Rivulus haraldsiolii
Costa, Wilson J. E. M.Rivulus luelingi and R. haraldsiolii, two poorly known species of the R. santensis group from southern Brazil, are redescribed. Rivulus luelingi is endemic to the area between the Guaratuba bay and the Itapocu river, and R. haraldsiolii to the area between the Cubatao river and the Tijucas river. The two species are found between Cubatao and Itapocu river basins, but they are never syntopic; R. luelingi inhabits temporary pools and swamps in open areas or near the forest border, and R. haraldsiolii inhabits shallow creeks within dense forest. Rivulus luelingi and R. haraldsiolii are diagnosed by the number of caudal-fin rays, vertebrae, scales on longitudinal series and scale rows around caudal peduncle, relative position of dorsal and anal fins, and caudal-fin length. Rivulus luelingi is distinguished from all other species of the R. santensis group in having unique color patterns of flank and caudal fin in males. Rivulus luelingi and R. haraldsiolii differ from all other congeners by having multiple contact organs per flank scale in males.
Redescription of Rivulus luelingi and R. haraldsiolii (Teleostei: Cyprinodontiformes: Rivulidae), two valid killifish species from the Atlantic forest of the coastal plains of southern Brazil
Ichthyol. Explor. Freshwaters, Vol. 18, No. 2, pp. 175-182