Freshwater species are organisms that live in rivers, lakes, and ponds. These species include fish like trout and catfish, as well as amphibians such as frogs and various invertebrates. Freshwater ecosystems are vital for biodiversity and provide essential resources for humans. Marine species inhabit oceans and seas, ranging from tiny plankton to large mammals like whales. Common marine species include sharks, coral, and sea turtles. Marine ecosystems are crucial for global climate regulation and support a wide variety of life forms, making them essential for ecological balance.