Lybia tessellata

Mendoza, Jose Christopher E. & Ng, Peter K. L., 2011, The Polydectinae Dana, 1851, of the Philippines, with description of a new genus for Lybia hatagumoana Sakai, 1961 (Crustacea: Decapoda: Brachyura: Xanthidae), Zootaxa 3052, pp. 51-61 : 53-54

Lybia tessellata (Latreille, in Milbert, 1812)

Grapsus tessellatus Latreille , in Milbert, 1812: 275 (type locality: Île de France = Mauritius).

Grapsus tesselatus [sic] —Latreille 1818: pl. 305 fig. 2. — Latreille 1829: 43 (note).

Melia tesselata [sic] — Latreille 1828: 705. — Ortmann 1893: 476. — Borradaile 1900: 580. — Bouvier 1915: 263 (86). Melia (= Lybia ) tresselata [sic] —H. Milne Edwards 1834: 431, pl. 18 figs. 8, 9.

Melia tessellata — Dana 1852b: 242; 1855: pl. 14 fig. 1a–d. A. Milne-Edwards 1862: 5. — Hoffmann 1874: 39. — Richters 1880: 140, 150, pl. 16 figs. 19–22. —De Man 1888: 326. — Borradaile 1902: 250, fig. 49. — Lenz 1905: 358. — Calman 1909: 705.

Lybia tesselata [sic] — Rathbun 1904: 102; 1911: 236. — Finnegan 1931: 647. — Balss 1938: 71. — Ward 1939: 10. — Tweedie 1950: 125. — Holthuis 1953: 23.

Lybia tessellata — Nobili 1906: 296. — Pesta 1911: 51, pl. 3 fig. 5. — Klunzinger 1913: 280 (184). — Barnard 1950: 249, fig. 46a, b. — Sankarankutty 1961: 121, 131, fig. 2A, B. — Guinot 1964: 100; 1967: 274; 1976: 70, figs. 17D, 18E, 19C, 20E– H, 22D, pl. 2 fig. 6. — Sakai 1965: 162; 1967: 78; 1976: 504, pl. 180 fig. 1. — Serène 1968: 88; 1984: 28, fig. 3, pl. 1 figs. D, E. — Kensley 1981: 44. — Dai et al. 1986: 352, pl. 51 fig. 1. — Dai & Yang 1991: 379, fig. 184, pl. 51 fig. 1. — Ho et al. 2000: 112. —Ng et al. 2008: 201(list).

Material examined. 2 males, 8.5 × 6.5 mm, 9.0 × 7.0 mm, 3 females, 8.5 × 6.5 mm to 9.5 × 7.0 mm (NMCR- 7258), Natangko Is., Mogpog, Marinduque Is., coll. R.G. Garcia, 15 Dec.1982; 1 male, 4.5 × 3.9 mm (NMCR- 7915), Melchor Is., Gasam, Marinduque Is., coll. R.G. Garcia, 9–15 Mar.1984; 1 male, 4.5 × 4.0 mm, 1 female, 6.9 × 5.8 mm (NMCR-9247), Maglawe, Currimao, Ilocos Norte, Luzon Is., coll. V.S. Palpal-latoc, Jun.1983; 1 female, 8.2 × 6.0 mm (NMCR-9025), Union, Nabas, Aklan, Panay Is., coll. M.R. Manuel & V. Bautista, Mar.1987.

Remarks. This is the type species of the genus. The present specimens agree well with published descriptions and illustrations of L. tessellata (type locality: Mauritius) ( Guinot 1976: 70, figs. 17D, 18E, 19C, 20E–H, 22D, pl. 2 fig. 6; Serène 1984: 28, fig. 3, pl. 1, figs. D, E). It is so-called (tessella, L., a small cubical piece of clay, stone or glass used to make mosaics) because of the live-colour pattern on its carapace, consisting of closely fitted polygons, mostly triangles, as in a mosaic or in tile-works. These polygons are surrounded by black or dark brown lines and are usually colored reddish-orange or lighter variations thereof. A prominent patch of reddish-orange is also seen on the suborbital region. The pereiopods are prominently banded with thin black lines and are also spangled with small, luminous white spots (cf. Sakai 1976: pl. 180 fig. 1).

This species is widespread throughout the Indo-West Pacific region ( Guinot 1976), although some records of L. tessellata , particularly from the Hawaiian Islands, are erroneous and are actually for a closely related species, L. edmondsoni Takeda & Miyake, 1979 (see Castro 2011). Surprisingly, no previous scientific records from the Philippines of this easily recognizable species have been found.