Saprolegniosis, the disease caused by Saprolegnia sp., results in considerable economic losses in aquaculture. Current control methods are inadequate, as they are either largely ineffective or present environmental and fish health concerns. Vaccination of fish presents an attractive alternative to these control methods. Therefore we set out to identify suitable antigens that could help generate a fish vaccine against Saprolegnia parasitica. Unexpectedly, antibodies against S. parasitica were found in serum from healthy rainbow trout, Oncorhynchus mykiss. The antibodies detected a single band in secreted proteins that were run on a one-dimensional SDS-polyacrylamide gel, which corresponded to two protein spots on a two-dimensional gel. The proteins were analysed by liquid chromatography tandem mass spectrometry. Mascot and bioinformatic analysis resulted in the identification of a single secreted protein, SpSsp1, of 481 amino acid residues, containing a subtilisin domain. Expression analysis demonstrated that SpSsp1 is highly expressed in all tested mycelial stages of S. parasitica. Investigation of other non-infected trout from several fish farms in the United Kingdom showed similar activity in their sera towards SpSsp1. Several fish that had no visible saprolegniosis showed an antibody response towards SpSsp1 suggesting that SpSsp1 might be a useful candidate for future vaccination trial experiments.

Objective: The study was carried out to investigate the use and impact of veterinary drugs, antimicrobials, and supplements in commercial aquaculture for fish health management measures in three selected areas of Mymensingh, Bangladesh. Materials and Methods: Data collection was conducted through questionnaire interviews with owners of 50 fish farms and 25 drug shop owners from Trishal, Fulpur, Tarakanda, and Sadar Upazila of Mymensingh district. Results: A total of 15 trade-named veterinary antibiotics and six categories of other compounds were identified in this study. Antibiotics were found as the most used veterinary drugs (80.85%), followed by disinfectants, nutritional supplements, saline, ammonia removal agents, probiotics, and pesticides. These veterinary compounds’ performances for fish health management were found to vary (10%–60%) significantly. Conclusion: This study’s findings urge the necessity to produce and approve effective aqua drugs and treatments to ensure farmed fish and public health.

Correction: On 29th April 2015 the page numbers of this article were changed from 159-166 to 161-168.The present study was conducted to evaluate the impacts of aqua-drugs and chemicals on fish health and production in Mymensingh, Bangladesh from July 2013 to June 2014. Data were collected through personal contact, market survey, focus group discussion and participatory rural appraisal with fish farmers, associations and aqua-drug sellers. Fifty five different types of aqua-drugs and chemicals were recorded in the study area, among those, 20 types were widely used by the farmers for different fish disease treatment. It was recorded that renamycine, cotrim vet, ossi-c, polgard plus and timsen were used for the treatment of EUS in pangus, tilapia and koi which had an average recovery of 75-85%. For the treatment of edwardsiellosis in pangus and koi, farmers used potassium permanganate, timsen, polgard plus, geolite gold and renamycine which had an average recovery of 65-80%, and for the treatment of dropsy in tilapia, aquamycine, ossi-c and potassium permanganate were used which had an average of 80-85% recovery. Histopathology of gill and liver of fishes were almost normal in control ponds, whereas, in drugs treated ponds the organs had pathological changes like necrosis, pyknotic cells, hemorrhage, hypertrophy, lamellar missing, talengiactasis and vacuums. However, production of pangus, tilapia and koi was 12000 kg/acre, 15000 kg/acre and 14000 kg/acre in drug treated ponds respectively, whereas, it was 5000 kg/acre, 9000 kg/acre and 8000 kg/acre in non-treaded ponds respectively.Res. Agric., Livest. Fish.2(1): 161-168, April 2015

A study was conducted to know the involvement of child labour in various aquaculture activities in two upazilas namely Trishal and Muktagacha in Mymensingh district. Data were collected during December 2013 to April 2014 from 35 aqua farms having 492 workers, among them 100 (20.33%) were identified as child labour. All the child workers were interviewed through structured questionnaire. Feed preparation, feeding, sorting and grading of fish and rearing of fry in ponds were the major activities where maximum child labours were found to involve. It was observed that the main cause of children to involve such activities was poverty and dropped out from school. Overall 71% child labour worked to support their family and 48% recruited according to their parent’s decision. About 55% child labour worked more than 60 hours per week and few (19%) of them got break during working hours. The child workers had very limited freedom in their working area and found to be abused mentally and physically to some extent by the farm owners. The children were also found associated with various hazardous works like contact with chemical, long time work in water logged area and lifting heavy weight. Generally, the farm owners recruited child labour in their farms as cheap worker and majority (77%) of the farm owners have no idea about the current laws of recruitment of child labour. More studies are needed to establish the extent of child labour in overall aquaculture sector of Bangladesh. It is also important to implement effectively the national minimum age legislation for aquaculture.Res. Agric., Livest. Fish.3(3): 433-442, December 2016