Discovery and description of two new ricefishes of the genus Oryzias (Atherinomorpha, Beloniformes, Adrianichthyidae) augments the endemic freshwater fish fauna of Southeastern Sulawesi, Indonesia

Oryzias asinua and O. wolasi are two new species of ricefishes described from several disjunct inland, freshwater habitats in the Indonesian province of Sulawesi Tenggara or southeastern Sulawesi. With O. woworae, the first described endemic ricefish of Sulawesi Tenggara, they comprise a group of small, colorful species characterized by orange to deep red dorsal and ventral margins of the caudal fin and the ventral margin of the caudal peduncle and at least the posterior portion of the base of the anal fin, and a bluish sheen on the body in both sexes that is most pronounced in live adult males. The two new species are distinguished from O. woworae by elongate middle dorsal-fin rays in males that reach the posterior extent of the first principal caudal-fin ray and by an orange--colored olfactory epithelium that marks each nasal organ in females. Oryzias asinua is relatively slender compared to O. wolasi and O. woworae: the body is narrow (21—25 persen SL, with a mean of 22.9, in O. asinua versus 23—32 persen SL, mean of 25.3 in O. wolasi and 22—30 persen SL, mean of 26 in O. woworae). Oryzias asinua has fewer procurrent caudal-fin rays in the lower lobe (4—5 versus 5—7 in O. wolasi and 5—6 in O. woworae). Oryzias wolasi is golden in life in both sexes and relatively deep-bodied, reaching 32 persen SL, has a deeper caudal peduncle (11—12 persen SL, mean of 11.2, versus 9—11, mean of 10 in O. asinua and 8—11, mean of 9.2, in O. woworae). Each species may be distinguished by its mitochondrial cytochrome c oxidase subunit 1 (COI) sequence or sequences, the DNA barcode. All species are allopatric. Description of O. asinua and O. wolasi brings the number of valid species in the beloniform family Adrianichthyidae to 33, 16 of which are endemic to Sulawesi. The two new species are just the second and third ricefishes described from the province of Sulawesi Tenggara, a neglected region in exploration and discovery of the freshwater fish fauna of the Indonesian islands of Sulawesi.Keywords: allopatry, Asinua Ricefish, Wolasi Ricefish, Oryzias woworae—species group, DNA barcode Copeia 2013 (3): 403-414. 2013