Mephisto, Tyler, 1966

Bemis, Katherine E., Tyler, James C., Psomadakis, Peter N., Ferris, Lauren Newell & Kumar, Appukuttannair Biju, 2020, Review of the Indian Ocean spikefish genus Mephisto (Tetraodontiformes Triacanthodidae), Zootaxa 4802 (1), pp. 82-98 : 96

Key to species of Mephisto

1. Red to pink with lighter, almost white, areas and with darker red blotches below spinous dorsal fin, below posterior part of soft dorsal fin, and above pectoral fin from behind eye; ventral part of head, beginning under eye, light in coloration. Spinous dorsal fin mostly dark red; soft dorsal and anal fins white proximal to body and darker at distal tips (see Fig. 1 A–D). In alcohol, blotchy pattern remains and darkest red areas in life are brown (see Fig. 4A ). Pelvic width 10.6–12.1% SL, pelvic width into pelvic length 2.6–3.2 times; 16–19 gill rakers; 17–20 pseudobranch lamellae…................. Mephisto fraserbrunneri

2. Red with lighter, almost white, areas and with darker red blotches and prominent ventral, white, rounded (more-or-less circular to oblong) markings of up to as large as pupil diameter, to about half-way up body (see Fig. 1E, F ). Pelvic width 7.8% SL, pelvic width into pelvic length 4.0 times; 15 gill rakers; 16 pseudobranch lamellae (measurements and counts based on holotype only)............................................................................ Mephisto albomaculosus

Figures

FIGURE 1. Color photographs of Mephisto. See Table 1 for collection localities. A. Mephisto fraserbrunneri, University of Kerala DABFUK/FI/301, 64.5 mm SL. Photograph by A. Biju Kumar. B. Mephisto fraserbrunneri, University of Kerala DAB- FUK/FI/303, 64.2 mm SL. Photograph by A. Biju Kumar. C. Mephisto cf. fraserbrunneri, specimen not retained, est. 54 mm SL. Photograph by Oddgeir Alvheim. D. Mephisto cf. fraserbrunneri, specimen not retained, est. 89 mm SL. Photograph by Tom Williams. E. Mephisto albomaculosus, holotype, NSMT-P 132271, 94.4 mm SL. Photograph by Oddgeir Alvheim, from Matsuura et al. (2018), photograph reprinted with permission from the Ichthyological Society of Japan. F. Mephisto cf. albomaculosus, specimen not retained, est. 94 mm SL. Photograph by Oddgeir Alvheim, from Matsuura et al. (2018), photograph reprinted with permission from the Ichthyological Society of Japan.

FIGURE 4. Mephisto fraserbrunneri, University of Kerala DABFUK/FI/301, 64.5 mm SL. A. Specimen in alcohol. White arrows indicate the length of the gill opening, which is the diagnostic character for Mephisto. B. Radiograph of same specimen. Images by Sandra Raredon.