Mummichog (Fundulus heteroclitus)

[brewmaster15]

The Mummichog (Fundulus heteroclitus) is a really amazing fish. Its a very common tidal species of Killifish ..Found along the east Coast of North America. This fish is an incredibly important fish for its role in the food web. Its a popular bait fish for fisherman. Its also been widely used in experiments. It was the first fish in space having been sent on the skylab in 1973. Fertile eggs were also sent and were hatched in space. This fish can tolerate polluted water, temps from 43F to 95 F. It can tolerate huge swings in salinity. They can tolerate very low oxygen. It really is a neat fish. I've used it as bait many times and awhile back kept a few in a fishtank and they bred for me. One thing cool about them is they change colors dramatically in various lighting and backgrounds.. In my tank, the blues really shown on them.

I decided to keep some again.I want to breed them and see just how well they do in Discus temps eventually. I may even try them together though I'm pretty sure the Mummichog will be too active. Because of their ability to tolerate extreme saline swings, I was able to keep them in fresh water Tank last time. My goal is a repeat of that, With that in mind I netted a bunch last week while crabbing.. This time of year Mummichog are really common , they travel in huge shoaling groups. Literally takes minutes to fill a bucket. Using a bucket with an aerator I took them home and set them up in an outdoor tank and began my QT. I kept them in fresh water with salt added at 1 tablespoon per 2 gals water and decreased that over a week to less than 1 tablespoon per 10 gals. I treated prophylactically for external parasites using malachite green and then moving to seachem paraguard.. I recently moved the group to a 75 gallon tank where I will keep them for the remainder of the QT. From this group I will choose probably 30 individuals . The remainder will be moved to my outdoor 125 pond where I plan to try and over winter them..still thinking on how to best do that. Normally they overwinter in mud in upstream tidal pools. The ones I keep I will try and breed.


These fish are active non-stop. Photography was very hard and I failed miserably so far. I will need to work on that.. Excuse the poor pics.

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The tank has two aquaclear 110's on it and is sand substrate. To give them some shelter there is driftwood and a bunch of submerged Pothos and its roots.. No heater running yet,, Tank is around 73F ( room temp)

Its been interesting in that only a short time has gone by and they have learned who brings the food. I am currently feeding them freeze dried Blackworm fines and my discus Chow which they do like alot but I think I need to pick up an economy flake as these guys are insane pigs.

[Second Hand Pat]

What a cool fish Al Are they live bearing? They almost look like guppies in the first photo but not so much in the other photos!
Pat

[brewmaster15]

They are egg layers Pat..they lay adhessive eggs so I should be able to easily remove them from the tank If I provide spawning sites/mops etc.

[brewmaster15]

Info on the skylab fish experiment is here..
https://history.nasa.gov/SP-401/ch17.htm

[Discus Fever]

Sounds like they lay eggs like the rice fish.

[brewmaster15]

Sounds like they lay eggs like the rice fish.

Theres alot medaka and mummichog have im common. Very similar fish. Both tolerate a wide range of salinity and temperatures . They both lay sticky eggs and are prolific. The both also are used in lab experiments and the medaka was bred in space.

Al

[brewmaster15]

Medaka (rice fish) space info..
https://pubmed.ncbi.nlm.nih.gov/1154...t%20to%20space.

MEDAKA also were used for space boneloss studies..

https://www.nasa.gov/mission_pages/s...medaka_studies

[bluelagoon]

I lived by the ocean as a kid; I had a fish tank full of those. I remember the males being more colorful than in the pic.

[Willie]

...These fish are active non-stop. Photography was very hard and I failed miserably so far. I will need to work on that...

That's an amazing picture for fast swimming fish, Brew.

[brewmaster15]

Thanks Willie.. hopefully I can do a little better after they settle in.
Al

[brewmaster15]

I lived by the ocean as a kid; I had a fish tank full of those. I remember the males being more colorful than in the pic.

Mervin when I last bred them mine were as well... that tank had very different color background and substrate. I bet these will color up too in time. Their tank currently was a blackwater tank...and I have only had them a little over a week

[brewmaster15]

So quarantine on these fish really was important. I knew it would be. I was hoping that the switch from salt water to fresh would have helped with any external parasites as these usually dont survive the different osmotic conditions. My biggest concern though was oodinium ..aka velvet. That one is a tough bugger as it handles a wide range of saline just fine.. I put the kellys through a daily treatment of paraguard by seache.and then fmg(formalin malachite Green) . I upped the tank temp to 84 F to cycle through any parasites faster. The appetite and behavior of the fish was excellent but I could see tell tale signs of oodinium... cloudy fins and some flashing on some. The problem is two fold. One is the large number of mummichog in the tank make it easy to find a host. The other is the fish collected could be at several different stages of infection when collected.

For an active oodinium infection there really is only 2 choices of treatments that work.. Chloroquine Phosphate which is a newer treatment and very expensive. The other is copper. ..cheap.. effective and deadly if used wrong.

Tough call. I opted for copper. Theres two main forms of copper. Chelated copper like "copper safe" and Ionic copper like. SEACHEMS CUPRAMINE. I have used both in the past. I really really dont like copper meds unless absolutely neccessary. In fact, oodinium is really the only thing I would treat with them. Copper meds become more toxic as the pH goes down. My preference if using it is ionic copper... cupramine. I have a bottle of that from my last use many years ago. I didnt have a current copper test kit so picked one up compatible with ionic copper.

The tank these mummichog are in has a sand substrate that unintentionally buffers the water in the 7's . For copper treatment that was perfect. Im a week into copper treatment and the. Fish are doing fine. Because oodinium gets some of its energy from light I have the tank blacked out completely with black plastic. I let some light in for about 30.minutes in the morning when I feed them ..they are really keen on fdbw fines. A week.into the treatment and there fins are all clear... no losses at from the treatment. I think I was lucky and caught it early. Usually a tank with oodinium experiences significant losses even if treated successfully. Copper toxicity to the fish can be a problem too. Mummichog are pretty hardy fish and I think thats helped here.

Tank is still blacked out. I will be continuing this treatment for another 2 weeks just to be sure. SEACHEM recommend 21 days... which makes sense with oodinium because of its life cycle. It has several stages some being resistent to treatment.

Once this is all done I will try and pick 30 to keep...

Al

[bluelagoon]

Nothing to due with mummichogs and that parasite, but on the news just now, they have discovered Whirling Disease in a lake in British Columbia.