An inspection was carried out at shrimp farms located South West of Lake Maracaibo (Zulia State, Venezuela), with high incidences of mussel bivalve.Morphological and genetic analysis helped to identify the species as the dark false mussel Mytilopsis leucophaeata Conrad, 1831, and this is the first record of the species from tropical waters of northern South America.The highest incidences of mussels were detected in ponds and channels but no live mussels were observed in the coastal intertidal area surrounding the entrances of the farms, although empty shells were detected there, suggesting their former presence.The environmental conditions of the artificial system of shrimp culture, is a niche suitable for the proliferation of the bivalve.The consequences of the presence of this bivalve in the production of shrimp are discussed.