Genetic confirmation of Tridacna noae (Röding 1798) in the Cook Islands

Abstract

Giant clams are common across a broad geographic range and contribute important ecological functions within coral reef environments. However, giant clams are subject to considerable harvest pressure and require careful management that is underpinned by accurate data collection. The taxonomy of giant clams has undergone many changes, and recently, Tridacna noae (Röding 1798) has been resurrected as a valid species, distinct from the morphologically similar Tridacna maxima (Röding 1798). Using genetic analysis, this research confirms the presence of T. noae for the first time in the Cook Islands, extending the currently known distribution of the species by 1340 km south-east. This confirmation highlights that T. noae was possibly previously misidentified, causing overestimations of the abundance of other giant clam species. This new record improves the accuracy of identification and stock assessments, and ongoing management in the Cook Islands.