Miersarma granosimanum (Miers, 1880)

(Figs. 24A, B, 25J, 29 A, 31 D, E, 32 D, 40, 44 I)

Sesarma granosimana Miers, 1880: 24, pl. 14 fig. 3; De Man, 1887: 644; Tweedie, 1940: 92; Tweedie, 1950: 343, fig. 2a.

Sesarma (Sesarma) granosimana – De Man, 1895: 143.

Sesarma (Holometopus) granosimana – Tesch, 1917: 155; Roux, 1933: 10; Serène, 1968: 107.

Pseudosesarma granosimanum – Ng et al., 2008a: 222.

Material examined. Lectotype (here designated): male (16.9 × 14.8 mm) (NHM 1880.6), Borneo, purchased by E. Gerrard from Dr. P. Bleeker collection. PENINSULAR MALAYSIA – 5 males, 8 females (ZRC 2002.0162), Malaysia, Johor, Muar, Tanjong Olak, Bukit Pasir, coll. Y.Y. Goh, 28 May 1998; 46 females, 33 males (ZRC 1973.11.2.191–268), near Sedili River, Johor, Sungei Kayu, swamp forest, coll. 1937; 7 males, 2 females (ZRC 1965.7.29.164–173), Sungei Kayu, swamp forest near Sedili River, Johor, coll. February 1937; 1 male (ZRC 1965.7.29.174), Sedili River, Johor, coll. October 1937; 2 males, 2 females (ZRC 1965.7.29.175–178), Kota Tinggi, Johor, no date. SARAWAK – 4 males, 2 females (ZRC 1965.7.29.179–184), Kuching, freshwater ditch, coll. M.W.F. Tweedie, December 1948.

Diagnosis. Carapace squarish; no epibranchial tooth present, lateral margin entire; posterolateral margins subparallel; outer surface of chela gently convex, covered with small squamiform granules, ventral margin of palm sinuous, serrated; suture between male thoracic sternites 3 and 4 undiscernible; male pleon broadly triangular; male sternopleonal cavity without press-button of pleonal locking mechanism on sternite 5; G1 slender, straight, relatively long chitinous distal part bent at almost right angles.

Colour. Not known.

Remarks. In Miersarma granosimanum, the entire surface of sternites 1–4 appears almost contiguous, without any trace of a ridge or suture. However, this surface is uneven and when dried, the separation between sternites 2 and 3 can just about be discerned.

The G1 is characteristically long and slender, with an elongate distal part. The G1 is somewhat twisted; viewed from one angle, it appears almost straight (e.g., Fig. 40B, C, J), but when slightly adjusted, it appears distinctly sinuous (Fig. 40F, G). In the lectotype male, the G1 is in poor condition and slightly shrivelled, the subdistal part of the G1 appears slightly damaged, with a small flange visible (Fig. 40D, E).

Roux’ (1933) record of the species from Palembang in Sumatra cannot be confirmed. It is retained as a synonym of M. granosimanum until the specimens can be re-examined.

Biology. Tweedie (1940: 92) writes that he obtained a “good series from fresh-water swamp-forest near the river Sedili, Johor. A single specimen from among nipah palms beside the river Sedili, where the water is slightly saline”. The more recent specimens from Muar (ZRC 2002.0162) were collected from behind a mangrove.

Distribution. Known from Peninsular Malaysia, Borneo, and Sumatra (Roux, 1933; Tweedie, 1940, 1950).