Breeding Goldfish – What Do Goldfish Eggs Look Like?

What do goldfish eggs look like?

Breeding Goldfish – What Do Goldfish Eggs Look Like?7 mins read

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Sydney Perry
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What do goldfish eggs look like?
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Goldfish have enchanted many beginners, and experienced aquarists will often know how to spot goldfish eggs from fish that are happy enough to breed. But what do goldfish eggs look like? As common as they may seem in the aquarium trade, there is nothing about the Goldfish that is common or ordinary. They are intriguing, intelligent, and sociable fish that make stimulating pets for both young and old.

Many individuals have delved into the notion of breeding Goldfish, whether for commercial, or personal purposes. But learning to recognize goldfish eggs in tank environments isn’t easy. Furthermore, it takes time to spot fertilized vs unfertilized goldfish eggs.

There are so many truths and myths regarding Goldfish breeding to unravel. Though they are easy enough to keep, breeding Goldfish is a more delicate process that will require time and plenty of patience. However if you are wondering ‘what do goldfish eggs look like?’ you have come to the right place.

What Do Goldfish Eggs In Your Tank Look Like?

Goldfish species information
Goldfish are found in two sub-categories namely, Ornamental, or Fancy Goldfish, and the Common Goldfish (pictured). Image from Flickr

Across many sources, it is found that Goldfish eggs are described mostly as looking like “small round bubbles”. Fertilized goldfish eggs will be clear, or a very light yellow color. They come with a tiny dark spot in the center of the egg. What’s more, they are very sticky and, thus will attach to a plant or spawning mop.

Female Goldfish are known to be able to lay up to 1000 eggs at once. This is sometimes in a single laying, or over multiple days usually a week. However, this depends mainly on water temperatures. You will notice that goldfish eggs change color, becoming much more see-through over a couple of days, if they are fertilized. On the contrary, unfertilized goldfish eggs remain the same color. So ‘what do goldfish eggs look like’ depends mostly on this.

The tiny black spots in the center of the eggs will become slightly more prominent in three or more days. These are the eyes of the goldfish fry (babies).

It is vital to keep the breeding tank water well oxygenated and aerated to prevent scum build up on the eggs, Methylene Blue or other water treatments can be used to achieve these results.

What Do Unfertilized Goldfish Eggs Look Like?

Are you wondering what do goldfish eggs look like when unfertilized? Or, how can you recognize unfertilized goldfish eggs? Goldfish eggs that are not fertilized will appear whiter and eventually develop a cloudy residue, in comparison to the more yellowish and transparent fertilized eggs that are clear and free from any residue. Unfertilized goldfish eggs in tank environments can often become food, so it’s best to identify them quickly.

Breeding Goldfish

Breeding Goldfish
Firstly, before even considering breeding, an adult male and female that is properly sexed will be required. Goldfish reach maturity at one year of age.

Now you know the answer to ‘what do goldfish eggs look like?’ you may want to breed your fish. Plus, now you know how to identify fertilized vs unfertilized goldfish eggs in tank and aquarium setups, it should be easy.

In their natural habitat breeding will usually only occur after significant temperature changes, during springtime. Goldfish require proper nutrition and a large enough living space for them to reach full maturity for breeding They are egg layers, or scatterers, with adhesive eggs that will attach to plants or spawning mops as provided.

Females may lay eggs regardless of the presence of a male or not, though, without a male. Thus the eggs remain unfertilized. There are however a few species humans breed selectively, mostly ornamental Goldfish species that are unable to breed naturally. This is because of their more altered shape. Thus breeders developed artificial breeding methods known as “hand stripping” to assist them in breeding.

  • Determining Gender

Firstly before even considering breeding an adult male and female that is properly sexed will be required. Goldfish reach maturity at one year of age. With goldfish eggs, you cannot determine the gender until the fry hatch and grow larger.

  • Males

Goldfish males will develop tubercles (small, raised pimple-like growths) on the covers of their gills and their pectoral fins. Furthermore, males have thinner concave vents (anal openings) in comparison to females. Males are generally thinner and more streamlined than females.

  • Females

Female goldfish generally have a more rounded and convex, protruding vent (anal opening) system with no tubercles. On top of this, females have a rounder and shorter body shape than males. Remember, a female with a round stomach may be carrying unfertilized goldfish eggs.

Breeding Goldfish, though they are such a common and readily available fish species in the aquarium trade, is much more intricate than it sounds. A perfect environment and fertile mates are required. Attention to the details and plenty of patience will however give surprising results.

1. Create a Favourable Environment

Use a 20-gallon or larger breeding tank that you have properly sterilized. Keep in mind the Goldfish are more likely to breed during springtime and need to properly adjust to the new environment. Use proper tank décor and plants to create a more natural habitat and include bushy plants or a spawning mop.

The diet of the Goldfish needs to be changed to a more protein-based diet gradually, with smaller regular feeds. Climate changes and seasonal changes can easily be simulated by dropping the temperatures to between 10°C (50°F) and 12°C (54°F), and then raising them to between 20°C (68°F) and 23°C (74°F) when ready for breeding. Lastly, proper regular water changes will have to be done daily, replacing 205 of the water in the tank with clean-conditioned water.

2. Isolating Males and Females

After you have determined the gender of the Goldfish visually certain behavioral patterns may also tell apart males from females. Males will chase females around during the breeding season, becoming more fervent in their advances as hormones increase. At this stage the females will be carrying the unfertilied goldfish eggs. You may wonder what do goldfish eggs look like when the female is carrying them? She will generally become rounder and plumper. This is what we refer to as pregnancy in fish.

Females may show no interest in the males, unfortunately, however, the males will increase their pursuits. To create a greater desire to breed it has been advised to isolate males and females from each other for a few weeks, before breeding. Generally females do not guard goldfish eggs in tank environments. Therefore you cannot identify them just by seeing them near the eggs.

3. Breeding

Choose the ideal mates, usually the most robust and eager partners, and males with the most tubercles.  The male and female can be introduced into the same tank, where the female will drop her eggs on some of the plants or provide a spawning mop, and the male will fertilize them by distributing sperm over the eggs swiftly.

It is vital to remove the male and female from the breeding tank after the eggs are fertilized. Goldfish have cannibalistic tendencies toward their own young and eggs. The eggs may take between 4 to 7 days to hatch which will depend largely on the temperature of the water.

Water Temperatures

Water temperatures for goldfish
The Goldfish fry will thrive in the same water conditions 70-75oF (21-24oC), used for hatching eggs, and can stay in these conditions until they grow to a suitable size.

Water temperature will play a vital role in breeding. This is especially to increase the desire to spawn in males and females. This also allows the eggs to hatch in a healthy and timely condition.

  •  Spawning  Temperature– As mentioned, Goldfish usually breed during spring, thus to simulate the season you can drop the temperatures to around 10°C (50°F) and 12°C (54°F), and after a while raise the temperatures to 20°C (68°F) and 23°C (74°F).
  • Hatching Temperature– Keep your breeding tank with the eggs at a constant temperature of between 70-75oF (21-24oC), and the young fry should hatch after a few days, usually around 3 to 4 days. Colder water can slow down the period to up to 7 days before hatching.
  • Water temperatures for the Fry -The Goldfish fry will thrive in the same water conditions 70-75oF (21-24oC), used for hatching eggs, and can stay in these conditions until they grow to a suitable size.

Caring For The Fry

The small Goldfish hatchlings, referred to as fry will spend their first two to three days hanging on to a surface such as a leaf. They may also hang onto the sides of the tank, and will not eat at first. It is crucial to keep the tank well clean, with plenty of oxygen for them, maintaining the ideal temperatures.

After around two or three days you can introduce fry food, or tiny Brine shrimp and infusoria. Algae is also a good option. Be careful with filters that have strong currents that can suck up, or harm small Goldfish fry. Your young fry should be mature enough at around 6 months of age for you to release into their own or communal aquarium.

Types Of Goldfish And Color Variations

Types of goldfish and color variations
The Common Wild Type of Goldfish is usually a red, orange, metallic, or calico color.

There are so many different Goldfish species in the Aquarium trade today. You cannot tell from the goldfish eggs what the fish will look like beyond the general species.

Here is a summary of some of the goldfish species. However, remember this information is for breeding purposes. Generally, goldfish eggs of all categories remain identical.

There are mainly two categories of Goldfish. These are the Common Goldfish, and Ornamental Goldfish.

Common Goldfish

Common Goldfish have a longer and more slender body, with a single tail, there are three species, namely:

  • The Common Wild Type of Goldfish is usually in red, orange, metallic, or calico colors.
  • The Comet Goldfish has more of a forked elongated Caudal fin.
  • The Shubunkin Goldfish with long Finnage-like Comets, however usually Calico in color with orange, white, black, red, and blue markings.

Ornamental Or Fancy Goldfish

Most ornamental Goldfish will have a shorter and rounder body. they also have a double tail, and longer more flowing fins. There are many species in this category:

  • Veil Tails – Ryukin, Orandas, and Telescope or Globe Eye.
  • Moors – Common Black Moors, Panda Moors.
  • Fan Tails – Bubble-Eye Goldfish, Celestials, Pearlscales, Demekins, Eggfish, Ranchus, PomPoms, and Wakins.

However, in this article we mostly look at the regular Common or Comet goldfish as a species.

Quick Tips On Caring For Goldfish

Quick tips on caring for goldfish
Goldfish thrive in temperatures around 65 to 75 °F (18 to 24 °C).

To fully comprehend Goldfish breeding and to breed healthy Goldfish it is crucial to know how to properly care for them. This includes how to keep them healthy in a suitable environment. Remember, goldfish eggs in tank environments that are dirty may become infected.

1. Aquarium

Firstly, Goldfish produce plenty of waste. Thus proper tank maintenance is crucial, and a strong filter with moderate flow will be essential. Depending on the species of Goldfish chosen to breed a tank of around 20 or more gallons will be necessary for one or two Goldfish, and larger for more.

Goldfish can live in an unheated aquarium, depending on the temperatures in your location, though with very low temperatures they may need heating. Goldfish thrive in temperatures around 65 to 75 °F (18 to 24 °C). Staying in between the pH levels of 6.5 to 8.0 is best according to a variety of resources, Goldfish are reasonably tolerant within these ranges.

A medium to finer gravel or sand will make an excellent substrate choice. This should have a few hiding spots and toys including caves, Driftwood, Rocks, Shipwrecks, and even terracotta pots. You can select between live or synthetic plants. Nevertheless, Live plants offer better tank cleaning capabilities and provide oxygen. Suitable Live plants need to be robust as Goldfish may be destructive and nibble on Plants. Some good choices include: Water Sprite, Anacharis, Java Ferns, Amazon swords, Water Wisteria, Cryptocoryne wendii, Bolbitis Ferns, Marimo Moss Balls.

2. Ponds

Most Goldfish species will thrive in outdoor ponds, especially in slightly warmer climates. They can survive for short periods underwater with a frozen surface, providing that there is enough oxygen in the water. Ponds will need proper filtration and regular maintenance to keep peak water conditions.

Some plant species and snails that are compatible may help with keeping algae under control. Though for breeding purposes, it’s best to focus on tanks. In tank environments, unfertilized goldfish eggs will stick to plants and rocks. This is often easier for breeders.

3. Feeding

In their natural habitat Goldfish have a diet consisting of various plant matter small crustaceans, and insects. They are known as opportunistic omnivorous feeders that tend to overeat. Overeating is detrimental to the health of Goldfish; thus it is important to adhere to a strict feeding regime. However, in this article, if you are wondering ‘do goldfish eat goldfish eggs?’, unfortunately they do. In fact, many species will eat goldfish eggs.

Feeding Your Fish

If you feed your fish properly it is less likely they will eat unfertilized goldfish eggs. Goldfish Pellets or flakes will mostly contain more carbohydrates than protein. Thus you can supplement their diet with blood worms, brine shrimp, and other meat-based foods. Blanched vegetables such as shelled peas, and green leafy vegetables are also a particular favorite among Goldfish.

Adult Goldfish need two feedings a day which they can finish within 2 – 3 minutes, whereas fry and juveniles require a higher protein-based meal in smaller amounts, more frequently. Most Ornamental Goldfish have an irritable digestive system and tend to become constipated easily. Thus, they need food that is lower in protein, starch, and sugar especially when they get older.

4. Temperament And Personality

Though Goldfish are very sociable, friendly, and tame creatures it is important not to handle them. They are outgoing, with some schooling behavior, and very friendly towards their own and other fish species. Keep in mind that they may become more territorial during spawning, as opposed to their generally peaceful nature.

An interesting fact is the associative learning abilities of Goldfish and their memory span of up to three months. This allows them to differentiate between different shapes colors, sound, and even their human companions. Some individuals find their Goldfish swimming towards the glass, or surface as they approach, begging for food. They may even learn to eat from the hand.

5. Compatible Tank Mates

 You will find under strict recommendation to never keep ornamental and common Goldfish together. This is as ornamental Goldfish are extremely delicate in comparison to most common Goldfish species. Many Goldfish may resort to fin-nipping behavior. Thus other smaller fish species with longer fins will not be ideal.

Similarly, Plecos, being nocturnal, may latch on to larger Goldfish while they sleep, devouring their slime coat and in some cases their eyes. This is also the case for Otos and Corydoras. It is best to keep Goldfish within their own family, either Common Goldfish only or ornamentals. A few other species you could consider include: Larger Snails, Platys, Giant Danios, Rosy Barbs, and Hillstream Loaches

Common Health Concerns

Common health concerns for goldfish
Goldfish may suffer from Ulcers that can become infected, especially when the slime layer on their skin is compromised.

Most Common Goldfish tend to be relatively robust and healthy. This is given that you keep their water conditions are clean and at optimal pH and temperature levels. However, Ornamental Goldfish may be slightly more fragile. Mostly Goldfish are prone to common freshwater fish conditions.

  • Parasites

Parasites such as Ich and Trichodina, as well as Chilodonella may arise in Goldfish. Goldfish may also contract worms or fish lice. You can treat these parasites separately by improving the environmental conditions and using chemical treatments.

  • Fungal And Bacterial Infections

Goldfish may suffer from Ulcers that can become infected. This is especially when something compromises the slime layer on their skin. Fungal and bacterial Infections may affect the swim bladder or fins of your Goldfish. To treat ulcers, add 4 grams of salt and 3 grams of urea per liter of water. Medication such as antibiotics is also a solution depending on the type of infection. Furthermore, it’s almost always best to quarantine.

  • SVC

Spring Viremia of Carp is a well-known disease affecting Goldfish and Koi alike. Most Goldfish with the condition usually have an external parasite or bacterial infection giving rise to the virus. The condition is fatal and contagious, thus quarantine is vital. This includes proper cleaning and disinfecting of your aquarium. However, not many individuals have experienced the disease so far in general home aquariums.

Final Thoughts

small Goldfish
Breeding Goldfish is an intricate process that requires the right water conditions, temperatures, and selection of fertile mates. Image from Flickr

Breeding Goldfish is an intricate process that requires the right water conditions, temperatures, and selection of fertile mates. By following the proper procedures Goldfish you can breed goldfish and raised fry. However, keep in mind that breeding Goldfish is not an endeavor to make money, but rather a hobby for interested Aquarists. Most ornamental Goldfish may be much more difficult to breed, if so at all.

Frequently Asked Questions

What is a Goldfish Spawning Mop?
The Spawning Mop as the name states is an artificial device, usually wool, resembling a mop with many strands tied together used during spawning. The sticky Goldfish eggs will attach to the spawning mop, which makes it easier to relocate the eggs if necessary.
Do Goldfish Reproduce Sexually or Asexually?
Goldfish are not asexual, females need a male for fertilization of their eggs. Females can lay eggs without the presence of a male, though the eggs will not be fertilized, and no fry will come from them.
How to Stop Goldfish from Breeding?
Some individuals find their Goldfish breeding freely in their ponds or aquariums without any specific intervention or planning. To reduce unplanned breeding, or stop Goldfish from Breeding the following can be implemented. Try to keep only one gender, male or female Goldfish. A group of males will get along easily, the same goes for females. Try to avoid gradual tank temperature increases, and keep the water at a constant cooler temperature. Reduce your water maintenance cycles for the spawning period, to create unfavourable breeding conditions. Similarly, you can cull the eggs or fry by introducing more bottom-feeding fish species, predatory fish species, or male Goldfish that will eat the eggs or fry.
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