Melanorivulus illuminatus (Costa, 2007)

Family:  Rivulidae (Rivulines), subfamily: Rivulinae
Max. size:  2.88 cm SL (male/unsexed); 3.32 cm SL (female)
Environment:  benthopelagic; freshwater; pH range: 5.85
Distribution:  South America: swamp adjacent to córrego da Queixada, rio dos Bois drainage, rio Paraná basin in Brazil.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 9-11; Anal spines: 0-0; Anal soft rays: 12-14; Vertebrae: 30-31. Differs from all other species of the subgenus Melanorivulus by the possession of six pelvic-fin rays. Can be diagnosed by the unique combination of the following characters: entire flank with longitudinal rows of red dots; head with reduced black pigmentation; presence of a longitudinally elongated white mark above caudal spot in females, vertically elongate spots on caudal fin, often forming bars; dorsal and anal fins in males rounded; caudal fin with 32-33 rays; scales in longitudinal series 33-35; scales in transverse series 8; dorsal-fin origin in vertical through base of 7th or 8th anal-fin ray; and tip of pelvic fin reaching between base of 1st and 3rd anal-fin rays in males (Ref. 78126).
Biology:  Found in interconnected pools, about 30 cm deep, with clear water (Ref. 78126).
IUCN Red List Status: Vulnerable (VU); Date assessed: 07 November 2018 (D2) Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.