Neostethus Regan, 1916

Parenti, Lynne R., 2014, A new species of Neostethus (Teleostei; Atherinomorpha; Phallostethidae) from Brunei Darussalam, with comments on northwestern Borneo as an area of endemism, Raffles Bulletin of Zoology 62, pp. 175-187 : 177

Neostethus Regan, 1916

Neostethus Regan, 1916:1 , 2

Type species. Neostethus lankesteri Regan, 1916 by original designation (use of “gen. et sp. n.” for one of two included new species).

Differential diagnosis. (modified from Parenti, 1989:269) Neostethus differs from all other phallostethines in having a priapium with an inner pulvinular bone (vs. lacking the bone), thin bony projections on the papillary bone that may number 80 or more (vs. lacking such bony projections) ( Parenti, 1989: fig. 3) and two ctenactinia (vs. just a single short or rudimentary second (and no first) ctenactinium in Phallostethus and Phenacostethus and one elongate first (and no second) ctenactinium in Gulaphallus ). Males lack an enlarged, fleshy seminal papilla and there is no translucent, membranous dome on the dorsal surface of the head as in Phallostethus and Phenacostethus . Males also do not have a perforated gular flap of skin through which the anterior end of the first ctenactinium projects or an aproctal axial bone that projects beyond the ventral body profile ( Parenti, 1989: fig. 4) which diagnoses Gulaphallus .

Composition. Twelve species, including the new species described herein ( Table 1).