The fauna of the tropical Indo-west Pacific is exceptionally diverse but poorly known with even relatively well-studied faunal components yielding new species after careful study, novel approaches (e.g., delineation of cryptic species via molecular analyses) and/or rigorous collection efforts. In an attempt to quantify the biodiversity of the western Pacific molluscan fauna, comprehensive, systematic collecting expeditions have been made since 1978, with a focus on New Caledonia. Building on earlier studies of cardiids from the western Pacific, we report one new genus of cardiid (Pseudofulvia n. gen.) and 10 new cardiid taxa from the area: Acrosterigma capricorne n. sp., Fulvia (Fulvia) colorata n. sp., F. (F.) vepris n. sp., F. (Laevifulvia) subquadrata n. sp., F. (L.) imperfecta n. sp., Pseudofulvia caledonica n. gen., n. sp., P. arago n. gen., n. sp., Ctenocardia gustavi n. sp., C. fijianum n. sp., C. (Microfragum) subfestivum n. sp. The new species are easily differentiated from conspecifics in details of hinge, dentition, lunular shape and area, rib number and/or rib ornamentation, but often differ in gross morphological features, such as coloration, shape and size as well. Ctenocardia gustavi n. sp., C. (Microfragum) subfestivum n. sp. and Pseudofulvia caledonica n. gen., n. sp. are relatively large-bodied, with a wide distribution throughout the western Pacific. In contrast, Acrosterigma capricorne n. sp. and Pseudofulvia arago n. gen., n. sp. are known only from the Austral Islands and considering the intensive collecting efforts in the region, they appear restricted in their distributions.
Mollusca, Bivalvia, Cardiidae, tropical western Pacific, diversity, new genus, new species.