Five species of molluscan borers belonging to families Teredinidae and Pholadidae were found infesting the mangrove plants of Karachi. Synonyms and differentiating characteristics of the following five species are presented and pallets and shells illustrated: Bankia rochi, B. campanellata, Dicyathifer manni, Lyrodus pedicellatus and Martesia striata. These are reported for the first time from Pakistan. No relation between size of wood and number of borers was found. In most cases, wood contained individuals of one species. However, occurrence of 2 or 3 species in the same wood was not...