Freshwater Fish and Resources

There will be a substantial difference in the natural setup you will find in the field and the actual set-ups in your tanks at home. I knew that before my first collecting trip but also knew that I could make adjustments as I went along.

It is important to make observations in the field that can be duplicated at home. Some of the things you see you can not duplicate and some you can. You are really looking for concepts to duplicate and not actual details.

For example...the types of darters we like to collect are generally found in swiftly moving water which is flowing over some pretty substantial gravel. The gravel is not aquarium gravel sized stuff...it's big. The water is not merely flowing...it's actually pretty dawgone swift, sometimes hard to stand up in. The water is also cold to touch (generally in the 50s and low 60 F). Scattered across the bottom are larger stones the size of one's fist and larger. The larger stones seem to create eddies in the current which the darters learn to use as part of their unique style of motion...darting.

So we set up the tanks with some pretty impressive rocks and gravel...install a power head (AquaClear 301 in a 15...Otto 1500 in a 30) and keep the water flowing directly over the fish day and night.

The gravel that we observed in the field had a more angular edge to the stones...sharper if you will. While there were a few choices that exhibited such an edge, the rounded stones were chosen for their darker color and ease on the fish-keepers hands while cleaning the gravel. The sized however seemed to be universal in a number of collection locations where we have either observed darters or collected fish for the breeding program.

We put about 2 1/2 - 3 inches of the gravel in the bottom of the tank and then place stones the size of one's fist into the gravel base. On top of those we place a couple of handfuls of pebble about the size of a 50 cent piece along one side of the tank. The fish like to hide amongst the rocks, scooting from site to site through the rushing water

You can tell by the air bubbles in the next photo that the water is pretty swift...the O2 is probably pretty high and the fish are happy. Darters love the fast water and when they are content and happy you will find that they like to perch themselves on the tops of the signal rocks.


Because we live in a temperate climate, our summer temperatures don't normally get too high...but there are those times when the air temperature might be in the 90s or pass the 100 mark.  When the temperatures go up we reverse the time of day for the fish and set the timers to light the fishrooms during the nighttime and let the rooms go dark in the day. The room has fans and they blow all day and night. With the fans and the reverse lighting we seem to be able to keep the fish in good condition despite the high temperatures.

The reverse of the situation is in the winter. We can get some pretty cold temperatures but generally speaking it does not freeze in the unheated portion of the fishrooms. Those area are great for over-wintering the native fish. We don't heat the tanks in the winter and have had absolutely no problems with freezing.

 
 
(click on the photo for larger images)

Feeding the darters has not proven to be too difficult. While we are fortunate to be able to feed all of our fish live foods, we have found that these fish will take flaked foods on a selective basis. They are pretty picky when it comes to flakes but they will take them. We really doubt the ability to achieve any long term success with these types of fish without some sort of live food in their diet...probably the core of the diet.

You can count on the fish relishing mosquito larvae, daphnia, blackworms, live brine shrimp, baby brine shrimp, and Grindal worms. We have fed each of these live foods on numerous occasions. Even the freshly collected fish will tear into any of these foods.

We change water in the darter tanks on a very regular basis. Twice a week, the fish get a shot of new water...20% each time. The tanks all have sponge filtration and a powerhead for circulation. We use our standard tap water (sans chlorinates) and the water is about 110 ppm in general hardness and has a pH of 7.0.