NANFA-- Etheostoma lawrencei with Eggs?

Mark (nanfa_at_jonahsaquarium.com)
Mon, 8 Mar 2004 22:43:59 -0500

Bob reminded me that I noticed some developments with my headwater
darters, Etheostoma lawrencei, that Geoff Kimber and I collected last
year. This is one of the newly described members of the orangethroat
"complex" (Does my throat look orange to you? Man, it seems like
it's taking on citrusey hue. Maybe it's just that orangethroat
complex creeping up on me again.) I think it was March 5th 2004,
last Friday, I noticed that the females were looking kind of plump
prior to feeding. Some of them had extended genital papillae (egg
tubes) showing. The interesting part is that these fish have been in
captivity for close to a year. I have done absolutely nothing to try
to encourage them to come into spawning condition. They were fed
erratically, the lights were on at all kinds of long, short and
inconsistent times. The temperature probably never fell below 65 F,
and was more like 68 to 70 for most of the time, since the basement
is heated and contains other tanks with electric heaters in them.
The only "natural" influence was the presence of two large windows in
this room. I'm guessing they are responding to the lengthening days
despite the fact that I often turn the bright room lights on to feed
after sunset and turn them off again after an hour or two. This
confirms a previous observation with captive rainbow darters that
spawned apparently in response to day length changes with no
significant cooling period. I think I will delay trying to spawn
these fish though, by putting them outside for a while in hopes they
will develop more eggs. They have either spawned already, or they
haven't really developed many eggs, since they are not nearly as
plump as wild females would be at spawning time.

Mark
Ohio
USA
<))><
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