BREEDING TECHNIQUES FOR TROPICAL FISH

1. Choose fish that display good markings and color, that should produce attractive young.
2. Only use mature, healthy fish for spawning because unhealthy fish, if they will spawn, may produce unhealthy or deformed young.
3. Be sure that the pair is compatible. Many species cannot be put together in a breeding tank and expected to get along and produce young. In fact with many cichlids, pairs form only after a group has been raised together for months if not years. In certain species, one partner will bully the other to death if there is not compatibility.
4. Avoid crossing different strains or color forms because the young are often unattractive.
5. Make sure that the pair are both of the same species because hybrids are sterile. With some cichlids and Killifish, females of different species look similar.

Egg-scatterers: These species simply scatter their adhesive or non-adhesive eggs to fall to the substrate, into plants, or float to the surface. These species do not look after their brood and even eat their own eggs. These, often schooling, fish may spawn in groups or in pairs. Often there is a large number of the small eggs laid. The fry hatch quickly. Egg-depositors: These species deposit their eggs on a substrate (tank glass, wood, rocks, plants). Egg depositors usually lay less eggs than egg-scatterers, although the eggs are larger. Egg-depositors fall into two groups: those that care for their eggs, and those that do not. Among eggs depositors that care for their eggs are cichlids and some catfish. Egg-depositors that care for their young can be divided into two groups: cavity spawners and open spawners. Cavity spawners lay their eggs in a cave, while open (shelter) spawners lay their eggs on an open surface. These fish form pairs and have advanced brood care where the eggs are defended and cleaned. The eggs take a few days to hatch, and the fry are often guarded by the parents. Various catfish, Cyprinds, and Killifish make up the majority of egg-depositors that do not care for their young. These species lays their eggs against a surface, where the eggs are abandoned. These species do not usually eat their eggs.

Egg-burriers: These species usually inhabit waters that dry up at some time of the year. The majority of egg burriers are annual Killifish which lay their eggs in mud. The parents mature very quickly and lay their eggs before dying when the water dries up. The eggs remain in a dormant stage until rains stimulate hatching.

Mouth-brooders: Are species that carry their eggs or larvae in their mouth. Mouth brooders can be broken up into ovophiles and larvophiles. Ovophile or egg-loving mouth-brooders lay their eggs in a pit, which are sucked up into the mouth of the female. The small number of large eggs hatch in the mother's mouth, and the fry remain there for a period of time. Fertilization often occurs with the help of egg-spots, which are colorful spots on the anal fin of the male. When the female sees these spots, she tries to pick up the egg-spots, but instead gets a mouthful of sperm, fertilizing the eggs in her mouth. Many cichlids and some labyrinth fish are ovophile mouthbrooders. Larvophile or larvae-loving mouth-brooders lay their eggs on a substrate and guard them until the eggs hatch. After hatching, the female picks up the fry and keeps them in her mouth. When the fry can fend for themselves, they are released. Some eartheaters are larvophile mouthbrooders.

Nest-builders: Nest builders build some sort of nest for their eggs. The nest is usually in the form of bubble-nest formed with plant debris and saliva-coated bubbles (labyrinth fish, catfish), or a excavated pit in the substrate (cichlids). Nest builders practice brood care.

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.

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.

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).

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.

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" 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.