Geoff, I have one word for you. One word. Are you listening?
Yes, Mr Fish-breeding-know-it-all.
Plasti- ...no wait, Daylength!
That's a word. I think.
OK, two more words: Bob Muller. Bob is a darter breeding expert. He has
covered the essentials in his email. But, I feel strongly that the
long-short daylength cycle is critical. Yeah, some fish might spawn
regardless, but if you can control the photoperiod to mimic short winter
days followed by lengthening spring days, you should be in the zone. Then
bring the temp up to near 70. If the females are plump with eggs, you
should have a spawn-fest. They might not get as plump as wild conditioned
fish, but that will just be fewer mouths for you to feed. I have observed
wild conditioned E osburni (a close relative of variatum) spawning in an
aquarium. I suggest you use a loose gravel like the red flint fine or
medium on the bottom. The actual spawning site will be unpredictable. I
am too lazy to pick eggs like Bob M does. I just cover the bottom with
gravel (I use an undergravel filter) and let them do it wherever they like.
Then, once the females have lost weight or you have observed the spawning,
remove all of the adults and wait. Hatch time will vary with species and
temperature. Three to five days is a good standard. The hatchlings will
be on the bottom until they absorb their yokes and then in the water column
after that. They will feed for a while and then drop out to their normal
bottom dwelling darter lives. They may be entirely invisible to you for
this whole time unless you have very good eyesight. The eggs will likely
be deposited in the gravel, buried shallowly and somewhat adhesive. The
fry will look like tiny slivers of glass drifting in the water. In a 55
gallon you will have to really hunt to see any. I have raised E osburni
fry on new-hatch Artemia (brine shrimp). So, hopefully, the variatum fry
will be large enough to take that too. Otherwise, Bob is the guy who can
suggest smaller feeds. I think it would be really great if someone can
produce this species for distribution. They are large and attractive in
the tank. Captive reared fish should be much easier to feed too. It
will likely take a long time to grow them, since they are so large as
adults. I have collected fry in New York in mid summer that were about 1
to 1.5 inches long.
If you have never seen one (not you Geoff!), here's a photo:
http://www.jonahsaquarium.com/picevariatum.htm
Mark
Ohio
USA
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