Neomerinthe pallidimacula ( Fowler 1938 )

Matsumoto, Tatsuya & Motomura, Hiroyuki, 2024, Neomerinthe ornithoptera, a new species of scorpionfish (Teleostei: Scorpaenidae) from the southwestern Pacific Ocean, with a reassessment of the diagnosis for N. pallidimacula (Fowler 1938), Zootaxa 5428 (1), pp. 135-145 : 142

Reassessment of Neomerinthe pallidimacula ( Fowler 1938) diagnosis

Neomerinthe pallidimacula was originally described by Fowler (1938) as Scorpaena pallidimacula , on the basis of a single specimen (USNM 98889, 76.0 mm SL) from Uanivan Island, Philippines, which remains the only known confirmed example of the species. Although N. pallidimacula has been distinguished from all other Indo-Pacific congeners by the lack of lateral lacrimal and second preopercular spines ( Motomura et al. 2016), a few specimens lacking lateral lacrimal and second preopercular spines have been observed in N. bucephalus , N. kaufmani , and N. megalepis (see Matsumoto & Motomura 2023; this study). However, N. pallidimacula clearly differs from the latter two species by having 45 scale rows in longitudinal series (vs. 37–44 in N. kaufmani ; 37–43 in N. megalepis ), 12 lower scale rows in the lateral line (vs. 8 or 9 in N. kaufmani ; 8–10 in N. megalepis ), and cycloid scales between the isthmus and posterior to the pelvic-fins (vs. ctenoid scales). Neomerinthe pallidimacula is similar to N. bucephalus in sharing the following morphological characteristics; numerous cycloid scales between isthmus and posterior to pelvic fins, 45 scale rows in longitudinal series (vs. 40–45 in N. bucephalus ), 12 scale rows below the lateral line (vs. 9–12), and 20 pectoral-fin rays (vs. 18–20). However, the former clearly differs from N. bucephalus in having a longer upper jaw, length 25.0% of SL (vs. 19.1–23.6% of SL in N. bucephalus , based on 60 specimens) ( Fig. 4A ), greater maxilla depth, 8.2% of SL (vs. 5.7–7.6% of SL) ( Fig. 4B ), shorter eleventh dorsal-fin spine, length 5.7% of SL (vs. 6.8–10.8% of SL) ( Fig. 4C ), and 22 pored lateral-line scales (vs. 23–25). In addition, the caudal-peduncle depth of N. pallidimacula is 11.3 % of SL, tending to be greater than that of N. bucephalus (8.6–11.6% of SL) ( Fig. 4D ). Although N. pallidimacula could be assessed only on the basis of a single specimen, comparisons were made with many examples of N. bucephalus . The study concluded that N. pallidimacula is a valid species, morphologically distinct from N. bucephalus .

Although Motomura et al. (2016) included in the diagnosis of N. pallidimacula , three white stripes on the lateral surface of the trunk, such a characteristic has been noted in some other long-term preserved specimens of the genus Neomerinthe [e.g., USNM 202511, 85.4 mm SL, holotype of N. kaufmani (see Matsumoto & Motomura 2023: fig. 9a); USNM 51266, 38.7 mm SL, paratype of Scorpaena izensis ( Jordan & Starks, 1904) and N. ignea (see Matsumoto et al. 2023: fig. 2d)], and it is clearly not diagnostic of the former species.

Figures

FIGURE 4. Morphological relationships of species of Neomerinthe. A, upper-jaw length; B, maxilla depth; C, 11th dorsal-fin spine length; and D, caudal peduncle depth (all as % of standard length) to standard length (mm) in N. bucephalus (circles) and N. pallidimacula (star).