The Difference Between Saltwater and Freshwater Fish

 
Mahi-mahi bursts out of the water.

Mahi-mahi bursts out of the water.

 
 

Let’s Look More into Saltwater and Freshwater Fish

When you normally think of fish you may think of delicious seafoods, like a flavor-packed Chimichurri snapper or a healthy tuna poke bowl. You may also think of where the fish swim, like oceans or bodies of freshwater. It’s important to know where the fish come from and how they affect you.

Saltwater Fish

Saltwater fish come from the ocean, rightfully named for the salinated water. Saltwater fish can thrive in more stable environments and lose more internal body fluids because of osmosis. Saline water is less diluted than internal fish fluids. Saline water replaces internal fluids for equilibrium and the fish replace lost water with large quantities of saltwater. Saltwater fish can survive in a variety of habitats, from the Arctic cold to tropical oceans, coral reefs, salt ponds, mangroves, and the deep sea. Many saltwater fish have adapted overtime to also survive in numerous habitats. A well-known example of a saltwater fish is Mahi-Mahi.

Freshwater Fish

Found in rivers and lakes, freshwater fish are able to adapt quickly to constantly changing environments and have a higher degree of diversity amongst species. It’s said that all fish originated as saltwater fish, but evolution kicked in and specific fish took advantage of untapped bodies of water inland and adapted to their new homes. Unlike saltwater fish, freshwater fish retain and absorb salt. Freshwater fish swim with 0.5 parts per thousand (ppt), or 10 grams of dissolved salt per liter of water, and the chloride cells in their gills pump sodium, calcium, and chloride in the fish. This process is osmoregulation or controlling the flow of water in the fish’s body. A great example of a freshwater fish is salmon.

Calamari (or squid) is a popular appetizer at many restaurants.

Calamari (or squid) is a popular appetizer at many restaurants.

Can a Saltwater Fish Survive in Freshwater?

Saltwater fish have hypotonic cells, keeping salt in their cells. When a saltwater fish is put in a freshwater environment, the environment is deficient in salt, and the water will go into the fishes’ cells, unfortunately, killing the fish.

What About A Freshwater Fish in Saltwater?

Opposite of saltwater fish, freshwater fish are constantly keeping a higher concentration of salt in their bodies than around them. If a freshwater fish is in saltwater, the salt enters their body at a higher concentration than they are able to handle. Sadly, this results in dehydration and death for the fish.

How Each Fish Impacts Your Food and Health

For many, the taste between saltwater and freshwater is most important. Saltwater fish tend to have a “briny,” or saltier taste, which makes sense as these fish retain more salt. On the other hand, freshwater fish is milder and does not have the briny taste. The taste choice is up to you!

While all types of fish are some of the healthiest foods to enjoy, there are small health benefits between the saltwater and freshwater fish. Shockingly, it’s not the levels of sodium. It’s the calcium levels in freshwater fish. Normally, freshwater fish have more calcium, monounsaturated fatty acids, and polyunsaturated fatty acids.  


Timoti’s

Join us this fall at Timoti’s in Ponte Vedra to enjoy fresh-caught seafood and family fun! Timioti’s offers fresh poke bowls, tacos, fried favorites, and refreshing cocktails. Our new Ponte Vedra location also features a playground for kids to play in. Timoti’s also has locations in Fernandina Beach, Five Points, and Amelia Island.