) filled with 220 L of sea water (45.0±0.5 g/L). The experimental diets were offered to fish three times daily (27.1±1.2°C). The lowest final weight was in VO group and the highest growth performance were in FO+2, RAF+2, RAF+4, MIX +2 and MIX+4 groups (p<0.05). In addition, feed intake (FI) and feed conversion ratio (FCR) ratio decreased in fish fed VO diet, but SL supplementation increased FI and FCR values (p<0.05). The amounts of n-3 / n-6 polyunsaturated fatty acids (PUFA) ratio, long chain-PUFA in fish fed diets containing FO increased. Plasma total protein and globulin in fish fed FO, VO+2 and RAF+4 were higher than those fed VO and RAF+2 diets. The highest and lowest plasma alternative complement activities were in FO+2 and VO groups, respectively (p<0.05). The fish fed with VO and RAF+2 diets had the highest and lowest plasma triglycerides levels, respectively. The highest and lowest plasma cholesterol were in RAF and FO+4, respectively. The findings of this investigation showed that dietary FO replacement with mixture of various lipid sources and SBL supplementation at 2% can improve growth, fatty acid profile and humoral immune responses in L. calcarifer juveniles.

The current study investigated the effects of different pellet binders on the pellet quality, growth performance, hemolymph biochemistry, and intestinal morphology of whiteleg shrimp for 3 months. The shrimp were randomly assigned to four dietary groups (three replicates/ group) in a polyethylene circular tank containing seawater. Experimental treatments included, the control group fed with the basal diet (BD) (G1, no pellet binder), and G2, G3, and G4 received the BD containing different pellet binders, including calcium lignosulphonate (at 1 % of diet), starch + gum based-binder (at 0.4 % of diet), and polymethyl carbamide (PMC) (at 0.5 % of diet), respectively. Different binders improved the pellet quality parameters, including water stability, leaching rate (p≥0.05), and water activity (p≤0.05), with a particularly pronounced improvement effect in the PMC-bound pellets. No differences (p≥0.05) were found in shrimp growth and feed efficiency utilization, whole body composition of nutrients, and digestive enzyme activities in response to the different pellet binders. The diets processed with starch+ gum, as well as lignosulfonate binders, resulted in higher glucose levels in shrimp hemolymph. Feeding shrimp with pellet binders significantly reduced hemolymph concentrations of triglycerides, total cholesterol, high- and low-density lipoproteins, and very low-density lipoprotein, with the most pronounced reductions occurring in the PMC and starch + gum-based binder groups (p≤0.05). In conclusion, the pellet binders evaluated in this study were beneficial in enhancing pellet quality; however, they did not improve shrimp growth performance. Polymethyl carbamide (an inclusion level of 0.5% of diet), gave the best results in both pellet quality and performance. However, findings suggest that PMC is more suitable for short-term application during shrimp culture. Also, suggest that starch+ gum-based binder could be used as a practical alternative to PMC since it enhances pellet quality and nutritional characteristics, while supporting shrimp performance without adverse impacts.

This study evaluated the benefits of Streptomyces spp. in striped catfish under intensive farming in the Mekong Delta, Vietnam. The lyophilized biomass of two strains, Streptomyces kunmingensis XK9 and Streptomyces angustmyceticus XK22 (10⁹ CFU/g), was incorporated into the catfish pellets at 1 g per kg and administered daily to fish throughout the seven-month trial. Streptomyces supplementation maintained water quality within optimal ranges for temperature, pH, dissolved oxygen, ammonia, and turbidity, whereas control ponds deviated after five months, potentially impairing fish performance. After seven months, fish receiving XK9 and XK22 showed significantly improved survival rate, growth performance, and feed conversion ratio compared with the control (p<0.05). Fillet quality was also enhanced in fish fed Streptomyces-supplemented diets, with significant improvements in proximate composition, amino acid profile, and fatty acid profile (p<0.05). The finding revealed the potential of XK9 and XK22 to improve water quality, enhance catfish growth performance, and enrich the nutritional value of striped catfish under intensive culture. The beneficial effects of these Streptomyces strains make them a promising alternative strategy for sustainable catfish production.

The wels catfish (Silurus glanis) is a widely distributed freshwater species of considerable ecological and commercial importance. Among its principal habitats is the Aras reservoir in northwestern Iran, where it constitutes one of the dominant targets of the regional fishery. However, unregulated fishing has led to a reduction in the stock abundance. The present study investigated the length–weight relationship and assessed the stock status of wels catfish in the Aras Dam reservoir. Stock assessment was conducted using the CMSY++ model. Model outputs indicated that both the relative stock size (B/BMSY) and relative fishing mortality (F/FMSY) were below unity, suggesting that the stock is currently subject to excessive fishing pressure. The maximum sustainable yield (MSY) was estimated at 2.98 metric tons. Historical data revealed that actual catches consistently exceeded the MSY until 2015. Thereafter, owing to intensive exploitation and a subsequent decline in stock biomass, annual catches fell below the MSY. The Kobe plot analysis demonstrated that overfishing has driven the population into the overfished quadrant. Collectively, these findings underscore the urgent necessity of implementing ecosystem-based fisheries management strategies. In particular, stricter regulation of fishing practices, enforcement of annual catch limits, reduction of fishing effort, and control of illegal harvest are strongly recommended to halt further depletion and to ensure the long-term sustainability of Wels catfish in the Aras Dam reservoir.

Microplastic (MPs) pollution poses a significant threat to coastal ecosystems and marine food resources. The mangrove ecosystem of Can Gio (MEC), Ho Chi Minh City, Vietnam, a UNESCO Biosphere Reserve, is under increasing pressure from anthropogenic activities. This study aimed to quantify and characterize MPs contamination in sediments and the commercially important blood cockle (Anadara granosa) to assess the spatiotemporal distribution of pollution. The sediment and cockle samples were collected monthly from two zones with differing human impact levels, Dong Tranh River and Thanh An Island, between July and September 2024. MPs were extracted via density separation and their characteristics (shape, color, and polymer type) were analyzed using microscopy and Fourier-transform infrared spectroscopy. The number of MPs in sediment and cockles ranged from 0.20 to 2.60 MPs/g and 0.20 to 2.20 MPs/g, respectively, with no zone-specific and temporal-specific differences for both types of samples. Black and white MPs were predominant in sediment and cockle, accounting for 50-80% of the total MPs abundance. Fiber contributed to more than 50% of MPs forms, followed by fragments and films. Small-sized particles (<1 mm) were dominant in both samples throughout the two zones and all sampling times. The primary polymers in both sample matrices consisted of nylon, PET, and rayon. Our findings indicate that local anthropogenic pressure is a key driver of MPs distribution in the MEC. The contamination levels in the cockles highlight a potential pathway for human exposure to MPs, emphasizing the need to implement pollution management strategies in the region.

The diet composition of the marbled flounder Pseudopleuronectes yokohamae was examined using 975 specimens collected from January to December 2022 in the coastal waters off Pohang, East Sea of Korea. The range of total length was 14.4–47.6 cm. Polychaetes were the most important prey item, accounting for 91.9% of the index of relative importance, with the Lumbrineridae family being the most dominant, followed by Ampharetidae and Terebellidae. The trophic level of P. yokohamae was 3.08. Polychaetes showed no significant differences in dietary composition among size classes (<25.0 cm, 25.0–30.0 cm, 30.0–35.0 cm, and ≥35.0 cm), although the mean prey weight per stomach differed significantly with size. Polychaetes were the dominant prey item across all seasons. Both the mean prey weight per stomach and mean number of prey items per stomach varied significantly by season. A two-way PERMANOVA revealed that both size class and season had significant effects on dietary composition (p>0.05). To assess the nutritional status of individuals, the condition factor was calculated. It was lowest in March and highest in November. Therefore, increase in feeding activity and prey intake during spring is likely associated with post-spawning energy recovery.

In the beginning of the 13th century the catch amount from Anzali Wetland was about 7.5  thousand tons that Caspian Sea fishes such as Kutum, Pike-perch and Caspian roach constitutes a major part, while the native fish species such as carp, bream, and Northern pike were also observed. Anthropogenic parameters and high destruction of Anzali Wetland in the most parts caused a great decrease for its fisheries potential while there is no any clear data from its fish stock. In this study, stock assessment of economic fish in Anzali Wetland through direct census and weighing of fish whom sold in the local markets during 2023. Totally 22 species of fish was traded in the local markets which were caught from Anzali wetland.  The highest amount of catch was from Northern pike, Carp, Prussian carp and Tench with 42.6, 24.8, 22.1 and 5.9 tons respectively. As respect to abundance, Tench had the second rank among these species with 23.9%. Total amount of fish was estimated about 94 tons/year that was varied between 168 to 279 kg/day during different seasons. The most and the least caught were 8.3 and 4 kg/day/person in summer and autumn respectively. The fishing potential of Anzali lagoon is much less compared to before and the fishing activity is not economical. It is necessary to carry out the rehabilitation activities such as dredging of substrate, controlling of invasive plants, and protecting of fish breeding habitats together with CEPA programme on communication, education, participation and awareness of local people.