The bobtail squid, Euprymna hyllebergi Nateewathana, 1997 was first described from the Andaman Sea of Thailand. Recently, the species was sampled in the Gulf of Thailand. Previously, 3 species of Euprymna have been identified from the Gulf of Thailand: E. morsei (Verrill, 1881), E. stenodactyla (Grany, 1833) and E. berryi (Sasaki, 1929) but these identifications remain unresolved since the material cannot be traced.