Notoscopelus kroyeri dorsal fin has 21 or 22 soft rays, the anal fin has 18 to 20 soft rays and the pectoral fins have 12 to 13. Like other members of the genus, it has many small photophores on the sides and flanks of the fish, arranged in a fashion that is characteristic to this species. Mature males have a gland consisting of eight or nine luminous scale-like segments on the dorsal surface of the caudal peduncle, but they lack the bioluminescent patches on the cheek and above the eye that are characteristic of some members of the genus. "N. kroyeri" is
Operculum (brain) frontoparietal operculum, covers the upper part of the insular lobe from the front to the back. The opercula lie on the precentral and postcentral gyri (on either side of the central sulcus). The part of the parietal operculum that forms the ceiling of the lateral sulcus functions as the secondary somatosensory cortex. Normally, the insular opercula begin to develop between the 20th and the 22nd weeks of pregnancy. At weeks 14 to 16 of fetal development, the insula begins to invaginate from the surface of the immature cerebrum of the brain, until at full term, the opercula completely cover the