Entire surface of body skin perforated by pores of ampullary organs; cephalic sensory canal system represented only by anterior portion of supraorbital canal enclosed by nasal bone, and posterior portion of postotic canal enclosed by pterotic and posttemporosupracleithrum; two anteriormost pores of supraorbital canal present medial to anterior and posterior nostrils, respectively; one or two pores of postotic canal on pterotic and between pterotic and posttemporosupracleithrum; body lateral line represented only by portion posterior to head, with one or two pores; head and body pit lines absent in most individuals; peritoneum and wall of pleuroperitoneal cavity blackish due to presence of many melanophores; eye small and supported by membranous outgrowth of hyomandibula and by membrane; and ceratobranchial and epibranchial bones without ossified gill rakers. The short dorsal fin has 5 precurrent rays plus 6 to 9 principal rays; anal fin has 4 precurrent rays and 6 to 8 principal rays.