Bioacoustics of Tuerkayana

1) The orbit with a large lateral gap closed by an obliquous margin and long, finely ornamented suborbital ridge, extending laterally below and beyond orbit, are characters shared by Leptograpsodes ( Figs 1G ; 2C ; 3D ) and Discoplax ( Fig. 6A ), but absent in Cardisoma ( Fig. 6B )and Tuerkayana n. gen. ( Fig. 6 C-E). Cardisoma Latreille, in Latreille, Le Peletier, Serville & Guérin, 1828 Cardisoma guanhumi Cardisoma guanhumi Latreille, in Latreille, Le Peletier, Serville & Guérin, 1828 (type species) Cardisoma armatum Cardisoma armatum Herklots, 1861 Cardisoma carnifex Cardisoma carnifex (Herbst, 1796) Cardisoma crassum Cardisoma crassum Smith, 1870 Discoplax A. Milne-Edwards, 1867 Discoplax longipes Discoplax longipes A. Milne-Edwards, 1867 (type species) Discoplax gracilipes Discoplax gracilipes Ng & Guinot, 2001 Discoplax michalis Discoplax michalis Ng & Shih, 2015 Tuerkayana n. gen. Cardisoma rotundum Tuerkayana rotundum (Quoy & Gaimard, 1824) n. comb. (type species) Discoplax celeste Tuerkayana celeste ( Ng & Davie, 2012 ) n. comb. Cardisoma hirtipes Tuerkayana hirtipes ( Dana, 1851 ) n. comb. Discoplax magna Tuerkayana magnum ( Ng & Shih, 2014 ) n. comb. 2) The organisation of thoracic sternites 3 and 4, completely fused without any demarcation, is shared by Leptograpsodes ( Figs 1C, D ; 3A ), Discoplax ( Fig. 5A, B ), Cardisoma ( Fig. 5D, E ) and Tuerkayana n. gen. ( Fig. 5G, H, J, K, M, N ). 3) The presence of a bridge at level of sternal suture 6/ 7 in Leptograpsodes ( Figs 1D, E ; 3A ), very thick in Discoplax ( Fig.5B, C ), less developed in Cardisoma ( Fig. 5E, F, C . guanhumi) (see Ng & Guinot 2001 : fig. 3A-C, C. guanhumi , C. carnifex and C. armatum , respectively), in Tuerkayana hirtipes n. comb. , and in T. aff. hirtipes ( Fig. 5H, I ), T. celeste n. comb. ( Fig. 5K, L ), T. magnum n. comb. ( Fig. 5N, O ), and T. rotundum n. comb. 4) The genital disposition is similar in Leptograpsodes ( Figs 1E ; 3B ), Discoplax ( Fig. 5C ), Cardisoma ( Fig. 5F ) and Tuerkayana n. gen. ( Fig. 5I, L, O ): the male gonopore, far from suture 7/8, occupies a posteriormost location in relation to sternite 8; it is close to P5 coxo-sternal condyle; the penis emerges just above this condyle, its proximal portion passing between sternite 7 and sternite 8. In T. magnum n. comb. ( Fig. 5O ) the gonopore is shortly separated from P5 condyle, the sternite 7 joining sternite 8 (a similar short joining is an individual variation observed in T. rotundum n. comb. ). In contrast, the male gonopore is quite distant from the P5 coxa in other gecarcinids, see below, Second gecarcinid subclade. 5) A similar stridulatory apparatus is shared by Leptograpsodes and Discoplax : in both sexes, pars stridens formed by the suborbital ridge and plectrum on the inner margin of cheliped merus, showing as distinct, demarcated, whitish ridge in Leptograpsodes ( Fig. 2C, D ) (at least up to some certain size) and as thickened ridge closer to the merus margin in Discoplax ( Fig. 11A ); these structures are absent in Cardisoma and Tuerkayana n. gen. The closest gecarcinid genus to Leptograpsodes is Discoplax with which it shares a wide, practically flat thoracic sternum, in the same plane (without inclination in the posterior portion, so the P1-P5 coxae are at a similar level), and a wide, not deeply hollowed sterno-pleonal cavity. Despite these similarities, there is no doubt that Leptograpsodes is not a gecarcinid. A main distinctive feature is the shape of sternite 8: weakly developed and unexposed medially in Leptograpsodidae n. fam ., and developed medially in all Gecarcinidae , except for Gecarcoidea , see below. The thoracic sternum of Leptograpsodes and Discoplax is very wide, whereas it is narrower in Cardisoma and Tuerkayana n. gen. The sterno-pleonal cavity is broad, not deeply hollowed in large-sized Leptograpsodes , narrower and deeper in Cardisoma and Tuerkayana n. gen. The current classification of Gecarcinidae does not reflect the existence of the two main subclades, supported by the congruence of morphological, larval and genetic data. Establishment of two subfamilies is strongly required but would not be appropriate in the present paper in respect of the project announced in Ng et al. (2008: 214) .