Acestrorhynchus lacustris

Acestrorhynchus lacustris is a species of fish in the family Acestrorhynchidae. It was described by Christian Frederik Lütken in 1875, originally under the genus Xiphorhamphus. It inhabits the São Francisco and Paraná River. It reaches a maximum standard length of 27 cm.

A. lacustris spawns between July–March.