Paraleptuca Bott, 1973

Shih, Hsi-Te, Ng, Peter K. L., Davie, Peter J. F., Schubart, Christoph D., Türkay, Michael, Naderloo, Reza, Jones, Diana & Liu, Min-Yun, 2016, Systematics of the family Ocypodidae Rafinesque, 1815 (Crustacea: Brachyura), based on phylogenetic relationships, with a reorganization of subfamily rankings and a review of the taxonomic status of Uca Leach, 1814, sensu lato and its subgenera, Raffles Bulletin of Zoology 64, pp. 139-175 : 156

Paraleptuca Bott, 1973 , status nov.

( Fig. 10C, D )

Paraleptuca Bott, 1973b: 322 . Type species: Gelasimus chlorophthalmus H. Milne Edwards, 1837 , by original designation. Gender feminine.

Amphiuca Crane, 1975:96 . Type species: Gelasimus chlorophthalmus H. Milne Edwards, 1837 , by original designation. Gender feminine.

Diagnosis. Medium-sized species (carapace width about 20 mm in adults); dorsal carapace with posterolateral striae; front broad; cornea round; eyestalks slender; adult male chelipeds extremely large, right- or left-handed, pollex without ventral carina, outer surface of major manus smooth, with small round depression near base of pollex, carpal cavity not continued distally; male pleonites free; with pleonal clasping apparatus; gastric mill without large brownish setae at base of posterior tooth plate. Indo-west Pacific.

Species included:

1. Paraleptuca crassipes ( White, 1847)

= Gelasimus gaimardi H. Milne Edwards, 1852

= Gelasimus pulchellus Stimpson, 1858

= Gelasimus latreillei H. Milne Edwards, 1852

= Uca novaeguineae Rathbun, 1913

2. Paraleptuca boninensis ( Shih, Komai & Liu, 2013)

3. Paraleptuca chlorophthalmus (H. Milne Edwards, 1837) = Uca amazonensis Doflein, 1899

4. Paraleptuca splendida ( Stimpson, 1858)

Remarks. In Crane’s (1975) system, Amphiuca (= Paraleptuca ) contained four taxa, viz., Uca chlorophthalmus , U. crassipes , U. inversa and U. sindensis . In contrast, Beinlich & von Hagen (2006) established Cranuca for U. inversa , and believed that the members of the U. lactea and U. triangularis species complexes should be included within their revised concept of Paraleptuca . However, this has not been supported genetically ( Shih et al., 2013b; Fig. 2 ). Uca sindensis has since been transferred to Austruca ( Shih et al., 2013b; Fig. 2 ); while P. boninensis and P. splendida have now been added to Paraleptuca ( Shih et al., 2012, 2013a).

The revised concept of Paraleptuca here shows considerable variation in morphology and coloration among the four species ( Crane, 1975; Shih et al., 2012, 2013a), perhaps due in part to their unusual distributions ( Fig. 4 ). Paraleptuca chlorophthalmus occurs only in East Africa; P. crassipes is widely distributed across the IWP; P. splendida is restricted to East Asia and Vietnam; and P. boninensis is endemic to the Ogasawara Islands (= Bonin Island), Japan. The latter species is morphologically closest to P. splendida , but genetically (16S and COI), it is nearly identical to P. crassipes . Only the sequences from the mitochondrial control region (= D-loop) can separate the species satisfactorily ( Shih et al., 2013a). This is a strong indication that it is a young species that evolved very recently.

Figures

Fig. 10. Photographs of some species of the genera Minuca, Paraleptuca, Petruca and Tubuca. A, M. herradurensis (Panama); B, M. rapax (Brazil); C, Pa. chlorophthalmus (East Africa); D, Pa. crassipes (Donghsa, Taiwan); E, Pa. splendida (Penghu, Taiwan); F, Pe. panamensis (Costa Rica); G, T. arcuata (Hainan, China); H, T. bellator (Labuan, Malaysia). C, courtesy of S. Cannicci.

Fig. 2. A Bayesian inference (BI) tree of the family Ocypodidae and outgroups, based on the combined 28S, 16S and COI markers. The solid circle at the node means it is strongly supported by both BI (≥ 90) and ML (≥ 70); and the open circle means only one method is strongly supported. Name of species or genus quoted means it is suggested as a synonym in this study.

Fig. 4. The distribution of 11 genera of fiddler crabs, mainly based on Crane (1975) and the website (http://www.fiddlercrab.info/index. html; Rosenberg, 2014).