The Incredible Bond Between Clownfish and Sea Anemones

Fans of Finding Nemo will love the crystal-clear underwater footage in a YouTube clip captured at Anilao in the Philippines. It provides a close-up view of two clownfish tending to their batch of eggs. Take a look and then read on to find out how clownfish reproduce and ensure the safety of their next generation.

Are These Really Clownfish?

Observant viewers may notice that these fish do not look exactly like Nemo. This is because there are over 30 different species of clownfish, each with a range of bright colors. The fish in the clip are saddleback clownfish (Amphiprion polymnus), also known as saddleback anemonefish. They are found in waters ranging from the Philippines to Indonesia and New Guinea, and can also be seen from northern Australia to southern Japan. These clownfish grow to around five inches and feed on zooplankton and algae.

Clownfish and Anemones

You can see in the clip that the clownfish has laid her eggs under a sea anemone. This particular one is called Haddon’s carpet anemone (Stichodactyla haddoni). The relationship between clownfish and anemones is called a mutually assistive symbiotic relationship. This means that both species get some advantage out of the arrangement.

The anemones are a type of predatory marine invertebrate. They protect the clownfish from predators and even supply some scraps of food that get caught in their tentacles. The clownfish helps lure unsuspecting fish toward the anemone with its bright colors. The fish are killed by the venom produced by the anemone’s stinging tentacles and eaten. Amazingly, the clownfish are immune to the venom. The base of the anemone provides an ideal place for clownfish to lay their eggs.

About Clownfish Eggs

The female clownfish lays hundreds of eggs in each batch, and this can occur at any time of the year. However, they typically hatch at night, often timed with environmental cues such as tides and moon phases, which can help disperse the larvae. Then, the male fish fertilizes the eggs and takes the main role in looking after them. In the clip, you can see both parents using their mouths and fins to clean and aerate the eggs. They usually hatch seven days after being laid, but in some conditions, it can take up to 10 days.  When they are ready to hatch, they look silver, and you can see the eyes of the baby fish inside. In the clip, you can clearly see the eyes inside the eggs, indicating they are less than 24 hours away from hatching. After hatching, the larvae will be widely dispersed by the current and will feed on plankton. Eventually, they will find their own anemones to live in.