Last night when I checkd on my fish room I found the pair of Southern
Starheads - F. notti had been battered pretty bad by the single Eastern
Starhead - F. escambiae I had introduced last week. This tells me a
little more about the variation of temperments among these closely
related species. Though they may look superficially alike - esp the
females the F. escambiae had no difference and did not care at all for
their company.
Even more noteworthy is the fact that this fish (F escambiae) was a
female! I have since transfered her back to a tank of her own kind.
Fundulus notti is in many ways closer to F. dispar of the upper
Mississippi system. Especially the males which resemble more the pattern
and build of dispar. In these species the males seem to be slighter in
stature than F. escambiae and overall far milder in disposition.
The Eastern Starhead on the other hand is a very fast moving and
aggressive fish. The ones that summer out in my pond dart very quickly
between the lilypads much like they did in the Florida slough where Mike
Qusipe and I first encountered them in 1996 & 97. My own personal theory
is to suggest that pretty compedative environment in the wild (these
fish were found in the company of Gambusia and probably keep them in
check by preying on their young) and the ever present threat of
predation by Florida's abundant bird populations has honed these fish to
be lean and mean. Mean as in Cyprinella class - in reference to my
previous experience with the Cyprinid king of Nasty : the Satinfin
Shiner: Cyprinella analostana which litterally beat the crap out of more
delicate tank mates. Maybe they should be called "Satan Fins"! These
fish are almost evil. I would be tempted to nominate the Eastern
Starhead to the Topminnow monarchy of Nasty but it may very well have a
close contender that is also a close relative : the Lined Topminnow - F.
lineolatus. According to Mike Thennet who is working with stock he
collected in southern Virginia "these fish are really mean"! They even
proved problematic at getting along with conspecifics in his tanks!
F. lineolatus is also a southern species that no doubt shares many of
the pressures as F. escambiae. When you live in a jungle that is
seething with life as opposed to a system where life is less abundant
you have to be a fast mover and a go-getter to survive!
The fact that Eastern Starheads are very handsome and interesting fish,
combined with their hardiness and being easy to breed makes up for their
aggressive demenor. Also in a captive setting they can co-exist with
other species that perfer different levels of the water column. The
culprit in this case did not harm any of the Pearl Dace and Golden
Shiners in the tank nor the single native Banded Killifish F. diaphanus.
Jeff from PA
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