I would recommend setting up the 29-gallon tank for the
threadfin rainbowfish, likely Iriatherina werneri, as a
boisterous community of barbs and tetras would be too
nippy for this peaceful species with its delicate, flowing
fins. I. werneri hails from central to southern New Guinea and
northern Australia where it inhabits ponds, slow-moving streams,
and U-shaped bodies of water known as oxbows (or billabongs, as our
Australian readers would know them).
This species, which reaches only 1½ to 2 inches in length, is best
kept in groups of at least six with the gender ratio being one male to
at least two females. Mixing the sexes in this manner will encourage
the males to display their most striking coloration as they try to
impress the females. The exact pH and hardness values of the water
aren’t crucial, provided the extremes are avoided, but the stability of
water parameters is important for this species—as is keeping nitrates
and other dissolved pollutants to an absolute minimum. Performing
large weekly water changes will help in this regard. This species
prefers a stable water temperature that falls somewhere in the upper
70s to low 80s.
I. werneri’s natural habitat contains ample aquatic vegetation, so
a heavily planted tank with some open swimming space toward the
front is preferred. A subdued lighting scheme will really bring out this
species’ delicate colors.
The threadfin rainbowfish, which has a small mouth and very
narrow throat, feeds primarily on diatoms and tiny crustaceans in
nature. Good alternatives for captive specimens include cyclops,
daphnia, and even finely crushed flake foods.
A heavily planted tank with subdued lighting and fewer males than
females will allow the threadfin rainbowfish Iriatherina werneri to look
I have a 20-gallon planted aquarium that is becoming
infested with snails. I think some eggs must have come
in with a batch of plants I added recently. How do I
get rid of them, or at least limit their numbers? I don’t mind having
a few in the tank, but they’re starting to reproduce out of control.
Also, I’d prefer to avoid adding any more fish if I can help it, so if
you can recommend any methods that don’t involve adding loaches
or other snail-eating fish, that would be great.
Tropical Fish Hobbyist www.tfhmagazine.com