Key for Karualona species of South-East Asia

1. Posteroventral angle of valves with several clusters of closely spaced denticles, with 3–5 denticles in each................................................................... .. Karualona serrulata Van Damme, Maiphae & Sa-adrit, 2013

1'. Posteroventral angle of valves with 2–5 widely spaced marginal denticles with setulae between them...................2

2. Posteroventral angle of valves with 4–5 marginal denticles; one-two posteriormost denticles curved downward................................................................................ Karualona kwangsiensis (Chiang, 1963)

2'. Posteroventral angle of valves with 2–4, rarely 5 marginal denticles; posteriormost denticles not curved downward................................................................................. Karulona karua (King, 1853) s. lato