Bioacoustics of Hymenoptera

SUPERFAMILIAL DIAGNOSIS (see Table 1 ) Carapace wider than long, widest in anterior half, generally transversally ovate or subquadrate, varying from not inflated to inflated and even vaultlike ( Fig. 1 ). Dorsal surface with regions hardly, weakly or distinctly demarcated. Lateral striae distinct, numerous ( Gecarcinidae restrict. ) or, if present, faint, and more often absent ( Cardisomatidae n. fam. ). In Cardisomatidae n. fam. , presence of a stridulatory apparatus only in Discoplax , with granular suborbital crest acting as pars stridens and thickened ridge on cheliped merus acting as plectrum. In Gecarcinidae restrict. , subhepatic and pterygostomial striae, one possibly acting as pars stridens (with inner surface of palm of chelae as plectrum): stridulation at least reported in Hartnollius lateralis but possible in other genera, which have similar striae. Carapace dorsal surface without grooves or with only a few grooves; cervical groove indistinct, shallow or deep; H-shaped depression; branchial regions more or less swollen, sometimes greatly swollen. Anterolateral margins strongly arched, convex, unarmed or granular, possibly with a single postorbital tooth or notch. Supra- and infraorbital margins not fusing or meeting along their outer edges. Orbits either proportionally very small, or small and deep, compared to carapace size ( Figs 2 D-F; 3B, C) ( Gecarcinidae restrict. ), or larger, transversally elongated ( Figs 2 A-C; 3A) ( Cardisomatidae n. fam. ). Fronto-orbital border more than half width of carapace ( Cardisomatidae n. fam. ) or half or less than half width of carapace ( Gecarcinidae restrict. ). Front entire, either relatively wide and weakly deflexed ( Cardisomatidae n. fam. ) or relatively narrow and strongly deflexed ( Gecarcinidae restrict. ). Antennular fossae linear, narrow or higher. Antennulae folded nearly transversally to slightly obliquely. Proepistome either prominently dome-shaped at various extent ( Cardisomatidae n. fam. ), or small and narrow, covered or not by subfrontal plate ( Gecarcinidae restrict. ). Antennae very small, nearly longitudinal; flagellum bent. Buccal frame either elongate-subquadrate, well delineated laterally, with wide, thick, straight anterior margin joining anterior border of epistome ( Figs 2 A-C; 3A) ( Cardisomatidae n. fam. ), or quadrate, subcircular or rhomboid, not delineated laterally, with its anterior border being the anterior limit of epistome ( Figs 2 D-F; 3B, C) ( Gecarcinidae restrict. ). Epistome with anterior margin either as two concave edges joining medially ( Cardisomatidae n. fam. ), or linear ( Gecarcinidae restrict. ). Mxp3, when closed, leaving rhomboidal gap, so food can still enter the mouth and be processed by mandibles; ischium and merus typically very wide; merus constricted at the point of its articulation with ischium; palp either articulating at antero-external angle of merus and normal, i.e., with three mobile articles visible externally ( Figs 2 A-C; 3A) ( Cardisomatidae n. fam. ), or articulating in middle of anterior border of merus and with first article fused to merus internal surface, the two mobile distal articles being concealed, not visible ( Figs 2F ; 3C ) ( Gecarcinus , Hartnollius ), or more or less visible ( Figs 2 E-F; 3B) (other genera of Gecarcinidae restrict. ). Mxp3 exopod either exposed and provided witht flagellum (concealed) ( Figs 2A, B ; 3A ; 4A ) ( Cardisomatidae n. fam. ), or conspicuously reduced in size, entirely concealed and without flagellum ( Figs 2E ; 3B, C ; 4B ) ( Gecarcinidae restrict. ). Pterygostomial region either as a broad densely setose area ( Figs 2 A-C; 3A) ( Cardisomatidae n. fam. ), or glabrous, naked ( Figs 2D, F ; 3B, C ) ( Gecarcinidae restrict. ). Pereopods 2-5 robust, unarmed (except dactyli); meri and dactyli rather long, with longitudinal setal ridges, often provided with spine-like stiff setae ( Cardisomatidae n. fam. ), variously armed with teeth and chitinous spines on dactylus ( Gecarcinidae restrict. ). Male pleon consisting of six free somites plus telson, entirely covering space between last pairs of legs; very long, its extremity ending either very close to suture 2/3 and even beyond it, or very slightly away. Male and female pleons bordered by thick fringe of setae along margins ( Cardisomatidae n. fam. ), or bordered by narrow fringe of setae along margins ( Gecarcinidae restrict. ). Female pleon either narrow, oval, and, thanks its dense fringe of setae on margins, completely filling thoracic sternum except for episternites, and leaving only a reduced lateral portion exposed; telson small and narrow, reaching more or less sternite 3 and mxp3 ( Fig. 8 ) ( Cardisomatidae n. fam. ); or much wider, discoid, leaving laterally and especially anteriorly a sternal portion exposed in addtion to the episternites; telson in the shape of a large triangle ( Fig. 9 ) ( Gecarcinidae restrict. ) (see Female pleon and pleopods ). Ridge on sternite 4 from more or less marked to very thick, surrounding telson and also extending partially along pleonal somite 6 ( Cardisomatidae n. fam. ) or surrounding telson only ( Gecarcinidae restrict. ). Pleonal somite 6 longest. Two main positions of sternal gonopore and penis: (1) in Cardisomatidae n. fam. , gonopore very close to P5 coxa (but without perforating it), and penis emerging from gonopore either at a relatively short distance from thoracic sternal suture 7/8 ( Figs 5C, E ; 7B : Cardisoma , Tuerkayana ) or emerging at a longer distance, far from thoracic sternal suture 7/8, in posteriormost location ( Discoplax ) (see Guinot et al. 2018 : fig. 5C, 5F, 5I, 5L, 5O: D. longipes , C. guanhumi , Tuerkayana aff. hirtipes , T. celeste and T. magnum respectively); (2) in Gecarcinidae restrict. , gonopore quite far from P5 coxa, and penis emerging at a longer distance in more sternal position, just below thoracic sternal suture 7/8 ( Figs 5D ; 7C, D : Gecarcoidea , Johngarthia ). Median line deep, either along sternites 8 and 7, reappearing sometimes on sternite 6 after median bridge ( Cardisoma ) ( Cardisomatidae n. fam. ) or along sternite 7, sometimes slightly extending on sternite 6 ( Gecarcoidea ) ( Gecarcinidae restrict. ). Locking structures either obscure, even absent ( Cardisomatidae n. fam. ) or present in Gecarcinidae restrict. as more or less developed sternal prominence or crest, or as a button more or less close to suture 4/5 ( Hartnollius ); but pleonal sockets not delimited, so pleonal locking no longer functional in the two families ( Guinot & Bouchard 1998 ). G1 long, slender, tip reaching thoracic sternal suture 4/5 or not reaching it completely ( Figs 5E ; 7B ) ( Cardisomatidae n. fam. ) or short, thick calcified part reaching about middle part of sternite 6 ( Gecarcinus , Hartnollius ), slightly behind ( Gecarcoidea , Johngarthia ) ( Figs 5F ; 7D ) ( Gecarcinidae restrict. ). G2 very small, spatuliform, without flagellum. Vulvae normally occluded by immobile, rigidly shut, calcified operculum (see below, Vulvae in Gecarcinoidea n. stat. ). No setal tufts of hydrophilic setae along first pleonal somites and setae on posterior margin of sternite 7 ( Cardisomatidae n. fam. ), or setal tufts of hydrophilic setae along first pleonal somites; setae on posterior margin of sternite 7, slightly on P5 coxae ( Gecarcinidae restrict. ).