Parathelphusa undetermined

Freitag, Hendrik & Yeo, Darren C. J., 2004, Two New Species Of Parathelphusa H. Milne Edwards, 1853, From The Philippines (Crustacea: Decapoda: Brachyura: Parathelphusidae), Raffles Bulletin of Zoology 52 (1), pp. 227-237 : 228

KEY TO THE PARATHELPHUSA SPECIES OF THE PHILIPPINES

1. Both first and second epibranchial teeth well-developed, sharp .................................................................................................. 2

– First epibranchial tooth poorly-developed or low, blunt; second epibranchial tooth poorly developed or small, blunt (except in P. rasilis – second tooth well developed, sharp) .................. 5

2. Cervical grooves deep. Ambulatory leg merus always with sharp subdistal spine on dorsal margin. Sixth male abdominal segment elongated, ca. 1.30 times longer than broad. Tip of G1 with distinct subdistal notch on outer margin ( Figs. 1A, C, D, 1F , 2 , 3A, 3C , 4A ) (Palawan) ...................................... P. cabayugan

– Cervical grooves shallow. Ambulatory leg merus with or without subdistal spine on dorsal margin. Sixth male abdominal segment stout, ca. 1.05 to 1.21 times longer than broad. Tip of G1 without distinct subdistal notch on outer margin ............................... 3

3. Postorbital cristae with lateral part strongly arched in adults. Ambulatory leg merus with sharp subdistal spine on dorsal margin. G1 distinctly bent outwards, very slender, upper half of proximal part subequal in width to distal part; tip of G1 truncate, directed upwards ( Figs. 5A, C, D , 6 , 7A , 8A ) (Palawan) ............................................................................... P. manguao

– Postorbital cristae with lateral part not arched or very gently arched. Ambulatory leg merus usually without subdistal spine on dorsal margin. G1 sinuous or gently curved outwards, relatively broad, proximal part distinctly broader than distal part; tip of G1 sharp ....................................................................... 4

4. Carapace dorsal surface flat, with gastric and branchial regions flat. Sixth male abdominal segment relatively slenderer, ca. 1.21 times longer than broad. G1 gently sinuous; tip of G1 gently curved upwards (Ng & Takeda, 1993: Figs. 1B , F-J, 2D, I-M, 3) (Palawan) .................................................. P. palawanensis

– Carapace dorsal surface convex, with gastric and branchial regions swollen. Sixth male abdominal segment relatively stouter, ca. 1.05 times longer than broad. G1 gently curved outwards; tip of G1 directed upwards (Ng & Takeda, 1993: Figs. 4B , E-J) (Palawan) ................................................ P. saginata

5. Ambulatory leg merus with sharp subdistal spine on dorsal margin. Tip of G1 with shallow subdistal notch on outer margin (Ng & Takeda, 1993: Figs. 8C, D , G-J) (Palawan) ..... P. nana

– Ambulatory leg merus without subdistal spine, or with subdistal knob or blunt tooth on dorsal margin. Tip of G1 without subdistal notch on outer margin ........................................... 6

6. First epibranchial tooth lobiform. Sixth male abdominal segment appearing relatively stouter, ca. 1.07-1.09 times longer than broad ...................................................................................... 7

– First epibranchial tooth small, low, but not lobiform. Sixth male abdominal segment appearing relatively slenderer, ca. 1.10-1.19 times longer than broad ......................................................... 8

7. Carapace appearing more squarish, with very gently convex anterolateral margins. G1 proximal part with distinct knob on outer margin; tip of G1 directed upwards (Ng & Takeda, 1993: Figs. 9A, G-L) (Balabac) ....................................... P. balabac

– Carapace appearing more transverse, with more distinctly convex anterolateral margins. G1 proximal part without distinct knob on outer margin; tip of G1 gently curved upwards (Ng & Takeda, 1993: Figs. 10A, B, I-L) (Balabac) ............. P. parma

8. Ambulatory leg merus with subdistal knob or blunt tooth on dorsal margin. Tip of G1 sharp, gently curved upwards (Ng & Takeda, 1993: 11C, D, G-J) (Mindoro) ................. P. mindoro

– Ambulatory leg merus without subdistal knob or blunt tooth on dorsal margin. Tip of G1 not sharp, directed upwards .......... 9

9. Second epibranchial tooth indiscernible. Sixth male abdominal segment appearing relatively stouter, ca. 1.10 times longer than broad. Tip of G1 sub-truncate (Ng & Takeda, 1993: Figs. 8A , F-J) (Palawan) .......................................................... P. obtusa

– Second epibranchial tooth well-developed, sharp. Sixth male abdominal segment appearing relatively slenderer, ca. 1.16 times longer than broad. Tip of G1 truncate (Ng & Takeda, 1993: Figs. 6A, B , G-I, 7A-H) (Palawan) ........................... P. rasilis

Figures

Fig. 1. Parathelphusa cabayugan, new species, holotype male (32 by 25.3 mm) (PNM 17259). A, dorsal view of carapace; B, frontal view of carapace; C, right third ambulatory merus; D, right fourth ambulatory merus; E, left chela; F, abdominal segments 5-7. Scales = 10.0 mm.

Fig. 2. Parathelphusa cabayugan, new species, left G1. A, B, E, F, holotype male (32 by 25.3 mm) (PNM 17259); C, D, G, H, paratype juvenile male (15.2 by 13.1 mm) (SPCP-ASTD). A, C, ventral view; B, D, dorsal view; E, G, ventral view of distal part; F, H, dorsal view of distal part. Scales = 1.0 mm.

Fig. 3. Parathelphusa cabayugan, new species, holotype male (32 by 25.3 mm) (PNM 17259).A, dorsal view; B frontal view; C, ventral view.

Fig. 4. Parathelphusa cabayugan, new species, paratype female (26.4 by 21.6 mm) (ZIH).

Fig. 5. Parathelphusa manguao, new species. Holotype male (21.9 by 18.2 mm) (PNM 17283). A, dorsal view of carapace; B, frontal view of carapace; C, right fourth ambulatory merus; D, right third ambulatory merus; E, right chela; F, abdominal segments 5-7. Scales = 10.0 mm.

Fig. 6. Parathelphusa manguao, new species, left G1. A-D, holotype male (21.9 by 18.2 mm) (PNM 17283); E-H, paratype juvenile male (13.8 by 12.3 mm) (ZIH). A, E, ventral view; B, F, dorsal view; C, G, ventral view of distal part; D, H, dorsal view of distal part. Scales = 1.0 mm.

Fig. 7. Parathelphusa manguao, new species. Holotype male (21.9 by 18.2 mm) (PNM 17283). A, dorsal view; B frontal view; C, ventral view.

Fig. 8. Parathelphusa manguao, new species. A, paratype juvenile male (13.8 by 12.3 mm) (ZIH); B, paratype female (26.6 by 22.3 mm) (SPCP-ASTD).