Breeding Saltwater Fish

Breeding saltwater fish can be a difficult process to be successful with. However, with the correct methods and strict attention to detail, you can successfully breed certain species in captivity, and even make an income from it if you wish.

Common saltwater fish that we keep in the hobby can be spawned readily in a regular saltwater home aquarium.

Mandarin Goby Pair

A pair of Mandarin Gobies, an incredibly difficult species to breed in captivity


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Butterfly Fish









There are certain essentials that you need to organize before you attempt to raise fry.

  • Broodstock. You are going to need at least one extra aquarium for larval rearing. The young fry won’t stand a chance in a community tank, and are difficult to manage and feed in a large display tank.
  • Live Food Cultures. You will need a constant supply of live foods for the young fry. Such foods include rotifers and phytoplankton.
  • Research. You’re going to need to arm yourself with as much information and as many case studies as you can. Having the knowledge prior to trying this will significantly improve your chances of success and will prepare you for any hurdles that you face (high likelihood with certain species).


In 1978, a study by Nakazono and Moyer and explains the breeding practices of the Centropyge interruptus, a species that exists in harems that contain a solitary superior male and up to four females. The harems display a pecking-order or ranked system of authority.

If the male is removed from the harem, the highest ranked female will transform into the male sex over an interval of around two to three weeks.

Breeding occurs in Centropyge interruptus (Nakazono and Moye) every day between May and October and appears to be directed by light conditions and temperature. Breeding won’t take place if the temperature dips under 22° C (72° F). Most of the breeding occurs between 10 minutes prior and 5 minutes following sunset unless it is densely overcast in which case the spawning will occur much earlier in the day.

The Bicolor Angelfish is rather easy to keep

A Bicolor Angel in a home reef tank

Breeding occurs in Centropyge interruptus (Nakazono and Moye) every day between May and October and appears to be directed by light conditions and temperature. Breeding won’t take place if the temperature dips under 22° C (72° F). Most of the breeding occurs between 10 minutes prior and 5 minutes following sunset unless it is densely overcast in which case the spawning will occur much earlier in the day.

Romancing comprises of circling and swift rushing of single females by the male. In the last phases prior to the actual breeding, the male shows a display of soaring where he swims high off the bottom of the tank over a female and then strikes an unmoving pose with all of his fins extended. Finally, the female advances close to the male and is embraced around the abdominal area by the male. This leads to an abrupt breeding burst in which sperm and eggs are released in unison throughout the open water. The eggs are light and drift to the surface where they are planktonic for an undisclosed period of time.

The Pomacanthus display various types of mating methods, which are dependent on the denseness of the population at the particular site. They will shape either stable pair bonds, harems comprises of a male guarding numerous females within a tiny area, or (in at least one breed) a big group congregating together to breed. In all methods though, these fish breed in couples.

Couples gather at the border of the reef at sunset, generally well over the substrate. They can often be involved in a romancing exhibition where the female and male swim in a quick head to tail rounding motion. Each pair will breed and climb into the water column, swimming in unison in an upward arc up to around 7 – 10 feet (2 – 3 meters) high above the substrate to eject pelagic eggs at the top. In the huge group breeding method, they are fairly promiscuous, and males will usually attempt to interrupt the breeding of conspecifics.

Adult Blue and Queen angelfish are usually found in couples all year round, so it is accepted that the female and the male have a celibate bond. Couples will breed by methodically ascending in the water column while uniting their stomachs, and discharging a generous number of sperm and eggs. A female is able to discharge eggs ranging anywhere from 25 to 75 thousand each night. This can tally up to as many as ten million eggs for the length of the breeding cycle. The eggs are pelagic and see-through, and float in the water column. The eggs will usually hatch in around 15 to 20 hours. At this point the pre-larval angelfish is connected to a big yolk sac, and has no useful fins. The yolk sac is immersed, and throughout this time the fish evolves into proper larvae and starts to feed on the plankton in the water column. Growth is swift, and after 3 to 4 weeks after conceiving, the fish will reach around 15-20mm in length and will establish on the bottom of the tank.

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Butterfly Fish

Marine Butterfly Fish are not freely sexed as females and males, as they do not display various color. However, there are a few species where the male may be bigger than the female.

The main visible difference can be seen in the bloated figure of a female a couple of days before breeding. They are known to have various social arrangements that are known to include schooling (most likely with group spawning) harems and monogamous couple bonds.

They are known to have various social arrangements that are known to include schooling (most likely with group spawning) harems and monogamous couple bonds. The reproductive behavior varies, and is connected to their life styles, which consequently is related to the quantity and distribution of food resources.

A Copperband Butterfly Fish

The Copperband Butterfly Fish

In the wild, diets differ widely among the various genera and comprises of zooplankton, live coral polyps and sessile invertebrates. Butterfly fish that are known planktivores have a food source that is unpredictable and short-lived, attributing itself to schooling fish, and they are assumed to breed in groups. Though butterfly fish that are corallivorous have a predictable and steady food source, they lend themselves to the guarding of territories in a monogamous or harem structure couple breeding. Monogamous coupling can be life-long with a few certain genera.

Butterfly fish have an extremely clear-cut breeding period, as it is related to a seasonable shifts (Dependent on the global location) where the water temperature is known to either rise or fall between 73° – 79° F (22.5° – 25.5° C). Aside from group breeders, a few species breed at their feeding area. However, there are also a few species that do a nomadic breed. These fish leave their feeding area at the conclusion of the day and make their way out to the edge of the reef where they set up a makeshift, smaller area. Here, they breed and then return to their feeding area at dawn. Females will breed once every night.

Displays of romance are known to be full of energy, with the breeding couple rounding each other head to tail, then pursing each other and also chasing away any intruders. Breeding ensues with the male under and behind the female as the couple ascend up into the water column, creating an arc. At the peak of the arc, many feet over the substrate, they discharge their pelagic gametes inside the water column. Sometimes, intruding males will try to join the breeding, ascending and discharging gametes in unison with the breeding couple.

The eggs are known to hatch anywhere between 1 – 30 days. Butterfly fish possess unusual larvae, referred to as Tholichthys, which have a spiny head. And are shielded by bony plates. These larvae will stay in a pelagic state for intervals ranging from a few weeks to a few months, and then eventually move into a benthic way of life as juveniles.

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Many Clownfish have been successfully bred in captivity. They are among the first marine species to be bred commercially. Most damsels and clownfish are substrate spawners, which means they lay their eggs on the substrate.

Generally, the male maintains and takes care of the eggs once the fish have bred. He will make sure they are fanned and guard them from predators. In order to breed them, acquire a couple or buy six or more of the variety you intend to breed.

This will ensure that you receive a female and male of the species. The highest success is attained if they are supplied a healthy host anemone that they will accept.

The Popular Clownfish

The most commonly known and bred saltwater fish is the Clownfish

Once they mature, after about a year or so, unless you purchase a couple, they will clear off a place close to the anemone and place its eggs there. The parents will tend to the eggs by guarding them against other fish and will constantly fan them. After around 8 days, the eggs will hatch around 1 hour after dark. This is so they have better opportunity of evading predators, even their own parents. From here on, the fry are alone and require baby brine or infusoria several times a day in order to survive.

It is usually advised to take out the eggs prior to hatching, and put them in a different aquarium dedicated to rearing the fry. Even then, a few of the small fry will die prior to reaching maturity.

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Damsel Fish

Unlike a few other saltwater fish species that are pelagic breeders, the Damselfish just like the Clownfish, are substrate breeders, which basically means that they deposit their sticky eggs on the substrate.

A male Damselfish will set up a territory and then prepare an area like a rocky ledge, a piece of rubble that has a smooth-walled fissure or a coral surface for the female to place her eggs on.

Once the breeding area has been arranged, the male will then attempt to draw a female into his region to place her eggs. The male employs various tactics to lure the female to advance, involving excited swimming movements and changes in color. In a few species uttering clicking sounds.

The pretty Azure Damsel

A vividly colored Azure Damsel

When the female enters the breeding are, she will lay up around 20,000 small oval-shaped sticky eggs on the prearranged smooth surface and then depart. The male will then rapidly fertilize the eggs.

Each mating and romancing process takes around 10 to 20 minutes and a male may persist to mate with numerous other females. In a few species, the male will look after the batches of eggs by blowing water over them with his fins, usually picking out and devouring dead eggs, likely to hinder a fungus from growing that could possibly threaten the entire batch. A few males provide no straight parental concern, other than to guard the eggs from predators. In all cases, the male will fearlessly and aggressively protect his area and the eggs from predators, even fish much bigger than himself.

The eggs will hatch in around 3 to 7 days. The larvae then floats away as plankton, feeding on the other phytoplankton and zooplankton for a few weeks, dependent on the species. A Damselfish can take around 2 to 3 years or sometimes longer in order to mature, with each species possessing its own time frame.

Amateurs have reported some success in breeding a diverse range of damsels in the aquarium. A few of these include the Blue Devil, Spiny Damselfish, the Fiji Blue Devil Damselfish, Domino Damsel, the Indian Dascyllus, Yellow-belly Damsel and the Yellow-tailed Damsel.

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Hawkfish are generally not sexually bicolored (Which means various sexes are unable to be determined by looks).

The Longnose Hawkfish, Oxycirrhites typus, is one exception to this rule, as the male has an extra black border on the tail and ventral fins. Hawkfish usually dwell in harems, with the biggest fish of the bunch being the male.

They are what are known as protogynous hermaphrodites, which essentially means that if the male is missing or killed, one of the females will transform in to a male to plug the gap. This is also presumed to be the case with Angelfish and Wrasses.

The Longnose Hawkfish

A Longnose Hawkfish in a reef tank

The hawkfish breed at nightfall. The male establishes an area which is comprised of 2 to 7 females. Every night around nightfall, he will visit each female on her coral block watching for the correct ones to romance. When he finds a fitting female, they swim upwards in unison in an arch discharging the sperm and eggs together.

Not a lot known about the eggs at this stage, which are presently pelagic, but it is implied that they spend around 3 weeks in this phase. The fact that they are pelagic for a long time is employed to clarify why they are so greatly dispersed around the ocean.

Though they have not been bred in the aquarium (with the Longnose Hawkfish being an exception), they will establish areas with the male and numerous females residing in a few different block or coral branches.

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Some information has been collected concerning the reproductive habits of marine Surgeonfish. Surgeonfish, alongside rabbitfish, are gonochoristic (Which means each fish is either female or male) instead of being hermaphrodites.

There are a number sexual variances in a few Naso species where the males are bigger than females. For the others, sexual dichromatism only occurs during breeding.

Breeding is bound to the celestial cycle, as a few surgeonfish will breed on a full moon and others around a new moon. A few surgeonfish are group breeders, with fish uniting from around the reef, usually in the late afternoon, building a big aggregate. Others such as the Zebrasoma species, breed in couples.

The stunning Kole Tang

A healthy Kole Tang 

The romancing comprises of males seeking out expectant females, and then altering their colors and conducting a twinkling movement in order to lure the female to breed. The couple rise together towards the surface in an arc shaped route, releasing their gametes into the open water in unison, at the peak of the arc. Males may breed with numerous females in a solitary session, whereas sexually mature females breed around once a month.

Following the hatching, the pelagic larvae survive on their egg yolk for a few days and on day four begin to eat plankton. They then start to grow into a specific larva, becoming more condensed, and growing thorns on the ventral and dorsal fins. Their bodies are have no scales, and are see-through with a silver color to the stomach. This post larvae state is referred to as ‘acronurus larva’, and is unmistakable to the Acanthuridae. As they age, the body turns into an oval shape, the spines on the caudal peduncle grow, and the thorns on the fins slowly vanish (except on a few of the Naso species and on the Blue Tang Paracanthurus hepatus).

The planktonic stage generally lasts around 10 weeks, after that the young will then establish themselves into a shallow reef. Although the behavior of the young will differ from species to species and with food availability, a few are very territorial at first. As they grow, a few species become less combative and start to roam wider regions of the reef in big schools.

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