Aquatic beings: life on water
What they are - biological definition
Aquatic beings are all living beings that live (all or part of their lives) in waters of seas, oceans, rivers, lakes, among other means with the presence of water. Many aquatic beings live in salt water, especially in the oceans, while others are freshwater beings (rivers, lakes, streams, etc.).
These beings can be animals (vertebrates and invertebrates) or other life forms such as plants, algae, plankton and so on.
They are active living marine animals that live in the water column. They have favorable physiology to make displacements, including against the marine currents. Examples of these beings include fish, whales, some crustaceans and cephalopods (squids and octopuses, for example).
They are beings that inhabit the superficial part of the water column (fresh and salt). These beings, which are microscopic, float and are carried by the water currents. They feed to other sea animals.
There are two types of plankton: zooplankton (are heterotrophs) and phytoplankton (are photosynthesizers).
They are beings that inhabit the region of the substratum of seas, oceans and rivers (bottom of aquatic ecosystems). Some live fixedly, such as algae and corals. Others like crabs and starfish, for example, live on the move.
They are particles of animal or mineral origin present on the surface of the water (sweet or salty). They are important as filter feeders such as mussels, oysters and sponges.