The killer whale or Orca is actually the largest member of the dolphin family. Dolphins have saved people at sea, and helped sailors since ancient times. There are many species and sizes of sharks , including hammerhead sharks and tiger sharks. Unlike whales and dolphins sharks are a species of fish, whereas whales and dolphins are mammals. Sharks are pre-historic and swam the oceans during the dinosaur era.
Most trout live in freshwater, and are closely related to the salmon family.
Carp are a long living freshwater fish. They are bony fish, but edible. Angelfish give birth to developed fish, not eggs. Their pectoral fins spread like wings. The most brightly colored fish, like the emperor fish , live in warm tropical waters.