To describe the importance of pathology & immunology in fisheries science at first we should know what is the meaning of pathology & immunology. The word pathology combines two words pathogen & logus. Pathogen means disease-producing organisms may be different micro or macro organisms such as viruses, bacteria & different parasites, & logus means knowledge . the branch of science which deals about the pathogens & their effects in another organisms is called pathology. The immunology can be defined as that branch of medical science which deals with study of development & function of both cellular & humoral components of the immune system by which the body reacts to expel, destroy or neutralize foreign substances including pathogenic microorganisms. So we see that pathology deals about the disease & the immunology deals about the defensive mechanism of organisms against the disease. Fish pathology deals about the different fish disease & their causative agent & fish immunology deals about the immune system of fishes or defensive mechanism of fishes.
In our country there is a huge scope of fish culture. It both satisfies our national protein demand & helps to earn a lot of foreign exchanges. But some problem associated in fish culture which decline the production of fishes. From them disease problem is most important problem & causes huge losses of fish production. Fishes are attacked by different micro & macro organisms which produce different abnormal condition or disease & causes the death of a huge no of fishes. These disease are not same in nature different pathogens are attacked different fishes & causes different types of disease. The symptoms of different disease are different in nature. For example in our country different types of fishes such as shrimp, carp, cat fishes are attacked by different viruses, bacteria & parasites which cause different types of disease such as
Pathology & immunology deals about this various types of disease. It deals about the different pathogens that cause disease & different host on which those pathogens are cause different disease. Some disease are caused by viruses such as white spot baculovirus, yellow spot disease, black spot disease, gill, tail & fin rot disease soft shell disease, some disease are caused by bacteria such as furunculosis, vibriosis, fish tuberculosis, columnaris, by providing this knowledge it helps to know about the different specific fish pathogens. It also provides us knowledge about the different symptoms of different disease. Thus by knowing the symptoms we can identify the normal & diseased fish & concerned about the different disease. It also provide us knowledge about the causes of this types of different disease. Such as sudden environmental fluctuations that accompany the rainy season, sudden changes in salinity and temperature, overcrowding, unhyiegenic conditions which accelerate the infestation of different paracites have been implicated in many outbreaks of disease. It mentioned that the diseases are not only caused by pathogens other causes are mainly environmental, nutritional, mechanical-traumatic & genetical or hereditary.
Thus providing the different situations which favorable for disease producing agents we can take the action or culture at proper condition which prevent the multiplication of different pathogens & different disease. Such as maintaining proper temperature & salinity & maintaining hygienic condition at the all stages of culture period help to prevent the attack of different pathogens. It is indeed important not only to recognize the direct cause of a fish disease, but also to determine the links of interrelations between fish & their environment to understand the deficiencies in the quality of water as well as defects in their maintenance & feeding. By providing the knowledge of the etiology of pathogens & symptomatology it helps to diagnose the pathogens more specifically. It also deals about the different chemicals or pesticides which help to protect fish from the specific types of pathogens or disease producing agents thus it constitutes the basis of all prophylactics & therapeutics with regards to fish treatment.
So at last we can say that without the proper knowledge of fish pathology & immunology we can not prevent the fish from different disease which cause the huge losses of production. If we do not take the proper steps against the different types of disease the main objectives of aquaculture can not fulfilled.
