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Feeding marine fish larvae with copepods increases their survival, growth rates, pigmentation and stress tolerance and reduces deformities compared to almost all other live feeds. Copepods are rich in Highly Unsaturated Fatty Acids (HUFA) and do not require any enrichment media except healthy and suitable marine microalgae as feed. This study aimed to investigate the effect of different adult stocking densities on the survival and population growth of Acartia southwelli. The experiment was conducted to assess the adult copepod density dependent nauplii production and survival at different stocking densities of (T1) 500, (T2) 1000, (T3) 1500, (T4) 2000 and (T5) 2500 adult copepods L–1. The rearing water quality parameters like salinity, temperature, photoperiod, pH, dissolved oxygen and algal concentration were optimal in all the experiments. The copepods were fed with mixed microalgae of Isochrysis galbana and Nannochloropsis salina at the ratio of 3:1, a concentration of 5×104 cells/mL/day. The results showed enhanced nauplii (N1) production per individual female on the first day in adult stocking densities of 2500, 2000, and 500 no. per litre and observed a sharp decline in the experimental tanks on the 7th, 8th and 9th days. The adult stocking density of T2 and T3 was higher in mean nauplii production from the 1st, 2nd, 3rd, 4th and 5th day. Total mean nauplii (N1) production per individual female over nine days was also significantly different across the different stocking densities (p<0.05). The study concluded that the moderate stocking density of A. southwelli (1500 adults L–1) and the mixed microalgae concentration (5 × 104 cells mL–1) are ideal for the mass production of nauplii. [ABSTRACT FROM AUTHOR]

Accidentally entangled and stranded egg masses of Sepia pharaonis in fishing gears were collected from various landing centres of Thoothukudi district. The stranded egg masses were incubated, hatched and larval rearing was carried out at the Molluscan Fish Hatchery of Tuticorin Research Centre of CMFRI. The average hatching rate of S. pharaonis was 95 % for the eggs collected from the fishing nets. The size of day 1 paralarvae of S. pharaonis was 5.46±0.06 mm and reached the average size of 40.10±1.15 mm length and 9.6±0.20 g weight on day 60 with the average survival rate of 70 %. Maximum weight gain (%) was noticed between 20 -- 40 days. The paralarvae of S. pharaonis fed with suitable live feeds until 50 days, after which fed with dead fish and shrimp. The juveniles were transformed as broodstock with an average length of 137.4±8.08 mm and weight of 229.7±21.54 g on 180th day of culture. In the hatchery, the first captive spawning was witnessed on 167th day and the eggs laid by the females ranged from 46 - 118. However, the captive bred egg masses failed to hatch out. Therefore, the hatchery technology needs to be perfected through the development of nutritionally improved broodstock diet to ensure better hatching. During the years 2016 - 2018, altogether 8400 numbers of hatchery reared 60 days old juveniles of S. pharaonis were ranched into the fishing grounds off Tuticorin coast. The biological significance of sea ranching activities to replenish the natural stocks requires further research and evaluation. [ABSTRACT FROM AUTHOR]

Hatchery produced silver pompano, Trachinotus blochii fingerlings were stocked in nine cages at three different stocking densities of 15 (SD15), 10 (SD10) and 5 individuals m−3 (SD5) in triplicate. The results indicated that the percent weight gain, specific growth rate, and average daily growth were decreased with the high stocking density (SD15), and better performance was also observed in the low stocking density (SD5) treatment. Better feed conversion ratio was observed in SD5. Among the stocking density treatments, SD15 showed a higher yield than the rest of the groups. Comparison of yield to SD5 as the control, yield for SD10, and SD15 was 141.9% and 180.8%, respectively. Though the observed growth performance of silver pompano was better at SD5, the yield was significantly (P <.05) higher at SD15. Thus, we conclude that silver pompano with a stocking density of 15 individuals m−3 is optimum for better production and yield. [ABSTRACT FROM AUTHOR]

A 45-day feeding experiment was conducted to determine the effect of dietary free gossypol on hematological and biochemical response of snubnose pompano, Trachinotus blochii. Fishes with the average weight of 11.43 ±0.25 g were randomly stocked in five treatments each with triplicates. Five isonitrogenous and isolipidic diets with graded level of free gossypol (0, 0.2, 0.5, 1 and 2 g/kg) were formulated and fed to respective treatments. There was significant difference (P<0.05) in moisture, ether extract, total ash and nitrogen free extract content among the treatments. There was no significant difference (P>0.05) in the hematological response among the treatments. Higher levels of hemoglobin, RBC, HCT and MCHC values were observed in control group. Lipid biochemical profile in terms of total lipid, triglycerides and very low density lipoprotein showed significant difference (P<0.05) among the treatments. However, serum cholesterol, phospholipids, high density lipoprotein and low density lipoprotein levels did not showed significant difference among the treatments (P>0.05). As a conclusion, based on the second degree polynomial regression analysis of serum lipid biochemical parameters such as total lipids and high density lipoprotein levels indicates that snubnose pompano can tolerate upto 1.2 g of free gossypol per kg diet without any adverse effect on general health. [ABSTRACT FROM AUTHOR]

A discussion of the Gibbs energies of transfer of cations from water to aqueous/organic mixtures is presented. There is still relatively little information about the solvation energetics of ions in aqueous-organic mixtures. There will be challenges associated with gaining reliable data for multivalent cations, as it is important to take account of the possible effects of ion-pairing and hydrolysis.

A cost effective indigenous re-circulatory vertical cellular unit was developed using HDPE trays (14 L volume) with 200 numbers. In the present study, two fattening trials were conducted for 60 days. In trail 1, soft shelled mud crabs of 200 numbers were stocked at the rate of 1 crab/tray. In trial 2, soft shelled mud crabs of 145 and 55 numbers of soft shelled blue swimmer crabs were stocked. The yield in trial 1 & 2 was 180 and 152 kg respectively with the weight gain percentage of 28.57 and 26.66% with 90% survival. The economic feasibility analysis of trail 1 & 2 for a period of 5 years revealed that the production unit is a viable enterprise with an average annual net income of Rs.7,46,026 – 10,96,026 with an initial investment of Rs. 650,000 suggesting a payback period of 0.59-0.87 years. Cost benefit ratio of 1.02-1.09 at 30% discount rate, internal rate of return and rate of return on investment were 112.10-167.38 % and 114.77-168.62 % respectively, under the assumptions of constant input and output price. The sensitivity analysis proved that cellular unit can withstand the risk of 30% reduction in production that indicates the financial viability. [ABSTRACT FROM AUTHOR]