Developed a model based on serum biochemical attributes of
L. argentimaculatus to find its applications in health monitoring. Basal reference intervals for nine relevant serum biochemical parameters in cage reared
1. Protease activity of P. olseni 2. Amylase activity of P. olseni 3. Relative expression profile of
selected osmotic responsive genes in the gills of Etroplus
suratensis exposed to fresh
water as compared to brackish water
4. Relative expression profile of selected osmotic responsive genes in the gills of Etroplus
suratensis exposed to marine
water as compared to brackish water 5. Tumours in cobia 6. Deformities in cobia
fingerlings
tissue proliferation and hyperchromatic nucleus admixed with cartilage and was diagnosed as Fibrochondroma. In another case, a hard, solid growth was observed on the caudal fin of cobia. Cytology of smears showed collagen and basophilic mucus cells. Histologically, the section revealed replacement of entire stratum compactum and dermis with osteocytes and osteoid structure. Osteocytes were hyperchromatic with vacuoles formation indicating dermal fibro-osteoma. Deformities were observed in hatchery Inositol Monophosphatse (IMPA), Isocitrate
dehydrogenase, L-Rhamnose binding lectin and Serine/ Threonine protein phosphatase showed a serious drop while L-Rhamnose binding lectin showed 0.25 fold increase.
Neoplasia: Incidence of tumours was reported in Rachycentron canadum from Mandapam. A cauliflower-like growth was observed in the gill rackers of cobia. Cytology of smears grouping of spindle shaped basophilic cells. Histologically, the section revealed fibrous
Fish Health and Marine Bioprospecting
1
L. argentimaculatus in comparison with its wild counterpart were established. Higher inter-subject variability of serum glucose level makes it unfit as a health index for the species. Ecotype had a significant role on modulating serum biochemistry (except on serum glucose and SGOT levels), while gender had no effect. Accordingly summary statistics and ecotype specific reference intervals were calculated for these parameters. SGOT was found to have the potential to be applied as a health index for L. argentimaculatus irrespective of ecotype studied. Consistency, minimum intra-ecotype variability coupled with results of PCA analysis, makes serum protein as the best fit for ecotype specific health index.
In lobster culture, bacterial loads showed an increase during two phases of maximum water temperatures in May-July and lowest salinity period in December-January. Husbandry protocols with steady water temperatures of 27-28 °C is essential for nursery phase
and continuous low salinity (26-28 ppt) leads to moult death syndrome and increased tail rot. Clam meat used as feed acts as a possible source for increased Vibrio load in lobster culture tanks. Experiments were conducted using clams treated with garlic extract, and preliminary results are promising with decreased bacterial load in tanks. However further studies are required for confirming the results.
Mass immunization against vibriosis was carried out in cobia fingerlings by intra-peritoneal injection of a multivalent vaccine. A booster dose on 35th DPV further enhanced the antibody levels and extended the protection. The vaccinated fishes neither showed stress nor mortalities indicating that the regular epizootics of vibriosis, usually occurring during the months of July to September (pre-monsoon), could be successfully prevented by vaccination and proper sea cage farming management.
1. Immunisation of cobia fingerlings
2. Mussel farmers meet at Edayilakkad
3. “Perkdetect”, a LAMP based diagnostic against Perkinsus infections in bivalves
National Surveillance Programme for Aquatic Animal Disease (NSPAAD): Under the National Surveillance
Programme for Aquatic Animal Diseases, regular screening of wild and farmed bivalves for OIE listed pathogens, Perkinsus olseni, Bonamia ostreae and Marteilia refringens were carried out along the east and west coasts of India including Lakshadweep Islands. A total of 1370 wild bivalve samples belonging to 15 species were collected and screened. P. olseni was observed in Perna viridis, P. indica, Paphia malabarica, Geloina bengalensis and Anadara granosa while P. beihaiensis was observed in P. viridis, P. malabarica and G. bengalensis. Mixed infections were observed in P. malabarica, P. viridis and G. bengalensis. The prevalence of Perkinsus infections in wild bivalves was 24.67%. A total of 1024 farmed bivalve samples were screened during the period. Overall prevalence of Perkinsus infections was 77.59%. Both P. olseni and P. beihaiensis as well as
Fish Health and Marine Bioprospecting
0 0.1 0.2 0.3 0.4 0.5 0.6 2nd 4th 6th 8th 10th 12th 14th 16th OD at 600nm Day intervals Optimum pH 4.6 5.6 6.6 7.6 8.6 9.6 2 3
mixed infections were observed. Bivalves from Lakshadweep Islands were free from Perkinsus infections. Infections with Marteilia and Bonamia were absent in the screened populations.
A mass awareness programme was conducted for mussel farmers at
Edayilakkad, Kasaragod district for creating awareness among the farmers to adopt better culture and management practices. All India Network Project on Fish Health: Information regarding the usage pattern of drugs and chemicals in aquaculture was collected through a questionnaire based survey. The results indicate that drugs/chemicals are not generally used in farms in Kerala.
Biosafety evaluation of Emamectin benzoate was carried out in T. blochii with treatment doses ranging from 50 to 500µg/kg biomass. Tissue morphological changes were studied using histopathology.
An economic loss assessment study based on loss/mortalities in mussel farming in Kasaragode district was carried out. Losses due to mortalities and reduced production during the period ranged from 62-78% on an average.
Screening of imported marine
ornamental fish for OIE listed pathogens was carried out and all the samples were negative.
Fish Health and Marine Bioprospecting
1