The fishes of the family Tripterygidae are commonly known as triplefins because its dorsal fin is divided into three segments. Of the 183 species recognized as valid only 16 are distributed in the eastern Pacific. Two endemic species and only members of the family are found in the FFS Malpelo Island: Axoclinus rubinoffi y Lepidonectes bimaculatus. In this work, additional data are provided on the adults and larvae of the triplefins of the sanctuary. The mean abundances of the larvae were 1,88 individuals/m2 for A. rubinoffi and 0.25 individuals/m2 for L. bimaculatus at the night stations where they were collected, 0.8 and 1.61 km to the west of the island and very close specifically on El Arrecife and La Nevera. The adults were collected around the island between 0-30 m depth and the abundance was 0.22 individuals/m2 for L. bimaculatus and 0.19 individuals/m2 for A. rubinoffi. The natural variability of the morphological traits of both species is extended and differences between the population densities with previous studies are found. To really understand the population dynamics of these species, it is necessary to evaluate long time series and include other methods such as genetic information.