Answers to commonly asked killifish questions
Richard Sexton
>I have a few quick questions about Killifish.
>
>I know that they live less than a year in the wild (since they can't live
>without water), but how long do they live in captivity?
Bzzzzzt! Wrong.
This is the second most popular misconception about killifish. The
first is: "Won't these here killer fish kill my fish?".
At any rate, killifish, family cyprinodontidae can be divided into
1) Plant spawners
and
2) Soil spawners
The formers lay eggs in the middle or upper regions of the water, and the
eggs hatch "within a month". The latter lay eggs in the substrate (whatever
it happens to be - they have their favorite, but basically a horny killifish
is not a picky killifish) and the eggs incubate in this substrate (no, not
in the tank, you take it out and partially dry it) for 3 - 9 months.
Now, there are African (most killies are from here), South American (less),
North American, and Asian killies.
Only the African and South American continents are home to soil spawners,
(Nothobranchius, and <Cynolebias, Pterolebias and Rachovia> respectively)
and of these, only the South American soil spawners are TRUE annuals.
That is to say, they live in temporary bodies of water; typically they
have water, from the torrential rains from March to September. At this
point, the pond dries up, the eggs are safe buries below 6" of dirt,
leaves and peat moss like stuff. Time marches on, as it is prone to
doing, and nest March, the rains come back and the fish hatch out.
These fish will indeed die in captivity in about a year (8 mos @ 80 F,
16 mos @ 65 F) in spite of anything you or any other scientist does.
Now, the Nothobranchius of Africa has the exact life cycle, except that
they will survive in captivity for about 3 years if well taken care of.
So, yes, there are some killies that die in a year. South American annuals.
But, don't worry, they're hard to find, and you'll probably never see them
in a fish store. All other killies are easier to keep and breed than
swords.
>Since these fish breed by diving into peat moss and depositing eggs, what
>happens when you keep them in a tank with regular aquarium gravel? Do
>they not breed, or do they breed anyhow and damage themselves by trying
>to plough through the gravel?
South American annuals pretty much HAVE to have about 4" of peat (preferably
peat fibres) as they are "divers". The African annuals are "ploughers"
and will spawn in a little peat, or sand, or gravel ina pinch. No, they
don't hurt themselves doing this.
>What happens if you keep the males and females seperated? Do they live
>longer? Do the males become aggressive? Do the females become egg bound
>and die?
It generally makes sense to keep the sexes seperate as the males tend
to drive the females pretty hard. You can keep, say 1 male with 3 or
5 females and lots of plants, or, with some of the less agressive species
a bunch of males and twice as many females. Males by themseles aren't
terribly agressive (with some notable exceptions: Aphyosemion occidentale
and Aphyosemion deltaense). *I've* never seen an egg bound female. They
simply drop eggs if they haven't had a chance to spawn.
>Durring the summer, my tanks hover around 78 - 84 degrees. My guppies
>don't seem to mind, but how would killifish do? I realize that this
>would shorten their lifespan, but by how much?
Some killies like it warm. Aphyosemion gardneri and australe don't seem
to mind warmer water (82). Basically, the only ones that object to warmer
water is the species that come from the forest basement where light and
heat never get doen that far: Aphyosemion herzogi, bochtleri, raddai and
the diapteron group. Don't worry, these fish are extremeley rare and cost
more than a small Buick; you may never see them, even in pictures. Even in
heat, they simply refuse to lay eggs, they don't die. All of the others
can tolerate heat. They may not spawn till it gets cooler again, but, no,
heat doesnt kill killies. Heat makes aquarium maintainence a bit tougher -
less dissolved oxygen - faster reproduction rates for bacteria, so you
need to be concerned about those things, but heat, per se, is not bad
for killies. They're from equitorial climates.
>I won't even be able to consider raising killifish for a couple of months,
>since I'm going to have to move my tanks twice in the next month or so.
>I'm just trying to decide if they might be something I want to pursue
>later down the line. Is there some sort of killifish association, and
>could someone give me it's address if there is one? I know that there is
>a killifish mailing list, but that won't do me much good, since I'll be
>losing my account in a month.
Killifish mailing list: (1) kil...@mejac.palo-alto.ca.us
...decwrl!mejac!killies
Brian Reid runs it. This is why he no longer does the alt.gourmand stuff.
Somebody (heh heh) gave him some killies. No he longer has any time,
instead he runs around with spawning mops in one hand and a Model III
egg fertility indicator in the other, saying: "Oooh! Ooh! A fertile
wachtersi egg! The gods have smiled!"
To join the AKA, send US $19.50 (US $21.50 Canada and Mexico, US $32 Foreign,
US $ 44 Foreign Air Mail) to:
Ronald Coleman
930 Merrifield Place
Mishawwaka, IN 46544
For a subscription to "California Killi News" a joint publication of the
West Coast Killi clubs, mail $5 for years subscription to me:
Richard Sexton
Palos Verdes Killifish Ranch
2400 Palos Verdes Drive West #19
Palos Verdes Estates, Ca., 90274
--------------
Footnote:
(1) Even if you aren't interested in killies, but are a serious aquarist
you may want to join the killies list as a lot of stuff pertains to general
medium to large scale aquarium maintainence and breeding setups.
--
Richard Sexton
Oleg Kiselev
>South American annuals pretty much HAVE to have about 4" of peat (preferably
>peat fibres) as they are "divers".
This is not true. I use 2" of peat in a 3" diameter, 4" tall glass
container to spawn Cynolebias whiteii, which are 2"-3" long fish. More peat
does not hurt, but is not necessary. Garden peat works just fine, but it
must not have any fungicides, pesticides or fertilizers in it and must be
rinsed before use to wash out fine particles. Using a top cover with a large
hole cut out in the center on the spawning jar will make sure that the peat
stays mostly in and the food stays mostly out. For smaller fish even 1" of
peat will be enough.
--
DISCLAIMER: I speak for myself only, unless otherwise indicated.
"No regrets, no apologies" -- R.Reagan
Oleg Kiselev lcc!ol...@seas.ucla.edu, ol...@locus.com
(213)337-5230 ...!{uunet|att|ucla-se|turnkey|alphacm}!lcc!oleg