Bodies is a living environment for aquatic biota such as fish, aquatic insects, water snails, animal organisms, aquatic plants, the tiny plants and others. In this environment there will be interaction between organisms (biotic) existing water environment (abiotic) as the medium of his life, as well as the interaction between water biota itself in order to survive. This interaction thus establish a system of environmental change.
But the system’s environment remains towards an equilibrium constant. Except when there is interference, the system of environmental change towards a new equilibrium. The system changes the environment can be caused partly by natural disasters such as volcanic eruptions, earthquakes and pollution by industrial activities and the community.
Animal needs water for the metabolism in the body is to get appropriate food, while for the water plants is how to get nutrients for survival. From the necessities of life for the aquatic biota will form a link between water biota (symbiosis) which vary among others.
1) Parasitism, the water biota are parasites by sucking the bodily fluids of other water biota (host) for life. Biota water is very detrimental to the host such as fish and shrimp are cultivated. Relationships of parasitism on aquatic biota can be seen in Figure 1.
2) Mutualism, the water biota that is mutually beneficial to other aquatic biota. Relationships of parasitism on aquatic biota can be seen in Figure 2.
3) komensalisme, namely water biota that are beneficial sided, while others are not affected biota. Relationships of parasitism on aquatic biota can be seen in Figure 3.
4) Predation, namely water biota that are preying carnivore with other aquatic biota smaller the measurement body. Relationships of parasitism on aquatic biota can be seen in Figure 4.
Figure 1. Relationship between Lernae cyprinacea parasitism and guppy