Effect of kisspeptin on change in level of reproductive hormones and gonadal maturation in air breathing fish, Channa striatus
Kisspeptin-10 is a very potent stimulator of the gonadotropic axis. Steroid hormone level was higher in murrel injected with natural kisspeptin-10 at 0.01 and 0.05 µg/g body weight of male and female fishes, respectively than the control. Efficiency of natural kisspeptin-10 compared with GnRH analogues and pituitary extract on gonadal maturation of Channa striatus showed that natural kisspeptin-10 injected fish had highest values of GSI, fecundity, ova diameter and steroid hormone levels.
Effect of synthetic kisspeptin-10 compared with natural kisspeptin-10 on the gonadal maturation of striatus showed that natural kisspeptin-10 had slightly higher effect than synthetic kisspeptin-10 on the gonadal maturity.
Synthetic kisspeptin-10 also responded well in breeding of murrels in pond after injection. But, in artificial fertilization, synthetic kisspeptin -10 responded well in females but not in males (especially during final spermiation). The effect of synthetic kisspeptin -10 tested on the induced breeding of Indian Major Carps was found satisfactory.
Impact of large scale cultivation of seaweeds on coastal environment of India
Total number of phytoplankton species recorded from the three stations viz. Tuticorin, Mandapam and Mullimunai were 33, 35 and 19 species, respectively. In Mandapam, Climacosphenia elongata was dominant in the seaweed culture site and normal waters. Leptocylindrus was dominant in Tuticorin. In Mullimunai coast, Coscinodiscus eccentericus was dominant.
A total of 35 zooplankton species were recorded and copepod nauplius was found dominant in all the stations. The overall density of zooplankton was relatively higher in seaweed culture site when compared to normal site. Among the benthos, macrobenthic polychaetes and meiobenthic nematodes were dominant both in the seaweed culture site and control site of all stations.
An export oriented marine value chain for farmed seafood production using cobia (Rachycentron canadum) through rural entrepreneurship
This project contributed in the introduction of new marine species Cobia in Indian aquaculture. Four technologies viz., pond culture of cobia, cage culture of cobia, cobia broodstock feed and value added cobia products were developed and approved by NAIP and published in the Compendium released by NAIP.
Technology on Pond grow out culture of cobia was developed for the first time in India by Fisheries College and Research Institute, Thoothukudi with the production of 1kg/sq.m at the stocking density of 1 fish/4 m2 with an average weight of 4 kg in a period of ten months.
Technology on Cage grow out culture of cobia was developed using formulated feed at a stocking density of 4 fish/m3 with the production of 8 kg per m3 with an average weight of 4.5 kg in a period ten months.
Impact of climate change on the population structure and virulence of viral and bacterial pathogens in marine environment and host response alterations due to pathogen-abiotic synergy
Environmental stress of high temperature and salinity induced genomic variations in Vibrio Multi abiotic stress caused by high salinity and temperature was found to bring about pathogen-abiotic synergy causing increased cumulative mortality in juvenile shrimps due to WSSV.
Medicinal herbs incorporated feed was found to upregulate immune gene (tubulin and penaeidin) expression in juvenile tiger shrimps. Herbal feed was found to delay and reduce the mortality rate in WSSV infected shrimps at low temperature (24 ºC) and at normal temperature (29 ºC) conditions.
Increasing fish production in Tamil Nadu through production and distribution of genetically improved Tilapia
Availability of genetically improved tilapia (Nile tilapia) within Tamil Nadu in the natural system was surveyed; and noticed that the Nile tilapia was available in the natural tanks in Krishnagiri district, Vaigai reservoir, Sattanur reservoir and also in the fish culture ponds of farmers in Thanjavur district. More than 90% of landings in Vaigai reservoir were dominated by Nile Tilapia with an average weight of 1 to 1.5 kg. Around 40 to 50 % of landings at Sattanur Dam were dominated by Nile Tilapia with an average weight of 1.5 to 2.0 kg.
Technique for the development of Tilapia broodstock, hapa breeding, sex reversal and larval rearing were standardized. Broodstocks were developed by stocking them in rearing hapas @ 6nos./m2. Sex ratio maintained at 1:1. Hatchlings were fed with diet containing 17 methyl testosterone hormone with shrimp starter feed for a period of 21 days. Two dosages of hormone (50 mg/kg and 60 mg/kg) were tried for inducing sex reversal. Rearing of sex reversed tilapia was carried out by feeding with Artemia followed by pellet feed.
Assessment of impact of trawling in Gulf of Mannar Biosphere Trust Region
Recruitment over fishing( fishing of brooders) was found to be the major problem due to trawling along the coast of Gulf of Mannar
Out of the 25 species examined, recruitment overfishing was reported in 11 species such as Scomberomorus commerson, Lethrinus lentjan, Lethrinus olivaceus, Alectis indicus, Decapterus macarells, Selaroides leptolepis,Stolephorus indicus ,Parupeneus indicus,Lutjanus quinoquelineatus ,Saurida tumbil,Lepturacanthus savala, Leiognathus dussumieri and was found to occur from March to May.
Three species such as Decapterus russelli, Nemipterus japonicas, Nebiea maculate were found to suffer both due to recruitment overfishing and growth overfishing. These species were found to be highly affected as both brooders and juveniles are captured heavily due to trawling
Square mesh cod panel of 30 mm at 30% of the cod end has to be fixed in the cod end of trawl nets of Thoothukudi.
Empowerment of inland fish farmers in value addition
Methodologies for the preparation of different kinds of value added fishery products from freshwater fishes such as cultivable carps and tilapia were evolved through trails in the The recipe and formula for the preparation of fish pickle, fish burger, fish macroni, fish noodles, fish cutlet and fish samosa were standardized. The consumer acceptability for different kinds of value added products from freshwater fishes were studied.
Demonstrations of the technologies to the public, training programmes were conducted in Kanyakumari and Tirunelveli Districts.
Messenger RNA based assay for RT-PCR detection of viable Salmonella and Vibrio cholerae from fresh and processed finfish and shellfish
A RT-PCR assay for the detection of Salmonella serovars using five specific mRNA genes hto, invA, hns, himA, and fimA was developed. Bioinoculation studies carried out proved the developed RT-PCR assay could detect the presence of enteric serovar Typhimurium in fresh and processed finfish and shellfish using a specific mRNA gene invA (275bp).
A RT-PCR assay was developed for the detection of different strains of Vibrio cholerae using specific mRNA genes rpoA, ctxA, tsf, groEL and rtxA. Bioinoculation studies carried out proved the developed RT-PCR assay could detect cholerae O139 (SG24) in fresh and processed finfish and shellfish using the specific mRNA gene ctxA (308bp).
RT-PCR assays developed could detect both the organism within 5 min of pre-enrichment in fresh and cooked finfish and shellfish. They were also detected by RT-PCR after 30 days in dried fish products. But, in the case of frozen products, only cholerae was detected after 30 days.
Nutritive values of fishes landed in the East coast of Tamil Nadu
Nutritive values including protein, fat, ash, cholesterol, calcium, iron and phosphorus contents of 80 fishes were tested. Protein varied from 8.49 to 26.14%; lipids from 0.13 to 14.72%; cholesterol from 4.86 to 180.52 mg%; calcium from 64.24 to 1887.10 mg%; iron from 0.06 to 28.46 mg% and phosphorus from 15.25 to 443.26%. Lethrinus elongatus had high protein, while
Leiognathus dussumiera had high lipids. Cholesterol was high in the squid Loligo duvaceli.
Fatty acid compositions of 53 fishes were tested by the gas chromatography. DHA was found to be higher in Pellona ditchela (29% of fatty acid), Stolephorus commersonii (20%) and S. devisi (18%). EPA was higher in Stolephorus devisi (11.4%), S.commersonii (9.9%), Portunus pelagicus (9.8%), Dussumeria acuta (9.7%) and Leiognathus dussumeri (9.6%). Therefore, small sized pelagic fishes are therefore good sources of DHA and EPA.
Instruments such as HPLC, GLC, thermalcyler, gel documentation system, refrigerated centrifuge, etc. were added to create facilities for testing the nutritional quality of fishes.