Divers spot creature hidden in tentacles of a sea anemone. It’s a new species
On reefs scattered across the western Pacific Ocean, large creatures anchored to the rocks let their tentacles flow with the water.
They belong to a species called Heteractis magnifica — the magnificent sea anemone.
Sea anemones have toxic tentacles that can shoot neurotoxins into unsuspecting prey, but while deadly for many, a group of fish has used this to their advantage.
Anemonefishes are a group of damselfishes “that exclusively live symbiotically with sea anemones,” researchers said in a July 10 study published in the peer-reviewed journal ZooKeys.
They are unaffected by the anemone’s deadly touch, and their “conspicuous behavior makes them a favorite among divers and photographers,” according to the study.
Now, researchers have noticed that some of the damselfish living in the anemones found in the eastern range of the fish, those closer to Fiji, compared to the western range look physically different.
They’ve been identified as two separate species, one for the first time.
Armed with hand nets, free and scuba divers took to the reefs off French Polynesia, the Federated States of Micronesia, Papua New Guinea and the Solomon Islands and collected damselfish from the genus Amphiprion, according to the study.
“The orange-fin anemonefish, Amphiprion chrysopterus, shows a wide distribution, from Australia to French Polynesia, extending north to Micronesia and the Marshall Islands,” researchers said. “Two main color morphs exist, with a morph that displays a white tail and a second morph that has an orange tail. In French Polynesia, only the orange-tail morph is present, while in the rest of the range, the white-tail morph is prevalent, while the orange-tail morph is also present, but very uncommon.”
When the researchers compared this to 800 images of the fish viewed on citizen science website iNaturalist, they found a clear divide between the two environments, according to the study.
Genetic testing of the fish collected by divers confirmed their suspicions — the Polynesian fish were their own species.
Amphiprion maohiensis, or the Polynesian anemonefish, has a “light orange to dark yellow” body with “two white to bluish bars, the first behind the eye, the second midbody,” researchers said.
The species was named for the Polynesian word “ma’ohi,” meaning “belonging of native land,” researchers said.
The fish were found in and around the magnificent sea anemone, which is “by very far the most common sea anemone in French Polynesia,” according to the study.
Both anemone and anemonefish benefit from their relationship, called mutualism. While the fish are protected from predators in the deadly tentacles of the anemone, the plant-like animal snacks on scraps from the fish’s meals, according to National Geographic.
French Polynesia is a group of islands in the middle of the South Pacific, between Australia and the west coast of South America.
The research team includes James O’Donnell, Ricardo Beldade, Jason Johns and Giacomo Bernardi.
