Heterandria formosa
by Tony Bernard
First published in the newsletter of the Hamilton and District Aquarium Society, February
2004
Aquarticles
Described in Hamburg, West Germany in 1912, H. formosa is the seventh smallest
fish known to man. Coming from the U.S., this little treasure is found in and around South
Carolina.
Males and females have the same markings, a colourless to cream body with a black
stripe down the lateral line. The caudal fin is transparent and there are faint vertical
markings in the body of the fish. The male's gonopodium is about a third the length of its
body. Sexing H. formosa is fairly easy because the gonopodium is visible at a
very small size. Females will grow to a length of 4.5 cm and the males will grow to just
under half that at 2 cm.
After acquiring a trio at our local club auction, I brought them home and put them into
a 5 gallon tank which was conditioned and running with a sponge filter. After hitting the
books I found that they prefer lots of plants, should be kept in a species tank and they
eat live foods - stuff like water fleas, brine shrimp, white worms, micro worms, you know
- the typical live food fanciers. While as luck would have it none of these things are in
my fish room, except for the vinegar eels and confused beetles hiding on the back shelf. I
would rather not work with the mess of the eels, so I picked out a few beetle larva and
watched them fall to their death at the bottom of the tank. Without any success with the
larva, I went to flake after a couple of days. It wasn't greedily accepted, but they ate.
I was lucky enough to find a large Java fern (Windelov variety) at another auction, and it
nicely filled my five gallon tank. The rest was now up to nature, and after a month they
were eating the flake and everyone's belly was nice and round.
I was surprised at how small the babies are - 5 mm was big for most of them. The female
will have her babies over a two to three week period, finishing up with around 20 young. I
think that she may have them continuously for close to a month. I have read that this
could go on for approximately 75days. My female seems to be having babies all the time,
there always seems to be lots of little ones about. They spend much of their time inside
the Java fern, till they reach the size of 1 cm, which takes about three months. They are
slow growing fish, but when you are only growing to 4.5 centimeters, I guess you don't
have to grow too fast.
With twenty five percent water changes once a week, everyone is doing well. I find that
I am quite fond of these fish. They are easy to keep and they breed regularly. It is
always nice to look into the tank and see countless little babies. Any one with a small
tank who is looking to fill it, should give formosa a try. You will not be
disappointed in this peaceful little fish.
|