Tag Archives: fish breeding

Live bearing fish in a home aquarium

In several other posts we have looked at fish breeding. We learned about fish that scatter their eggs and fish that hide or anchor their eggs. Fish that harbor their young within their bodies are called livebearers. This group of fish sometimes harbors the eggs in the mouth of the parent and sometimes in the abdomen.

There are about 4 species and a couple of sub-species commonly that are used in a fish tank aquarium. Included in this group are Mouth-breeding Betta, Moffat’s, Gunther’s Cichlid, and Black-chinned Mouthbreeders. In this method of spawning, the female drops her eggs and they are fertilized by the male. Then the eggs are picked back up and kept by one of the parent fish in the mouth until they hatch. The mouth of the parent is not only an incubation chamber, but after the young hatch, a place of safety to dash into in case of danger. Watching the young dash for safety can remind one of people rushing into the New York subway during rush hour.

Many more species of common fish tank fish retain the eggs within their abdomen, and include more than 20 species and several subspecies. Some of the more common to a home aquarium are the Guppy, Molly, Swordtail and Platy. Some of these species will inter-breed in captivity. This knowledge has given amateur and professional breeders a field day in producing many variations in colors and bodies that would not occur in nature.

Animals that retain fertilized eggs within their abdomens are called ovoviviparous. Eggs are produced and then fertilized internally by the male as he swims along beside the female, and the fertilized eggs are carried within the abdomen until they hatch. (This is not the same situation as found in mammals. Mammals not only retain the eggs, but set up a nourishment system from the mother to the young through the placenta. Ovoviviparous species simply retain the eggs and do not provide a maternal nutrition source.). Additionally, in some species the female fish can retain sperm cells for many months and as many as 8 broods have been produced from a single insemination.

As a general rule a well-fed mother will not eat her young. This does not say that other fish in a community tank will not feed on the newborns.

Fries can be produced and survive in a community tank. However, if the expansion of your fish population is your goal, a properly setup breeding tank will give you better results.

Related Posts:

Breeding fish in a home aquarium
Crustaceans and larvae as fish food
Fishing games—a sea of options
Fishing as a pastime for you and your family
More about egg-laying fish

More about egg-laying fish

By Rita:

In an earlier post I briefly described the most common egg-laying style of fish in a fish tank aquarium, egg scattering, and provided some insight as to why these eggs often did not reach adulthood.  In this post I will discuss some of the other egg laying strategies. Each group is presented in order of parental attentiveness to the offspring.

The egg scatterers have no parental interest in the eggs or the fry.  They are also likely to eat their own eggs after the spawn.

The egg hangers on the other hand are not as apt to eat their own eggs.   The spawning fish lay and fertilize each egg then hang them by a fine, sticky thread from plants usually near the top of the aquarium.  Beyond that there is no parental care.   This group of fish includes Lyretail, Panchax, Lampeye, and Rivulus plus others.  Most of this group is not common to the average tropical fish aquaria.  One of the reasons is they are among the more expensive fish. The expense is due to the fact that it takes more time and space for breeding. The female will lay up to 200 eggs over a 20-day period.  The young will then hatch in a staggered period according to the day laid.  This can result in a hodgepodge of growing fry.  The younger fry is in danger of being eaten by the earlier hatched larger fry.

Nest builders are the another group and they take a slightly more active parental role. The nest is first prepared either by sticking bubbles together or gluing aquarium debris into a nest.  The eggs will be deposited into the nest.  The nest is then protected until the eggs hatch.  Once the fry hatch they are on their own. The fish that comprise this group are the Sticklebacks, Siamese Fighting-Fish and Gourami.

The most protective of their eggs and off spring is the egg hiders and the egg anchorers.  This group consists mostly of Cichlids and Dwarf Cichlids.  It also includes Angelfish, Jack Dempsey and a few others.  As the group name implies the eggs are attached to a surface either secluded (the egg hiders) or in the open.  Both partners concern themselves with preparation of the spawning bed, the care and protection of the eggs, and the care of the fry for a period of time after hatching.

To leave a pair of spawning fish in a community tank is always a risk. A properly prepared breeding tank would greatly increase the chances of having viable young.