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Re: MEP observations

Tyrone Genade wrote:

> 
> This is one for Dr. Watters and Co to work one but I think every 
> one can chew on it for a while.
> 
> Otto Schmidt gave Dirk and I a group of MEP (diff strains) from the 
> stuff he brought back from TAN.
> 
> I have just learnt that Dirk's has burnt out. Interestinly mine are 
> going that way too. Int he space of a week I have lost 2 of my 3 
> females and the 3rd is loosing weight rapidly in spite of my best 
> efforts.
> I can't speculate on their age.
> 
> Any ideas/comments?
> 
> Is the body clock of wild fish more fine tuned that captive stock?
> Was it the stress of the trip?
> Barry, Brian: are you MEP also dying?
> 

All of the N. melanospilus that we brought back from Tanzania this year
were relatively young, especially the Mvumi population where many of 
the specimens were barely sexually mature.

Wild-caught Nothos, unless they are very old and "on their last legs" 
when caught, are capable of surviving in captivity for remarkably long 
times. For example, I had numerous populations of N. ugandensis still 
alive and spawning in my tanks more than a year after we collected them
in 1999. In fact, I still have a spawning group of N. ugandensis (UG
99-5) collected from the wild about 16 months ago. And these were all
quite mature fish at the time of collection.

Many of the populations of wild Nothos that we collected in Tanzania in
1997 lived for well over a year and I had wild specimens of N.
fuscotaeniatus and N. albimarginatus that lived for more than 2 years 
after we collected them ! I have also had relatively "short-lived" 
Nothos such as N. orthonotus live for more than a year after capture in
the wild.

I don't believe that the body clock of wild Nothos is any more 
fine-tuned than that of captive bred specimens. In fact, in my 
fish-room, on average, wild specimens seem to outlive captive raised 
ones by quite a bit.

Getting back to the TAN '00 N. melanospilus, I have not experienced the
deterioration that you have. I have lost a few specimens as a result of
aggressive behaviour but those that have survived that are still doing 
well. Wild N. melanospilus can be among the most aggressive of Nothos 
and some are very difficult to keep. Even the females will shred 
and kill each other.

I don't think I can really shed any light on the problem you are 
experiencing (at least, not "from a distance"). However, some key 
factors to consider might be: 
1. Keep an eye open for overly-aggressive behaviour and separate the 
fish when necessary. Once a fish gets beaten up/harrassed beyond a 
certain point they may simply continue to go downhill regardless of 
what you do. You may have to be satisfied with a limited number of eggs
from the wild fish as a consequence of putting the sexes together over 
peat for short periods of time only. This is commonly necessary when 
handling the more aggressive species of wild Nothos.
2. Keeping large wild Nothos (especially the females) sufficiently 
well-fed can also be a problem. If they are on their own and not 
subject to the attention of the male(s) or having to compete with other
females, then this is not really a problem. However, in general, we do 
not feed our fish as well, nor as often, as they do in the wild. One 
only has to see the plump nature and healthy sheen on a freshly caught 
wild Notho female to realise that. Are you still feeding your wild 
Nothos flake food ?!? 
3. Also, wild fish will live much longer (and still spawn well) at 
relatively low temperatures - many of my tanks are at about 24 C which 
is quite a bit cooler than the temperatures of pools in the wild.
__________________________________________________
Brian R. Watters
Professor and Head
Department of Geology
University of Regina
Regina, Sask. S4S 0A2, Canada
Tel: (306) 585-4663
Fax: (306) 585-5433
E-mail: Brian.Watters at uregina_ca

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