Ancistrus cf. temminckii was first found on O`ahu in 1985. Species in the genus Ancistrus are distinctive because of their prominent snout tentacles occurring in both sexes, with the tentacles having the greatest development in breeding males. The largest Ancistrus cf. temminckii specimen collected in Manoa Stream was 78 mm.

This species appears to preferentially select high velocity riffle and run habitats, and is less common in pool habitats. In Manoa Stream, bristle-nosed catfish densities are high and may also be in part contributing to the near absence of the native goby Awaous guamensis.

Native stream gobies are undoubtedly adversely affected by loricariid catfish through competition for food and space, and introduced parasites. Loricariid catfish found in O`ahu streams feed primarily on algae but will also readily consume fish eggs. Although habitat disturbance and other introduced fish are factors, native gobies such as Awaous guamensis are rare in the lowest sections of south shore O`ahu streams containing very high densities of introduced suckermouth catfish such as Manoa and Nu`uanu Streams.