Aquatic Diseases
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Aquatic Diseases
Objectives
- To recognize the relationship between disease, stress, nutrition and water quality.
- To identify common aquatic diseases.
- To recognize symptoms and determine treatment options of common aquatic diseases.
Diseases
- Are abnormal conditions of organisms that impair bodily functions with specific symptoms and signs
- Result from the following:
genetic or developmental error
illness or sickness
infection
poisons
nutritional deficiency or imbalance
Robert Koch
- First demonstrated the disease process in 1876 while studying anthrax
- Identified the anthrax epidemic in domesticated animals and sought a solution
- Determined a bacterium caused the illness by establishing a method of research
Koch’s Method
- Consisted of the following steps:
find which organisms are common to all infected animals yet absent in healthy ones
isolate the organism
reproduce the disease under controlled conditions
re-isolate the same organism from the experimentally infected animals
Disease
- Occurs from the following three factors:
susceptible host
pathogenic agent
environment which is unfavorable to the host yet favorable to the agent
Stress
- Is defined as a stimulus which disrupts homeostasis in an animal
- Causes animals to use more energy to maintain homeostasis rather than fight diseases
- Is different among aquatic animals because they are always immersed in their environment and cannot escape it
some pathogens are always found in water
Homeostasis – an organism’s ability to
maintain internal equilibrium
Diseases
May be broken into the following four categories:
- infectious
- non-infectious
- treatable
- non-treatable
Infectious Disease
- Develops from an infection
- Potential relies on the following:
- number of organisms
- infectivity: ability to get into host
- virulence: ability to cause disease
- host susceptibility
