>Mys, what species have you spawned with your reduced photoperiod method?
>
>
>
Pteronotropis: signipinnis, hypselopterus, & welaka* ( *needed some
extra help, of course, but conditioned well with this method )
Hybopsis: sp. unknown. A super common, plain silver, undescribed local
species.
Notropis: asperifrons, petersoni, something that looks like harperi but
isn't, and now my rainbows are turning blood red, ( although they're
recently wildcaught and apparently getting ready to spawn as a result of
the changes between their creek & my tank, which is probably similar to
what would have happened if I had done it the hard way )
Okay, so it's not a very long list, but so far the method seems to work
okay for me. I'm sure that some of these might well spawn without any
photoperiod manipulation, but I do it as a standard procedure. In all
fairness I have to mention that I've also failed to get results with
some species, such as Lythrurus atrapiculus. I'm pretty sure that most
Cyprinellas & Luxilus would also respond very well to this, but I
haven't tried them yet.
I had to sell my old chiller for emergency cash, but now I just run the
air conditioner in the fish room with the doors closed to get the temps
down to 60, which is as cold as my AC can go. I usually do all my
spawning in the spring anyway, taking advantage of the naturally cool
temperature. Of course, we didn't really HAVE a winter this year, and
it's made things a bit tough.
I suppose some experimentation would be in order to see if the temp &
photoperiod changes will work by themselves instead of in conjunction,
but I wouldn't bet on it. ( Spawning )hormone production is certainly
regulated by photoperiod, but without the correct temperature they still
won't spawn. Hmmm..... keeping them-in-the correct temp but changing
only the lighting might be a good way to measure the effects of
photoperiod, and likewise keeping the temp too low but adjusting the
lights might also reveal something. Or not. I sure wish I had more room
for experimental tanks, but I don't. Of course, I'm sure that this has
all already been studied in detail by researchers aplenty, so I wouldn't
think it would be too hard to find whatever they wrote about it.
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