Question

Gambusia is
(a) Parasitic fish
(b)Pest of fish
(c)Fish predator of mosquitoes larvae
(d)Mosquito spreading yellow fever

Answer 1

Hint: This western mosquito-fish is a species of freshwater fish. It is ambiguously called mosquitofish or by its generic name, Gambusia.

Complete answer:
Gambusia is a viviparous fish and belongs in the family Poeciliidae and order Cyprinodontiformes. Gambusia is mainly found in freshwater habitats, but some species may also be found in brackish or saltwater habitats. It contains over 40 species. They are mainly found in Mexico, Texas, and the Greater Antilles, but are also commonly found in the eastern and southern United States. Mosquitofish are generally dull grey colored and very small in size, they have a large abdomen, and rounded dorsal and caudal fins, and an upturned mouth.

Additional Information: Gambusia species are also often called topminnows or mosquitofish, which, however, refers more specifically to two species, G. affinis and G. holbrooki. These fishes are frequently introduced into ponds to eat mosquito larvae. The female fish can be easily distinguished from the male through various features like larger size and a gravid spot at the posterior of abdomen in females. The name "mosquitofish" was given because this species of fish eats mosquito larvae, and has been used more than any other fishes for the biological control of mosquitoes. Mosquito larvae make up only a small portion of their diet but they generally eat zooplankton, beetles, mayflies, caddisflies, mites, and other invertebrates.
So, the correct answer is 'Fish predator of mosquitoes larvae'

Note: Mosquitofish or gambusia was introduced directly in many parts around the world as a biocontrol and mainly to lower mosquito populations. But this in turn negatively affected many other species in each distinct bioregion. For example, mosquitofish that were introduced in Australia are classified as a noxious pest that may have exacerbated the mosquito problem in many areas but by outcompeting native invertebrate predators of mosquito larvae.