It probably isn't necessary for you to raise live food year round unless your are a die-hard hobbyist and you have fish that refuse to eat anything else. But you should be able to get through the warm months of the year feeding live food to your fish without much difficulty. I generally feed processed foods to my fish over the cold months, supplementing with newly hatched brine shrimp and frozen food. When it gets warm enough, I will go outside and start numerous cultures of mosquito larvae, brine shrimp, and daphnia. My fish will get live food supplemented with occasional processed flake foods until the end of the season.
Earthworms can be cultured indoors, in a large wooden box in a cold
basement, year round. There is commercially available bedding materials (in
the sporting goods section of most department stores), but dirt is essentially
what they live in. Earthworms don't like their dirt too moist or too dry, and
nothing smells worse than rotting dead earthworms -- so I no longer culture
them. I suggest you check out my sources for more specific culturing information,
and I'll stick to collecting my worms on parking lots only during spring, summer,
and fall... Just remember -- a clean worm is a healthy worm, so never take worms
from chemically treated soil. Earthworms can survive for several days submerged
in water in your refrigerator, which allows most of the soil in their gut to
pass through their system, so that you won't dirty your tanks as much. I usually
stick earthworms under very hot tapwater to kill them humanely prior to chopping
them up with a razor blade (or cutting large ones apart with surgical scissors)
to feed them to smaller fish, like killies. It is important not to overfeed!
Fathead minnows, and their pink (albino?) form, the Rosies, are so prolific
and easy to breed and raise that I'll say very little. You can have seemingly
limitless numbers of these fish, from very tiny up to 3 inches (7.5cm) in length
by placing a dozen or so in a garden pond which isn't too clear. Apparently,
they find each other and don't know when to quit breeding. Starting with that
small number doesn't seem to matter -- you will have thousands in a couple months.
Probably any species of minnow that can survive in a garden pond would work
just as well, but the rosies are nice because they are visible even in murky
conditions. The normal fatheads are not normally visible, but at least the males
change in appearance during mating, and almost act like cichlids. These fish
are available from pet and bait stores in the Northeast U.S., but I have no
idea where else they are available.
Green water is lower than pond scum. Actually, it IS pond scum -- infusoria.
It consists of various algaes and single-celled creatures, and if you hold it
up to the light and the solution isn't too dense, you may be able to see some
of these creatures (they are very small, but still barely visible). The best
way to make green water is to put old aquarium water from your fish tank into
a clear container and place it in a sunny window for a few days. Some sources
recommend putting a thumbnail-sized piece of dried lettuce to water and putting
it on the windowsill, and others suggest placing a handful of grass lawn clippings
in water and putting it on the windowsill. What I've found is that the windowsill
fills up really quickly! Seriously, all of the above will work eventually. If
your water is especially soft and acidic, you might find that the water greens
up faster if you add a pinch of baking soda (Sodium bicarbonate). Just be sure
you don't dump pH adjusted water in with sensitive fish.
Brine shrimp are easy to hatch, but a little harder to raise to adulthood
than most hobbyists will bother with. Hatching instructions will certainly accompany
the eggs, plus they frequently are listed with the popular brands of salt mixes
(both marine mixes and the various freshwater salt mixes). I've found that getting
large numbers of brine shrimp to reach adulthood is simple: do it outdoors!
You will need a large shallow container, such as a kiddie swimming pool. I use
rectangular, black, plastic containers which are marketed as lotus planters
or cement mixing tubs, depending on where I shop. They can hold about 25 U.S.
gallons (~90 liters). I usually dump whatever leftover brine shrimp culture
water I have indoors from my winter cultures into one of these containers and
place it in my garden in springtime, where it will get direct sun for the entire
day. If necessary, I will top it off with additional salt water, but because
my old culture water has some brine shrimp and plenty of unhatched eggs, I don't
need to add any eggs. In a couple weeks, this container will be teaming with
brine shrimp without any human intervention. Surprisingly, I normally don't
need to add additional salt, even though the container overflows from rainfall
fairly often.
Mosquito larvae are probably the easiest live food to obtain and raise.
You need to meet the conditions that mosquitos are looking for in order to lay
eggs, and they will do everything else. I've found that filling a garbage can
or a mixing tub with water, adding either a nylon bag of cow manure or just
dumping a couple handsful of dried chicken manure to the water and waiting a
few days is all that is required. Again, my stuff sits out in the middle of
my garden in full sun, but you may find better luck in partial shade. The water
turns brown from the manure and then probably green from algae. Then black from
all the floating mosquito larvae. Remember that the source of food for your
mosquito larvae is green water and/or bacteria feeding on the manure -- watch
what you get that water on, and wash your hands! Many people recommend rinsing
live food from such containers in a net under running tapwater before adding
them to your tanks. I usually bring a container of tapwater out to the garden,
net the larvae, and just put the larvae into the clean water (and say, "Close
enough!").
Daphnia, or water fleas, are a crustacean like brine shrimp (or lobsters,
for that matter). They have feathery, antenna-like legs which are used to pull
themselves through the water and at the same time scoop up infusoria and algae
for them to feed on. Daphnia species vary in size, the largest (Daphnia magna)
reaching just under 1/4 inch (~6mm) in length. The only difference between raising
daphnia and mosquito larvae is that daphnia will require calcium in the water
(in order to grow their exoskeletons). Mosquito larvae could care less about
calcium, so add a nylon filter bag of crushed coral to your mosquito culture,
and you will be all set to raise daphnia in it as well. That's what I do.
Sometimes, you get more critters than you bargained for in your live food cultures.
Not all of these are bad things to have. My daphnia and mosquito larvae cultures
always contain bloodworms (midge larvae), ostracods (seed shrimp or clam shrimp),
cyclops (another tiny crustacean), etc. Fine and dandy -- all things my fish
will eat. What has to be watched out for are more destructive creatures: diving
beetles and their larvae, the water tigers; water boatmen; hydras; damselfly
and dragonfly larvae; planaria; leeches; and snails. Some of these are fine
anyway -- some fish are large enough, bold enough, and just plain dumb enough
to chow down any of the above. However, baby fish in your aquaria have no defense
against a ruthless dragonfly nymph or water tiger. That's why it's a good idea
to really look closely at what you are trying to put in your tank BEFORE you
put it in! □
