Re: NANFA-L-- mummichog and Fundulus

Scott Davis (
Sun, 20 Aug 2006 18:58:51 -0700 (PDT)

They probably are mating. Slip down to the tank at the first strong light in the morning or when the sunlight might first strike the tank. A happy killie is a spawning killie. However, if they are not fed a copiously, they may return to browse on their eggs.

Also, you can put a female (the less colorful, less slim ones) in a jar and hold a flashlight up behind her. This "candling" of her will probably reveal that she is carrying eggs.

A number of eggs may be laid every day. A couple of hours after laying they are hard enough to pick. Any eggs, which crush, were probably infertile anyway. And, for no discernable reason, there may be a break for some time and then they will begin producing eggs again.

What do you have in the aquarium with them, which would be a likely surface to leave eggs? If you have plants and gravel, there are probably eggs in them. Do a good water change, feed them extra well - maybe include a few redworms and even nightcrawlers sliced to size and rinsed. (The fats and oils in creatures such as the earthworms, and on a smaller scale Daphnia, seem to especially have some of the fats and oils found in eggs.) Then pull your Fundulus out of that aquarium and give them a new home. In about two weeks fry should hatch. They should take newly hatched baby b.s. (bbs' food value is best up to a couple hours after hatching), sifted Daphnia (and whatever is growing in there - which here includes Cyclops, Ostrocods and Niad worms) and probably powdered flake food which could include some spirulina flakes. For a filter, the safest would be a big sponge filter or a box filter with the top off.

If you have a reasonably bare tank, you might try making some spawning mops using acrylic yarn. In the past we used pieces of styrofoam boxes, corks (always popular with wine drinkers) and even fishing bobbers as floats for the mops. Recently Bob McDonald and the Michiana aquarium society crowd showed us how easily old, rinsed, prescription bottles can float mops. When a significant segment of the hobby is graying, those are very available and my fish never suffer from high blood pressure. ;)

A number of folks will also leave some mops on the bottom of the tank. That is wise as alternative spawning sites and shelter for hard driven mates and fry. However bottom mops are also depositories for detritus and that can become a health issue if one is casual about tank maintenance.

One can fastidiously pick eggs and put them in a flat-bottomed holding container of seasoned water. For the first three days check and remove any whitish infertile eggs with a pipette or eyedropper. Of course one could take a mop of eggs and just toss them in a large container of water, like the rainbowfish crowd does.

Winding some yard around the book of your choice easily makes mops. (There is room here for a dig at whatever author you can think of, whose books might best serve humanity as something to wind yarn around.) The larger the book, the larger the mop. I would not skimp on material. Make sure that there are at least 100 strands in that mop. Wind the yarn around the book. Tie one end together. Take a scissors and cut the other and voila! There's the mop!

I usually assembly line the mop making, often in front of a ball game on TV. A whole bunch of medicine vials can be soaking in the meantime.

One old timer even had a mop tree. It was an attractively proportioned branch, which he had anchored on his lab table. He hung extra mops there to dry on winter days.

I boil them in the porcelain line soup pot my bride bought me (so I'd leave her kitchen stuff alone) when nobody else is in the house. That sterilizes them, boils out any extra dye and hopefully any other noxious substances. Boil gently or they get all twisted up with each other.

In the really old books, nylon baby yarn was recommended. It is very hard to find these days. Fish do seem to prefer soft yarn (or worn yarn) for laying eggs. It still wouldn't hurt to look for soft stuff. Stay away from natural fibers, go with the inert stuff. :)

For a good visual on making acrylic spawning mops, see:

Some months back, on the Livebearer Mailing list, it was suggested that mops could be used to shelter fry and harassed females. I read that and issued a Homeric Doah!

If you have flashlight tanks, (Dave Lain's terminology) rejoice! You now can have inexpensive "plants."

There is a 20-gallon tub in a sheltered corner of the back yard with a pair of F. notatus, some plants and pots trashed by the raccoons and about a dozen 1" fry. There is also some duckweed there for them to browse on. It is great fun dropping some Daphnia out of a mop into that tub. Don't trust mother nature to feed them so well there will be fry - supplement. The Daphnia are great because they forage and reproduce until eaten.

Small shiners are an interesting possibility as food. As we tell newbies to the hobby, If a fish can fit into the mouth of another, it will.

A couple of students who have even gotten out with us sampling, took a pair of Fundulus notatus home with them and via the mops in fairly bare tanks have about 20 youngsters coming up. Not much in the decoration/ alternative spawning site department in their tanks. Some rocks were added for the female to shelter behind. The male claimed the rocks as his territory and the female has the run of the tank. Go figure!

My buddy with the heteroclitus tank continues to skim fry, so with faithful feeding and hiding places that can be done there. And another Chicago area friend, who was out east rescuing killies from a bait shop tank, has set up some mummichogs too.

Someone on the East Coast can better access the commercial value, but F. heteroclitus are a common research animal, especially in studying the effects of pollution. I thing it was heteroclitus which went on a space shuttle mission and in zero gravity finally settled upon "up" as the direction of the strongest light. Theyre are also used as bait minnows and are undoubtedly important forage for all sorts of birds and larger fishes in the marshes and estuaries.

Christopher Coates, then a curator with the New York Aquarium, wrote a general aquarium book in the '30s or '40s. It continued to be reprinted well into the '50s. He did well by the exotic killies, considering what was known of them then and also recommended some of the natives. He was the one, I think, who mentioned that mummichogs were wrapped in only wet seaweed leaves and sold as bait. He also mentioned a scam where someone sold a bunch of them to the aquarium wholesalers, from whence they went out to the hobby (for a brief time) as high-priced African killifish!

There are now feral populations of heteroclitus on the western shore of the Iberian peninsula, probably courtesy of ballast water dumped by ocean going vessels. Ironically, they may spread to the north coast of Africa if they can negotiate the Straits of Gibraltar.

All the best!

Scott, an even worser speller but very thankful for spell checking.
Thorncreek drainage, on the way to Lake Michigan. too darn far from brackish marshes.

< I have this pair of mummichogs that I thing are mating how do you tell if they are or not?
Also are small shiners ok for feeding the mummichogs? Also what is the value
of small mummichogs?
Robert Nichols the bad speller
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