People generally talked about saltwater and freshwater fish but there are some species which can live in both salt and fresh waters the adjust their habits according to the environment. The water composition decides where a fish can live.

If you wan ta fish at home you need to gain full knowledge of water composition. So that you can give them right environment to survive.

Before all fishes were live in salt water but the food resources required them to adopt a freshwater or die so some species adapt the new life and start living in fresh water.


Freshwater and Saltwater fish are not same when it comes to their physiology. Osmoregulation is a process used by both types to live in their habitat. This means the working of their body tissues kidney and other organs.

Those live in salt water contain less salt in their body tissue. Saltwater fish uses its skin and gill to continuously losses water content out of the body this is due to the salty environment. We all know salt water increases the chances of dehydration but saltwater fish drink salty water in large quantity and produce little urine go through the salt out of the body. This prevents the dehydration make them hydrated all the time. All saltwater fishes use this method to live in high salt content water.

On the other hand, the freshwater fish contains more salt in their body tissue. They produce more urine to avoid excess drinking of water. They excrete more urine to reduce the amount of water content from their body.


There are two types of freshwater one is cold fresh water other is warm water. Goldfish is mainly known as the main fish which live in cold waters whereas angelfish, cory cats etc are the tropical water fish. Saltwater fish- clown fish, eels, lionfish etc.


HEALTHY HEART: Fish is high in omega 3 fatty acids and does not contain any amount of cholesterol. Cholesterol is responsible for heart attacks and other heart diseases. Omega 3 fatty acids help to lower the body fat and lower the fat content in blood. Unsaturated fats in fish do not increase your weight in fact, it puts your body weight under control. This reduces the risk of stroke and other respiratory problems.

HEALTHY BRAIN: The DHA and EPA found in oily fishes increase our brain power by providing it all the essential nutrients which nourish the brain cells and make weak cells strong and more active. In fish, both these elements are found ready to consume form which increases our intake of these.

GLOWING SKIN AND LONG HAIR: Omega 3 fatty acid promote skin health and give long and strong hair. We have a protection layer over our cells and this layer is called cell membrane. Omega 3 maintain the health of this layer and hence also protect our internal skin cells from outer virus attack.

IMMUNE SYSTEM: Fish contains all essential mineral and vitamin which are required for our good health. When we consume in ready-made form by eating fish our body gets all of them and this makes our immune system healthy.