TABLE 3. Differences between Coelorinchus yurii and C. mascarenus in light of the ontogenetic variations in C. amirantensis. CharacterCoelorinchus yurii (HL 154–156 mm)Coelorinchus mascarenus (HL 72–95 mm)Ontogenetic variations in Coelorinchus amirantensis (HL 79–126 mm)Light organExternally invisible; no bold melanophore pigmentation along midline of bellyShort cleft-like in front of anus; with bold melanophore pigmentation on silvery background along midline of bellyNone [light organ externally invisible]Spinule rows on scales from cheek and opercleStrongly divergent (Fig. 12A)Parallel to weakly divergent (Fig. 12B)None [spinule rows divergent at all sizes]Spinule rows divergent, Spinule rows parallel to slightly None [spinule rows divergent at 3–5 in number; medial divergent, (5)6–8 in number; all sizes, 3–5 in number, medial Predorsal scales row conspicuously raised medial row only slightly less row conspicuously raised, more in comparison with that of inclined than that on flank scales strongly in smaller specimens] flank scales (Fig. 5J) (Fig. 5D)Scales between first dorsal- Spinule rows more or less fin base and lateral line divergentSpinule rows clearly parallelNone [spinule rows always parallel to slightly divergent]Lateral buttresses of spinules of flank scalesStrongly developed (Figs. 5K–L)Small to absent (Figs. 5E–F)Present [buttresses better developed in larger specimens]Spinules on scales from area between nasal fossa, orbit and suborbital ridgeArranged in 1 to 3 rowsPresent [in clusters or in 1 short Arranged in clusters, rarely in 1 row in smallest specimens to 1-3 short row on some scales rows in larger specimens]Scales in nasal fossaPresent along anterior and lower border (Fig. 16D)AbsentPresent, but nasal fossa better scaled in smaller specimensAbout 4; scales tightly Scale rows in narrowest joined, those in lowermost part of suborbital shelf row enlarged (Fig. 12C)Usually 1 (rarely 0 or 2); scales more or less separated by bare interspaces, all small (Fig. 12D)Present, but number of rows decreasing with growth; scales tightly joined at all sizes, those in lowermost row enlargedScale attachment on flanks, Adherent breast and bellyDeciduousNone [adherent at all sizes]Scale attachment on under- Firmly adherent everyside of snout whereStrongly deciduous in central portion of preoral region (or largely scaleless here in some specimens) and behind mouthNone [adherent]Suborbital shelfMore steep (Fig. 13B)More angular (Fig. 13A)Similarly angular in all specimens examinedSuborbital shelf width9.0 % HL5.6–6.5 % HL (mean 6.1 %)6.5–7.9 % HL, not corresponding with growthBody colorDarkerPalerDarker at all sizes

Published as part of Prokofiev, Artem M. & Iwamoto, Tomio, 2020, Revision of the Grenadier Genus Coelorinchus (Teleostei: Macrouridae) from the Mascarene Ridge, Western Indian Ocean, with Description of Two New Species, pp. 272 in Proceedings of the California Academy of Sciences 66 (9) on page 272, DOI: 10.5281/zenodo.11105838