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Re: KillieTalk Digest V1 #4

 
>Subject: KillieTalk Digest V1 #2
>

> 
>
>If something upsets this balance then a situation will arise such as we
encountered at location TAN 97/36. At this locality, there were large
numbers of N. ocellatus (we were catching up to 8 specimens at a time with
each short sweep of a seine) and all except the very largest specimens were
basically starving and very thin. This was in spite of the fact that the
pool was also loaded with N. melanospilus (plus relatively small numbers of
N. janpapi and an undescribed Notho). The majority of N. melanospilus were,
in my opinion, too large for all but the largest N. ocellatus to be able to
eat. The large (actually enormous !) N. ocellatus were in superb condition,
no doubt because they could eat just about eveything else in the pool
(except for the 20 inch Clarius catfish !). What could upset the balance
leading to this situation ? A hatch of N. ocellatus that is too successful
leading to overpopulation ? This seems most likely. Late hatching of the N.
ocellatus (or early hatchin!
>g of the other species) might also be a factor.
>
Gentlemen,
Did you ever find a pool where only the N ocellatus were present ?
If there were many other species present for them to predate on , could we
assume that at some point the ocellatus might consume all the existing prey?
In that case they would definately turn on each other. This might account
for the thin specimens.
 Are you also observing any delay mechanism in the eggs as with other
Notho's . In this I mean do subsequent wettings produce fry after the peat
is redried?

As I recently mentioned to Brian , I have been keeping his N.melanospilus
Ifakara pop and have definately noticed this same phenomenon with this species.
The hatch can be quite large and if left together can result in a few very
large fish and no corpses.
We may have more predatory Notho's out there than we now are aware of.

Ted
Ted Klotz                                       Email:tpklotz at borg_com
9969 Bethel Rd.                                 Voice:(315)831-5682
Remsen,N.Y. 13438
U.S.A.