Blood worms are a type of food fed to freshwater fish species that are carnivores or omnivores. These types of fish need meat-based food; they will not thrive on plants or fish flakes alone. Your omnivore or carnivore fish species require a diet that is high in protein. Blood worms can increase the protein and iron in your fish's diet, though they are not usually suitable as a complete diet because they lack a wide range of amino acids, vitamins, and minerals.
Blood worms are the larvae of midge flies. They look like little red worms, and are about half an inch long. Blood worms are known to be a nutritious food source, and are full of protein. In the wild, these worms form a very important part in the aquatic food chain; as a result, blood worms make a very natural meal for your fish. They can be fed to nearly all freshwater fish; only those that are strict herbivores will not eat blood worms.
In the wild, blood worms can be found at the bottom of many stagnant ponds or even deep puddles. However, you should not attempt to catch your own worms by looking in such places. In the wild, they may have diseases or parasites that can't be seen; these can infect your aquarium if you feed the worms to your fish.
Instead, purchase your worms from an aquarium store or bait shop. Blood worms can be purchased frozen or freeze dried from most aquarium supply stores because they are one of the more popular fish foods. Blood worms may also be available as a live food in plastic containers. Although these are the most natural way to feed the worms to your fish, they cannot be stored for months at a time, making them impractical for most situations.
If you are trying to get your fish to breed, feed live blood worms rather than frozen or freeze-dried ones. Many fry fish will only eat the worms that are live and moving. Predatory fish that are used to eating live prey will also enjoy the live varieties rather than the frozen ones.
The downside of feeding live blood worms is that their life cycle is short, about 10-12 days in total. For this reason, live blood worms are usually only an economical choice for those with large tanks, many fish, or multiple tanks. Otherwise, the container of live blood worms may be too much for you to use up by the time their life cycle is over. In fact, you should plan to use any live blood worms within just 2-3 days of purchase.
Most aquarists rinse the fresh bloodworms before feeding, and avoid adding the storage water to their aquarium, because of the possibility that they are carrying diseases. In fact, this is a concern when feeding any live food to your fish. Feeding frozen or freeze-dried worms can help to alleviate this concern.
Though your fish may enjoy the live worms, most fish will also eat he frozen varieties. Frozen blood worms are most often found in small plastic trays with a foil cover. This type is the most common form of blood worms found in most aquarium supply stores. They are meant to be stored in your freezer, and can be kept for up to six months. These types of blood worms are usually preferable because they can be stored for much longer periods of time than fresh worms, allowing you to feed a little each day.
Each time you feed the fish, simply pop out one of the ice-cube shaped pieces of frozen bloodworms, and drop it into the aquarium. It will melt, softening so that the fish can eat the individual worms that make up the cube. If you have a small tank with only one or two small fish, you may want to cut the cube in half. Otherwise, it may be too many worms for your fish to eat at one time.
It is easy to overfeed your fish when using bloodworms if you assume that the cube size is the appropriate size for your aquarium. The usual rule of only feeding what the fish can eat in 3 minutes may not be appropriate for frozen bloodworms; depending on the temperature of the tank, it may take several minutes just for the worms to thaw so that the fish can eat them, even if your fish begin attacking the cube right away. The first few times you add blood worms to the tank, watch your fish as they eat. If there are many blood worms that fall to the bottom of the tank uneaten, you may want to feed a smaller portion next time.
Frozen blood worms also come in sheet form. These sheets allow you to easily feed varying amounts of the frozen worms. Break off a piece about the size of a quarter for a larger tank or one with many community fish. A piece approximately the size of a quarter is the right size for an aquarium with just a few fish.
The freeze dried type of blood worms is usually packaged in a small plastic tub. This dried food tends to be the least nutritional form of blood worms. As you use it, you'll find that the bottom of the tub is turned nearly to dust. It should be fed only to fish that feed from the surface of the tank, because it will never sink to the bottom. If you use freeze dried blood worms, re-hydrate them by soaking in water for 2 minutes before feeding them to your fish. They are the least nutritious type of blood worm, and should only be used when live or frozen varieties are not available.
Blood worms can be given as a standard part of your fish's diet, or as a treat once or twice per week. Though they should not be given as the only source of food, many fish will become very excited when you drop the blood worms into the aquarium. They may even begin to attack the frozen cube before the water begins to thaw the worms.