Guppy, also known as guppy and rainbow, is a popular small tropical freshwater ornamental fish. Originated in South America, Venezuela, Guyana, the West Indies, northern Brazil and other places, after being introduced around the world. Loved group activities. Known for their bright colors and distinctive tail fins, males are usually more showy than females, with long tails covered with spots or stripes of various colors, and look as beautiful as a peacock's open screen. Females, on the other hand, have a relatively modest color and are larger, but have a shorter tail. Gentle character, suitable for mixed with other small peaceful ornamental fish.

It is a small marine fish of the seahorse genus in the family Hippocampus. Usually living in tropical and subtropical coral reef areas, it is known for its unique appearance and behavior. The body is horse shaped, with a pair of big eyes on the head and a curled tail that can firmly grasp seaweed or seaweed, thus maintaining stability in the water flow. Their body length is generally around 15 centimeters, and their body color varies from yellow, orange to red, sometimes with black or white stripes. This protective color helps them hide in the underwater environment. It is a species where males become pregnant, and females lay eggs in the male's brood sac, which is then incubated and protected by the male until the birth of a small seahorse.

It is a fish species that lives in the ocean and is known for its unique defense mechanisms and potential toxicity. The body is usually round or oval in shape, with smooth skin and a small body size, typically ranging from 10 to 40 centimeters in length. Having sharp teeth, suitable for chewing hard foods such as shellfish and crustaceans. One of the most well-known characteristics is its ability to expand. When threatened, pufferfish quickly swallow large amounts of water or air, causing their bodies to expand into a ball shape to scare away predators. This swelling behavior not only protects pufferfish from predators, but also makes them difficult to swallow. Pufferfish have toxins in their bodies.

It is a small marine fish belonging to the family Clupeidae. Usually living in the upper waters of the ocean, especially in temperate and tropical regions. Small in size, generally between 10-15 centimeters in length. Known for their silver white body and silver scales, their slender body has a streamlined shape, which makes them very agile when swimming underwater. It is a social animal that often gathers thousands of people together to form spectacular schools of fish. Mainly feeds on plankton, such as planktonic animals and small crustaceans. Because of its rich nutritional value and economic value, sardine play an important role in global fisheries.