A new species of scorpionfish, Ebosia saya (Scorpaenidae: Pteroinae), from the western Indian Ocean and notes on fresh coloration of Ebosia falcata

Abstract

A new scorpionfish, Ebosia saya sp. nov. (Scorpaenidae: Pteroinae), is described on the basis of 10 specimens collected from the Saya de Malha Bank in depths of 95-126 m. Comparisons with two valid Indo-Pacific species, Ebosia bleekeri (Döderlein in Steindachner and Döderlein 1884) (western Pacific Ocean) and Ebosia falcata Eschmeyer and Rama-Rao 1978 (northern and eastern Indian Ocean), showed E. saya to be most similar to the latter, with both species sharing 8 (usually) anal-fin soft rays, 17 (usually) pectoral-fin rays, the elongated parietal spine of males relatively narrow and strongly falcate posterodorsally, and the pectoral fin predominantly yellow in males, whereas E. bleekeri has 7 (usually) anal-fin soft rays, 16 (usually) pectoral-fin rays, the elongated parietal spine of males relatively broad and weakly falcate, and the pectoral fins entirely red in males. However, E. saya differs from E. falcata in having 5 scale rows above the lateral line [vs. 4 or 5 (modally 4) in E. falcata], slightly greater total numbers (5-20, mean 12.3) of preocular, supraocular, and postocular spines at 60-90 mm 8.4), shorter postorbital length 18.1-19.2 (mean 18.7) % SL [vs. 19.8-23.5 (21.5) % SL], and the blotch above the pectoral-fin base and blotches on the pectoral-fin membrane all relatively smaller. Fresh coloration of E. falcata is described for the first time, based on specimens from the Andaman Sea (easternmost record for the species).

A new species of scorpionfish, Ebosia vespertina (Scorpaenidae: Pteroinae), from the southwestern Indian Ocean

“…Further sexual dimorphism included the third preopercular spine base, with females possessing a spineless ridge or a single spine on the base and males usually a ridge with 1-5 small spines, and the number of supraocular spines, with 1 or 2 in females and 1-7 in males, although the number of spines tended to increase with growth in both sexes. Sexual dichromatism has been reported for E. bleekeri and E. saya, wherein males possessed yellowish soft-rayed portions of the dorsal and anal fins (plus a yellow caudal fin in E. bleekeri and yellow pectoral fin in E. saya), whereas females of both species possessed all red fins (Matsunuma and Motomura 2014). Although life or fresh coloration of female E. vespertina was undetermined in this study, males possessed bright yellow soft-rayed portions of the dorsal and anal fins, and yellow caudal and pectoral fins when fresh (Fig.…”

“…In contrast, orbit diameter and all fin ray length proportions [except dorsal-fin spines (significantly damaged in most specimens examined)] became significantly less with growth. The supraocular skin flap became shorter (reduced in size) with growth in E. vespertina, as in congeners ( Matsunuma and Motomura 2014).…”

“…Counts generally followed Motomura et al (2005a-c) and Motomura and Johnson (2006); predorsal scale and cheek scale counts followed Motomura et al (2006b) and , respectively. Measurements of the diameter of the blotch above the pectoral-fin base and blotches on the pectoral-fin membrane followed Matsunuma and Motomura (2014). The last two soft rays of the dorsal and anal fins were counted as single rays, each pair being associated with a single pterygiophore.…”

“…Sexual dimorphism and dichromatism. Sexual dimorphism of parietal spine morphology in E. vespertina was recognized on the basis of five male (70.5-106.1 mm SL) and six (58.9-96.0 mm SL) female specimens, their sex having been determined by gonad examination (see Matsunuma and Motomura 2014). In males, the parietal spine becomes a thin elongated bony crest, strongly curved posterodorsally with growth, its posterior margin reaching a vertical through the second to fifth dorsal-fin spine bases (Figs.…”

“…The genus is characterized by having the coronal, parietal and nuchal spines bases continuous, and the parietal spine elevated, being a thin bony crest in males ( Jordan and Starks 1904;Eschmeyer and Rama-Rao 1978; Matsunuma and Motomura 2014). Three valid species are currently recognized in the genus, viz.…”