Cirrhilabrus hygroxerus, a new species of fairy wrasse (Pisces: Labridae) from the Timor Sea, northern Australia.

A new species of labrid fish, Cirrhilabrus hygroxerus, is described from 19 type specimens, 38.4–56.1 mm SL, collected from the eastern Timor Sea, Northern Territory, Australia. The new taxon belongs to a species complex containing five other Indo-Pacific species, comprising C. humanni (western Lesser Sunda Islands of Indonesia and East Timor), C. joanallenae (western Sumatra), C. morrisoni (Hibernia Reef, western Timor Sea), C. naokoae (Nias Island, western Sumatra), and the widespread C. rubriventralis (Red Sea, western Indian Ocean, Maldives, and Sri Lanka). Members of this complex typically have a single row of scales on the cheek and share the unique combination in the terminal-phase (TP) male of an elevated anterior dorsal fin, rounded caudal fin, and large fan or club-shaped pelvic fins without filamentous extensions. The new species is most similar to C. humanni and C. morrisoni, and the three species have apparently allopatric distributions in the Timor Sea-western Sunda Islands region. These three species share a uniquely shaped dorsal fin characterized by the presence of an anterior elevated, spike-like pennant. The best means of separating these species are differences in the color patterns of the TP male, primarily on the head, upper body, and on the dorsal, anal, and pelvic fins. The new species is distinguished by a combination of a yellow-orange upper head, blackish upper body, mainly blackish dorsal fin, and scarlet-red pelvic and anal fins. The female of C. hygroxerus is most similar to that of C. morrisoni, sharing a yellowish head and yellow pectoral-fin base.