Journal of Fisheries

Stock assessment of Crossocheilus diplochilus (Heckel, 1838) in Dal Lake of Kashmir Himalayas

Sinan Nissar — 2025-04-11

The intricate dynamics governing population parameters stand as pivotal pillars in the realm of fish management and conservation. Accordingly, the various parameters of population dynamics of Crossocheilus diplochilus (Heckel, 1838) from the Dal Lake of Kashmir valley were investigated. The study reported that the fish exhibits a length range of 5.4 to 14.8 cm and a weight range of 1.24 to 17.19 g. The b value was reported to be 2.9 depicting negative allometric growth. The Fulton and relative condition factors were reported to be 0.86 and 0.99 respectively. The growth constant, asymptotic length, age at zero length and growth performance index were reported to be 0.33 year^–1, 17.40 cm, –0.62 years and 2.0 respectively. Fishing mortality was found to be higher than the natural mortality. The exploitation ratio was reported to be 0.52 which was found to be lower than the exploitation rate producing maximum yield (0.81). This is suggestive of an underexploited state of fishery of C. diplochilus from this lake.

The role of integrated prawn farming in climate change adaptation in Bangladesh: ecosystem services, economic viability and barriers

Md. Asadur Rahman — 2025-03-28

The integrated rice-prawn-vegetable culture (RPVC) is an effective farming method that ensures the efficient utilization of water and land. This study aims to evaluate the role of RPVC in climate change adaptation, its ecosystem services, and economic sustainability in Bangladesh. Integrated RPVC provides farmers with ecosystem services, including reducing use of the fertilizers and insecticides and lowering financial instability. The vegetable platform shades prawn ponds naturally, while prawns consume insects in rice fields. After rice plants are harvested, their roots can serve as food for prawns. Majority of the respondents (85%) reported that adopting RPVC increased the overall productivity. Farmers faced a variety of climatic hazards; ranked as: drought (86.3%) > erratic and sudden heavy rainfall (81.5%) > temperature fluctuation (69.6%) > salinity intrusion (67.2%) > storm (28.5%). The ecosystem services provided by RPVC helped farmers to mitigate the adverse impacts of these climate-induced challenges through ecosystem-based adaptation. Integrated RPVC has also enabled farmers to maintain a consistent cash flow throughout the year. By promoting the production of multiple commodities—rice, prawns, and vegetables—the system reduces the risk of financial destitution. Despite benefits, farmers also encountered several challenges in implementing RPVC including water shortage (85.2%), disease (73.5%), theft (60.4%), increased feed costs (70.7%), lack of information (65%), increased labor cost (58.8%), and not getting expected market value of farming products (63.2%). However, if these barriers are addressed, the integrated RPVC system holds significant potential to foster long-term socio-economic growth in the southwest region of Bangladesh.

Social values of angling tourism in the Garo Hills of Meghalaya, North East India: fish farmers’ perspectives

Annastaycya Simsang Sangma — 2025-03-18

Angling tourism is gaining popularity and offers an alternative livelihood opportunity for the fish farmers of the Garo Hills region of Meghalaya, India. This research aims to provide insights into the social value of angling tourism among the fish farmers involved in angling tourism in the area and to identify its determinants. A sample of one hundred fish farmers was selected using snowball sampling from five districts of the Garo Hills, and data were collected using a semi-structured interview schedule. Most farmers considered fisheries a secondary occupation and were sceptical of angling tourism. The multiple stepwise regression analyses revealed that entry fees for daily angling besides competition and secondary occupation negatively impacted social value scores. In contrast, the educational status of fish farmers, annual investment in angling tourism, fish farming experience, total registered anglers annually, and family type positively impacted social value scores. The study confirmed that angling tourism fosters sustainable development within rural communities by nurturing social values and augmenting biodiversity conservation, and economic benefits. Overall, the study provides valuable information on the scope and prospects of angling tourism in leveraging social values and its potential to uplift rural people's social and financial status.

Comparative efficacy of different doses of inducing agent on breeding performance of a near threatened catfish pabda (Ompok bimaculatus Bloch, 1794) in West Bengal, India

Samiran Patra — 2025-03-10

In India, diversification in shrimp culture area is required due to climate changes, fluctuation in resources, and its marginal profit. Near Threatened pabda (Ompok bimaculatus) may be an alternative aquaculture species which can fulfil all the demands for the shrimp farmers. In this study, healthy, disease-free, 12-month reared brood fishes were collected and stocked in eight tanks (8×4×2 feet) sex wise (130 pairs) with shower facilities. Synthetic hormone was used to induce both male and female fishes at 0.3 and 0.6 ml (T1); 0.5 and 0.7 ml (T2) and 0.7 and 0.8 ml (T3) kg^-1 body weight (bw) respectively, having 3 replicates for each treatment. Ovulation period (7 to 11 hours), relative fecundity (105.20±39.93 eggs g^–1 bw of female), fertilization rates (67.37±20.73 to 75.88±24.84%), hatching rates (62.57±18.46 to 79.67±26.68%) and survival rates (55.01±14.93 to 65.62±19.91%) were observed. Among treatments, T2 exhibited better breeding performance but no significant differences with other treatments were observed. Important water quality parameters like temperature (28.27±1.68°C), pH (7.10±0.44), dissolved oxygen (4.25±0.37 mg L^–1), hardness (210.96±9.31 mg L^–1) and alkalinity (202.78±8.00 mg L^–1) were also recorded during this experiment. After 48 hours of hatching, hatchlings were reared in aerated tanks for another four days with close observation and fries were harvested 24 days of rearing. From the present experiment, T2 exhibited best effective dose for successful induced breeding of pabda.

Identification, isolation and pathogenicity of Aeromonas salmonicida and his-topathology of infected Oncorhynchus mykiss in Punjab and northern areas of Pakistan

Muhammad Akram — 2025-02-15

Aeromonas salmonicida causes furunculosis in the Oncorhynchus mykiss (rainbow trout) and the effective control over this infection requires knowledge of the genetic variability and epidemiology of A. salmonicida. Pathogenic strains were isolated from kidneys, muscles, liver and spleen of rainbow trout from the provinces, Punjab, Khyber Pakhtunkhwa and Gilgit Baltistan, Pakistan. On the base of 16S rRNA sequencing, physiological and biochemical characterization, isolated bacterial strains were identified as A. salmonicida (NCBI Ref. ArS-Pak-19 [MW307221], ArS-Pak- GB1-19 [MW720959], ArS-Pak-MRE-19 [MW720960], ArS-Pak-SW2-19 [MW720961], ArS-SW1-Pak-19 [MW720962]). Isolated strains were resistant to antibiotics like sulfamethoxazole, penicillin, vanomycine, rifampicin and bacitracin but were extremely sensitive to spectinomycin, ciprofloxacin, ofloxacin, levofloxacin and nalidixic acid. To check out the pathogenicity, rainbow trout were experimentally infected with isolated strains. Experimental fishes showed the same symptoms as were recorded in naturally infected fish including jaw bleeding, intra-abdominal fluid, intestinal bleeding and gill filament anemia. After ten days of post-challenge study, histopathological analysis revealed that there were severe alterations in the spleen, liver and kidney of the infected fish. The present study provides further research foundation and for upcoming research on A. salmonicida disease, its control and epidemiology.