Question

Differentiate between freshwater and marine fish. Name them.

Answer 1

Hint: Marine water is salt water, while freshwater varies completely from marine water. Both habitats are completely distinct from each other. To survive in a particular environment, fish attains different physiology. Freshwater fishes and marine water fishes cannot survive in each other's environment.

Complete answer: Rivers, streams, lakes and ponds are the example of freshwater. The salinity of freshwater is very less, approximately 0.05%. While oceans and seas are examples of the marine water ecosystem. The salinity is very high. Fishes that survive in marine water are known as saltwater fishes. Oxygenation levels vary in both types of habitats. The physiology of fishes determines the habitat they would be able to survive. A freshwater fish tends to retain more salt in the body as compared to the surrounding water. This ability to retain salt in the body helps them to survive in water with salinity less than 0.05%. Marine water fishes lose their maximum water from the body via the process of osmosis. The body tissue avoids salt accumulation to avoid dehydration. The freshwater fishes easily survive in an aquarium, unlike that of marine fish. Marine fishes are very sensitive. The specific salt concentration is mandatory for survival. Freshwater is less than 3 percent of all the total water on the earth surface. Whereas, freshwater fishes are almost half of all fish species. Examples of freshwater fishes are Pacu, Red-tailed, Guppy, Red-eye puffer, Golden barb, Catfish and Angelfish. Examples of marine water fishes are Eels, Jellyfish, Seahorses, Clownfish, Dolphin, Sharks and Tuna.

Note: Saltwater fishes urinate very less compared to freshwater fishes to remove excess salt from the body. Some fishes live in brackish water. The waterbody where freshwater unites with the saltwater is known as brackish water. It is the site where rivers flow into oceans.