Neofundulus splendidus n. sp. is described from Bolivia, departamento de Santa Cruz, río San Miguel, upper Mamoré basin. Neofundulus splendidus n. sp. is distinguished from the remaining Neofundulus species by a combination of characters: Large black spot at humeral region with diameter of approximately 1.5-2.0 of pupil in males and females (vs. black spot in humeral region, when present, small- half of pupil), 40-41 scales in longitudinal series (vs. 35-38 in remaining congeners).This is the first record for the genus Neofundulus in río Mamoré basin.

Holotype: MNKP-11205, 01 male, 63.5mm SL, Bolivia. Deposited at Museo Noel Kempff, road San Miguel to San Juan, Departamento Santa Cruz, San Miguel city, río San Miguel, río Mamoré basin (16°46’22.0”S 61°11’12.6”W), altitude 440 m, 20 February 2012, Didier Pillet, Bruno Accorsi, Jean Marc Beltramon, Michel Beuchey& Christine Lambert.

Max. size 63.5 mm.
Dorsal 10
Anal 14,
D/A 2.7,
LL scale count (average)40-41
Pre- dorsal length to % SL – 67.1 %
Depth to % SL – 22.0 %

Nielsen D.T.B. and R. Brousseau, 2013. Description of a new species of annual fish of the genus Neofundulus (Cyprinodontiformes: Rivulidae), from the upper río Mamoré basin, Bolivia. Aqua International Journal of Ichthyology, pp 109-114, figs., 3, tab. 1.