News / Species Spotlight / White Cap Clownfish (Amphiprion leucokranos) (06/26/18)

White Cap Clownfish (Amphiprion leucokranos)

Species Spotlight - White Cap Clownfish (Amphiprion leucokranos)
The coral reefs of New Guinea and the Solomon Islands sit in an interesting part of the Pacific Ocean, as far as clownfishes are concerned. Its here that two distantly related and widespread species overlap, and, where they cross paths, these two produce a beautiful hybrid whose true nature has only recently been revealed.

The Orange Skunk Clownfish (Amphiprion sandaracinos) is an endemic species in the Coral Triangle, which reaches its easternmost extent in the Solomon Islands. On the other hand, the Blue Stripe Clownfish (Amphiprion chrysopterus) is found across the Central Pacific (absent only from Hawaii) and reaches its westernmost extent at Halmahera and West Papua in Indonesia.

The Orange Skunk is a specialist of reef-associated carpet anemones in the genus Stichodactyla, while the Blue Stripe is more of an anemone generalist, tending to occur most readily along outer reef slopes. But, for reasons that are unclear, these two seem unusually fond of one another, despite being very different species, both morphologically and ecologically. In New Britain, where they have been studied most extensively, they are often found cohabitating anemones, along with their interspecies progeny, the White Cap Clownfish.

In 1973, in the early days of coral reef exploration, ichthyologist Gerry Allen described this fish as its own species, Amphiprion leucokranos. And, to this day, youll still see it treated as valid by governmental bodies and scientific databases, but genetic study and captive breeding has revealed this fishs true hybrid identity. For instance, when commercial aquaculturists succeeded in breeding the leucokranos hybrid, the resulting offspring showed a wide range in body shapes and color patterns. Some were taller, like A. chrysopterus, while others had the distinctive elongate body of a skunk clownfish. The extent of the white markings varied from a full white bonnet to those which had little more than a white spot on the operculum.

Eventually, Amphiprion will need to be taxonomically revised, and, when this happens, well inevitably bid farewell to the fish that weve come to know and love as A. leucokranos. And well probably have to do the same with Amphiprion thiellei while were at it.