Freshwater Tropical Fish Care & Spawning Guide

Breeding Fish and the Home Aquarium

Many novice aquarium owners fail to take the possibility of their pets spawning into consideration. If you have recently purchased a larger aquarium you should keep the smaller one and use it as a breeding tank. Most tropical fish species are known for spawning in aquariums. Using a breeding tank will isolate the breeding pair and protect the eggs and fish fry from being eaten by the other members of a community tank after spawning has occurred.

Breeding Egg Scatters

Many freshwater tropical fish are egg scatterers. Egg scattering fish do not exhibit signs of parental instinct. They are notorious for eating their own future offspring.  Aquarists frequently add floating plants to their breeding tank to hide the eggs from predation. Another trick is to place a layer of marbles on the bottom of your breeding tank. Most fish eggs sink. The eggs will slip down between the rounded surface of the marbles and out of the adults’ reach. Either way, it is advisable to remove the adults from the breeding tank after spawning. Details on individual species spawning habits is available in our freshwater tropical fish care and breeding guide.

Breeding Live Bearers

Guppies, mollies and swordtails are live bearing tropical fish. They will eat their newly born fry. The best way to avoid this is by using a breeding trap. Breeding traps are inexpensive and readily available at fish stores. Breeding traps are typically transparent plastic containers comprised of two compartments. Place the impregnated female in the top compartment of the breeding trap. As the female gives birth the fry will drop through to the bottom compartment. After the female is done giving birth remove her from the trap. The plastic piece that separates the breeding trap into two compartments can then be removed to give the fry more room to maneuver. The fry can be kept in the trap while they are young. But remember that they are in an isolated compartment for their own protection. Replace part of the water with aquarium water regularly to keep it fresh.

Breeding and Brood Care

Cichlids are unquestionably among the most popular freshwater tropical fish to exhibit parental instincts as part of the procreation process. Oscars, discus, and angelfish are all South American cichlids. Cichlids have varied and highly complex breeding habits all of which include advanced parental care. Breeding and parental care fall into four basic categories in relation to initial spawning: substrate or open brooders, secretive cave brooders, and two types of mouth brooders; ovophiles and larvophiles.

·        Substrate brooders lay their eggs in the open.  They first clean a hard surface such as a rock or piece of wood to deposit their eggs on during spawning.

·        Secretive cave brooders lay their eggs in caves, crevices, holes or abandoned mollusk shells. They frequently attach their eggs to the roof of the breeding camber.

·        Ovophile mouth brooders use their mouths as incubators during spawning. The eggs will incubate in the mouth until they hatch. Free swimming fry may remain in the mouth’s protective custody for several weeks before being released.

·        Larvophile mouth brooders lay their eggs either in the open or in a protective enclosure like cave brooders. After the eggs hatch, the larva is scooped up in the mouth to develop into fry.

Mouth brooding is typically a maternal function in cichlids.  The male’s duty is to stand guard over the female or their brood to protect them from predators. Male’s become extremely territorial after spawning. A breeding tank will alleviate the territorial squabbles that are certain to occur in a community tank and safeguard eggs and fry from predation.

Breeding instinct and parental obligations do not stop once the fry are free swimming. Both parents will assist their brood in foraging for food, teaching them the skills they will need to survive on their own. Foraging and survival skills often include upturning leaves and rocks and digging in riverbeds or aquarium substrate in search of food for the fry to feed on. Parents and fry have actually been observed communicating during this learning process, both in the wild and in captivity. Communication between parents and offspring consists of a series of body movements such as shaking and fin flickering.

Cichlids are not the only freshwater tropical fish to demonstrate advanced parenting instinct as interregnal part of breeding. Many species exercise various forms of parental obligation to their brood after spawning. Cichlids were picked as general example of more advanced breeding instincts because of their immense popularity among freshwater aquarium owners.

Feeding Fry

There are a number of products available on the market for feeding fry. Liquid fry food, infusoria, or rotifers are among them. An economical and readily available substitute is powdered eggs. Some aquarium owners feed their fry hard boiled egg yolks that have been strained though a cloth or pulverized in a food processor. Still others simply use raw egg yolk. Whatever your choice, remember that fry are very small. They don’t each much. Over feeding your fry will only serve to foul up your aquarium water. Once fry are a week or so old, their diet can be changed to newly hatched brine shrimp or finely crushed fish flakes.

Tropical Fish & Commercial Breeding 

A number of fish species are raised on fish farms to keep pace with the thriving aquarium trade industry. Fish farms are of particular importance in providing freshwater tropical fish for the aquarium trade. These fish are raised in ponds typically located in the more tropical regions of the world, Texas, Florida, South America, and Asia. There are a number of benefits in purchasing fish cultivated in commercial breeding facilities as opposed to ones caught in the wild. Commercially raised fish are brought up in a smaller volume of water per fish than those found in nature. These confined conditions naturally boost the fish’s immune system. They have already been exposed to and developed immunity against a number of ailments common to home aquariums. These fish are conditioned from birth to receive food rather than forage for their survival. Consequently, they do not have to be acclimated to accepting standard aquarium food fare. Fish raised for the fish hobbyist industry are healthier, more disease resistant, and much less to apt to suffer the trauma experience from a species suddenly yanked out of its natural habitat. They are accustomed to functioning in an environment surrounded by other fish rather than the vast expanses often found in nature. Probably the most important aspect of purchasing a commercially raised product falls in the realm of ecological impact. You are not playing a role in further depleting our planet of one of its most valued resources.

A prime example is the bala shark.  These freshwater sharks are native to Southeast Asia. They inhabit the streams and rivers of Thailand, Borneo, Sumatra and the Malay Peninsula. The industrialization of these regions is threatening the Bala shark’s natural habitat. Their numbers have drastically diminished in the wild. Bala shark’s rarely breed in captivity. Fortunately, for their continued viability as a species, they are commercially raised in Asia with the use of hormone injections to help induce the spawning cycle.