Sunday, July 27, 2008

A NEW FAIRY WRASSE RISES FROM THE CONFUSION

Cirrhilabrus beauperryi (male): a newly described species once confused with C. punctatus. Photo taken in Milne Bay, PNG. Scott W. Michael.

Cirrhilabrus beauperryi (male): the same specimen seen above exhibiting temporary spawning colors. Scott W. Michael.

Cirrhilabrus punctatus (male): from Vanuatu. Scott W. Michael.

Cirrhilabrus punctatus (male): from Savu Savu, Fiji. Scott W. Michael.

Cirrhilabrus punctatus (female): from Beqa, Fiji. Scott W. Michael.

There are species within the genus Cirrhilabrus that are highly variable. So variable in fact, that some ichthyophiles have suggested that more than one species may be lumped under a common binomial. Are these geographical variants or a true species? The “lumpers” would say there is only one species, while the “splitters” would argue there are two or more. Molecular analysis has enabled ichthyologists to solve some of these taxonomic quandaries once and for all. Such is the case with Cirrhilabrus punctatus - the finespotted fairy wrasse.

For a number of years it was thought that C. punctatus was simply a highly variable fish. It was originally described (in 1989) from Fiji, Tonga, New Caledonia, eastern Australia and southern Papua New Guinea (PNG). Many authors extended its range to include the northeastern coast of PNG and the Solomon Islands. Even though the color of the fish in this area differed from the original description of C. punctatus, it did have the characteristic dots on the head and body and was considered by many to simply be a color variant.

Enter the intrepid Lord of the Reef Fishes, Dr. Gerald Allen. Recently, Dr. Allen has discovered that the fish that occurs on reefs off of Milne Bay Province (Papua New Guinea), Madang (PNG), Bismarck Archipelago, and the Solomon Islands (which has often been lumped with C. punctatus) is actually a distinct species that has been dubbed Cirrhilabrus beauperryi.

Dr. Allen states the following regarding their chromatic differences:

“The two species are clearly separable on the basis of colour pattern. Terminal-phase individuals of C. beauperryi are generally purplish grading to blue ventrally and greenish or yellowish brown dorsally with a broad purple stripe along the basal half of the otherwise pale yellow dorsal fin. In contrast, terminal-phase C. punctatus are generally reddish brown to dark grey on the upper two-thirds of the head and body and abruptly white below with broad black stripes along the base of mainly red dorsal and anal fins. They also differ noticeably with respect to the colouration on the base of the pectoral fins: in C. beauperryi it is mainly violet with a narrow, inconspicuous purple bar; that of C. punctatus is prominently marked with a broad black bar. The pectoral-base marking is also useful for distinguishing initial-phase fish. The terminal phase of C. beauperryi also exhibits a unique median head profile characterized by a rounded forehead and concave interorbital region. DNA analysis reveals the two species are genetically distinct.”

This new species brings the number of fairy wrasses up to 45. It is the second most speciose group in the family Labridae behind the genus Halichoeres, which includes around 80 species.

References:

Allen, G. R., J. Drew and P. Barber. 2008. Cirrhilabrus beauperryi, a new wrasse (Pisces: Labridae) from Melanesia. Aqua –International Journal of Ichthyology, 14: 129-140.
Copyright (2008) Scott W. Michael

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