Raising North American Killies
by Ray Wolff

If anyone is interested in trying some brackish North American species, I recommend pulvereus and confluentus, the bayou killie and marsh killie respectively. Others that are nearly as good are grandis (cocahoe - gulf killie), heteroclitus (mummichog), and luciae (spotfin killie). Xenica (diamond killie) are hit and miss. I had little luck with similis (longnose killie). I have not tried any others, except Floridicthys carpio (gold spotted killie), they didn't like me, but I hear plenty of people have success with them.

fundulus Pulvereus, male
fundulus Confluentus, male

All fundulus are secondary freshwater fish, meaning they derived from brackish/sale stock. They can all handle some salinity, and it is a great benefit in treating bacterial diseases. But many don’t require any special conditions.

The pulvereus and confluentus compliment freshwater topminnows in their ease of keeping. I keep them in ordinary tap water in tanks with dark gravel and lots of mops, filtered with sponge filters and 12 to 14 hours of light. I feed them mostly prepared foods of
different varieties. The temps range from 72 to 78 in no particular pattern. I find huge, hard eggs in the mops, usually near the knot. They are easy to pick and transfer to dishes to hatch. The babies take BBS immediately, as well as crushed flake foods. So hatching and rearing is a snap. Many eggs are laid in the gravel as well. These can be sucked up with a gravel vacuum into a ice cream pail. Let the water settle, then pour off the top slowly. Then hold it up to bright light and pull the eggs with an eye dropper. These can be stored in the incubation dishes with eggs picked from mops.

Grandis, heteroclitus and Lucania parva also tolerate ordinary water, or rainwater. Luciae require brackish water since they are susceptible to bacterial infections. I use canning salt or Instant Ocean and make it half the strength of sea water. I think it is something like 1.012 to 1.016 specific gravity or 21 ppt on the floating plastic needle box salinity meter.

Some easy topminnows I have played with include: chrysotus (golden topminnow), cingulatus (banded topminnow) and rubrifrons (red-faced topminnow). The blackstripe and kin are good too. Sciadicus (plains topminnow) are a bit more trying. Starheads are funny, I have had some that were easy, and then had the same species from another area give me trouble. Escambie (eastern starhead topminnow) were the easiest that I have tried. I have not tried dispar (northern starhead topminnow), since it’s endangered in Wisconsin. Probably the easiest one, ha ha. I have found zebrinus (plains killie) and diaphanus (banded killifish) to be the most trying of freshwater killies, and would suspect that waccamensis (waccamaw killifish) and seminolis (seminole killifish), being similar, would be too. Jordanella (Florida flagfish) is another one that is easy to keep, as long as it has a good diet of different greens. The lucanias (bluefin and rainwater killies) and leptolucania (swap killie -lemon killie - pygmy killie) are good too, but can be touchy since they are picky eaters. You will need an assortment of live foods if you want to give these a try. The studfish I have kept have all been tough customers, although I have kept catenatus (Northern studfish) from western TN with no problem.

All these fish will also do well in large ponds. Some need space or production of young is nil. If you are having trouble breeding any NA species, I would recommend a pond of 200 gallons or more.

These are my own opinions and recommendations. Hope they help anyone wanting to get into the world of North American killifish. If you have additional questions contact me: Ray Wolff, Phone: 715-424-0259, E-mail: choupiqu@wctc.net.