help identifying fish?

I collected seven of these fish today from a sleugh off the Willamette river in Salem, Oregon. They are about an inch long with very streamline shaped bodies, a black strip through the eyes, and the body is basically a dull gray with mottled/speckled markings if you look real real close. Under the aquarium light they almost seem to have a yellowish tinge to them, but i am not sure if it is just my lighting or not.

i've been observing these fish for two or three months before i decided to collect them. They congregate within two or three feet of the shoreline in shallow water and in some cases only inches deep. The adults appear to venture into slightly deeper water. A couple months ago there seemed to be hundreds of them up and down the shore, but now the population has depleted to isolated pockets. I guess they are somebodies dinner.

The water bottom is covered in small pebbles and tons of loose sedimant that clouds the water with any movement, and there is heavy vegitation as well; Egeria and Myriophyllum and some type of plant that grows dense foliage above the water.

i have them in a 20 gallon long aquarium and they are staying near the surface in the rear, so it is very hard to get a photo, and my camera doesn't have much of a zoom.
Here is the best shot I could get:



I also saw moving around on the bottom along with these guys what look liked a pleco that i presume was some sort of sculpin. By the time i got my net out I couldn't find him any more!

so does anyone know what kind of fish this might be?

Gambusia affinis

Yeah, great, Dambusia in Oregon. The legacy of someone's great idea to introduce them there.

Robert,

Welcome to the forum! We're glad that you could join us and we hope that you find your stay both enjoyable and informative. We have a lot of good information here and we hope you can use it. To let you know, I agree with Will's identification of your fish. They look like Gambusia to me. Though in many parts of the U.S. Gambusia are invasive species, I did a cursory examination of your state's Department of Fish and Wildlife website and it looks like it should be OK for you to keep them. In fact, it looks like their use is encouraged in Oregon as mosquito control in closed systems. "Closed systems" being ponds or aquaria that have no inlet our outlet to a natural waterway. You can find some info about that out here. Still and all, you should probably check with your Department of Fish and Wildlife just to be sure it's OK to keep them. I'm sure you wouldn't want to keep a prohibited species in your tank! Anyways, welcome, and if you need help with questions to ask your Department of Fish and Wildlife, just let me know. My contact information is below. Welcome!

Brian

so they are not a native specie? They were introduced? Thats interesting. I wonder how they got into Oregon. oh thats the common mosquito fish! I didn't recognize the name. I'll be darned. I've heard so much about this fish in the past.

So i found an introduced fish amoung Egeria and myriophyllum, both introduced plants...

Edited by RobertHudson, 23 August 2009 - 06:14 PM.

so they are not a native specie? They were introduced? Thats interesting. I wonder how they got into Oregon. oh thats the common mosquito fish! I didn't recognize the name. I'll be darned. I've heard so much about this fish in the past.

So i found an introduced fish amoung Egeria and myriophyllum, both introduced plants...

Yep, gambusia. I've recently found them here in Lancaster County, PA as well. They had to be introduced as the lake I found them in has no inlets from other streams. I've noticed only the females seem to have that black eye stripe.

Dean