Don’t look now, but there are worms all around you. I’m calling
this article Worms in the Aquarium Part One
because the GSAS
meeting starts in one hour and I’m going to have to do this off the
top of my head.
Here we go:
There are two types of Tubificid worms (Phylum Annelida, Order
Oligochaeta, Family Tubificidae) which are raised and sold as fish
food.... the red Tubifex (Tubifex tubifex) which has been in
the hobby for about 100 years, and the black Tubifex which is a
similar species that is darker in color. The Amino acid profile of the
proteins in Tubifex is very good, but the Fatty Acid profile is pretty
bad. Therefore, fish fed Tubifex grow quickly but don’t show as much
color as they do deformities. The black Tubifex is hardier, more
resistant to desiccation, and less likely to cause disease in
fish. Before the advent of frozen Bloodworms (not really a worm, I’ll
talk about these later) Tubifex were routinely used as food for fish
that refused flake food and when people wanted to condition
their
fish, that is, fatten them up for breeding. Some pet stores sell
Tubifex as Live Bloodworms
which is a misnomer because Bloodworms
are the larvae of a type of fly. Because Tubifex feed on anaerobic
bacteria they can cause intestinal disorders in fish (food poisoning,
basically) and septicemia (which means blood-poisoning). Predatory
Cichlids such as Oscars can become quite ill after eating Tubifex
because they eat the worms regardless of whether the worms are live or
severely decomposed. Cichlids from lake Malawi and lake Tanganyika
crave these worms because they are a rare delicacy in those lakes. The
consequence of feeding live Tubifex worms to African Cichlids is a
disease known as Malawi Bloat
which is a severe bacterial
infection in the intestine (Malawi Cichlids have very long intestines
because most of them are herbivores). Tubifex were once commonly
collected in open sewers in Mexico because they thrive in polluted
waters with high aeration and good circulation. These days, most
Tubifex come from Worm Farmers or from trout or salmon hatcheries,
where they are collected from the race-way effluent. At one time these
worms were fed to small salmonids but this practice ended when it was
discovered that the worms served as a carrier for the intermediate
form of a sporozoan (Myxobolus) that is responsible for Whirling
Disease. Yes, this disease does occur in some tropical fish.
Steve Ward works behind the counter at B&D Aquarium in West Seattle. He’s also one of GSAS’s longest-running active members.