Bioacoustics of Glyptograpsidae

To these synapomorphies corroborated by molecular studies, some characters must be added: absence of pleonal-locking mechanism, no button, no socket, the pleonal area where the socket is usually located being occupied by the G1’s tip; sterno-pleonal cavity very broad, with conspicuous rim at level of telson; thoracic sternum ( Fig. 8D, E ): suture 2/3 well marked, sternite 1 extending into a narrow process between mxp3; sternite 2 with a membranaceous depression; sternite 8 rather wide but not greatly exposed medially; median line extending on sternite 7; male gonopore with a posteriormost location in relation to sternite 8; penis short, with a sclerotised proximal portion ( Fig. 8F ). COMPARISON WITH LEPTOGRAPSODIDAE N. FAM . Glyptograpsidae shares with Leptograpsodidae n. fam . the median line extending on sternite 7, but the sternal emergence of the gonopore far from P5 coxa (N. K. Ng et al. 2007 : fig. 4G), the dispositon of sternite 8, the shape of penis are distinctive characters. The glyptograpsid suborbital ridge (N. K. Ng et al. 2007 : fig. 5G) does not consist in a stridulatory crest. Family PERCNIDAE Števčić, 2005 INCLUDED GENERA. — The family is monogeneric, with six species that show an active swimming capacity ( Zenone et al. 2016 ) by means of a developed setation (rows of postero-dorsal setae) on the long pereiopods that allow them to cling to hard surfaces. Species of Percnidae are, with the Plagusiidae and Varunidae, the only grapsoids able to extensively swim thanks to specialised modifications.