Mosquito Fish: Pro or Con?

[Sisha]

Also, although goldfish fierce predators, they vacuum things into their mouths when they feed. So they probably just suck in the mosquito eggs, rather than actively pursuing the larvae.

Hahaha, My father has 2 tanks he breeds mozzie larvae for Mums goldfish. They fight over them, sends them into a frenzy. I love getting revenge on the buggers

 

[Wayfarin]

While mosquitofish are probably the best choice as a predator of wrigglers due to their prey drive, the species of fish probably doesn't matter as much as the size of the fish, the availability of food, and the abundance of cover for the larvae.

Small fish (that can subsist on tiny prey) in a pond with minimal cover for the larvae and minimal food for the fish should control mosquitoes breeding within the body of water (but not the mosquitoes that choose to breed elsewhere, since mosquitoes may actually refrain from breeding around fish, as they can smell the bacteria on their skin).

It's worth mentioning that fish will not control mosquito populations anywhere but the pond that they're swimming in. Since pregnant female mosquitoes may actually avoid ponds with fish, mosquitofish won't necessarily eat all of the mosquitoes before they transform into adults. Many mosquitoes will simply lay their eggs elsewhere, so that the larvae will have greater success reaching maturity.

 

[Wayfarin]

Interesting subject- thought I'd add a couple thoughts.

It is possible to find fish that you didn't place in your pond- sometimes fish eggs get stuck to the feet of aquatic birds, which can act as a sort of fish delivery service.

Also, although goldfish fierce predators, they vacuum things into their mouths when they feed. So they probably just suck in the mosquito eggs, rather than actively pursuing the larvae.

I am in Western NY, and the Gambusia is forbidden. Which seems a little odd, since Gambusia holbrooki are native in Pennsylvania.

Welcome to the Garden Pond Forum!

You could try rosy red minnows/fathead minnows (Pimephales promelas) as an alternative. And they have the added benefit that they aren't anywhere as aggressive as Gambusia.
Being so small, they are more likely to notice the mosquito larvae than the mature goldfish are.

 

[hamstermann]

I thought Gambusia also jumped to eat the adults. Is that wrong?

 

[Wayfarin]

I thought Gambusia also jumped to eat the adults. Is that wrong?

I don't believe they do that. Perhaps an odd adult is captured at the surface after emerging or laying eggs, but that's about all I suspect.

Our pet Gambusia affinis has been fed crushed adults before. Their long legs seem to be annoying to swallow. They would be difficult to catch in midair.

 

[hamstermann]

I don't believe they do that. Perhaps an odd adult is captured at the surface after emerging or laying eggs, but that's about all I suspect.

Our pet Gambusia affinis has been fed crushed adults before. Their long legs seem to be annoying to swallow. They would be difficult to catch in midair.

Well that's a bummer. So it sounds like if I just want something to eat mosquitos, goldfish are just as good at it as gambusia. Good to know, thanks!

 

[JMJ]

Well that's a bummer. So it sounds like if I just want something to eat mosquitos, goldfish are just as good at it as gambusia. Good to know, thanks!

Not sure what your hardiness zone is, but Poecilia- sailfin, black and other molly species will eat mosquito larvae and graze on alga while not being aggressive like gambusia. They‘re usually available at fish stores. all varieties get a bit bigger than Gambisia and they’re a lot prettier and will be really showy when the males are courting females in a pond. The wild variant of sailfin molly is native to my area in zone 9b and they overwinter pretty well with the mild freezing we get every winter.

 

[hamstermann]

I'm in 7a or b, can't remember which. I had Mollies back in my aquarium days - the population explosions were crazy! Maybe the goldfish would keep their population down though. I'll research it - thanks!

 

[JMJ]

I'm in 7a or b, can't remember which. I had Mollies back in my aquarium days - the population explosions were crazy! Maybe the goldfish would keep their population down though. I'll research it - thanks!

They may actually keep one another’s populations in check. No problem!

 

[Wayfarin]

Well that's a bummer. So it sounds like if I just want something to eat mosquitos, goldfish are just as good at it as gambusia. Good to know, thanks!

I didn't say that.

Gambusias certainly have their pros and cons, but one pro that they have going for them is their preference for moving prey. Goldfish and other cyprinids are more opportunistic, and may need to be starved of fish flakes to be motivated to forage.

In my experience, mosquitofish are much more attentive than fathead minnows, which are easily distracted. I suspect that goldfish are the same, since they are always swimming around, rarely taking the time to patiently observe their surroundings.

Additionally, since adult goldfish can get surprising big, I'd worry that they might outgrow their preference for mosquito larvae. They might even prefer to prey on some mosquito predators, such as dragonfly naiads (the largest of which are too big for mosquitofish and minnows to bother).

 

[Wayfarin]

I'm in 7a or b, can't remember which. I had Mollies back in my aquarium days - the population explosions were crazy! Maybe the goldfish would keep their population down though. I'll research it - thanks!

Another option would be those medaka rice fish, which are becoming popular among aquarists. They are much more resilient than sailfin mollies to cold temps, and are much more colorful than mosquitofish (and nowhere near as aggressive).

And they are proficient predators of mosquito larvae.

Their only downside is that they (or at least the colorful ones) are expensive to replace if preyed on, and I'd imagine that they'd fall prey to an assortment of predators (goldfish, frogs, and even dragonfly naiads).

 

[GBBUDD]

I found out the hard way be careful what you wish for, i put a small school of minnows that are used as bait fish around here in my pond. Well without a predator in the pond things QUICKLY got out of control. Thank god the species was not cold water tolerant and when winter rolled in it took care of the population explosion

 

[bagsmom]

I have rosy red minnows and they do a great job of foraging in the shallows. I suspect that they are eating goldfish eggs, too - which is good and bad. The first year, they sort of exploded but now seem to be maintaining a manageable population. The pond is decent sized, so it seems able to handle the crowd.

 

[Wayfarin]

I found out the hard way be careful what you wish for, i put a small school of minnows that are used as bait fish around here in my pond. Well without a predator in the pond things QUICKLY got out of control. Thank god the species was not cold water tolerant and when winter rolled in it took care of the population explosion

What's wrong with the minnows in the video? They don't appear to be overpopulated or causing problems for the other fish.

Well, except for the fact that, upon close inspection, these "minnows" may actually have been golden orfe or ides (fish which can grow larger than goldfish and could easily overload your filtration system with their waste).

 

[Sisha]

Well that's a bummer. So it sounds like if I just want something to eat mosquitos, goldfish are just as good at it as gambusia. Good to know, thanks!

I enjoy watching my goldfish jump out of the water to catch mozzies. Even funnier when 2 jump after the same one