Infectious diseases are of concern to the aquaculture industry due to the rapid transmission among the population which can incur severe production and financial implications. In production systems outbreaks of disease are typically caused by opportunistic pathogens who take advantage of the reduced-resistance and high density situation.
Finfish eggs are prone to fungus, and to a lesser extent bacterial infections. Some species are particularly vigilant, removing dead or fungal-invested eggs from the rest in order to eliminate the risk of spread. This occurs predominantly in “mouth-brooders”, those that store and protect eggs within the mouth. However, others are not so attentive and as a consequence, mild fungicides such as Methylene Blue or diluted Formalin may be used.
The implication of using such methods could result in toxicity towards the handler and fish if incorrect usage occurs, and therefore signals the need for effective yet safe controls. Currently, the use of copper sulfate at concentrations of 5ppm is being conducted by scientists at the Harry K. Dupree Stuttgart National Aquaculture Research Center, Stuttgart, AR. The data will be submitted to FDA for consideration once this is complete.
For further information please refer to http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=184374.
Tags: Fungicides
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One of the ways to get around the use of chemicals in aquaculture to control parasites is through the use of biotechnology.
Several approaches are currently being researched currently
1) Genetic modification of a fish species to contain a antimicrobial protein from another species eg: Atlantic salmon engineered to produce rainbow trout lysozyme – a potent microbicide against gram negative species
2) Genetic modification of a fish species to contain a antimicrobial genes from other organisms like insects. eg: catfish made to produce cecropin, an antimicrobial protein from the silk worm
3) DNA vaccination – foreign dna is inserted into a fish and it produces a protective protein in that animal only ie: it doesn’t pass on the alteration to its offspring, making it unlike proper genetic modification. There are currently trials undertaking place in Canada , for vaccinating against furunolisis in salmon.
No doubt with the continuing application of biotechnology to aquaculture, GM breeds will become a viable option in the future. For instance it may be possible to produce “super-species” that are immune to disease, yield better growth and are resistant to global warming.
g.reutens,
Found an article that talk in detail on how to control fish parasites by the use of Formalin. This parasiticides is said to be useful and efficient in control of fungi in fish hatcheries. It is also effective against many external parasites.
Explore more from this link: http://edis.ifas.ufl.edu/VM061