|
|
Editor's note: This is an excerpt from a letter sent to Gary Craven by a friend.
One story I wanted to relate to you since you're the vice-president of the Central Iowa Water Garden Association. I sure your already aware of how careful you have to be when introducing different species to your garden pond.
My son-in-law brought back with him, from a fishing trip to Southern Missouri, a Studfish, and a Mosquitofish. The Studfish, or Killifish (topminnow), is supposed to feed on insects and invertebrates found on the surface. Its jaws are grooved, which allow them to separate and extend. They are in the family known as Cyprinodont, which translates to "toothed carp" referring to their many small teeth on the jaws.
As you can see, I did some research on this fish. Unfortunately, it was after it caused trauma to several of my goldfish. A few weeks after the Studfish was introduced to our pond, I started noticing some of the goldfish had damaged scales. I thought it was ick. I took one of them to a local tropical fish dealer, who told me it was not any disease, but trauma. He suggested it was caused by Blue Herons who have become very common in our area lakes, and have been known to visit garden ponds and have eaten their fill of fish (they can eat 30lbs of fish a day). By that time, I had already removed the Studfish from the pond as a precaution.
I never saw any signs of a Blue Heron getting in my pond, and the damaged scales on the goldfish have healed. None of them died. I'm now sure the Studfish was the culprit all along.
That brings us to the Mosquitofish. It has not attacked any of our adult goldfish, but it is a livebearer. It's like a guppy, and it is very prolific. It can have several broods of young from one fertilization. I estimate we now have over a hundred of the little buggers. I read where they have been implicated in the disappearance of the plains topminnow from 11 localities on the Platte River in Nebraska within a few years after its establishment. Scary stuff. My next project is to try to rid the pond of these little guys without harming the goldfish.
At the risk of boring you some more, I must also mention I put in two 1 1/2" catfish when I first stocked my pond two summers ago. I bought my larger goldfish from a local bait shop, and the smaller goldfish were feeder fish I bought for 99 cents a dozen. Anyway, those two catfish (flatheads according to my son-in-law) spawned last summer. Out of the many, many baby cats from that spawn, three survived. The largest of the original pair (we think it is the female) is over 12" long now. It has actually eaten at least one frog, and we suspect, because our frog population never seems to go beyond one at any one time, she's eaten a few more.
Not being much of a fisherman, it never occurred to me that the reason the bait shop had goldfish, was that they are used for bait! And guess what kind of fish you catch with goldfish? Catfish!
So far, we don't seem to be loosing any of our goldfish. Many of whom were born in our pond. But the only fish that have reproduced in our pond this summer has been the mosquitofish. This could be because the size of our pond had stopped the proliferation. Or it could be the cats are now feeding on the young fish. Or who knows when they may start feeding on the larger fish. A possible ecological disaster in the making?
I'm sorry to be so long winded, but I'm in real estate appraising, and our workload has really dropped off since rates have increased. I'm the part-timer, so the full-timers are getting what little work is coming in right now.
I'll mention to Deb Spencer that you sent me her way if I see her when we visit her store in Lawrence.
Charlie