Fish breathe by drawing water in their mouths and forcing it out of the body via a number of gill slits. The gill slits are rich in blood vessels, enabling the direct absorption of oxygen. While all fish have gills, some fish are also able to extract oxygen from the air via gulping.
Most fish have swim bladders that are permanently sealed, but other fish have swim bladders that can hold varying amounts of air. Salmon have open swim bladders, and they must gulp air at the surface to keep them full. Some fish, such as sharks, lack swim bladders entirely. This causes them to sink if they do not maintain forward motion.
Fish have fins that are adapted to their lifestyle. Some have evolved into long, barbed structures, suitable for defense. Other fish have fins suited for achieving great speed or for walking along the bottom of the ocean.
Answer:
They are called a Colony so the answer would be D
Explanation:
Enjoy the correct answer
If I'm right I'd say They control and direct the quantity of food passing through the digestive organs and prevent backward movement of partially digested food. Hope it's helpful.
Answer:
B
Explanation:
By combining drip and flood irrigation. Drip irrigation is a type of micro-irrigation system that has the potential to save water and nutrients by allowing water to drip slowly to the roots of plants, either from above the soil surface or buried below the surface. The goal is to place water directly into the root zone and minimize evaporation.
Flood irrigation is a practice in which an entire field is covered with water, while furrow irrigation adds water through furrows adjacent to crop beds. In flood irrigation systems, soils experience highly anoxic periods which promote denitrification processes.
