Pakoko wrasse

description

Description. Dorsal rays IX, 11; anal rays III, 11; pectoral rays 12 (including upper rudimentary ray); 14 principal caudal rays; pelvic-fin rays I, 5; lateral line continuous, arched over pectoral fin, angling downward below posterior three or four dorsal rays, then becoming straight along midbody for peduncular portion, 27 pored scales (plus one on base of caudal fin); anterior lateral-line scales with 2 or 3 pores, gill rakers 17 (15 – 17); 25 vertebrae, last rib on vertebral centrum 9, last epineural on vertebral centrum 14 (Fig. 2); body depth 2.7 in SL (2.7 – 3.0); body width 7.4 in SL (7.0 – 8.5); head length 3.2 (2.9 – 3.2) in SL; snout 3.2 (3.2 – 4.0) in HL; orbit diameter 4.6 (4.4 – 5.1) in HL; interorbital width 3.7 (3.5 – 4.3) in HL; suborbital depth 0.2 (0.1 – 0.2) in HL; upper-jaw length 5.0 (4.5 – 5.9) in HL; least depth of caudal peduncle 1.9 (1.9 – 2.2) in HL; caudal-peduncle length 3.0 (2.3 – 3.8) in HL; caudal fin slightly rounded, 0.8 (0.7 – 0.8) in HL; pectoral fin 1.4 (1.5 – 1.6) in HL; pelvic fins not reaching the anus, 1.7 (1.7 – 1.9) in HL; first dorsal spine 3.3 (3.3 – 4.2) in HL; remaining dorsal spines progressively longer; longest (usually fifth or sixt

Macropharyngodon pakoko, a new species of wrasse (Teleostei: Labridae) endemic to the Marquesas Islands, French Polynesia

diagnosis

Diagnosis. Macropharyngodon pakoko can be distinguished from congeners by the following combination of characters: dorsal rays IX, 11; anal rays III, 11; pectoral rays 12 (including upper rudimentary ray); anterior lateral-line scales with 2 or 3 pores, gill rakers 17 (15 – 17). Color pattern of females: no black spot on chest at base of gill openings; spots on body widely spaced, particularly on head; caudal fin with small bright yellow spots in vertical rows; pelvic fins pale with three cross-bands of reddish orange to yellow; small reddish spots along the base of anal fin. Male body green, the scales with a dark purplish brown bar, those laterally and ventrally on body with bar preceded by a blue line; curved black humeral blotch, outlined with iridescent blue followed by a broad, irregular longitudinal band of a dark yellow-orange network superimposed over and adjacent to the bar pattern on the scales; head green with an anastomosing pattern of red bands edged with dark purple and iridescent blue; inverted irregular “ U ” - shaped band on cheek; small black spot at upper base of pectoral fin; dorsal and anal fins reddish with blue-ringed green spots with black border, some spot

Macropharyngodon pakoko, a new species of wrasse (Teleostei: Labridae) endemic to the Marquesas Islands, French Polynesia

discussion

Molecular analysis. Molecular data were examined for 9 of the 12 species of the genus (Table 1) and includes the hypothesized (based on color and morphological characters) closest relatives of M. pakoko. Two analyses (NJ and ML) resulted in identical tree topologies (Fig. 5). The topology of our trees (Fig. 5) is similar to that of Read et al. (2006) based on COI but also 12 S and 16 S rRNA mitochondrial sequences. Our mtDNA analysis reveals a well-supported genetic divergence between M. pakoko and its congeners (Fig. 5).

Macropharyngodon pakoko, a new species of wrasse (Teleostei: Labridae) endemic to the Marquesas Islands, French Polynesia

discussion

Remarks. Read et al. (2006) note that the species of Macropharyngodon are relatively uniform both ecologically and morphologically. In Randall’s (1978) key to the then known taxa (10 taxa included in the key), morphological characters distinguished only three of the taxa with life color characters needed to differentiate the remaining seven taxa. Our analysis of available molecular data (nine species) show clear genetic differentiation of all nine lineages that support the color pattern characters differentiating these nine morphologically similar taxa. Macropharyngodon pakoko is most similar morphologically and in color pattern to the relatively widespread M. meleagris, which is known in the Pacific and the eastern Indian Ocean from Cocos (Keeling) Islands to Southern Japan and the Great Barrier Reef, Lord Howe Island, and New Caledonia, east to the Line Islands and French Polynesia, except Rapa and the Marquesas. Although these two species have broadly overlapping morphological characters, they are readily distinguished genetically and by their diagnostic colour patterns. These two species are in turn similar to M. geoffroy (endemic to Hawaii) and M. ornatus (found in the Indian

Macropharyngodon pakoko, a new species of wrasse (Teleostei: Labridae) endemic to the Marquesas Islands, French Polynesia