Amatitlania nigrofasciata

'The height of the body is contained two times and one sixth in the total length (without the tail), the length of the head three times; the free part of the tail is considerably deeper than long. The head is as high as it is long, with the upper profile convex to the muzzle, where it is straight. The muzzle is of moderate size, the width of the preoperculum being equal to that of the orbit. The eye is somewhat closer to the end of the muzzle than to that of the operculum; its diameter is considerably less than the width of the interorbital space, and one quarter of the head's length. The jaws are of equal length. The soft dorsal and anal fins have scarcely any scales at their base, and are more or less produced in the middle, the longest rays reaching the middle of the tail. The dorsal fin begins at the vertical of the humerus; its spines are of moderate strength, rather short, the length of the twelfth being somewhat less than one third of that of the head. The anal spines are as long as, but rather more robust than those of the dorsal fin. The tail is rounded, two ninths of the total length. The pectoral is as long as the head, without the muzzle, extending to the second or third anal spine. The ventral is barely produced. This species is very dark in color. The ground color is a dark blackish-purple brown. A curved black band runs from the nape around the margin of the operculum to the interoperculum. A second is nearly concentric with the first, running from the nape to the back of the pectoral and ventral. The third is short, like a spot, between the front dorsal spines and the lateral line. The following ones are subvertical, slightly inclined backwards, and wider than the intervals between them. The second-to-last connects the ends of the dorsal and anal fins; the last crosses the root of the tail. The fins are black.'

— Günther, A.C.L.G. (literal translation of the description)