The gobioid fish genus Ptereleotris Gill, provisionally placed in the Microdesmidae by Hoese, is one of 5 named genera of the Ptereleotrinae. This genus is characterized by an elongate, compressed body; highly oblique mouth; a single posterior interorbital pore (when head pores are present); divided pelvic fins with I,4 rays; a dorsal fin formula of VI-I,23-39; and very small embedded scales which are primarily cycloid and nonimbricate. It has 6 generic synonyms: Vireosa Jordan and Snyder, Ioglossus Bean, Encaeura Jordan and Hubbs, Laccoeleotris Fowler, Pogonoculius Fowler, and Gracileotris Herre.
It consists of the following 12 Indo-Pacific species: Ptereleotris arabica, n. sp.; P. evides (Jordan and Hubbs) (P. dispersus Herre, Vireosa sakurai Schmidt, and P. tricolor Smith are synonyms); P. grammica Randall and Lubbock, P. hanae (Jordan and Snyder), P. heteroptera (Bleeker), P. lineopinnis (Fowler), P. melanopogon, n. sp.; P. microlepis (Bleeker) (Eleotris elongata Alleyne and Macleay, P. playfairi Whitley, P. letholepis Clark, P. andamensis Herre, and Gracileotris bockensis Herre are synonyms); P. monoptera, n. sp.; P. uroditaenia, n. sp.; P. zebra (Fowler); and P. sp.
Ptereleotris lineopinnis is known from a single specimen from a fish stomach from South Africa (2 specimens from the Mariana Islands, also from the stomach of a fish, seem to be this species); P. arabica is endemic to the Red Sea and Persian Gulf; P. uroditaenia is represented by one specimen from the Solomon Islands and underwater photographs taken on the Great Barrier Reef; P. melanopogon has been collected only in the Marquesas. The remaining species are more wide-ranging in the Indo-Pacific region.
Ptereleotris arabica is allied to P. hanae, sharing with it the rounded caudal fin with long trailing filaments (2 in arabica, 2-6 in hanae); it differs from hanae in having a distinct median fold on the chin, the fifth dorsal spine longest, and 26-29 dorsal soft rays. Ptereleotris uroditaenia is related to P. grammica, having the same fin-ray counts and an elevated first dorsal fin; it is readily distinguished from grammica by the 2 converging black bands in the caudal fin and lack of dark stripes on the body. Ptereleotris melanopogon has a blackish chin barbel, a rounded caudal fin without filaments, a high first dorsal fin (second spine prolonged in adults), a blackish lateral stripe, and a broad blackish bar passing ventrally from the eye. Ptereleotris monoptera is distinctive in its continuous dorsal fin (the last spine of the first dorsal and the initial spine of the second dorsal are broadly joined by membrane), its high number of dorsal and anal soft rays (the dorsal rays 35-39, the anal 33-37), and its emarginate caudal fin, the lobes filamentous in adults. The twelfth species of the genus, represented by 2 juveniles taken off Madang, New Guinea, is designated only as Ptereleotris sp. pending the collection of adults.