Spawning tank

Spawning tank

Though some species readily spawn in the aquarium, the eggs or fry often do not survive because of predatory parents or other fish. Often the fry die because of unfavorable, unclean water conditions.

Many species that practice brood care will harm other tank mates in attempting to guard the eggs. Because of all these problems; most aquariasts who breed fish use a separate spawning tank.

The spawning tank should be like the hospital tank with protected heater so the the fish are not burned; a slow-moving filter (sponge filter), so the eggs or fry are not sucked up; and good aeration. Depending on the spawning method, the spawning tank can be set up in a number of different ways.

Egg-scatterers: Because egg scatterers often eat their own eggs, the spawning tank has to be set-up so the eggs fall out of the reach of hungry parents.

A 5-10 gallon tank is sufficient for spawning for most eggs scatterers.
For egg scatterers like barbs and danios, which lay non-adhesive eggs, the spawning tank can be furnished with a substrate consisting of two layers of marbles or a nylon netting just above the tank floor.

As the eggs are laid, they fall through the marbles or the netting out of the reach of the parents. After spawning is over, the eggs or the parents can be removed.

For egg scatterers that lay adhesive eggs like tetras, the spawning tank should be furnished with a substrate.

The tank should be planted with fine-leafed plants. The eggs are laid amongst plants, and adhere to the fine-leaves. The parents should be removed after spawning.

Rainbowfish also lay adhesive eggs, however, most species spawn continuously over a period of several weeks.

Thus, the eggs or the plants that the eggs are attached to, should be removed daily and placed in the rearing tank. Larger rainbowfish require a spawning tank of 20-30 gallons.

Egg-depositors: Depending on the type of egg depositor, the tank should be furnished differently.

For those egg-depositors that care for their young, the parents can remain in the tank after spawning. Substrate spawners, depending on the species, should be given a tank furnished glass panes, broad-leafed plants, or flat stones for spawning sites.

Some species such as Discus and Angelfish prefer vertical surfaces. For cavity spawners, flower pots turned on their side, coconut shells, and rocky caves are suitable spawning sites.

The tank should be furnished with either live or plastic plants to give the fish a sense of security.

Egg-depositors that do not care for their young, should be given a tank furnished with fine and broad-leafed plants, Java Moss, or artificial spawning mops. After spawning the parents or plants with the eggs should be removed. If the plants containing eggs are removed, new plants should be placed in the tank for future spawnings.

Killifish eggs often develop best when they are kept in a shallow dish.
Egg-burriers: A peat-moss substrate is one of the best substrates for egg-burying species. The peat moss can be removed after spawning and placed in a plastic bag to be stored for weeks to months (depending on the species).

A new peat moss substrate can be placed in the tank for further spawnings. In order to initiate hatching, the stored peat can be immersed in soft water.

Mouth-brooders: Ovophile mouth-brooders can be bred in the main aquarium because the eggs are protected in the mouth cavity.

However, it is better to separate mouth-brooders with eggs because of their potentially aggressive behavior. There are no special breeding tank requirements other than the usual tank set-up for the species.

Larvophile mouth-brooders should be placed in a breeding tank because the eggs are not protected in the mouth, but laid on a surface where the are open to predators.

Nest-builders: Nest-builders should be provided with material with which to build their nests.

For bubble-nest builders, fine leafed and floating plants should be provided, and the tank should have no water current to disturb the nest. Species that build nests in the substrate should be given fine gravel or sand.

Livebearers: Small livebearers can be bred in breeding traps where the newborns fall out of the reach of the mother. However, a more preferable set-up is a separate, heavily planted tank.

As the female releases the young, she can be fed so that she is not to eat the fry. As soon as all the young are born, remove the mother.


Stimulating Spawning

One of the best ways to induce fish to spawn, especially difficult-to-spawn species, is to simulate natural conditions.

Among factors that encourage fish to spawn are the environment, the food, and the rainy season.

Water Conditions:

The right water conditions are among the most basic requirements in spawning fish. Thus the water conditions should be similar to those in the natural environment of the species.

By following the suggestions under "breeding" or "water" in the species descriptions, approximate natural water conditions can be found. Another important environmental conditions is the the right tank set-up including hiding places, spawning sites, lighting, water current, and social conditions (schools).

Food:

The right foods are important to encouraging spawning. Without proper foods, natural conditions cannot be entirely recreated. Some of the live foods that often can make a difference in spawning success are mosquito larvae and fruit flies.

Stimulating the Rainy Season:
Many fish species spawn during the rainy season in nature. By simulating the rainy season in aquaria, difficult-to-spawn species can be induced to spawn. Rains affect the water chemistry, the water height, and the water temperature.

In order to simulate rainy conditions, the tank level should be reduced to half its normal height. Each day add 5% of the tank volume. The water added should be very soft and slightly cooler than the tank temperature.

To simulate the rain, use a drip system or spray bar for several hours a day and simulate storms by flashing light in a dark room. Thunder can be created by playing a recording of a storm, a recording of music with bass, or a recording of rattling thin metal cake pans.

The process can be repeated until the fish show signs of spawning preparation. In addition to the "storms," the fish should be fed heavily with mosquito larvae, shrimp, and flying insects.

This process will stimulate some hard-to-spawn species, but not all. Many species will respond to just one altered water condition, such as a series of water changes with soft water replacement, or a decrease in the water temperature.

Target Fish:

"Target fish" can be used to help strengthen the bond between a fish pair. Target fish can be another of the same species or a similar species that is placed in the tank with the breeding pair.

This third fish will serve as an object of the aggression of the pair. The pair will work together to chase off the target fish and not fight between themselves.

Only use the target fish method in a large tank with plenty of hiding places, so that the target fish is not harmed.