do mosquito fish bother goldfish?

[pafek]

I have noticed a recent change in the behavior of my goldfish- they used to zoom up to the surface of the water when I would feed them. Now they come up quickly, but then hang around the bottom of the pond waiting for food to sink. I have had a population explosion of mosquito fish (Gambusia) in the pond- are they bothering the goldfish? I have been scooping out the mosquito fish (I give them to a local pond store and I get free plants in return!), but there are still quite a few, and I really think they are ganging up on the goldfish at feeding time. Has anybody else had this experience? I like the mosquito fish since they, well duh!, keep the mosquito larvae out of the pond, but if they are too much of a nuisance I will have to get rid of a lot more! The water parameters are all fine, and the goldfish behave normally (swimming around) except when I feed them.

 

[springfield1952]

I've also got a sizable population of mosquito fish with koi and goldfish. In my pond, I haven't seen any strange behavior at feeding time. In fact, the mosquito fish don't pay attention to the feeding and both the koi and goldfish come right up to feed. I've had the mosquito fish for about 3 years now - our county mosquito abatement program put them in and things have been fine. I like the idea of scooping some out and using them for barter - clever!

Curt.

 

[addy1]

I had tons of those mosquito fish in my arizona pond, never saw a problem between them and the goldfish. They used to swim up the stream and back down.

 

[JoaniePA]

Do the mosquito fish contribute to any noticeable degree to the fish carrying load of the pond? I have 11 fish now and the pond is only about 1100 gallons.

 

[addy1]

Not that I noticed, but my pond was big around 14k gallons. They do poop so they do count.

 

[Waterbug]

I've never heard of or seen a problem between Mosquito Fish and other fish. I have heard of different fish eating fins and scales of other fish which is the only thing I can even think of that Mosquito Fish could do to other fish, but again, never heard of this being true.

A better guess might be a Heron or maybe raccoon bothering them and now not liking any big shapes above the water. When I've seen this it only lasted a few days and the fish started coming back up.

If they're eating at the bottom it would mean they feel OK.

Could it be the food? Mosquito Fish can eat flake food very well and so could really go after it. With pellets they have a harder time and so give Goldfish and Koi the upper hand.

Mosquito Fish population is strongly tied to food supply. It's one of the reasons they're so good at mosquito control. In a just a couple of days their numbers can balloon given food. I find it amazing. Without food numbers decrease slowly, larger adult remain and you see few tiny young. I think the adults might eat the smaller fish when there's no other food but I've never actually seen it happen. So I'd consider the type of food being used depending if you want more or fewer Mosquito Fish.

I assume a floating food is being used? You could switch to a sinking food, but I wouldn't. Wastes food and it's the Goldfish's job to come to the surface.

The larger the pellet size that the Goldfish can still take the better. They get more food and the less the Mosquito Fish get.

 

[pafek]

I did switch to pellets a week or so ago, on the same theory that it would be harder for the mosquito fish to eat, but the pellets I got were quite small. and the mosquito fish still gnaw away at them. Of course today the goldfish were back to being more aggressive- grabbing food from the surface, so maybe something did just scare them and they've gotten over it! Thanks everyone for the advice!

 

[Nova]

I don't have a problem with the mosquito fish in the school pond but a teacher wanted a couple to put in her aquarium with her one goldfish. After a week the mosquito fish had eaten the fins off the goldfish. The mosquito fish are back in the pond.