Several different foods suitable for marine livestock could be used for overall feeding and this variation is a good thing, as it increases the chances of fish etc ingesting all that they need. Whatever food is used, it should be marked as ‘marine’ – flake food for example. The aquarist should ensure that particular livestock receive sufficient natural foods, such as algae, if this is important to their well-being.
Most aquarists feed frozen and flake foods. The flake is rich and good to use provided overfeeding doesn’t occur. The same point about overfeeding applies to frozen foods as well, but not the richness. Frozen foods are very useful and it is good to include them. Mysis shrimp is an example.
Another frozen food that could be used, in addition to any other flake and frozen type to increase the food base that is being offered, is brine shrimp. It would be unusual to find a frozen food supplier who did not stock this. The shrimp are in flat packs made up of ten or more blisters, and each blister is designed to be removed individually. Once removed, if necessary it can be further reduced in size as the blister portions are easy to cut when frozen. Then the food can be placed in a small container such as an egg cup and some RO (reverse osmosis) or seawater added, after which it should be left to defrost. Defrosting should not be speeded up by using a microwave or hot water as it has been reported that the nourishment value of the food is reduced.
Once defrosted the water that the food is in should be drained off as far as possible before the food is put into the aquarium, where it will be caught by the seawater currents and float off. It shouldn’t last long – fish find it attractive.
I am not a food specialist in any way. What I understand from reading is that frozen brine shrimp is not particularly nutritious, less so than mysis shrimp for example. In its basic form from frozen it has good roughage value. The food can be nutritionally enhanced when it is alive by what is fed to it, and brine shrimp that has been reared in this way is often described as ‘enriched’. One of the foods that could have been fed to achieve this is spirulina algae. This could be stated on the package.
Brine shrimp does not have to be used from a frozen state, it can be fed live. Many local fish shops (LFS’s) supply them live and pre-packaged, though in my area the availability has diminished a great deal. When purchasing them in this way, have a look at the package – usually a clear plastic bag – and ensure they are alive. There’s not much point in paying for live when they’re not.
Another way of obtaining live brine shrimp is for the aquarist to produce them. This is not difficult. What are required are agitated salt water (some from a seawater change perhaps), a suitable container (containers designed for the purpose of breeding brine shrimp are available) and brine shrimp eggs. The eggs go into the container and after a while very small shrimps appear. These can be recovered by a fine net or even a pipette type device. All instructions are with the container. Some containers are a complete kit.
If the aquarist requires bigger brine shrimps they will have to be fed and grown on – once the egg-sac has been consumed feeding is required.
I used to produce brine shrimps and quickly learned that when the instructions advise ‘a small pinch of eggs’ that is definitely what is required. At first I put in too many eggs and ended up with far too many shrimps. I also used to put them in the aquarium when small, just as the egg-sacs had been more or less used up. The fish I kept, which were small, used to eat them as fast as they could, and even some of the corals, such as toadstools, used to tuck in.
I had the ‘brilliant’ idea of dispensing with the breeding container and put the eggs directly into the aquarium – it contained warm moving salt water after all. Unfortunately this was not successful, and I put the failure down to insufficient turbulence to move the eggs.
I now use ‘enriched’ frozen brine shrimp among the other foods that I feed, which includes other frozen varieties and flake.
Brine shrimp is fine for the marine aquarium, but needs to be mixed with other foods and not be the only food. When I say mixed with other foods, I do not mean literally. Brine shrimp could be fed for one meal on its own; the next meal could be flake, the next mysis shrimp, the next flake, and the next brine shrimp again. There isn’t any reason why the number of varieties could not be greater. Advanced aquarists sometimes mix different frozen and flake foods, divide them into portions, and freeze them. Others try fresh foods mixed and freeze them.
Brine shrimps are very good for enticing reluctant feeders to eat- maybe a new fish has been added. They swirl around in the currents and the majority of fish chase them, and hopefully the new fish will join in once its initial shyness has gone. They are also captured by some polyps and ingested.
Brine shrimps are a good addition to the food arsenal kept by the aquarist. Frozen is the usual type used and this is understandable = just pop them in a box with the other frozen fish foods and store them in the freezer.