If you’re new to fishing, or even if you’ve been fishing for a while, you may not completely understand the difference between saltwater and freshwater fish. There are many differences in these two similar creatures, including biology, habitats and lifecycles. Charter fishing in Hawaii is a great way to explore the lives of many different kinds of fish. In the meantime, learn everything you need to know about the key differences between freshwater and saltwater fish:
- Location: Saltwater fish are located in salt water, such as large oceans and seas. Freshwater fish, meanwhile, are located in lakes, rivers, ponds and streams. These two diverse groups may never encounter each other at all!
- Physiological adaptation: The key difference between saltwater and freshwater fish lies in their adaptability to their environments. Their bodies have evolved to handle different levels of saline in their environment. Saltwater has 3.5 percent salinity, or 35 grams of salt per liter of water. Freshwater has 0.1 percent salinity, or 1 gram of salt per liter of water. You may be surprised to learn that even freshwater does include some salt! However, the percentage gap between the two makes a big difference in the physiological makeup of the different types of fish.
- Biology: The way the fish have adapted to their different environments is another large distinction between the two. The body tissues of saltwater fish contain less salt than the water in their environment. The saltwater draws water from the fish’s body tissues through its skin in a process called osmoregulation. To prevent dehydration, saltwater fish drink large amounts of saltwater and produce small amounts of very salty urine. They also secrete salt through their gills. In this way they’ve adapted to their super salty surroundings. On the other hand, freshwater fish’s skin contains more salt than the freshwater they live in, meaning their bodies continually draw in water from their environment through their skin. This way, they drink very little water and produce a lot of very diluted urine to avoid having excess water in their bodies. If you were to reverse the fish and put them in each other’s environments, neither one would survive long.
- Diversification: While there is much less freshwater on the planet, there are actually quite a few fish species found living in freshwater. Freshwater makes up 2.5 percent of the water on Earth, and 40 percent of all fish species are found here. Since there is so much diversity in freshwater habitats, there is a high diversity of freshwater species. This makes freshwater fish more adaptable and hardier than saltwater fish.
- Adapters: There are a few species that can live in both freshwater and saltwater. Euryhaline species, such as the green crab and the bull shark, have physiological adaptabilities for both types of environments.
If you love fish, you might be interested in charter fishing in Hawaii. The Sea Wife Charters won West Hawaii’s Today’s Best of West Hawaii award for Best Fishing Charter in 2009 and 2010. We are a keep-your-catch boat and have one of the highest catch rates. Come check us out!