Guppies feed on mosquito larvae.
The guppy is a freshwater fish originally found in some parts of South America and the Caribbean, although it has been introduced to areas around the world. Their scientific name is Poecilia reticulata, while another name by which they are commonly known is the million fish. In addition to its popularity as a freshwater aquarium fish, the guppy has been introduced to many ecosystems to feed on pests. Guppies are typically 2.5 to 6.0 cm long, give birth to live young, and display a variety of appearances due to selective breeding.
Guppies were originally found on Caribbean islands such as Barbados and in South American countries such as Brazil and Venezuela. They are now found all over the world, with examples of accidental and intentional introduction. In cases where the introduction was intentional, the reason may have been that the guppies acted as a control for mosquito populations. The guppy feeds on mosquito larvae, but it can also act as an invasive species and adversely affect the ecosystem.
The guppy is sexually dimorphic, meaning the females are larger and have different colors than the males. While wild female guppies typically have uniformly gray bodies, males can display a variety of different colors and patterns. Also, selective breeding has led to many different lineages of guppies. These fish are still the same species, but will show similar visual characteristics to other individuals of the same lineage. These strains include varieties such as grass and snakeskin and exhibit variations in the color and shape of the fins.
With its many different varieties, the guppy is a very widespread aquarium fish. They can survive in high salt water despite being freshwater fish, so they are often used in tropical freshwater and saltwater aquariums. Guppies are generally considered good fish for community tanks, although males can occasionally show aggression towards each other and other important swimmers.
Guppies breed in freshwater and saltwater tanks, and gestation usually takes a month or less. They are ovoviviparous, which means that while they give birth to live young, there is no amniotic connection between the mother and the unborn eggs. After birth, the cubs are immediately able to swim and eat, and the female guppy can conceive again within hours. They are therefore known as very prolific breeders, and space can quickly become an issue in smaller aquariums.