Fish Diseases and Their Control
FISH DISEASES AND THEIR CONTROL
Lecture Prepared by:
Prof. G.N.O. Ezeri
Aquaculture and Fisheries Management University of Agriculture, Abeokuta, NIGERIA.
ADVANCES IN FISH DISEASES
FIS 710 (3 Units) Core Course
Outline
• Types of fish diseases, (parasitic, bacterial, fungal, nutritional etc.) • Laboratory methods for fish disease diagnosis, • Prevention, control and therapy of fish disease
Introduction
• Higher stocking densities call for the introduction of large quantities of concentrated feeds and mineral fertilizers. • This affects the environmental factors in the aquatic environment • environmental changes are stressful and lower body resistance of fish to disease
• Infections and other diseases therefore sets in • Such unfavourable conditions include
– crowding, – temperature fluctuations, – inadequate dissolved oxygen, – excessive or rough handling, – sublethal levels of toxic materials.
• Fish diseases are the end result of interactive of the etiologic agent, the susceptible the fish and the environmental condition
Physiological And Biochemical Changes
• These are non-specific physiological and biochemical changes which take place in three phases:
– The alarm reaction – The stage of resistance during adaptation to achieve homeostasis under the changed circumstances taking place. – The stage of exhaustion when adaptation has ceased to be adequate and homeostasis is not achieved.
Classification of diseases
• Generally, diseases are classified as
– infections, – parasitic, – non-communicable and – diseases of unknown etiology.
• Infections diseases are caused by viruses, bacteria, fungi and less frequently algae. • Parasitic diseases are caused by protozoa, helminthes and parasitic crustacean. • Non-communicable disease include
– nutritional fish diseases (e.g goiter or hyper plasia of the thyroid gland) – diseases associated with physical or physicochemical abnormalities of water e.g gas bubble disease – low
Lecture Prepared by:
Prof. G.N.O. Ezeri
Aquaculture and Fisheries Management University of Agriculture, Abeokuta, NIGERIA.
ADVANCES IN FISH DISEASES
FIS 710 (3 Units) Core Course
Outline
• Types of fish diseases, (parasitic, bacterial, fungal, nutritional etc.) • Laboratory methods for fish disease diagnosis, • Prevention, control and therapy of fish disease
Introduction
• Higher stocking densities call for the introduction of large quantities of concentrated feeds and mineral fertilizers. • This affects the environmental factors in the aquatic environment • environmental changes are stressful and lower body resistance of fish to disease
• Infections and other diseases therefore sets in • Such unfavourable conditions include
– crowding, – temperature fluctuations, – inadequate dissolved oxygen, – excessive or rough handling, – sublethal levels of toxic materials.
• Fish diseases are the end result of interactive of the etiologic agent, the susceptible the fish and the environmental condition
Physiological And Biochemical Changes
• These are non-specific physiological and biochemical changes which take place in three phases:
– The alarm reaction – The stage of resistance during adaptation to achieve homeostasis under the changed circumstances taking place. – The stage of exhaustion when adaptation has ceased to be adequate and homeostasis is not achieved.
Classification of diseases
• Generally, diseases are classified as
– infections, – parasitic, – non-communicable and – diseases of unknown etiology.
• Infections diseases are caused by viruses, bacteria, fungi and less frequently algae. • Parasitic diseases are caused by protozoa, helminthes and parasitic crustacean. • Non-communicable disease include
– nutritional fish diseases (e.g goiter or hyper plasia of the thyroid gland) – diseases associated with physical or physicochemical abnormalities of water e.g gas bubble disease – low