First Specimen-based Records of Canthidermis macrolepis (Tetraodontiformes: Balistidae) from the Pacific Ocean and Comparisons with C. maculata

Abstract

Canthidermis macrolepis (Boulenger, 1888) is newly recorded from Japan and Micronesia on the basis of nine specimens (206.9–349.8 mm SL), having been previously reported from the northwestern Indian Ocean and northern South China Sea (the latter based solely on DNA barcoding). The species is probably widespread throughout the Indo-West Pacific region but has been confused with Canthidermis maculata (Bloch, 1786). Detailed morphological comparisons of both species resulted in the following differences being recognized between them: numbers of body scale rows [38–41 (modally 40) in C. macrolepis vs. 40–49 (44) in C. maculata], second dorsal-fin rays [25–27 (26) vs. 22–26 (24)], anal-fin rays [22–24 (23) vs. 20–23 (21)] and pectoral-fin rays [14–16 (15) vs. 13–15 (14)]. Sequences of the mitochondrial DNA COI gene determined from the presently-reported specimens of C. macrolepis, which also differed in color from similarly sized C. maculata, having a uniformly grayish body without spots, were also compared with congeners. The Japanese standard name “Bouzu-mongara” is newly proposed for C. macrolepis.