ISBN 978-0-7938-0655-3 © 2008 T.F.H. Publications, Inc. Used with permission.
Worms are an excellent food source for fish. They are easily cultured,
reproduce quickly, are high in food value, and are eaten by fish from tiny
fry to adult stages. They are recognized as food immediately by most fish,
so even finicky feeders will take them almost as soon as they hit the water.
Their value as an easily recognized food is so universal that, as has been
noted, many predators have modified body appendages that appear wormlike and serve as lures for an unsuspecting fish. The fact that these predatory
techniques are present in animals that have survived for thousands of
generations is testament to the universal appeal of worms as fish food.
Grindal worms are small and white,
usually reaching a maximum size of
about three-eighths of an inch (barely
1 cm). They get their name from Mrs.
Morten Grindal, a Swedish hobbyist,
who first isolated these dwarfs from
cultures of their larger cousin the
whiteworm, or who collected them in
the woods near her home and began
culturing them, depending on the teller
of the story. Either way, she developed
the basic method for culturing them.
Incidentally, it is reported that she
actually named them mikroworms,
but when they crossed the Atlantic,
a nematode species already had a
similar name, so American hobbyists
began referring to them as Grindal
worms in her honor. This name is now
almost universally used by hobbyists
around the world.
Along with their small size, they are
prized by aquarists since they can be
easily cultured in small containers
at room temperature with no special
considerations. Anecdotally, they are
often said to be lower in fat than
whiteworms, and therefore can be fed
as a staple diet. This more likely results
from the fact that the fish eat a smaller
volume over time of these much smaller
worms than it does from their supposed
lower fat content.
Floating plastic worm feeders are ideal
for feeding Grindals to your fish.
• starter culture of Grindal worms
• culture containers (anything from
margarine tubs to plastic shoe
• culture medium for soil method
(straight peat moss, African violet
potting soil, commercial worm
bedding, or other acidic medium)
• culture medium for soil-less
method (polyester batting or
kitchen scrubby pads without soap)
• plastic needlepoint canvas
• cover for either method (opaque
plastic sheets, can lids work well)
• foods (cat or dog kibbles, fish food,
corn meal, baby cereal, oatmeal,
There are two main methods of
culture—one with soil and one without.
The method without soil has been
developed in the past few years and
has become wildly popular, as it is
much easier and much cleaner than the
method with soil.
Fill the culture container with
approximately 1 to 1. 5 inches ( 2. 5 to