A report of two non-native shipworms (Mollusca: Bivalvia: Teredinidae) in the warm waters of Ladysmith Harbour, British Columbia, Canada

Natural wood and test panel surveys conducted in 2014 and 2023–2024 found three species of shipworms, one native and two non-native, in Ladysmith Harbour, British Columbia, Canada. The native species Bankia setacea (Tryon, 1863) is a northern cold water species, documented as resident since the 1800s. It was documented in the 2014 surveys and again in 2017 in Ladysmith Harbour. It is oviparous and the largest of the three. The other two species, Teredo bartschi W. Clapp, 1923 and Teredo navalis Linnaeus, 1758, are non-native brooders with cosmopolitan distributions. The known distribution in Canada of Teredo bartschi is limited to the warm waters at the head of Ladysmith Harbour and was collected in 1981, 2014, and 2024. This is the northernmost record on the northeast Pacific coast for Teredo bartschi. The 1981 sample reported as both Lyrodus takanoshimensis (Roch, 1929) and Lyrodus pedicellatus (de Quatrefages, 1849) in Ladysmith Harbor are corrected herein to Teredo bartschi. Surveys in 2024 found Teredo navalis for the first time at this location; this is the second record of this species in British Columbia. Possible pathways of introduction of the two non-natives include the import of oysters in wooden crates from Japan for aquaculture, the historical activity of wooden vessels, both commercial and recreational and log transport.