About Stegastes beebei (Nichols, 1924)
This species has an oval, compressed body with one pair of nostrils. The margin of the preopercle is serrated, as is the margin of the bone under the eyes; this infraorbital bone has no notch, and the bone located before it also has no notch. The mouth is small and protrusible, with teeth arranged in a single row that are long and closely set. Individuals have approximately 11 (range 10 to 12) lower gill rakers. They possess a single continuous dorsal fin, and there are no projecting short spines at the upper and lower base of the tail fin. The caudal fin is bluntly forked. Scales are moderately large and rough; the entire body is scaled, most of the head is scaled (with scaling on the snout extending all the way to the nostrils), and the basal portions of the median fins are also scaled. The lateral line contains 20 scales, rarely 19. It is incomplete, ending beneath the end of the dorsal fin base. This species can grow up to 17 centimeters in total length. Adult Galapagos ringtail damselfish are dark brown with darker scale outlines, and often have a white band on the caudal peduncle. They have blue irises, and the outer edges of the pectoral fin are white or yellow. Juveniles are dark overall, with red coloring on the nape, upper back, and spiny dorsal fin, and a dark ocellus at the rear base of the dorsal fin. This species is distributed in the eastern Pacific Ocean, found off the coast of Panama, at Malpelo Island (Colombia), Cocos Island (Panama), and the Galápagos Islands.
