Thelphusula dicerophilus Ng & Stuebing, 1990

Ng, Peter K. L. & Ng, Paul Y. C., 2018, The freshwater crabs of Danum Valley Conservation Area in Sabah, East Malaysia, with a description of a new species of Thelphusula Bott, 1969 (Crustacea, Brachyura, Gecarcinucidae, Potamidae, Sesarmidae), ZooKeys 760, pp. 89-112 : 89

Thelphusula dicerophilus Ng & Stuebing, 1990 Figure 6A, B

Thelphusula dicerophilus Ng & Stuebing, 1990: 46, fig. 1, pl. 1; Tan and Ng 1998: 813, fig. 6C; Ng et al. 2008: 73.

Material examined.

Holotype: male (14.0 × 12.0 mm) (ZRC 1989.3588), in pitfall trap, adjacent to pool of rhinoceros mud wallow, Danum Valley, Lahad Datu, Sabah, ca. 4°55'N 117°46', coll. R. Stuebing, 4 March l988. Paratypes: 1 female (18.3 × 15.0 mm), 2 juveniles (ZRC 1989.3592-3594), in pitfall trap, adjacent to pool of rhinoceros mud wallow, Danum Valley, Lahad Datu, Sabah, ca. 4°55'N 117°46', coll. R. Stuebing, 1 March 1988; 1 male (18.5 × 15.4 mm) (ZRC 1989.3591), in mist net in rhinoceros mud wallow pool, Danum Valley, Lahad Datu, Sabah, ca. 4°55'N 117°46', coll. R. Stuebing, 2 March l988; 1 male, 1 female (ZRC 1989.3589-3590), in rhinoceros mud wallow pool, Danum Valley, Lahad Datu, Sabah, ca. 4°55'N 117°46', coll. R. Stuebing, 2 March l988. Others: 1 female (11.0 × 9.5 mm) (ZRC 1997.0138), in pitfall trap, Danum Valley Field Centre, Lahad Datu, Sabah, coll. C. Colón, 14 October 1996; 1 male (16.4 × 13.5 mm) (ZRC 1997.0140), in pitfall trap, Danum Valley Field Centre, Lahad Datu, Sabah, coll. C. Colón, 10 October 1996; 1 male (20.0 × 15.8 mm) (ZRC 1997.0141), in pitfall trap, Danum Valley Field Centre, Lahad Datu, Sabah, coll. C. Colón, 17 October 1996; 1 male (22.0 × 17.6 mm) (ZRC 1997.0142), in pitfall trap, Danum Valley Field Centre, Lahad Datu, Sabah, coll. C. Colón, 19 October 1996; 1 male (10.5 × 9.0 mm), 1 female (17.8 × 14.9 mm) (ZRC 2017.1272), in mud and leaves under wooden walk-way, Orchid Trail, Danum Valley Field Centre, Lahad Datu, Sabah, at night, coll. local rangers, 20 July 2017; 1 female (26.1 × 21.3 mm) (ZRC 2017.1047), in pool along wooden walkway at night, Orchid Trail, Danum Valley Field Centre, Lahad Datu, Sabah, at night, coll. local rangers, 20 July 2017; 1 female (24.0 × 17.5 mm) (ZRC 1997.0139), Kunak, Baturong, Binuang River, Lahad Datu, Sabah, coll. R. Stuebing, 20 March 1989.

Colour.

In life, the carapace is reddish brown with the ambulatory legs lighter in colour; the chelipeds are orangish red with the fingers pale-yellow (Fig. 6A, B).

Remarks.

The present series of specimens do not change the original description of this species in any way. The species does grow substantially larger than the type series, with the largest specimen here, a female measuring 26.1 × 21.3 mm (ZRC 2017.1047).

The available collection data indicates T. dicerophilus is a semiterrestrial nocturnal species and forages on the forest floor, usually in wet, swampy areas, digging burrows in the soft substrate; they were often caught in pitfall traps set near these areas (see also Ng and Stuebing 1990). This contrasts with the more aquatic habits of its congener in Danum Valley, T. capillodigitus sp. n.