Parasesarma ungulatum (H. Milne Edwards, 1853)

Lagare, Nickel Jean S., Mapi-Ot, Emmarie F., Molina, Ziljih S., Neri, Jemateo B., Nuñeza, Olga M. & Mendoza, Jose Christopher E., 2020, On a collection of freshwater and estuarine crabs (Crustacea: Brachyura) from Mindanao Island, the Philippines, Zootaxa 4868 (3), pp. 301-330 : 312

Parasesarma ungulatum (H. Milne Edwards, 1853)

Figs. 4B , 8 A–D

Sesarma quadrata, de Elera 1895: 543 .

Sesarma ungulata, De Man 1887: 655 (as a synonym of S. quadrata (Fabricius)) .— Estampador 1937: 538; 1959: 95.

Material examined. 1 male, 18.6 by 16.0 mm, ( ZRC; ZSM181405 ), Brgy. Badtasan, Kiamba town , Saranggani prov, coll. Z.S. Molina, 13 Jan. 2018 .

Remarks. Henri Milne Edwards (1853) described Sesarma ungulata from Celebes (= Sulawesi), providing a very short description. Long synonymized under Sesarma quadrata (Fabricius, 1798) (= Parasesarma plicatum (Latreille, 1803)) , S. ungulata was recognized by Rahayu & Ng (2010) as a distinct species of Parasesarma in their revision of the Parasesarma plicatum species complex. They selected a dried male specimen (MNHN BP 3694) deposited in the Museum national d’Histoire naturelle, Paris, to be the lectotype, thus stabilizing the taxonomy of the species. Other authors ( Rahayu & Ng 2010; Maenosono & Naruse 2015; Li et al. 2019) have also recorded specimens from several other localities (viz. Papua & Lombok, in Indonesia; Peninsular & Eastern Malaysia; Singapore; Gulf of Thailand; Hainan & Hong Kong, China; Ryukyu Is., Japan; and Taiwan). The only record of this species from the Philippines is De Man’s (1887), where, in his treatment of Sesarma quadrata , he regarded S. ungulata as a junior synonym, stating “…die Varietät ungulata mit acht Querwülsten bewohnt die Philippinen und die Küsten von Celebes” (De Man 1887: 655). Estampador (1937, 1959) subsequently cited De Man’s record in his checklists but did not mention any specific locality. De Elera (1895) recorded “ Sesarma quadrata ” from Manila, Luzon I., which we consider to be most probably a misidentification of P. ungulatum .

The present male specimen from Kiamba generally agrees with the description and figures of Rahayu & Ng (2010: 11, figs. 8–10), primarily in the general shape of the carapace and male pleon, the proportion of the ambulatory legs, the number of tubercles on the dorsal surface of the chelar dactyli, and the general shape of the G1. It differs in the live colouration ( Fig. 4B ) as it does not have the light-coloured, transverse, postfrontal band and bright red chelae seen in the specimen from Papua (cf. Rahayu & Ng 2010: fig. 8). Furthermore, the corneous distal tip of the G1 has a protruding distal border ( Fig. 8C, D ) rather than a truncated distal border (cf. Rahayu & Ng 2010: fig. 10A–D). It should be noted that Rahayu & Ng (2010) did not examine fresh material from Sulawesi, the type locality, itself. Given Kiamba’s proximity to Sulawesi, we have opted to provisionally identify the Kiamba specimen as P. ungulatum until such comparison can be made.

Figures

FIGURE 4. Colour photos of recently preserved crabs (dorsal habitus). A, Parasesarma sanguimanus Li, Shih & Ng, 2019, male, 20.2 by 16.8 mm (ZRC), Kiamba, Saranggani; B, Parasesarma ungulatum (H. Milne Edwards, 1853), male, 18.6 by 16 0 mm (ZRC), Kiamba, Saranggani; C, Sesarmops imperator Ng, Li & Shih, 2020, male, 35.6 by 33.7 mm (ZRC), Mambajao, Camiguin Island; D, Sesarmops mora Li, Shih & Ng, 2020, male, 25.8 by 23.9 mm (ZRC), Maigo, Lanao del Norte; E, Tiomanium indicum (H. Milne Edwards, 1837), male, 42.5 by 36.7 mm (ZRC), Sindangan, Zamboanga del Norte; F, Pseudograpsus crassus A. Milne-Edwards, 1868, male, 34.5 by 30.0 mm (ZRC), Iligan, Lanao del Norte. Scale bars: 10 mm.

FIGURE 8. A–D, Parasesarma ungulatum (H. Milne Edwards, 1853), male, 18.6 by 16 0 mm (ZRC), Kiamba, Saranggani; E, F, Sesarmops imperator Ng, Li & Shih, 2020, male, 35.6 by 33.7 mm (ZRC), Mambajao, Camiguin Island; G, H, Sesarmops mora Li, Shih & Ng, 2020, male, 25.8 by 23.9 mm (ZRC), Maigo, Lanao del Norte. A, left chela, external view; B, left chela, dorsal view; C, E, G, right G1, pleonal view; D, F, H, right G1, sternal view. Scales: A, B = 2.0 mm; C–H = 1.0 mm.