Nuptial coloration of Pseudanthias sheni. Picture by Itaru Takaku, Yakushima Diving.

Pseudanthias sheni is a gorgeous, and almost doppelgänger of Pseudanthias pleurotaenia, or the square-spot anthias. Unlike the latter, the Shen’s anthias is somewhat more subdued in coloration, with more shades of white. The caudal fin of P. sheni is comparatively lighter in color and more white compared to its close cousin. Like many other species of anthias, P. sheni is haremic with males tending to large groups of females.

The males of Pseudanthias sheni are also gaudily colored and very much different compared to the females, which in this species, is an overall yellow-orange with little markings. Females of P. sheni look almost identical to those of P. pleurotaenia. Keep reading for more titillating pictures of P. sheni, including some really awesome spawning ascent shots.

Pseudanthias sheni with a female in the background. This picture was most likely taken during a spawning ascent. Photo by Tsuyoshi kawamoto.

Nuptial phase P. sheni with female. Picture by Tsuyoshi Kawamoto.

While the differences between the two species may be subtle, one look and its quite obvious that P. sheni is indeed a distinct species. The head and ventral fins of P. sheni are also different from the standard square-spot anthias. This large species was originally reported to be endemic to the Rowley Shoals of Australia, but has since been reported from Indonesia where they often mingle with the similar looking P. pleurotaenia.

When in nuptial display, the coloration turns from a light salmon-lavender hue to an intense purple and magenta. There haven’t been much reports on P. sheni entering the trade but that’s most likely due to the confusion between it and the square-spot anthias. Take a good look at every square-spot anthias you see the next time. You might just be looking at P. sheni in disguise.

P. sheni in its relaxed non-nuptial coloration. The color of P. sheni is lighter as compared to P. pleurotaenia, with an overall peachy-lavender hue as compared to the dark magenta purple of the latter. Picture by NabiinSea.

Here’s a brief and rather unclear video of P. sheni in the wild, but it’s pretty obvious even in this video that the coloration of P. sheni differs from that of P. pleurotaenia. Video taken in Ambon, Indonesia.