When it comes to really giving our fish the best care and giving ourselves the best chance at spawning a fish species there are two rules that I would choose to print on the front cover of every fish book and magazine.
- Rule 1. Do frequent and regular water changes.
- Rule 2. Feed a varied diet that includes some live foods.
Follow these two rules and you’ve covered 95% of what you need to do in order to successfully keep and spawn most fish.
Indeed there are certain species that do better and require certain water parameters and environmental considerations and it is to the advantage of all fish that we as aquarists seek out information and learn what these additional requirements may be.
However this series of articles will look at only one of these rules and hopefully give you some ideas of what you can do to satisfy the term, varied diet.
What does a varied fish food diet mean?
It is my opinion that varied diet does NOT mean feeding a can of flake manufactured by Tetra and then buying a container of HBH and feeding until that is gone and switching to different manufacturers with each new can of food.
Certainly there are nutritionally complete foods that are on the market and most manufacturers are responsible in offering flake and pellet foods that fish will live and grow on.
This is not an attempt on my part to discredit the suitability of foods that are offered to us by manufacturers. Quite the contrary, it would be a sad day for my fish and me if all flake foods were pulled from the shelves.
I believe that varied diet is a diet that contains foods that are rotated constantly and consistently with live, frozen, flake or pellet and fresh, natural foods.
Although, we have good intentions as aquarists in meeting this goal we often fall short, falsely believing that it is time consuming or expensive. Neither is true and with a series of future articles I hope to give you a few ideas that require little time and are inexpensive.
Understand your fish
The first thing you should do when deciding on a diet for your fish is to learn what the diet is in the wild. Most advanced aquarist manuals will give you a clue to what the species eats in the wild.
In general fish will break down into three groups.
- Carnivore / Piscivorous: An animal that feeds on flesh / feeding on fishes.
- Herbivore: Any animal that feeds chiefly on grass and other plants.
- Omnivore: An animal that feeds on both animal and vegetable substances.
Knowing any of these feeding habits of the species of fish you are keeping will allow you to give your fish a varied diet.
Also note that very few species are exclusive feeders. For example many African cichlids may be listed as herbivores, but it would be a mistake to put them with much smaller fish and expect that the smaller fish would not be eaten.
At the other extreme the Piranha is well known as a carnivore yet examination of stomach content of wild caught fish when dissected often reveals vegetable matter in the form of plant seed that has fallen into the river
If you can find no reliable information on the species that you are keeping, study the fish. If we remember just a few items of natural selection and adaptation of species we can gain some valuable clues.
Often, simple feeding habits of the fish in the tank will give you a strong clue as to what your fish eats in the wild. Mouth size and position can give us further clues or a well guessed confirmation.
An example would be the top feeders and from this broad group we could focus further on a fish that most of us have at least casually observed, the Hatchetfish.
Studying the Hatchetfish shows that it has a small mouth located high on the jaw.
What does this tell us?
Not much by itself other than it’s probably not going to be eating Oscars in one bite. It doesn’t by itself tell us that this is a carnivore, omnivore or herbivore.
However watching the Hatchetfish further will show us that this is a species that spends most of its time hovering very slightly below the water surface as if waiting. If we take this information and combine it with what we know of mouth shape and placement, we have the clues we need to make an educated guess at what this species eats.
We can fairly surmise that the fish is waiting for food as it hovers below the surface and it will feed at the surface. There are not going to be many tiny fish falling onto the surface of the water, therefore we can safely assume that it is not primarily piscivorous.
What then would most often be on the surface of the water that could be assimilated as food?
We could safely conclude that this species is primarily a carnivore. If we wanted to keep this fish in the best of health we would want to be sure that it’s diet was heavily supplemented with insects.
To wander a bit off the subject, I believe that only one species of Hatchetfish has been successfully spawned. If I were to seriously set out to spawn one of the unspawned species, I would make exhaustive studies of not only the water parameters in the wild but probably just as important, I would make an all out effort to learn what insects are native to the area.
In particular what insects lay their eggs in water and what time of the year this is done and does this correspond to any particular breeding season of the Hatchetfish species.
It may not be that the adult fish need the insect to breed but that the fry need the larval or freshly hatched insect as part of their diet, to live. Is it during a dry period or during traditional wet seasons. The ‘hard’ fish to spawn are usually the ones that we have to satisfy some particular requirement that will always fall into either environmental/food or both.
Study your fish and watch how they eat.
- When there is no food in the tank do they seem to pick at the glass or rocks?
- Do they hover at the top?
- Do they appear to hide and lay in wait as an ambush type predator?
- If you are using a power filter, do they spend a lot of time in the current of the overflow?
These are all valuable clues that can help you determine the foods that are most often eaten and found in their natural environment and the foods you can feed to keep your fish their healthiest.