Saturday, December 16, 2017

[Ichthyology • 2017] Cirrhilabrus greeni • A New Species of Wrasse (Pisces: Labridae) from the Timor Sea, northern Australia

 Cirrhilabrus greeni Allen & Hammer, 2017


A new species of labrid fish, the Sunset Fairy-wrasse, Cirrhilabrus greeni n. sp., is described from seven specimens, 39.4–47.3 mm SL, collected from the eastern Timor Sea, Northern Territory, Australia. The species is clearly distinguished by its terminal-phase male color pattern, consisting of pink to reddish hues on the upper half of the head and body and yellow on the lower half, in combination with a mainly yellow-orange dorsal fin and a scarletred anal fin. The caudal fin of the male is particularly distinctive, being emarginate but appearing lunate due to a clear central portion and tapering red bands along dorsal and ventral margins. Females can be distinguished from sympatric congeners by having a large black spot on the upper caudal peduncle. Sequencing of the mtDNAbarcode marker COI reveals that the new species has identical sequences to C. rubripinnis and C. aff. tonozukai from the Philippines, which have very different color patterns and tail shapes from the new species, indicating the new species has diverged recently and/or there is historic or episodic hybridization within the species complex. 

Key words: taxonomy, systematics, ichthyology, coral-reef fishes, Indo-Pacific Ocean, fairy wrasse, DNA barcoding. 

Figure 3. Cirrhilabrus greeni, aquarium photographs of live male holotype, 47.3 mm SL, eastern Timor Sea (M.P. Hammer).

Cirrhilabrus greeni, n. sp. 
Sunset Fairy-wrasse

Diagnosis. Dorsal-fin elements XI,9; anal-fin elements III,9; pectoral-fin rays 15; lateral-line scales 16–17 + 6–7; median predorsal scales 5; single horizontal scale rows on cheek below eye; gill rakers 13; body depth 3.6- 3.7 in SL; head length 2.9–3.0 in SL; snout length 3.5–4.3 in HL; dorsal fin mostly uniform height; pelvic fins of TP male moderately elongate, reaching posteriorly to about base of first soft anal-fin ray, 2.7–3.9 in SL; caudal fin distinctly emarginate, appearing lunate in males due to tapering red bands along dorsal and ventral margins. TP male in life mainly reddish on upper half of body and bright yellow below; dorsal fin mainly yellow orange, grading to reddish basally with dark-edged white or clear bands on basal half of soft rays; anal fin scarlet red; caudal fin translucent medially with tapering red bands along dorsal and ventral margins; pelvic fins pinkish; pectoral fins translucent with brilliant red triangular mark immediately above base. Female in life rosy pink on upper two-thirds of head and body, grading to whitish ventrally; body with 4–5 narrow reddish stripes on upper half; dorsal fin pinkish yellow with faint red bands and dark brown first spine; anal fin pink with faint red bands; caudal fin with numerous transverse rows of faint red spots, except darker red along edge of lower lobe; black spot, about one-third to half pupil size, on upper side of caudal peduncle.

Etymology. The species is named in honor of Tim Green of Monsoon Aquatics (Darwin, Australia), who collected the type specimens.

Distribution and habitat. The new species is currently known only from the eastern Timor Sea (Fig. 5), approximately 300 km northwest of Darwin, Australia and 300 km southwest of the Tanimbar Islands of Indonesia. It was collected and observed in depths of about 18–40 m. The habitat consists of sloping rubble bottoms with scattered low outcrops of rock or coral and occasional large coral outcrops. It co-occurs with several other members of the genus including C. hygroxerus and four species of undetermined status that are related to C. cyanopleura (Bleeker, 1851); Cexquisitus Smith, 1957; Cpunctatus Randall & Kuiter, 1989; and C. temminckii Bleeker, 1853.

Allen, G.R. and Hammer, M.P. 2017. Cirrhilabrus greeni, A New Species of Wrasse (Pisces: Labridae) from the Timor Sea, northern Australia. Journal of the Ocean Science Foundation. 29, 55–65. DOI:  10.5281/zenodo.1115674

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