Dr. Rick Stuart-Smith, Reef Life Survey, Australien
Info
Clownfish are among the most popular marine fish due to their fascinating symbiosis with certain sea anemones and, not least, thanks to the film “Finding Nemo.”
Enthusiasts and anyone interested in anemone fish may have already seen photos of Amphiprion chrysopterus in the marine encyclopedia and noticed that the animals shown have white and yellow tails.
Some may have wondered why this is the case.
This question has preoccupied researchers James L. O'Donnell, Ricardo Beldade, Jason Johns, and Giacomo Bernardi to such an extent that they decided to conduct a larger study.
The anemonefish, Amphiprion chrysopterus, is widespread, from Australia to French Polynesia and north to Micronesia and the Marshall Islands.
There are two main color morphs, one with a white tail and one with an orange tail.
In French Polynesia, only the orange morph occurs, while in the rest of the range, the white morph predominates and the orange morph also occurs but is very rare.
Here, researchers investigated the possible occurrence of a cryptic species in French Polynesia based on morphology, mitochondrial markers, and complete genome sequencing. The morphological and genetic results confirmed the identification of a separate group in French Polynesia, which we describe here as a new species: the Polynesian anemonefish Amphiprion maohiensis.
The main difference is in the tail region, where individuals in the eastern part of the range have an orange caudal fin and orange caudal peduncle, while most individuals in the western part of the range have a white caudal fin and white caudal peduncle.
Complete genome sequencing is consistent with mitochondrial data in terms of separating individuals from French Polynesia from those collected in Micronesia. Morphological differences were limited but also separated individuals from French Polynesia.
The coloration of the caudal fin did not prove to be a characteristic feature of the species, as orange caudal fins also occur in individuals from Fiji and adjacent areas, as well as in the Mariana Islands.
The elevation of the clade comprising individuals from French Polynesia to species rank is based on converging lines of evidence.
Mitochondrial COI data distinguish this group as a monophyletic clade that is clearly separated from its close relatives (more than twice the genetic divergence between the closely related species Amphiprion sandarocinos and Amphiprion perideraion).
Complete genome sequencing is consistent with mitochondrial data regarding the separation of individuals from French Polynesia from those collected in Micronesia.
Morphological differences were limited but also separated individuals from French Polynesia.
The coloration of the caudal fin did not prove to be a characteristic feature of the species, as orange caudal fins also occur in individuals from Fiji and adjacent areas, as well as in the Mariana Islands. Further studies are needed to fully clarify the status of the populations in these areas.
Holotype:
The holotype was collected from Opunohu, Moorea, French Polynesia.
Paratypes:
The paratypes were collected from Raroia Atoll, Tuamotu Archipelago, French Polynesia.
Coloration
All specimens we observed in French Polynesia have an orange caudal peduncle and an orange caudal fin.
In contrast, the specimens we observed in the western part of the distribution range (Solomon Islands, Papua New Guinea, and Micronesia) had a white caudal peduncle and a white caudal fin.
However, some specimens from Micronesia with orange coloration have also been reported in this region.
The georeferenced images we analyzed from iNaturalist comprised 880 records (retrieved on 04/2025).
Some images contained multiple individuals, while others showed only the front part of the body (the rear part of the body was usually obscured by the tentacles of the host anemone).
This dataset yielded 565 individuals for which the color of the caudal fin could be determined.
The color of the caudal fin was either white or orange at a given location, with no location having both color types, except for three individuals (assuming the georeferenced images have the correct coordinates).
In the Solomon Islands, where individuals have white caudal fins, one individual had a black caudal fin and one individual had an orange caudal fin.
In Vanuatu, where individuals have white caudal fins, one individual had an orange caudal fin. Among the remaining 562 individuals assessed, no further cases of sympatric caudal colors were observed. As described in the introduction, all individuals east of Fiji had an orange caudal fin. Individuals west of this line had a white caudal fin, with the exception of individuals in the Marianas, where all individuals had an orange caudal fin.
Coloration of Amphiprion maohiensis in adult condition:
Iris dark; body light orange to dark yellow; two white to bluish stripes, the first behind the eye, the second in the middle of the body; all fins orange
In Vanuatu, where individuals have white caudal fins, one individual had an orange caudal fin!
Habitat and host anemone:
The Polynesian anemonefish is usually found in association with Radianthus magnifica (formerly Heteractis magnifica), the magnificent sea anemone, which is also by far the most common sea anemone in French Polynesia.
Rarer species of sea anemones may also occur and be associated with Polynesian anemonefish, suggesting that they do not have an exclusive association with Radianthus magnifica.
Etymology.
The term “ma'ohiensi” refers in Polynesian to belonging to the homeland, ma'ohi.
Apostrophes are not allowed in species names (International Code of Zoological Nomenclature, Article 32.5.2), so the species name is “maohiensis.”
Common name.
The researchers propose “Polynesian anemonefish” as the common name for this species, which occurs predominantly, if not exclusively, in French Polynesia.
Similar species: Amphiprion chrysopterus Cuvier, 1830
Enthusiasts and anyone interested in anemone fish may have already seen photos of Amphiprion chrysopterus in the marine encyclopedia and noticed that the animals shown have white and yellow tails.
Some may have wondered why this is the case.
This question has preoccupied researchers James L. O'Donnell, Ricardo Beldade, Jason Johns, and Giacomo Bernardi to such an extent that they decided to conduct a larger study.
The anemonefish, Amphiprion chrysopterus, is widespread, from Australia to French Polynesia and north to Micronesia and the Marshall Islands.
There are two main color morphs, one with a white tail and one with an orange tail.
In French Polynesia, only the orange morph occurs, while in the rest of the range, the white morph predominates and the orange morph also occurs but is very rare.
Here, researchers investigated the possible occurrence of a cryptic species in French Polynesia based on morphology, mitochondrial markers, and complete genome sequencing. The morphological and genetic results confirmed the identification of a separate group in French Polynesia, which we describe here as a new species: the Polynesian anemonefish Amphiprion maohiensis.
The main difference is in the tail region, where individuals in the eastern part of the range have an orange caudal fin and orange caudal peduncle, while most individuals in the western part of the range have a white caudal fin and white caudal peduncle.
Complete genome sequencing is consistent with mitochondrial data in terms of separating individuals from French Polynesia from those collected in Micronesia. Morphological differences were limited but also separated individuals from French Polynesia.
The coloration of the caudal fin did not prove to be a characteristic feature of the species, as orange caudal fins also occur in individuals from Fiji and adjacent areas, as well as in the Mariana Islands.
The elevation of the clade comprising individuals from French Polynesia to species rank is based on converging lines of evidence.
Mitochondrial COI data distinguish this group as a monophyletic clade that is clearly separated from its close relatives (more than twice the genetic divergence between the closely related species Amphiprion sandarocinos and Amphiprion perideraion).
Complete genome sequencing is consistent with mitochondrial data regarding the separation of individuals from French Polynesia from those collected in Micronesia.
Morphological differences were limited but also separated individuals from French Polynesia.
The coloration of the caudal fin did not prove to be a characteristic feature of the species, as orange caudal fins also occur in individuals from Fiji and adjacent areas, as well as in the Mariana Islands. Further studies are needed to fully clarify the status of the populations in these areas.
Holotype:
The holotype was collected from Opunohu, Moorea, French Polynesia.
Paratypes:
The paratypes were collected from Raroia Atoll, Tuamotu Archipelago, French Polynesia.
Coloration
All specimens we observed in French Polynesia have an orange caudal peduncle and an orange caudal fin.
In contrast, the specimens we observed in the western part of the distribution range (Solomon Islands, Papua New Guinea, and Micronesia) had a white caudal peduncle and a white caudal fin.
However, some specimens from Micronesia with orange coloration have also been reported in this region.
The georeferenced images we analyzed from iNaturalist comprised 880 records (retrieved on 04/2025).
Some images contained multiple individuals, while others showed only the front part of the body (the rear part of the body was usually obscured by the tentacles of the host anemone).
This dataset yielded 565 individuals for which the color of the caudal fin could be determined.
The color of the caudal fin was either white or orange at a given location, with no location having both color types, except for three individuals (assuming the georeferenced images have the correct coordinates).
In the Solomon Islands, where individuals have white caudal fins, one individual had a black caudal fin and one individual had an orange caudal fin.
In Vanuatu, where individuals have white caudal fins, one individual had an orange caudal fin. Among the remaining 562 individuals assessed, no further cases of sympatric caudal colors were observed. As described in the introduction, all individuals east of Fiji had an orange caudal fin. Individuals west of this line had a white caudal fin, with the exception of individuals in the Marianas, where all individuals had an orange caudal fin.
Coloration of Amphiprion maohiensis in adult condition:
Iris dark; body light orange to dark yellow; two white to bluish stripes, the first behind the eye, the second in the middle of the body; all fins orange
In Vanuatu, where individuals have white caudal fins, one individual had an orange caudal fin!
Habitat and host anemone:
The Polynesian anemonefish is usually found in association with Radianthus magnifica (formerly Heteractis magnifica), the magnificent sea anemone, which is also by far the most common sea anemone in French Polynesia.
Rarer species of sea anemones may also occur and be associated with Polynesian anemonefish, suggesting that they do not have an exclusive association with Radianthus magnifica.
Etymology.
The term “ma'ohiensi” refers in Polynesian to belonging to the homeland, ma'ohi.
Apostrophes are not allowed in species names (International Code of Zoological Nomenclature, Article 32.5.2), so the species name is “maohiensis.”
Common name.
The researchers propose “Polynesian anemonefish” as the common name for this species, which occurs predominantly, if not exclusively, in French Polynesia.
Similar species: Amphiprion chrysopterus Cuvier, 1830
