Review of the Chromis xanthura species group (Perciformes: Pomacentridae), with description of a new species

• Published in: Ichthyological research 2018-04, Vol.65 (2), p.177-191
• Main Authors: Motomura, Hiroyuki, Nishiyama, Hajime, Chiba, Satoru N.
• Format: Article
• Language: English
• Subjects: Animal behavior; Animal morphology; Animal Systematics/Taxonomy/Biogeography; Biomedical and Life Sciences; Biometry; Chromis; Chromis xanthura; Colour; Ecology; Fin ray counts; Fins; Fish; Freshwater & Marine Ecology; Juveniles; Length; Life Sciences; Marine fishes; Meristic counts; New species; Oceanic islands; Sibling species; Zoology
• ISSN: 1341-8998; 1616-3915
• DOI: 10.1007/s10228-017-0601-8

A taxonomic review of the Chromis xanthura species group, defined here as having 13 dorsal-fin spines, three upper and three lower procurrent caudal-fin rays, two black bands at the preopercular and opercular margins, and a yellow caudal fin when juvenile, resulted in the recognition of three species, Chromis xanthura (Bleeker 1854 ), Chromis opercularis (Günther 1867), and Chromis anadema sp. nov. Chromis xanthura and C. opercularis , the Pacific and Indian Ocean paired sister species, respectively, are redescribed, with confirmation of two color types of C. xanthura (having a white or black caudal peduncle and fin) as a single species on the basis of morphological and molecular analyses. Chromis anadema sp. nov., described from the oceanic islands of the Pacific Ocean on the basis of 21 specimens, is characterized by having 28–33 gill rakers; longest dorsal-fin soft ray length 20.0–24.7% of standard length (SL); first anal-fin spine length 5.0–6.1% of SL; caudal-fin length 33.4–43.8% of SL; posterior tips of caudal-fin lobes not filamentous in adults; broad black bands along preopercular and opercular margins, sum width of two bands 28.9–38.7% of head length; distal half of soft-rayed portion of dorsal fin transparent in adults; triangular black blotches at upper and lower caudal-fin base in adults; caudal peduncle and fin bluish black in adults; and body grayish, and all fins (except for pectoral fin) bright yellow in juveniles.