Insulamon, NG & TAKEDA, 1992

Freitag, Hendrik, 2012, Revision Of The Genus Insulamon Ng & Takeda, 1992 (Crustacea: Decapoda: Potamidae) With Description Of Four New Species, Raffles Bulletin of Zoology 60 (1), pp. 37-55 : 38

KEY TO THE INSULAMON SPECIES

Proper identification without comparative material should be based on adult males.

1. Carapace not broader than 1.29 times length, and G1 with long distal part (tip) of terminal segment as long as or longer than dilated proximal base ( Figs. 3D , 7F ) .................................... 2

– Carapace at least, but usually more than 1.29 times as broad as long, and G1 with short distal part (tip) of terminal segment always shorter than dilated proximal base ( Figs. 5 F–K, 9F, 11F) ....................................................................................... 3

2. Male telson less than 1.2 times as broad as long ( Fig. 2C ). Tip of G1 sharply tapered ( Fig. 3 C–E). (Calamian Islands) ........ ................................................................................. I. unicorn

– Male telson more than 1.2 times as broad as long ( Fig. 6C ). Tip of G1 not sharply tapered, rather clubbed or hooked ( Fig. 7 D–H). (Palawan) .................................................. I. magnum

3. Male sixth abdominal somite not broader than 1.9 times length, and tip of G1 distinctly hooked, perpendicular to the longitudinal axis ( Fig. 9 D–H). (Palawan) .................... I. johannchristiani

– Male sixth abdominal somite at least, but usually broader than 1.9 times length; tip of G1 more or less straight, not hooked, pointing somewhat in the direction of the G1 longitudinal axis, not perpendicular ( Figs. 4 A–C, F–K, 11D–H). (Palawan) .. 4

4. Distal portion of G1 terminal segment corkscrew-like, curly at its base; proximal portion of terminal segment slender, not inflated subproximally and appearing evenly tapered ( Fig. 11 D–H). Terminal segment of mandibular palp most narrow medially, not evenly tapering. (Palawan) ........... I. porculum

– Distal portion of G1 terminal segment not corkscrew-like at its base, only slightly twisted or bent at its base and proximal portion of terminal segment at least slightly, usually distinctly inflated subproximally and not evenly tapered ( Fig. 4 A–C, F–K). Terminal segment of mandibular palp evenly tapering towards apex. (Palawan) ................................ I. palawanense

Figures

Fig. 3. Insulamon unicorn, male (38.8 by 30.2 mm) from San Nicolas (164a): A, left second maxilliped; B, left third maxilliped; C, left G1, ventral view; D, tip of left G1, ventral view (SEM picture); E, left G1, dorsal view; F, left G2 basal segment (flagellum broken off), ventral view. Scale bars = 1 mm.

Fig. 7. Insulamon magnum, new species. Paratype male (33.6 by 26.2 mm) from Pasadeña (114a): A, left third maxilliped; B, left second maxilliped; C, left G2 ventral view; D, left G1 ventral view; E, left G1, dorsal view, F, tip of left G1, ventral view (SEM picture). Paratype male (26.9 by 22.0 mm) from Manguao (11b) tip of left G1: G, ventral view; H, dorsal. Scale bars = 1 mm.

Fig. 5. Insulamon palawanense, new species. Holotype male:A, left G1 ventral view; B, left G1 dorsal view; C, tip of left G1 ventral view (SEM picture); D, left G2 ventral view; E, left third maxilliped; paratype males, left G1 tip ventral, gradual variations from southern to northern specimens: F, from Salugon (147c), (30.5 by 23.3 mm); G, from Luzviminda (155) (24.7 by 19.1 mm); H, from Irawan (60), (33.7 by 25.0 mm); I, from Tarabanan (16b), (26.1 by 20.2 mm); J, from Dumarao (135), (29.3 by 22.1 mm); K, from Bagong Bayan (129c), (31.1 by 23.5 mm). Scale bars = 1 mm.

Fig.2. Insulamon unicorn, male (38.8 by 30.2 mm) from San Nicolas (164a): A, dorsal view; B, frontal view; C, ventral view.

Fig. 6. Insulamon magnum, new species. Holotype male from Lake Manguao catchment: A, dorsal view; B, frontal view; C, ventral view. D, ov. female (44.0 by 34.2 mm) from Abongan (108), ventral view.

Fig. 9. Insulamon johannchristiani, new species. Holotype male: A, left third maxilliped; B, left second maxilliped; C, left G2 ventral view; D, left G2 ventral; E, left G2 dorsal; F, tip of left G1 ventral (SEM picture). Paratype male (23.1 by 17.8 mm) from Taytay (65), tip of left G1: G, ventral view, H, dorsal view. Scale bars = 1 mm.

Fig. 4. Insulamon palawanense, new species.Paratype male (35.3 by 26.3 mm) from Dumarao (135):A, dorsal view; B, frontal view; C, ventral view. D, paratype female (28.5 by 22.2 mm) from Bagong Bayan (129c), ventral view.

Fig. 11. Insulamon porculum, new species. Holotype male: A, left third maxilliped; B, left second maxilliped; C, right G2, ventral view, flipped; D, left G1 (with G2 flagellum) ventral view; E, left G1dorsal view; F, tip of left G1 ventral view (SEM picture). Paratype male (23.5 by 17.7 mm) from Taranaban (16b), tip of G1: G, ventral view; H, dorsal view. Scale bars = 1 mm.