Clownfish 101

Is it challenging to breed clownfish?

Yes, it can be quite challenging. We offer equipment, foods, live rotifers and weaning diets to make it easier. In our experience, mastery of rotifer culture is vital to your success. With consistent effort and attention to detail, you can be successful.

How do I get my clownfish to spawn?

Typically, 2 small, young clownfish will form an adult pair that will spawn for many years. They are male when they are young. When they begin to pair up, one of them will change sex and become a female. Tank water must be stable and clean. Feeding them with nutrient dense food throughout the day is ideal. We recommend our TDO Chroma BOOST pelleted food, Arcti-Pods and Mysis-Feast for all your broodstock nutrition.

How often should I feed my clownfish pair (broodstock)?

At least twice a day. We recommend feeding TDO Chroma BOOST (Small or Medium) at least twice a day.

You can use an auto-feeder to make it easier. We also recommend incorporating other food types into their diet. Simply feed small amounts and rotate food options. These foods that we make are a great addition to the diet:

• Arcti-Pods: concentrated copepods
• Mysis-Feast: concentrated mysis shrimp high in omega 3 fatty acids
• R.O.E.: concentrated fish eggs rich in fats, proteins, and vitamins

How often do clownfish spawn and should I keep a log?

They typically spawn every 7-10 days. Once the pair begin spawning, start a log to track how often they lay they eggs and when the embryos hatch. Keeping track of when the eggs are laid and when they hatch allows you to remove the embryos 24 hours in advance of hatch to transfer to the larval rearing tank. We recommend that you allow a new pair to spawn 3 times before taking on larval rearing. They very often do not have well-developed eggs and fertilization can be low for the first two to three spawns.

How do I know when the eggs are about to hatch?

The eggs, which are orange or red in coloration, transition to an embryo. Embryos become brown, and you can see the eyes, clearly. The eyes become very shiny and silvery when the embryos are mature and ready to hatch.

My clownfish laid eggs on my reef rock. How do I collect them?

We recommend the Vossen Larval trap for collecting larvae. 

Will clownfish spawn on other surfaces?

Clownfish will spawn on a variety of surfaces. We recommend that you train them on to a floor tile or small, clay flowerpot. It is much easier to remove the embryos the day before they hatch this way. It can be tricky to train them to spawn on these types of items if the pair is in your reef tank.

What size tank is appropriate for a breeding pair?

If you are serious about breeding clownfish and want to house multiple pairs, we recommend keeping the pairs in separate tanks, this way you can manage their spawning habits and remove the embryos without disturbing the rocks and animals in a reef tank or community tank. Clownfish pairs do not need reef rock in an aquarium to spawn. They will also spawn just fine in a 10 gallon tank.

Does my clownfish pair need an anemone?

No. They do not even need structure beyond the floor tiles or pots you have in there for them to spawn on.

How do I hatch the embryos in a larval rearing tank?

The night before a hatch, remove the substrate where the embryos are attached. Transfer them to a larval rearing tank that has the same temperature and salinity as the broodstock tank. It is ok for them to be out of water for a minute or so. If there are things growing on the substrate like bacteria, algae or sponges, simply scrub them off being careful not to damage the embryos. Use aeration to keep the embryos clean and free of fungus before they hatch. You can use a bubble wand or air stone for this. Make sure the aeration is gentle and covers the entire nest.

Do I need a heater in the larval rearing tank?

Yes, unless you have a warm, climate-controlled room. They do best from 78° – 80°F

When do I add rotifers?

Add them after the fish hatch.

When do I add greenwater?

Add greenwater after the fish hatch.

What is “greenwater”?

Greenwater is a technique that involves adding algae (alive or dead) to a larval rearing tank for a few reasons as seen below. If you don’t want to grow live algae, we recommend our Rotigreen Omega.

Colonizes the digestive flora of the fish gut — marine fish are born with only a partially-developed intestinal tract, and it can take up to four weeks for the gut to fully develop. Our Instant Algae brand of microalgae and the associated “good” bacteria enter the gut and help jump-start digestion.

Enrichment of the rotifers — many hatcheries keep a background level of live rotifers in the tanks so the fish can continue feeding. Our greenwater microalgae feeds the rotifers and maintains enrichment levels.

Reduces or eliminates “nose bumping” syndrome — in larval tanks the water is typically so clean and clear that the fish lose depth perception and run into each other and the sides of the tank, bruising themselves and creating bacteria problems. Our Greenwater clouds the water and helps fish avoid collisions.

How do I store and use the greenwater food, RotiGreen Omega?

If the algae arrives frozen, put it in a refrigerator in a container for 24 hours to thaw. If it is thawed upon arrival, complete the following steps:

• Pour the algae into ice cube trays.
• Place the cubes into a freezer bag to prevent “burn”.
• Thaw a cube in a sealed container in the refrigerator 24 hours in advance of using it.
• Use the thawed portion within 3 weeks.
• Note: The size of the cubes depends on how much you go through. No matter the size of the cube/portion, it needs to be used within 3 weeks to avoid spoilage.

How much greenwater do I use?

Use enough to cloud the water, but not very dark green. You basically want enough tint to keep the larvae swimming around the tank and not pinning themselves to the glass.

Feeding rotifers to your larvae

Clownfish larvae begin feeding on the day of hatch, so it is important to have live rotifers in the tank with them. We recommend 10 rotifers per ml as an initial stocking density. It is beneficial to feed your larvae a few times a day, but make sure not to overfeed the tank. If your rotifers get out of control in the tank, they can cause ammonia to spike and dissolved oxygen to drop. This can result in the death of your larvae. If rotifers get out of control, you can simply siphon water out of the tank to dilute them. Make sure to avoid siphoning out the larvae.

How do I keep the larval rearing tank clean?

It is advisable to do daily water changes to avoid high ammonia. You can use a rigid airline connected to a flexible airline to siphon waste off the bottom of the tank. Turn off the aeration during this step so you can see where you are siphoning so that you avoid sucking up the larvae.

What is weaning?

In fish culture the term weaning is used to describe the transition in the feeding of larvae, or juveniles, from live food to dry, or refrigerated diets.

How do I wean my fish off rotifers?

Weaning your fish off live rotifers makes growing your fish much easier. Once they are on to a dry food and other prepared food items, they grow quite rapidly and are easier to manage. Below is an example of a weaning schedule for the A. ocellaris or A. percula clownfish species. It is meant to be a visual guide to show how there is overlap when weaning. The key is to not switch from one food type to another, suddenly. This feeding chart does not necessarily apply to all species of clownfish. Our Hobbyist Breeder Pack is perfect for weaning your fish off live rotifers.

Do I need to hatch and feed baby brine shrimp when weaning?

If you are using TDO Chroma BOOST, there is no need to hatch brine shrimp every day. You can go from live rotifer to TDO which is much simpler.