Pseudograpsus crassus A. Milne-Edwards, 1868

Fig. 4F

Pseudograpsus crassus, Ward 1941: 2 .

Material examined. 1 male, 34.5 by 30 mm, 2 females, 37.3 by 32.0 mm, 30.1 by 26.9 mm (ZRC; NJL160831–33) Iligan town, Lanao del Norte prov., coll. N.J. Lagare, 19–21 Sep. 2016 .

Remarks. Pseudograpsus crassus A. Milne-Edwards, 1868 (type locality: Sulawesi, Indonesia) has been recorded mostly from Indonesian islands, including Halmahera, Karakelong, Flores, and Sumba, and from freshwater habitats up to an altitude of 800 m asl (Holthuis 1978; Cai & Ng 2003). Pseudograpsus crassus has only been previously reported once from the Philippines, particularly in a list of crabs collected from the Davao Gulf by Ward (1941). The present material from Iligan agrees well with published descriptions and figures (A. Milne-Edwards 1868: 176, pl. 26 figs. 6–10; Tesch 1918a: 98). Their live colouration is quite distinctive, with the carapace and chelipeds having a marmorate to reticulate patterning of dark brown and yellow (Fig. 4F). The crabs were found hiding beneath rocks along the slow moving stream about 1 km inland, and syntopic with the freshwater potamid crab, Isolapotamon sp., as well as other grapsoid crabs, Utica gracilipes and Sesarmops imperator .