Barrier Reef Anemonefish, Amphiprion akindynos

The Barrier Reef Anemonefish (Amphiprion akindynos) is native to the marine lagoons and reefs in the Western Pacific Ocean.  It lives at a depth of around eighty-two feet in temperatures fluctuating between fifty degrees Fahrenheit to 89.6 degrees Fahrenheit. Its range includes northern New South Wales, the Loyalty Islands, Tonga, New Caledonia, Coral Sea, and the Great Barrier Reef. They are typically seen near or within the tentacles of their host anemones. They will inhabit anemones like the Magnificent Anemone, the Bubble-tip anemone, the Sebae anemone, the Green Carpet Anemone, the White Beaded Anemone, and Merten’s Sea Anemone. Stinging anemones do not affect these fish, due to the substance in the mucous that covers their bodies that prevents the anemone’s nematocysts from activating.

Adult Barrier Reef Anemonefish is amber-brown with black edges surrounding their bodies. Two distinct white bars appear on their sides. The first bar can be found on the head just behind the eyes, and it may be thin or broken. The second bar is located behind the dorsal fin. The caudal fin, or tail fin, is white. Baby Barrier Reef Anemonefish differs in color from adults, and is typically brown in color with three white stripes. Subadults also differ in color, as they are changing from young to adult fish colorings. Subadults are usually yellow, and retain only two white stripes. Each dorsal fin has ten to eleven spines while the anal fin holds two spines. The Barrier Reef Anemonefish is small, weighing in at .97 ounces with an average body length of 3.5 inches.

The social hierarchy of the Barrier Reef Anemonefish is structured with one alpha female, the largest of the fish, one alpha male, the second largest, and up to four males in lower ranking. Although there is little aggression between the alpha female and males, aggression between males is common. If the lowest ranking male is kicked out, he will have to find another colony or risk dying. In the case that the alpha female dies, her mate will take over and within a few days will turn into a female fish.

As nesting fish, the male Barrier Reef Anemonefish will create a nest by clearing a rock of debris that is near the host anemone, and aggression towards the female increases during this time. Occasionally, the female fish will help get rid of any algae on the rock. The mating ritual consists of the female zigzagging over the nest rock, with the male following behind her to fertilize the eggs. This process will create 100 to 1000 oval eggs. The eggs will hatch in six or seven days, during which time the male guards them from predators. Each egg that hatches contains a male fish, but the sex of the baby fish will change to female if they rise to the top of the hierarchy.

The diet of the Barrier Reef Anemonefish contains zooplankton and algae. The alpha male and female will travel farther to find food than the other members of the group, and any food matter that the fish drop may benefit the host anemone. These fish can live to be ten years old in the wild, and in captivity can live to be eighteen years old. In March of 2005, the Barrier Reef Anemonefish became Queensland’s state aquatic symbol.

Image Caption: Amphiprion akindynos. Credit: Leonard Low from Australia/Wikipedia(CC BY 2.0)