RE: NANFA-L-- minnow questions

Peter Unmack (peter.lists at)
Sun, 1 May 2005 13:54:28 -0500 (CDT)

On Sat, 30 Apr 2005, Crail, Todd wrote:

> I yet to see either genus for myself in the field (Todd needs to get out
> west),

Actually, Hybognathus occurs all over the place from the Rio Grande
across the Great plains, across the northern US states and down the east
coast. Macrhybopsis is more in the south from around Alabama to New
Mexico, but also occurs throughout the central region of the Mississippi
Valley and it's major tributaries.

On Sun, 1 May 2005, John Knight wrote:

> I've never kept Hybognathis (Just look too "dumb" for my taste), but
> have tried Macrhybopsis (aestavalis) on several occasions, with no
> luck. They appear to be incredably sensitive to oxygen depravation.
> Most have died in my holding tanks on the way home. The few I have
> managed to get to my tanks, just don't do well.

That is slightly surprising, we have had "M. aestivalis" in captivity for
about a year or so now and they'd done reasonably well without any special
care. The ones we have though are all fairly small, up to 2 inches or so.
They've mostly been fed flake food. I just have them in a bare tank. We
collected ours during hot summer weather in southern Oklahoma,-in-times
with a 2-3 hour drive home on top of it all, I didn't record water temps,
but-in-times it was feeling kind of warm on the feet (many of these
streams often get really hot by about lunch time, 90-100oF). I've found
that if you treat the fish really really nicely you can bring most things
home despite the heat (as well as trying to get out to collect in the
morning). Don't sit the seine on the bank, but lift fish out of the water
from the net-in-the edge of the stream so that the fish are nearly always
in the water, keep densities lower. I think for some of the slightly more
difficult fish some folks are just too rough, you can't treat them like
red shiner. I did briefly have Macrhybopsis storeriana (silver chub), but
they didn't want to eat anything and died. Others have reported good
success with this species though.

And the reason I wrote "M. aestivalis" is that their taxonomy is a bit of
a mess. There are actually 8 described and probably 2 or more undescribed
species in the genus and-in-least in the Plains they also hybridize making
it difficult to tell what you have in some areas.

Peter Unmack
Canadian River, Oklahoma
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