Friday, July 28, 2017

The Best Fish,... Unless You're A Mosquito ... Then It's The Worst Fish.

Here is my favorite fish on the planet.
Gambusia Holbrooki, or just plain "Mosquito Fish".

So why... with over 27,000 species of fish, would anyone choose a small, not very colorful, freshwater minnow-sized fish as their favorite?

I was hoping you'd ask.
Pull up a chair and let's talk.

Let's get this out of the way first... Gambusia holbrooki are considered an invasive species in Australia, New Zealand, and even western North America.
In fact, they are exotic and potentially (almost assuredly) invasive in areas outside the mustardy region in the map below.

For clarity, "exotic" means you are a species outside of your native range ... like peanuts, apples, peaches, and oranges.
"Invasive" means you are exotic and you are causing problems in the region you have arrived in ... like burmese pythons, walking catfish, hydrilla, and retirees from up north.
US auto-generated map
Map From USGS
I just wanted to acknowledge the fact that yes, if you take a small, aggressive, super prolific fish out of its native habitat and plunk it into an exotic habitat like Australia, you are going to have problems.

We totally get that here in Florida.

I am lucky enough to live solidly in the native range of this awesome animal and I plunk them into every water bearing location at Pure Florida HQ.

If it routinely holds water, from ponds, outside turtle tank, aquaculture tanks, wetland plant beds, wildlife watering holes in the woods, ... they all get stocked with Gambusia.
Why? Because these tiny fish love mosquito larvae, aka "Wrigglers".
It works too. 
I live beyond most county mosquito control spraying (thank goodness) and the adult mosquito population here, even after a record breaking rainy summer is extremely low.
The reason is most of their children never become anything but Gambusia chow.

Here's a video I made on the kitchen table to demonstrate a Gambusia's appetite for wrigglers.

I dipped a single female Gambusia from my aquaculture tank and placed her in a very small tank on the kitchen table. I allowed her an hour or so to adjust to the strange new situation, and then I introduced 20-30 mosquito larvae.

She didn't stop until there were none left.
I'm sure that if I had added more wrigglers she would've nailed them too.

Like my Labrador Retriever "Bear", I'm not sure if these fish ever get "full".

On top of a relentless appetite for mosquito larvae, Gambusia also have this trick up their fins ... they breed like guppies, in fact, take a look at them... they even look like guppies without all the fancy colors.

They are live bearers, or more correctly, they are "ovoviviparous", which just means that after mating,(the males have a specialized pelvic fin that functions as a penis). the females keep the eggs inside of her until they hatch, and then they are expelled.

They can breed multiple times throughout the year if the conditions are good, so a few Gambusia can go a long way.

There you have it, my favorite fish out of over 27,000 species.
For eating the most dangerous insect on the planet and helping to control it WITHOUT pesticides that kill far more than just mosquitoes, my choice for BEST FISH EVER is the tiny Gambusia.

Teaser: There's another reason for this honor also, but that's another story.

Soon come.


Lisa at Greenbow said...

What interesting little fish. I don't think I have ever seen one. I have heard of people buying fish to control mosquitoes so maybe this was it. I like the way the fish spit out what was unpalatable to it.

Anonymous said...

That Gambusia does a grand job on those mosquito larvae. Lucky you that you are in the native range of this hungry little fish!

Anonymous said...

I almost never have any mosquitos in my Ozark forest even though I have a lake and a pond (and a constantly wet acre below the leaking dam) that should breed larvae like crazy. Perhaps they do, but something is keeping the flying mosquito population in check. My guess is I have a healthy population of bats and nightjars and a vigorous patrolling population of dragonflies. (Now if I could just get the tick and chigger population under control.)

Gordon said...

That is totally amazing, especially interesting to me as I use to keep tropicle fresh water fish.
All the best and down with spraying, Gordon.

Alexandria Pest Services, Inc. said...

Thanks for sharing such an informative post.