In the aquatic environment as a medium of live aquatic biota, frequent changes in water quality parameters such as the degree of acidity (pH – element content of H + or OH-), dissolved oxygen (O2), content of ammonia NH3, the acid content of sulfide (H2S), water temperature and others. Changes in water environment can affect aquatic life, especially for water biota that have tolerance to changes in water quality parameters were narrow.
Influence for fish and shrimp can cause physiological stress (organ functions – such as gills, heart) that is less good. Physiological stress can lead to poor condition of the fish and shrimp so easily attacked by parasites or bacteria.
In certain circumstances the change of water quality parameters can also lead directly to death for the fish and shrimp, such as low dissolved oxygen, high ammonia content and sulfide acid. Changes in water environment unfavorable imbalance can be caused by the decomposition of organic material decomposer (decomposing organisms) and their fill from outside the water environment. Disease environmental impact on fish and shrimp are still common. Based on the cause of this disease can be divided into two groups, namely caused by abiotic and biotic factors.
A. Abiotic Factors
1) Temperature / temperature
4) Material contamination
B. Factors Biotic
Algae that cover the surface of the water will disrupt the process of respiration of fish. While the algae growing in the water will affect the movement of fish. The fish will be caught in the algae. Besides single-cell algae that form filament will get into the gills and the sheet will disrupt the process of respiration of fish and shrimp, so that over time the fish and shrimp will be deprived of oxygen.
over time the fish and shrimp will be deprived of oxygen. Some of the algae that grow excess (blooming) will have an effect on reducing the oxygen content in the water, especially at night time, namely the metabolic processes of algae. Besides a result of the decay process of dead algae can cause toxic materials such as ammonia. Some algae would be toxic to fish, for example of the type of Mycrocystis aeruginosa.
Protozoa are zooplankton, which has the same population growth in the presence of phytoplankton. Some types of protozoa such as Euglena sp can poison fish and shrimp when the population is high (blooming). But some types of phytoplankton abundance and composition sector in the waters of a biological parameter that can be used as an indicator to evaluate the quality and fertility is a body of water.
This is because phytoplankton is a contributor to oxygen and as a food source for zooplankton. The important role of phytoplankton as early binding make solar energy an important role phytoplankton to marine life and lake. Thus the presence of phytoplankton can maintain stability in an aquatic environment. Fish have different morphological and physiological other animals, namely:
1) Skin the fish do not have the horny layer
2) Not having a multicellular glands and sebaceous gland
3) In a system of bone and cartilage changes over the life of fish
4) osteoclast is generally not found in fish
5) Having dark muscle in the lateral part
6) different Osmoregulation
7) Physiological influenced by environmental temperature
So that the fish has resilience to the environmental balance that is different from other animals. In normal conditions the fish are physiologically primarily on immune function will produce antibodies that balanced the firepower of the parasite or bacteria present in the environment. This balance will keep the fish and shrimp continued to grow normally. The shrimp have different morphological and physiological fish, namely:
1) Skin shrimp coated with chitin loud enough
2) Have the hepatopancreas functioning for metabolism and maintain the shrimp immunity against the disease.
3) Breathe with gills
4) On the bottom of the waters
5) Physiological influenced by environmental temperature
Shrimp so resilient to the environmental balance of different fish.