Seasonal changes in selected immune response of Mystus gulio and Mystus vittatus.

Estuaries are considered as highly potential area for that including feeding, spawning and nursery rearing of most of the finfishes and shellfishes. In the present investigation, two species of catfish (M.gulio and M.vittatus) were selected to study the impact of season on their immune organs (kidney and spleen) and selected immune response from Vellar estuary. The physico-chemical parameters (pH, temperature, salinity and rainfall) were measured during the sampling period 2009-10. The non-specific immune parameters (WBC count, lysozyme activity and NBT assay) were analyzed. The immune organs (head-kidney and spleen) variation was also observed by histological studies. Our results stated that the WBCs count of M. gulio and M. vittatus increased during summer (10.3 and 10.1 X 106 ml-1) season and decreased in monsoon (6.8 and 7.0 X 106 ml-1). In contrast, lysozyme activity was highest in post monsoon (1540 and 1525 U min-1 ml-1) and lowest in summer (1000 and 960 U min-1 ml-1). The activity of NBT was highest in monsoon (0.68 and 0.65 at 540 nm) and lowest in summer (0.012 and 0.2 at 540 nm). The histological observation implies that the cell variations were different in respect to different seasons.

Infection and immunization trials of Asian seabass (Lates calcarifer) against fish pathogen Vibrio anguillarum.

Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio sp. Fish disease will be controlled by proper vaccination trials and maintenance of fish form. Pathogenicity for Asian seabass (Lates calcarifer) against V. anguillarum results in necrosis and haemorrhagic areas near the base of fins, exopthalmia and ulcers on the skin surface. Around 50, 100, 200 )l of formalin killed bacterial cells were injected (Intraperitoneal) to three different size (5-10, 20-30, 35-50g) of seabass fishes respectively and control sere as saline were maintained separately. The Relative Percentage Survival (RPS) for vaccinated fishes was 60, 75, and 62.5 respectively and the vaccinations for 20-30 g fishes stay alive. These results stated that the vaccination for fishes with 20- 30 g size may fabricate good immune response.

The immune response in catfish, Mystus gulio.

Light microscopic studies of the immune response of Mystus gulio were carried out. Antigen binding cells have been detected by plaque-forming cell (PFC) assay test in the spleen, head-kidney (HK) and thymus. Among these three organs, the HK is more pronounced in its response, and it is compared, on the basis of its histology of higher vertebrates. The peak response after primary and secondary immunizations was on day 7, in both circulating blood and the immune organs. The results suggest that HK in these fish might be the major organ for antibody secreting cells. The HA (haemoagglutinin) response was also for longer duration but only slightly more intense. The PFC response after the secondary immunization was for much longer duration and much more intense than after the primary immunization.

Industrial application of keratinase and soluble proteins from feather keratins.

Feather keratin is highly resistant to degradation, but some keratinase producing microorganisms can easily degrade these insoluble keratins. These keratinase producing species have an important application in removal of poultry waste and recycled into valuable byproduct. Bacillus sp was screened from soil samples of slaughterhouse and poultry farm area using azokeratin medium. Highest keratinase activity (122.5 KU ml(-1)) was observed at 8.0 pH. Submerged fermentation was carried out at 8.0 pH up to 5th days. On 4th day enzyme production was highest (140 KU ml(-1)) with 1% feather (w/v). Crude protein content was high on day 5, around 1.44 mg ml(-1). 75% of filtrate was found to be crude protein. The molecular weight of this keratinase was 32 kDa by SDS-PAGE. The crude protein from feather has of high nutrient value and could be used as animal feed for livestock and fish feed in aquaculture.

Structure of immune organ in edible catfish, Mystus gulio.

The light microscopic study describes the anatomy and histomorphology of head-kidney in bagrid catfish, Mystus gulio. Showing numerous lymphocytes, interrenal cells, reticular cells, postcardinal vein, blood sinuses and melanomacrophage centers.