Presumptive stridulatory organs in<i>Paranthura</i>cf.<i>japonica</i>Richardson, 1909 (Isopoda: Cymothoida: Paranthuridae)

Abstract Morphological diversity of sound-producing structures has not been well investigated among members superorder Peracarida. Presumptive stridulatory organs have reported in some amphipods and tanaidaceans, sound production by these documented two isopod species Oniscidea Sphaeromatidea. We describe three presumptive the paranthurid Paranthura cf. japonica Richardson, 1909, first case known Cymothoida. One type, consisting a scale-bearing knob on posterolateral corner pereonite anterolateral succeeding pereonite, was found between pairs pereonites (1, 2 2, 3). A second type involves serrated structure sub-posterolateral region 1 with sharp margins 3 appearing to provide corresponding plectra. The third an extension bearing pair posteroventral margin 2; anterior-ventrolateral edges appear All occurred both sexes P. japonica. Our discovery novel, intertidal indicates that much remains be learned about biology even common peracarid species.