Common Name: Northern Saddleback Anemonefish
Scientific Name: Amphiprion annamensis Chevey, 1932
Distribution: Philippines, west to Gulf of Thailand and north to Vietnam, Hainan and the Ryukyu Arc.
Type Locality: South coast of Vietnam
Identification: Caudal fin black, with white margins. Middle stripe abbreviated and greatly thickened, often appearing nearly circular. Posterior stripe absent. Body and fins highly variable, from solidly orange to solidly black; intermediate specimens develop black medially.
Similar: Most like the Melanesian Saddleback Anemonefish (Amphiprion laticlavius), which has a similar middle stripe, but differs in having a yellower base color and in developing back along the back (rather than medially).
Notes: The oldest available name for this distinctive species appears to be A. annamensis Chevey 1932, originally treated as a subspecies. The epithet derives from “Annam”, an earlier name for Vietnam, from which the type specimen was described.
It’s unclear why this species is so variable in color, as there is no obvious correlation with location, host anemone, size or sex.
Taxonomy Note: This species was treated as a synonym of Amphiprion polymnus in Allen 1991 and subsequent references. The elevation to full species status used in this classification should be considered provisional until a full taxonomic revision is published.