What is the difference between freshwater fish and seawater fish (detailed introduction)

Freshwater fish and saltwater fish are classified according to the type of water they live in. They have significant differences in physiological characteristics, behavioral habits and ecological adaptations. Here’s a detailed look at the differences between freshwater fish and saltwater fish:

freshwater fish

Living environment: Freshwater fish live in freshwater environments, including rivers, lakes, freshwater wetlands and streams.

In vivo regulation: In order to adapt to the difference in osmotic pressure of water, freshwater fish usually accumulate salt in their bodies because the salt concentration in fresh water is lower than that in their bodies.

External Characteristics: Some freshwater fish species may have special protective mucus or scales on their bodies to protect themselves from freshwater parasites.

Behavioral characteristics: Some freshwater fish species tend to feed at the bottom of a body of water, while other species can feed at the edge or on the surface.

sea ​​fish

Living environment: Saltwater fish live in a marine environment with high salinity.

Internal Regulation: Saltwater fish generally need to excrete excess salt compared to freshwater fish. They normally excrete excess salt through their kidneys and urine to maintain salt water balance in the body.

External characteristics: Some saltwater fish have smooth scales and are better adapted to moving water.

Behavioral Characteristics: The behavioral habits of saltwater fish may vary from species to species, but many species of saltwater fish have adapted to the marine environment by swimming in groups, feeding, and reproducing.

Summary of differences

Living environment: Freshwater fish mainly live in freshwater environments, while saltwater fish live in marine environments with higher salinity.

In vivo regulation: Freshwater fish adapt to low-salinity environments by accumulating salt in their bodies, while saltwater fish need to eliminate excess salt to maintain salt water balance.

External characteristics: Due to differences in living environments, freshwater fish and saltwater fish may also differ in external characteristics, such as scales, body shape, and color.

Behavioral characteristics: Freshwater fish and saltwater fish also show differences in foraging, reproduction, and group behavior.

Both freshwater and saltwater fish play important roles in the ecosystems in which they exist. They adapt to different living environments and have different physiological characteristics and behavioral habits, so understanding them can help better protect and manage aquatic ecosystems.

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