The good news is that most fish will eat mosquito larvae or wrigglers.
But a homeowner, gardener or aquarium owner who wants to stock their pond or tank with fish that will eat these pests but leave tadpoles alone have several options.
This article discusses seven fish that eat mosquitoes while not necessary bothering the tadpoles, but first:
The Mosquito Larvae Stage
As many people know, most female mosquitoes need to have a blood meal before they can reproduce. She seeks out a meal very soon after she herself hatches out of a pupa.
After she mates, she lays eggs on the surface of the water or in a place that will soon be covered with water.
The newly hatched larvae are almost microscopic, but after a few days, they’ll grow much larger. This is especially true if the weather is warm.
Depending on the species, a mosquito larva can spend less than a week or more than a month in this immature state. They are called wrigglers because of the way they wiggle around in the water.
The wriggler needs to breathe air, and it has a tube that it sticks up through the surface of the water. It can retract its tube if it needs to sink, but it cannot stay submerged for very long.
One of the rare mosquito larvae that don’t need to breathe air belongs to the species Taeniorhynchus.
The wriggler sheds its skin four times during the larval stage. The last time it sheds its skin it becomes a pupa or tumbler.
It does not eat, but it still stays in the water and breathes through two tubes at its front end. It takes about two to four days for the pupa to become an adult.
When the adult is ready to emerge, the skin of the pupa splits down the middle, and the adult pulls itself out. Until it dries off and flies away, the mosquito is at risk of being eaten by an animal in the water.
In some cases, the mosquito is eaten by a fish even after it’s flown away. A fish called an archer fish may see a mosquito resting on a leaf above the water and squirt a stream of water at it.
If the water hits the mosquito, it falls into the water and the fish eats it.
7 Fish that eat mosquito larvae but not tadpoles
These fish are so good at eating mosquitoes that they take their name from them. A mosquito fish can scarf up as many as 160 wrigglers an hour.
These fish are native to the eastern United States and as far south as Alabama and as far west as Texas. The female is larger than the male and grows to about 2 3/8 of an inch to his 1 3/5 inch.
The non-gravid females are a dull gray, somewhat slender with round, transparent fins while the males are heftier.
He is a transparent gray with a blue iridescence on his sides, an olive-brown back and a silver belly with a black bar that runs through his eye.
He has an elongated part of the tail fin called the gonopodium, which he uses to impregnate the female.
The mosquitofish isn’t particular about the pH, or acidity or alkalinity of the water, nor does it mind if the water is hard or soft.
Hard water has a lot of minerals such as calcium and magnesium, and soft water doesn’t.
One reason why mosquito fish are so useful in catching wrigglers is that they thrive in the still water wrigglers are found in.
The mosquitofish can also tolerate water temperatures from 37 degrees Fahrenheit to 86 degrees F. However, it is a somewhat combative fish, and it is best to keep it with its own kind. They bear live young but may eat them if they are not removed from the area.
These fish have been bred to be anything from the simple golden-red fish people used to win at carnivals to extravagant animals with fantails, bulbous heads, and neon coloration.
In the wild, a goldfish can grow up to one and a half feet long and is not really gold as much as a grayish-yellow or grayish silver.
Like the mosquitofish, goldfish prefer slow or still water which makes them good for eating mosquito larvae.
They can survive under quite cold conditions as long as the water isn’t frozen solid and don’t care too much about water pH or hardness.
Unlike the mosquitofish, the goldfish is tranquil and gets along well with other cold-water fish.
Like the goldfish, the guppy has been bred for the delectation of aquarium owners. Because of this, it comes in a wide variety of colors, patterns, and fin shapes.
It is in the same family as the mosquitofish and is native to the Caribbean.
The wild guppy has irregular black spots and patches with iridescent red, blue, and green on the sides. Females are a little drabber, but they are bigger than the males.
They are as long as 2 1/4 inches while males are 1 1/4 inches long. Like the mosquitofish, the male has a gonopodium.
Guppies prefer water that’s between 68 and 75 degrees Fahrenheit and thrive in hard or even very hard water.
They are a schooling fish and get along well with other live-bearing fish like the mosquitofish. Unfortunately, guppies may also eat their young.
Koi is a cousin of the goldfish. They both belong to the carp family. These fish are bred for their vivid colors and patterns. In Japan, these colors and patterns have their own specific name.
For example, a Kohaku koi is white with red markings on its dorsal side. Koi can be tame enough to be fed by hand, but they also eat mosquito larvae who have the bad fortune to hatch in their pond.
A koi can grow to over three feet long. They are torpedo-shaped with prominent cycloid scales and barbels, or whiskers that are lacking in the goldfish.
They can reportedly live longer than humans, and one koi was said to be over 200 years old at its death. But koi usually live about 50 years.
This firm-fleshed white fish that has become a favorite at the dinner table is native to the Middle East and most of Africa.
This fish has a large head, thick, deep body, a long dorsal fin that runs down nearly the length of its back and a tail fin that’s slightly rounded or straight-edged. Depending on the kind of tilapia, its coloring can be varied.
Tilapias range in size from about 4 3/4 inches to 8 inches long, again according to the species. Male and female look alike, though gravid females are plump.
Tilapia are known for their tolerance of all kinds of freshwater. They do well in water that’s not only still but stagnant.
They have even been found in hot soda lakes in Africa that are only a few inches deep. Some species do best in moderate temperatures while others can tolerate temperatures as high as 90 degrees F.
But a pond or aquarium for a tilapia needs to be deep and have lots of plants, rocks, and bogwood.
Tilapia are schooling fish, but some species are belligerent while others are docile. It is important that the owner chooses a species-appropriate to their pond or tank.
Tilapia reproduce easily in captivity as long as the parents get along. They are mouth breeders, with either the male or female incubating the eggs in their mouth.
This little fish is often used as bait by anglers, but it provides another service when it eats mosquito larvae that hatch in its pond or tank.
They only grow to about 1 1/2 inches long and have long, slender, compressed bodies. Minnows can come in many different colorations though they are mostly dark brown on top, have a green iridescence and dark line from the gill opening to the tail.
Male minnows are a bit more slender and more brightly colored than females.
True minnows can be told from similar fish because they have teeth in their throat.
Minnows prefer their water temperature to be at least in the 60s year-round, and in the summer they prefer it to be no warmer than 72 degrees F.
They need fresh water, and the aquarium owner may find they have to change the water regularly. This may interfere with the minnow feasting on wrigglers, but it may decrease the number of wrigglers altogether.
The environment should have plants but enough clear space for the minnow to swim freely.
The minnow is a schooling fish with a lively disposition and swims and feeds near the surface. It reproduces easy in captivity but should be kept with members of its own species.
This is probably because other, larger fish tend to eat it.
#7. Zebra Danio
This beautiful little fish gets its name because of its stripes, which look black and white at first but on closer inspection are a beautiful deep blue and gold.
Native to northeastern India, the zebra danio has a small, slim compressed body and two pairs of barbels. It grows to about 2 to 2 1/2 inches long, and the female has more silver in her body and is a bit larger than the male.
This fish swims on the surface where it can pluck not only wrigglers but mosquito pupae. It prefers fresh, shallow water that moves somewhat and is exposed to the sun.
The pH and water hardness don’t matter. Like the minnow, the zebra danio likes vegetation in its habitat but also needs room to swim around. It also prefers a gravelly bottom for spawning.
The zebra danio is an active but nonassertive fish that lives peacefully with other fish, especially if they are close relatives.
Many fish feed on mosquito larvae and these seven fish not only eat them but tend to leave tadpoles and polliwogs alone. They are beautiful fish to stock a pond or aquarium with.