Andrew,
> One of the local killiphiles here in Canberra, who is without email access,
> asked me to pose this question to the list... He has bred quite a few
> Aphyosemion gardneri Akampa, and a fair percentage of the fry (approx 15%)
> are developing "pin tails", that is the caudal fin grows to a point, rather
> than the normal "fan" (bad term, I know) shape.
>
> He culls the pintails out, but they seem to be consistently thrown by this
> particular strain of Akampas. His question was, has anyone else seen this?
> Is it genetic, or environmental? This particular bloke is quite
> knowledgeable, he has hundreds of Pseudomugil gertrudae in his fishroom that
> he bred himself (quite an achievement, believe me!).
The only time I've seen what I would call 'pintail' (looks like pictures of the
pintail strain of guppies where the middle rays are the longest) in killies has been
when they've had velvet. This seems to occur from time to time in many killie
fry tanks if you're not absolutely careful about clean water. I've seen the
symptoms in a couple of species of Aphyo (or Fundulopanchax) fry. It can be cleared
up by adding some salt to the water and avoiding all uneaten food remaining in the
tank. Often some snails will help in this regard.
If it it is velvet then it would explain why culling isn't helping. Is this problem
occuring in adults or fry, BTW? If it's adults then you should be able to see
other symptoms of velvet such as a cloudyness on the body and in the pectoral
fins. I've only seen it develop to what I would call 'pintail' in fry, most commonly
at around 1cm or so in length.
Velvet can also be a hassle in Notho fry tanks and occasionally with Cynos.
Both seem to respond to salt addition. I keep a background level of about half
a tea spoon to 4 litres of water in all my killie tanks and sometimes double this
for Notho tanks. This level doesn't seem to harm snails or java moss.
If it's not velvet (isolate some affected fry and try adding some salt and see what
happens) then I have no idea what it is. Maybe it is a true mutation like the one
that occurs in guppys?
Later,
Andrew.