Identity of the tree-spider crab, Parasesarma leptosoma (Hilgendorf, 1869) (Decapoda: Brachyura: Sesarmidae), with descriptions of seven new species from the Western Pacific Author Li, Jheng-Jhang Author Rahayu, Dwi Listyo Author Ng, Peter K. L. text Zootaxa 2018 2018-09-19 4482 3 451 490 journal article 29418 10.11646/zootaxa.4482.3.2 fd24ef18-76ac-46f1-aec2-2faf5b0ff325 1175-5326 1440707 3FBE11E2-9F97-4A29-92A9-67780C782E0D Parasesarma purpureum n. sp. ( Figs. 13 , 14 , 19F , 20E , 21F , 22D , 23D , 24E ) Material examined. HOLOTYPE : male (15.9× 13.7 mm ) ( ZRC 2012.0755 a), Peninsular Malaysia : Tioman Island , 7 July 2012 , B.Y. Lee . PARATYPES: 3 males (10.7× 9.2 mm , 13.9×12.0 mm, 15.5× 13.3 mm ), 4 females (12.6× 10.7 mm , 13.5×12.0 mm, 14.9× 12.7 mm , 15.6×13.0 mm) ( ZRC 2018.0794 ), same data as holotype. —3 males (11.9×10.0 mm, 12.7× 10.8 mm , 14.2× 12.8 mm ), 4 females (10.9×9.0 mm, 12.1× 10.6 mm , 12.6× 10.5 mm , 14.0× 12.2 mm ) ( ZRC 2018.0795 ), Peninsular Malaysia : Tioman Island , 4 July 2012 , B.Y. Lee. —2 males (11.4×10.0 mm, 11.7× 9.8 mm ), 1 female (13.5×11.2) ( ZRC 2018.0796 ), Peninsular Malaysia : Tioman Island , 5 July 2012 , B.Y. Lee. —3 males (12.7× 10.8 mm , 13.1× 10.8 mm , 13.1× 10.9 mm ), 3 females (12.3× 10.4 mm , 13.6× 11.5 mm , 16.1×14.0 mm) ( ZRC 2018.0797 ), Peninsular Malaysia : Tioman Island , 6 July 2012 , B.Y. Lee. —1 male (12.2× 10.5 mm ), 1 female (14.5×13.0 mm) ( ZRC 2012.0755 b), Peninsular Malaysia : Tioman Island , 7 July 2012 , B.Y. Lee. —3 males (15.0× 13.5 mm , 13.4× 11.8 mm , 10.9× 9.8 mm ), 2 females (13.9×13.6, 12.3×11.1) ( ZRC 2018.0799 ), Malaysia : Borneo : Sabah , 27 February 2018 , J.- J. Li et al. . —1 male (12.6× 11.5 mm ), 1 female (15.4× 13.8 mm ) ( MZB Cru 4800), Malaysia : Borneo : Sabah , 27 February 2018 , J.- J. Li et al. . — 1 male (13.7× 12.4 mm ) (NMNS-7779-027), Malaysia : Borneo : Sabah , 27 February 2018 , J.- J. Li et al. . — 2 males (14.5×13.0 mm, 14.3× 13.4 mm ) ( NMCR 50704 ), Malaysia : Borneo : Sabah , 27 February 2018 , J.- J. Li et al. . FIGURE 13 . Parasesarma purpureum n. sp. . A–D, holotype male (15.9×13.7 mm) (ZRC 2012.0755a), Tioman Island, Peninsular Malaysia; E, F, paratype female (ZRC 2012.0755b), same locality. A, E, dorsal views; B, F, ventral views; C, D, frontal views. Diagnosis. Carapace ( Figs. 13A, E , 14A , 22D ) squarish in general outline, 1.2 times broader than long; regions well defined, separated by shallow grooves; postfrontal region distinct, separated into 4 lobes by deep grooves; front deflexed downwards ( Figs. 13C, D ) margin slightly concave in dorsal view; lateral margin straight, subparallel along most of length before curving to join almost straight posterior carapace margin; cornea extending or just reaching tip of external orbital tooth ( Figs. 13A, E , 14A , 22D ). Ischium of third maxilliped with shallow median sulcus, merus with distinct submedian ridge; exopod slender, tip reaching half-length of outer margin of merus, flagellum long. Male cheliped palm with 2 transverse pectinate crests (12 and 7 corneous teeth, respectively) on upper surface; upper surface of dactylus with 9 or 10 symmetrical, obliquely elongate dactylar tubercles, proximal tubercles steep, sharp, the others tubercles large, distalmost tubercle indistinct ( Figs. 14C, D , 19F ). Ambulatory legs relatively slender for this species-complex, P3 and P4 about 1.6 times carapace width; P3 and P4 coxae without dense setae; P3 merus 2.6 times as long as broad; P3 propodus 4.4 times as long as broad; P3 dactylus 0.4 times length of propodus ( Fig. 20E ). G1 relatively stout ( Figs. 14E–H , 21F ,); apical process corneous, short, bent at angle of 45°, long, stout, ending in rounded tip. G2 longer than quarter length of G1 ( Fig. 21F ). FIGURE 14 . Parasesarma purpureum n. sp. , holotype male (15.9×13.7 mm) (ZRC 2012.0755a), Tioman, Peninsular Malaysia. A, dorsal view of carapace; B–D, tip of left cheliped; E–H, left G1; B, lateral view of pectinate cristae on palm; C, dorsal view of palm and dactylar finger; D, lateral view of dactylar finger; E, G, dorsal (sternal) views; F, H, ventral (pleonal) views; E, F, distal part of G1. Scale bars: 1.0 mm. Colour in life. Carapace dark brown, fingers of chelipeds are pale white, ambulatory legs violet or purplish brown. ( Fig. 22D , 23D , 24E ). Remarks. Parasesarma purpureum n. sp. , is most similar to P. kui n. sp. (from Taiwan ) with regards to its relatively broader carapace. However, the following differences are observed; the carapace surface of P. purpureum has scattered tufts of short setae, the dactylar tubercles of the male chela are consistently nine in number ( Figs. 14D , 19F ,); the corneous tip of the G1 is proportionately broader ( Figs. 14E–H ); and the general colour in life is dark purple, or brownish-purplish with white chelae ( Figs. 22D , 23D ). By contrast, in P. kui n. sp. , the carapace surface is glabrous; the dactylar tubercles are nine or ten ( Figs. 10C, D , 19D ); the corneous tip of the G1 is proportionately narrower ( Figs. 10E–H ), and in life, the colour of the carapace is black or light brown, with the chelae possessing orange fingers ( Figs. 22C , 23C ). Etymology. From the Latin purpureum for “purple” with reference to the general colour of the new species. Distribution. So far known from Tioman Island, Peninsular Malaysia ; and Sabah , East Malaysia , Borneo. Ecology. Parasesarma purpureum n. sp. in Malaysia (Tioman Island and Sabah) is often observed at night and climbing on mangrove tree trunks and aerial roots above the water level.