What stimulates a species to reproduce?
Homo sapiens do very nicely on 5 pints followed by a curry on a
Saturday night. But what stimulates our killies & what can we
do to induce them to spawn?
Pairing ratio. Do you have a pair or trio? A trio
comprising 2 females can prove difficult as the redundant female
can harass a spawning or eat eggs layed.
Water. Killies prefer soft water on the acid side. If you use tap
water on the hard side this could be your problem. Try rainwater.
If this is collected off glass or plastic it should be as good as
it gets unless you are in an area where airborne pollutants might
affect your water. Its not a bad idea to do a pH check first
to make sure its not too acid & buffer it up if needed.
Temperature. We all assume our fish come from warm climates.
Killifish are the most diverse group of fish known. Ranging from
the Argentinian pampas where climate is similar to the UK to the
Pupfish of USA where temperature exceeds our scale of what a fish
can live in. Many mountain Aphyosemion
for example only do well at 68F or below.
pH. In nature organic waste breaks down and releases trace
elements and tannins which are beneficial to fish. If fish are
kept in an alkaline environment and
slowly introduced to an acid environment this can induce spawning.
Light. Always overlooked but this can be a trigger to
spawn. Natural daylight is a great spawning inducer.
Water flow. Many
Aphyosemion are found in
fast flowing streams. To induce this scenario turn up the airline
to produce a water flow.
Food. Mosquito larvae are well known as a good food to induce
spawning. I consider them to be the best conditioning food.
Bloodworm is also good, as well as roe. Roe is a bit hit and miss
but is worth considering in conditioning a pair for breeding.
Remove all uneaten pieces.
Barometric Pressure. Another overlooked attribute to spawning and
a controversial one. Little has been written about this. Few
(including myself) believe this influences the onset of breeding
where a sudden drop in barometric pressure occurs. This is easily
observed by recording egg production daily. Observe production
prior to a thunder storm and just after and draw your own
Are they ready. We have all had fully grown fish
we could not induce to breed.I have found that
A. poliaki for example which
we raised on from a wild import were fully grown for months before
starting to lay. F2 fish from this collection are showing the same
pattern. Im sure we have all found this sort of thing in the
past. Perhaps the moral is not to give up on a species but to keep
trying different things and if all else fails keep them in good
condition and have patience.
How has this years collection been. My Spring pond has been going
well through to late July where it normally dies back around June.
My late summer pond has produced very little this year but in the
spring it contained a lot of glass larvae. Alan provided some
large Daphnia (possibly
magna) earlier in the summer
months which has produced a good crop of food to fill the gap.
Mosquito larva is in good supply this year which has been fed to
the fish at least twice a week. The Ps.
annulatus really go for them as they tend to hang out
under floating leaves.
As promised in a past issue I have
included photos just back from developing. I dont yet have a
digital camera but still have the utmost confidence in my trusty
panchax was the first killie I kept as it was imported
in quantity when I served my apprentiship in the fish trade in
1969. At the time all I could find was these and
Jordanella floridae. I was
pleasantly surprised when Alan presented me with a pair he bid for
at our Midland auction. As you can see by the photo the
outer (marginal and sub-marginal) bands go all round the caudal
fin instead of the usually imported variety where these bands
appear at the upper and lower edges.
panchax EXAME (Indonesia)
Another new population gained at the same
auction was Fundulopanchax mirabilis
intermittens Etuku which has a near solid yellow caudal
mirabilis intermittens Etuku
This one has proved
difficult to get eggs from but I think the problem here lies with
the size of the fish. Many years ago I had the same sub-species
and they grew to quite a large size before starting to lay.
intermittens grown on from eggs sent to me from
Sweden in the 80s.
Fundulopanchax I wonder if
members realise their are different forms of Fp.
gardneri nigerianus Gold. The differences are quite
easy to spot but I cant recall seeing photos of them
together for comparison. Currently, populations which have been
cracked to stabilise a gold form are Nsukka and Misaje (sometimes
referred to as the USA strain). To seperate them look at the anal
and lower caudal fins. Obvious (?).
gardneri nigerianus Misaje Gold
gardneri nigerianus Nsukka Gold
Not my best photos but they
do serve as a decent comparison highlighting the basic differences
between the two varieties. I have no doubt other populations will
be produced in the gold form in the future.
We all have to do it. I mean
take the other half and the kids for a break down the seaside. So
it was that I departed my home turf for that fair town of Swanage,
home of past conventions. Alan was entrusted with the maintenance
of my humble fish house for a week and as predicted did a great
job in keeping things ticking over, even cleaning out that big
tank I always meant to get round to cleaning. We are not all lucky
enough to have a killie wise fish keeper to look after our babies
in the holiday period and Im wondering how you deal with
this problem. A method shown by a member many years ago was to
leave the lid off jars of wingless fruit flies. The tank lids were
left ajar just enough for the flies to drop into the tanks. He
dropped the water level by 50% to help prevent the fish from
jumping out. Another member who lost fish through the good
intensions of friends decided to leave them to their own devices
for a few weeks and returned to find his fish alive but in need of
nourishment. At least the fish were alive to carry on breeding
once back up to weight. Your views.................
Have you ever browsed other Killifish
Association' websites only to find them written in their own
language? Many members are probably already aware of the software
available to translate this material into English. I use the
AltaVista site called Babelfish at
It's a free online bit of software which is easy to use. To
operate- firstly copy the text you want to translate and paste it
into the box marked Text- Text for Translation. Then click the
Translate button and in very short time (depending on the length
of the piece) the English translation appears. This can then be
copy/pasted to a word processor etc. Now if somebody could tell me
how to copy/paste a PDF file...