News / Species Spotlight / Species Spotlight - Radiant Wrasse (Halichoeres iridis) (10/19/17)

Species Spotlight - Radiant Wrasse (Halichoeres iridis)

Species Spotlight - Radiant Wrasse (Halichoeres iridis)
It might not be apparent at first glance, but the Radiant Wrasse (Halichoeres iridis), with its deep burgundy coat, is a close relative to one of the yellowest fishes in the sea, the Canary Wrasse (H. chrysus). They occur on different sides of the Indo-Pacific, but, aside from these minor details, theyre basically identical in all other aspects of their biology and ecology.

Youll find H. iridis in the Western Indian Ocean, all along the African coastline, up into the Arabian Peninsula and east into Mauritius and Reunion. Beyond this region, there is an abrupt changing of the guards, with the yellow and white H. leucoxanthus taking over in the Maldives and Andaman Sea, and, in the West Pacific, we find our yellow friend, H. chrysus. All of these are most common in depths from 10 to 30 meters.

One cant help but wonder why the Radiant Wrasse developed these sumptuous colors, when all its closest relatives are such a bright, sunshiny shade. The only trace of yellow to be found in H. iridis is on the head, though even this turns increasingly green with age. The dorsal fin is typically white throughout in juveniles and females, with three prominent black spots present. Large males, on the other hand, keep only a small black spot anteriorly, and the fin develops bands of yellow and red similar to those found in many other Halichoeres wrasses.

Just like with the Canary Wrasse, the Radiant Wrasse is a terrific addition to a reef aquarium. Specimens are fully grown at around four inches, making them ideal for medium-sized tanks. A wide variety of benthic invertebrates are fed upon in the wild, and this species is likely to help in controlling some of the noxious flatworms that aquarists often struggle with. But almost any food offered will be happily eaten.

Though groups are often seen in the wild, its usually best to keep just one specimen per tank, though, for those with especially large systems, it would likely be possible to acquire several juveniles at once to create a functional harem. As with most wrasses, this is a protogynous hermaphrodite, with the dominant fish in a group eventually turning into a male.