By doing a quick online search you can usually figure out if the species of fish you are breeding will give birth to live small fish or if it will spawn. In this way you can understand if you need to look for a protruding and swollen abdomen in pregnant fish or for small eggs similar to jelly balls in the aquarium. If you are waiting to see the birth of new minnows, try to find out as much as possible about your particular species, since it will not be easy to raise the young if you are not an expert.
Steps
Method 1 of 3: Recognizing a Pregnancy and the Fry
Step 1. Follow this method for species that have internal fertilization and give birth to live fish
Guppies, Mollies, Swordtails and Platys are probably the most common aquarium species whose females "give birth" to live fry. The males and females of these species mate, after which the females form the eggs inside their body; within a month or two (for almost all aquarium species) the eggs hatch inside the abdomen of the female, which gives birth.
Search online for the name of your species to find out if it is fish that produce eggs (oviparous) or eggs are formed inside the body (viviparous)
Step 2. Identify the males and females
As a general rule, viviparous males are lighter or more vibrant in color and have a narrow, long anal fin in the lower area near the tail. The females have a more grayish color, with a triangular or fan-shaped anal fin. If you can recognize their sex, you can more easily understand if they are fighting (usually two males or two females) or if they are mating or preparing to do so (one male and one female).
For some species it is more difficult to distinguish the two genera and it may be necessary to consult an expert at an aquarium store
Step 3. Observe the mating rituals
Different species of fish behave very differently during intercourse, intercourse and other attitudes related to mating. In many species, as in most of the gouramis, the male chases the females in a very energetic manner throughout the aquarium, sometimes causing them to scratch, bite or other injuries. In other species, such as discus, the male and female cooperate together to defend an area of the aquarium from other fish. In both cases, when actual mating occurs, the male and female often grab each other, flip, twist each other, or make other difficult-to-see movements.
Step 4. Check for a swollen abdomen of the female
In viviparous species, the female swells in the posterior area of the abdomen. This dilation generally develops over 20-40 days, both in a large rounded shape and in a more "square" shape.
- Some species, such as the Molly balloon fish, have a more anterior enlargement, just below the gills.
- Among other things, know that overweight males can also develop a bulge in the front area of the chest. If the fish does not eat for two or three days, the swelling due to being overweight may subside, while the swelling of the female will be noticed anyway.
Step 5. Look for a red or black dot
The pregnant female often develops a "pregnancy spot" on the abdomen near the anus. This is often black or red in color and takes on a more pronounced appearance during pregnancy.
In some fish, this spot is always present, but it typically becomes brighter or darker during pregnancy
Step 6. Start preparing for the arrival of the new fish
Breeding baby fish, or fry, can be very difficult indeed and usually requires the need for a whole separate aquarium just for them, so that the adults or the water filter won't harm them. If you are not ready for the task, you should contact an aquarium shop or an experienced fish enthusiast who is willing to help you or get the fish from you. If you decide to take care of the fry, you can start by following the advice in the section of the article that deals with the breeding of young, but be sure to do a research on the specific fish species of your aquarium, in order to obtain the best recommendations.
Method 2 of 3: Identify Nesting and Egg Laying
Step 1. Follow this method for oviparous fish species
There are many aquarium fish that fall into this category, including discus fish, bettas and most gouramis. The females of these species lay hundreds of eggs, usually in nests prepared on the bottom of the aquarium, on the wall or even on the surface of the water. If, in the same container, there is a male, it can fertilize the eggs after having previously mated, depending on the species. At the end of the process, the eggs will hatch from live fish.
- Do an online search to find the name of your species and to find out if it lays eggs (oviparous species) or gives birth to live specimens (viviparous).
- Females of some fish species are able to store sperm for months before using it to fertilize eggs, so sometimes even if you have a female-only tank, they can still reproduce.
Step 2. Pay attention to the nesting marks
Some spawning fish create nesting areas to keep the eggs safe. These areas may look like small holes or piles of gravel, but they are not always visible. Some gouramis can form elaborate nests created by a mass of bubbles, usually made by the male on the surface of the water.
Step 3. Check for eggs
Some females of these species swell when the eggs develop inside them, but this is usually not a significant change and it doesn't last long. Once laid, the eggs often resemble tiny balls of gelatin that disperse in water, although in some species they gather in a mound in the area set up by the mother for nesting or stick to the bottom or sides of the aquarium.
Many oviparous species, including most gouramis, also have mating rituals. Often these are very energetic “shows” that can last up to a couple of hours and end when the eggs are laid
Step 4. Prepare for the moment the eggs hatch
Caring for new babies, or fry, can be difficult, but even if you are caught off guard, you will still have some time before the eggs hatch. Ask an aquarium shop if you are interested in raising fry yourself, as the procedures to follow may vary by species. If the minnows are born suddenly, consult the next section on breeding fry for basic advice, but do not assume that the method is perfectly effective for each species.
Method 3 of 3: Raising the Fry
Step 1. Research as detailed as possible about the species in your possession
What is reported in this section can give you the basics and some useful emergency indications to follow if the aquarium suddenly fills with young new fish. However, be aware that caring for fry is a real challenge and the more you know the specific characteristics of your animals the better.
- For more details on a particular species, read these tutorials so you will know how to breed and breed discus fish, gouramis, bettas and guppies.
- Ask the clerks of the aquarium shop for advice or find out in the online forums for enthusiasts. Generally, these are able to give you more useful news than pet stores.
Step 2. Replace the filter with a sponge one
If a water filter is installed in the aquarium that sucks it in or creates a current, turn it off and instead put a sponge filter that you can get at an aquarium store. Otherwise, the current could exhaust the young fish or even suck them into the filter and kill them.
Step 3. Separate the fish
Many fish keepers set up a new aquarium, in which they place their eggs or fry. However, if you are not particularly knowledgeable in this area and are short on notice, you may have a hard time creating a safe and stable environment for newcomers. Alternatively, to separate the fish, you can put a plastic net that divides the aquarium (you can always buy it in the aquarium shop). Depending on the species, adults can take care of the young, but sometimes they are predators instead, so try to find advice on the internet about the species you have. If you can't get news, decide how to separate the fry based on the behavior of the parents:
- If the parents lay their eggs in a nest and defend them from other fish, use the net to divide the parents and the eggs on one side, leaving the other fish on the other.
- If the mother has given birth to the young (viviparous) or has scattered the eggs in the water, place all the adult fish to one side of the net. Young fish should swim through the net to hide from them.
Step 4. Feed the fry
Sometimes you can buy a specific "fry" product at aquarium stores, but you often find yourself having to choose from a wide variety of other options. Infusoria, liquid fish food or rotifers are usually safe products. However, as the chicks grow, they may need other food which can vary depending on the species and size. Ask an aquarium store clerk for advice based on the species you are breeding.
If you can't get to the store, feed the fry with sifted and squeezed hard-boiled egg yolk through cheesecloth
Step 5. Establish a plan for caring for fish as they become adults
Set up a new aquarium in advance if you plan to keep some of the fry as they grow. If not, contact your local aquarium stores or other aquarium enthusiasts early so that you can arrange to sell or gift your young fish once they reach adulthood.
Advice
If you don't want the fish to reproduce, you need to separate the males from the females. If it is too late, go to an aquarium store that may take the fish
Warnings
- If your fish is getting fat, moving slowly, and looking shaggy, seek professional advice or visit a pet store. It could be a disease and not a pregnancy.
- Never release a fish into the wild, unless it was previously taken from that very same water source. Otherwise, you could unintentionally cause an infestation and a serious imbalance in the local environment.
- If you have not provided adequate accommodation for the fry, know that most, if not all of them will die.
