Journal of Fisheries

Analyzing population dynamics and growth patterns of Cyprinus carpio and Carassius carassius in Anchar Lake, Kashmir

2026-01-19T07:15:52+00:00

The present study examines the population dynamics of Cyprinus carpio (common carp) and Carassius carassius (crucian carp) in Anchar Lake, Kashmir, through the analysis of length- weight relationships (LWR), growth patterns, mortality rates, exploitation rates, and recruitment dynamics. The length-weight relationships for both species exhibited negative allometric growth, with C. carpio showing a regression equation of log W = 2.80 log L – 1.56 and C. carassius showing log W = 1.52 log L + 0.01. Growth parameters were estimated using the von Bertalanffy growth function (VBGF) yielding asymptotic lengths (L_∞) of 31.60 cm for C. carpio and 30.00 cm for C. carassius, with respective growth coefficients (K) of 0.44 year^–1 and 0.38 year^–1. The total mortality rates were 1.26 year^–1 for C. carpio and 1.54 year^–1 for C. carassius, with fishing mortality rates of 0.44 year^–1 and 0.79 year^–1 respectively, indicating that C. carpio is subject to moderate exploitation (E=0.35) while C. carassius is overexploited (E=0.51). Recruitment patterns for both species were highest in spring and early summer, with C. carpio showing optimal recruitment between April and May. Virtual population analysis (VPA) and yield-per-recruit analysis revealed that C. carpio is currently harvested sustainably, while C. carassius faces overfishing risks. The study highlights the need for adaptive management strategies, including stricter fishing regulations and seasonal closures, to ensure the long-term sustainability of these fish populations in Anchar Lake.

Evaluation of a government-funded business incubation program in the fisheries sector in Indonesia

2026-01-19T07:16:26+00:00

Government-funded business incubation programs have been increasingly implemented to support micro and small enterprises (MSEs) in Indonesia’s fisheries sector; however, their effectiveness is not well understood. Prior studies largely relied on administrative data and manager perspectives, giving limited attention to beneficiary experiences. This study evaluated the effectiveness of a government-funded incubation program targeting fishery processing and marketing MSEs in Indonesia from the viewpoint of incubator tenants. Using importance-performance analysis (IPA), the research examined ten essential program attributes across 47 MSEs that participated in the program between 2018 and 2022. Data were collected through structured questionnaires measuring both perceived importance and actual performance of program services. Statistical analyses including reliability tests, validity tests, and paired t-tests revealed significant gaps between importance and performance for all attributes (p < 0.05). The IPA matrix placed five attributes in the “Keep Up the Good Work” quadrant (processing technique training, good manufacturing practice/sanitation standard operating procedures training, laboratory testing support, design and packaging support, and promotion materials development), one critical attribute requiring immediate attention in the "Concentrate Here" quadrant (market expansion assistance), and four attributes in the "Low Priority" quadrant (quality certificate assistance, license and permit facilitation, business management training, and financing and investment support). The findings indicated that while the program performed well in technical and operational support, market expansion services required substantial improvement. This study contributed to the limited empirical literature on government-funded fishery incubation programs in developing countries and offered actionable recommendations aligned with stakeholder priorities.

Feasibility of cage culture of Asian seabass in coastal rivers of Bangladesh

2026-01-19T07:17:34+00:00

Despite its aquaculture potential, Asian seabass (Lates calcarifer) has not yet been adopted for cage culture in Bangladesh. This pilot study aimed to assess the feasibility of cage culture of this species in coastal rivers of Bangladesh. A total of six cages (18 m³ each) were installed in a coastal river and each was stocked with 50 fish (7.70 ± 0.18 g). Three feeding treatments were applied: 100% live feed (live and/or trashed juvenile tilapia) (T₁); 50% live feed with 50% formulated feed (T₂); and 100% formulated feed (T₃). The experimental fish were reared for 12 weeks and fed at 8% of their body weight during the initial 3 weeks and at 6% during the later weeks. Fish refused formulated feed. Survival in T₃ (64%) was significantly lower compared to that in T₁ (88%) or T₂ (82%) but did not differ between T₁ and T₂. Mean specific growth rates (SGR) were 1.66, 1.12, and 0.90 % d^–1; daily growth rates (DGR) were 2.20, 0.74, and 0.44 g, and weight gain (WG) values were 182.50, 61.10, and 36.50 g in T₁, T₂, and T₃, respectively. SGR values significantly differed among the treatments. DGR and WG values in T₁ were significantly higher than that in T₂ or T₃ but did not differ between T₂ and T₃. Results indicate that cage culture of Asian seabass in Bangladesh requires live and/or trash fish as feed, or else advances in domestication and artificial feed development.

Antimicrobial resistance and phage sensitivity of Chryseobacterium sp. isolated from diseased rainbow trout (Oncorhynchus mykiss)

2026-01-19T07:19:35+00:00

This study aimed to isolate and characterize bacteriophages infecting Chryseobacterium sp., an opportunistic pathogen responsible for considerable mortality in rainbow trout (Oncorhynchus mykiss Walbaum, 1792) aquaculture. Chryseobacterium isolates were recovered from diseased trout collected from aquaculture facilities in Mersin and Van (Türkiye) using Anacker–Ordal medium. Identification was performed through API 20E/20ZYM biochemical profiling and 16S rRNA gene sequencing. Antibiotic susceptibility was evaluated by the Kirby–Bauer disk diffusion method following CLSI and EUCAST guidelines. Phages were isolated from water samples via 0.22 μm filtration and purified using the double-layer agar method. Antimicrobial susceptibility testing revealed that Chryseobacterium isolates were sensitive to enrofloxacin, oxolinic acid, and ciprofloxacin, but exhibited pronounced resistance to most β-lactam and aminoglycoside antibiotics. A total of 19 lytic phages (CV1 – CV19) were successfully isolated. They displayed latent periods between 2.5 and 7.5 h and burst sizes ranging from 20 to 235 PFU per cell. The highest burst size and shortest latent period were recorded for the CV5 phage. Adsorption rate constants showed phage-specific variability, with overall values ranging from 1.05×10⁻⁶ to 2.55×10⁻⁶ mL·min⁻¹. Genome sizes were estimated at 48 – 75 kb. TEM revealed typical tailed morphologies consistent with the order Caudovirales. Host range assays showed strong species specificity, with limited cross-activity against Flavobacterium psychrophilum and Enterococcus faecalis. The findings confirm that these phages possess traits favorable for use as eco-friendly biocontrol agents, offering a promising strategy to mitigate Chryseobacterium-associated infections and reduce antibiotic dependence in trout hatcheries.

Assessment of fish consumption behaviour and market forecasts for sustainable fisheries in Manipur, India

2026-01-17T07:15:32+00:00

This study analysed the socio-economic characteristics, consumption behaviour and expenditure patterns of fish-consuming households in Manipur, India, using data from 450 households across six districts belonging to different social background. Secondary data (2015 – 2025) obtained from government records supported a production-requirement forecast. The regression model demonstrated a moderately strong relationship between the predictors and the dependent variable (R² = 0.588; adjusted R² = 0.581). A paired t-test revealed that monthly expenditure on fish alone ₹5,326.88 (~59.20 $) was much higher than other non-vegetarian foods ₹2,310.44, comprising nearly 70% of the total non-vegetarian expenses. Holt’s exponential smoothing model (R² = 0.813, MAPE = 2.71%) projected that fish demand will exceed supply from 2024 – 2029, indicating a widening gap. The study concludes that fish holds cultural and nutritional importance in Manipur and calls for enhanced aquaculture, better market infrastructure, and improved consumer awareness for sustainable fish supply and food security.