Culturing and Reproduction of Mosquito Larvae for Aquarium Fish

Life Cycle of the Mosquito

Mosquitoes can be found all over the world and have adapted to all climatic conditions. They are prolific breeders and in most countries are considered to be pests forcing governments to taker measures to control the populations of them. There are four main stages to their life cycle. They all start out as eggs which will hatch into larvae. These will then develop into pupae and eventually the metamorphosis will take place for adult mosquitoes to emerge from the pupae. The cycle and their lifespan is very short thus making them have the ability to increase in population very quickly. It is the female mosquito that is guilty of irritating humans with their blood sucking and the can pass on several diseases, they produce a saliva that thins down the blood so that they can feast on it more readily. Their blood intake is important as this produces amino acids in their bodies which they use to produce the eggs.

The eggs can be laid in any area of stagnant water and these very quickly hatch out and the larvae emerge. They rest at the water surface by their tails, consuming bacteria in the water and if disturbed they will swim below the surface until any threat has dissipated. At this stage they are known as wrigglers due to the strange swimming motion as the body wriggles through the water. All larvae will change four times before developing into a pupa, each of these changes are known as “instars” where modifications are made and each time the larvae will shed their exo-skeleton as they grow in size.

Pupae are cocoons where the mosquito undergoes the largest changes, the body completely transforms into the adult shape ready to emerge and reproduce thus completing the full cycle. Surprisingly during the pupae stage air still needs to be available so it is common to see the pupae rising to the surface to breathe this. After a few days the cocoon splits and the adult mosquito emerges. It is important to understand how the mosquito reproduces if you wish to culture your own stock for feeding the fish, once you have done this a few times you will find it easy and you have a never ending supply of food.

Culturing your Mosquito Larvae

Culturing your own stock of mosquito larvae is very simple and you hardly need any equipment at all. The fish will benefit form feeding on these and they are also excellent for conditioning fish when preparing them for breeding. The only equipment required is basically a black bucket and water. It is best to set up your culture mid summer as mosquito need the sun and warmth before they will breed, once they start you will soon have a plentiful supply to harvest. Try to use a decent size bucket for this, the larger the bucket, the more larvae you will get. Use black as this colour absorbs the heat and the water will be warmer, perfect for the mosquito. The goal here is to get some algae in the water as this is the food supply for the mosquito, once the water has aged for a couple of weeks you should see it starting to turn green, at this time you know that the algae is taking over and starting to colonise the water. Some people will even use an old fish tank for this purpose as this gives full visibility all round as to how your crop is doing. Try to allow the bucket to fill with rainwater or use treated mains water, this will allow the algae to take over quicker as they do not like chlorine and this will inhibit their colonisation.

The water will warm in the day and should start to look like a thick green colouration after two weeks, the mosquito will son emerge to feast on this new food supply. The mosquito will lay their eggs on the surface of the water and they should be visible, the are very small but there will be hundreds of them. After 48 hours, the eggs should hatch and the larvae will be seen suspended upside down at the water surface feeding on the algae. Leave them for another day to fill themselves up and grow slightly and then take a very fine net and harvest the larvae to feed to the fish. There will be small larvae that slip through the net, these should remain in the bucket to grow to feeding size. The easiest way to do this is to place the net on top of another small bucket and pour the water through the net, once the larvae are netted return the poured water back to the original bucket.

While the weather is warm the mosquito should continue to lay their eggs supplying you with free fish food, always try to harvest the larvae before any turn into pupae and especially before they get the chance to turn into adults. The last thing we want to do is to allow even more mosquito to fly around irritating us all and passing on diseases.

Even if you finish with excess larvae you can store these easily ready for the winter months by filling an ice cube tray with water and dropping several larvae into each compartment. These are then frozen ready to be taken out a cube at a time to feed the fish.

Frozen Mosquito larvae and Daphnia - Pictures