Fish growth parameters and their monitoring

Recent studies have predicted that fish consumption in developing and developed countries will increase by 57 percent and 4 percent, respectively. Rapid population growth, increasing affluence and urbanization in developing countries are leading to major changes in supply and demand for animal protein, from both livestock and fish. The need for suitable sites has resulted in the cage aquaculture subsector accessing and expanding into new untapped open-water culture areas such as lakes, reservoirs, rivers and coastal brackish and marine offshore water

Fishery and estimation of potential yield of Bombayduck Harpadon nehereus (Hamilton, 1822) along Gujarat coast, India

Bombayduck Harpadon nehereus (Hamilton, 1822) is one of the key fishery resources landed along the Indian coast with uniqueness in distribution and exploitation. The resource is known for discontinuous distribution, majorly along the north-west and north-east coasts of India. Gujarat is the lead state to contribute nearly 64.72% (72,949 t) to the total national landings of the resource (11,2705 t) in 2018. Dolnet gear contributes nearly 95% of the total landings of the resource in the region. The landings and the corresponding catch per unit effort (CPUE) showed a fluctuating trend over the study period of 1994-2014. The catches fluctuated between 35,235 t (2016) and 92,188 t (2004), whereas the CPUE oscillated in the range of 15 to 20 kg h-1 (1998) and 30.76 kg h-1 (2003). The period of 1994-2000 was the most productive period with an average catch of 72,133 t, whereas the succeeding decade was the leanest phase with an average annual catch of 50,035 t. The estimated potential yield (= maximum sustainable yield, MSY) was estimated at 73,700 t and 70,108 t using the Bayesian surplus production model (CMSY & BSM) and basic Schaefer surplus production model respectively. The present catch and exploitation levels were found to be close to the optimum level and a further increase in effort for the resource is not recommended

Decision support spatial suitability map for Seaweed Farming in India

Decision support spatial suitability map for Seaweed Farming in India. Seaweed Mariculture Area-Wise Locational Distribution in India

तकनीकी पुत्स्यिका: खुला समुद्रीय पिंजरा पालन

Technical Guide: Open Seacage Farmin

Stranding of whale shark off Madhavpur, Gujarat

A dead male whale shark (Rhincodon typus) was found off Madhavpur coast, near the fish landing centre on morning of 28th September, 2017. The investigations were covered at the joint team of ICAR-CMFRI and Wildlife Trust of India (WTI), Veraval, Gujarat. The carcass showed an injury below the first dorsal fin but cause of its death could not be ascertained. Some measurements of the stranded whale shark were recorded before it was burie

Broodstock development and induced spawning of the John’s snapper Lutjanus johnii (Bloch, 1792) under controlled conditions

Broodstock of the John’s snapper Lutjanus johnii were raised in sea cages from wild collected juveniles of the species. Individual fishes were tagged using passive integrated transponders (PIT), cannulated and gonadal biopsies were examined periodically for assessing the maturity status. The matured fishes were shifted from cages and maintained in indoor FRP tanks. Females were given two doses of human chorionic gonadotropin (hCG) and ovaprim @ 800 - 900 IU kg-1 and 1.25ml kg-1 respectively. Males were given only hCG in a range between 400 and 600 IU kg-1. Two successful spawning were obtained with 80-85% fertilisation rate. In both the trials, embryonic development was observed to be arrested before hatching which could be attributed to nutritional deficiency of the broodfishes and high water temperature in the spawning tank

Observations on variations in physico-chemical water parameters of marine fish cage farm off Karwar

An investigation was undertaken to study the fluctuations in the water quality parameters in a marine fish cage culture site off Karwar during the period 2009-2011. Two stations viz., one from cage site (Station 1) and the other away from the cage site (Station 2) were selected for the study. Water samples were collected at weekly intervals. Temperature of Station 1 varied from 28.5 ± 0.89 oC to 32.5 ± 1.04 oC during the first crop of Asian seabass culture in 2009-10 and it ranged between 26.7 ± 0.83 to 32.5 ± 0.79 oC during the second crop of seabass culture in 2010- 11. The salinity was minimum during July 2010 and maximum in May 2010. There was no significant difference observed between the water quality parameters of the two stations (p>0.05). However, difference in salinity was significant between the two culture periods in Station 1 (p<0.05). No significant difference was observed in the nutrient levels of the cage and reference sites and also between the two crops. No significant difference was observed between the mean weight of the fish and temperature of both the sites and periods. A positive correlation was observed between the weight gain of fish and salinity of water at cage site

કેજ મેરીકલ્ચર તકનીકી પુસ્તિકા

Cage Mariculture: Technical Guid

Farming of cobia, Rachycentron canadum (Linnaeus 1766) in open sea floating cages in India

Experiments on culture and growth performance of cobia were undertaken in marine cages installed in the Arabian Sea off Karwar on the south-west coast of India. Hatchery produced cobia fingerlings were stocked at two densities of 3.5 fish cubic m-1 and 14.1 fish cubic m-1 in circular HDPE cages. Mean weight and specific growth rate (SGR) of cobia stocked @ 3.5 fish cubic m -1 were 10.5 kg and 2.2% day-1, respectively, at 300 days of culture (DOC). Cobia stocked @ of 14.1 fish cubic m-1 attained an average weight of 3.68 kg and SGR of 1.9% day-1 at 300 DOC. SGR was found to be positively correlated with water temperature and salinity during the culture period. No significant variation was found in SGR and feed conversion ratio of cobia stocked at two different densities. However, absolute growth rate, relative growth rate and mean weight of cobia varied significantly between the two groups