Insulamon johannchristiani, Freitag, 2012

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 : 48-49

Insulamon johannchristiani new species

( Figs. 8 A–D, 9A–H, 13H–I)

Type locality. — Lake Manguao catchment, Taytay Municipality, Palawan Island, Philippines

Palawan, Taytay, Bato, mountain creek near highway, secondary forest, shallow, rocks, sand, CPOM, c. 80m asl, 10°44'56"N, 119°30'20"E (101), coll. H. Freitag, 22 Aug.2007; 1 male (34.2 by 26.8 mm) (SMTD-Crustac-S112), Palawan, Taytay, Bato, mountain creek, degraded primary forest, rocks, sand, CPOM, riffle & fall, 10°44'57"N, 119°30'09"E (122), coll. H. Freitag, 6 Nov.2007; 3 males (33.6 by 26.2 mm, 27.1 by 20.6 mm, 23.1 by 17.8 mm) (SMF-38298), Palawan, Taytay, Poblacion, Tubog Creek tributary, public water source/ shallow spring, leaves, gravel, 10°49'02"N, 119°30'53"E (65), coll. H. Freitag, 21 Apr.2007; 1 male (31.1 by 24.0 mm) ( WPU), Palawan, Taytay, Poblacion, small hill stream, c. 4 km SE town proper, rocks, sand, leaves, degraded forest, c. 15 m asl, c. 10°48'05"N, 119°33'02"E (100), coll. H. Freitag, 21 Aug.2007; 1 male (29.7 by 22.0 mm) (NHMW-25177), Palawan, Taytay, Abongan, Ibangley, Abongan River tributary, highway km 178, shallow, sand, CPOM, 10°37'36"N, 119°23'07"E (108), coll. H. Freitag, 28 Sep.2007; 2 males (25.2 by 19.5 mm, 24.9 by 19.5 mm) (ZMUC-CRU-10085), Palawan, El Nido, road to Taytay, 0.5 km S of town proper, small creek, semi-primary forest, c. 10 m asl, 11°10'29"N, 119°23;39"E (70), coll. H. Freitag, 5 May 1995; 1 male (20.6 by 15.8 mm), 1 female (34.8 by 25.7 mm) (SMTD- Crustac-S113), Palawan, El Nido, Villa Libertad, small creek near Type material. — Holotype: male (38.5 by 28.7 mm) (NMCR- 39016), Palawan, Taytay, Poblacion, Manguao, W spring Enolbong Creek , temporary mountain tributary N coast, primary forest, rocks, gravel, CPOM, c. 20 m asl, 10°46'40"N, 119°32'19"E (121b), coll. H. Freitag, 5 Nov.2008.

Paratypes: 1 male (28.8 by 21.6 mm) ( PCSD), same label as holotype ; 1 male (34.5 by 26.9 mm) ( ZRC 2010.0339 ), Palawan, Taytay; road to Lake Manguao, Manguao Stream tributary, primary forest, c. 35 m asl, 10°47'N, 119°31'E (13b), coll. H. Freitag, 29 Apr.2008 ; 1 female (27.4 by 20.7 mm) (NMCR-39017), Palawan, Taytay, Poblacion, Southern Manguao Stream tributary, primary forest, c. 30 m asl, 10°46'00"N, 119°30'43"E (63a), coll. H. Freitag, 16 Apr.2008 ; 1 female (25.9 by 19.7 mm) (SMTD-Crustac-S107), Palawan, Taytay, Southern Manguao Stream tributary, primary forest c. 30 m asl, 10°46'17"N, 119°30'55"E (63b), coll. H. M. Macmac, 19 Aug.2007 ; 1 ov. female (27.2 by 22.0 mm) (SMTD- Crustac-S108), same locality as previous specimen, coll. H. Freitag, 19 Aug.2007 ; 2 males (32.2 by 24.2 mm, 31.2 by 24.0 mm) ( ZRC 2010.0340 ), Palawan, Taytay, Poblacion, Manguao , Malarad Creek , tributary NE coast, degraded primary forest, rocks, boulders, gravel, CPOM, c. 20 m asl, 10°46'22"N, 119°33'36"E (120), coll. H. Freitag, 4 Nov.2008 ; 3 males (26.3 by 20.5 mm, 20.0 by 15.0 mm, 19.6 by 15.2 mm) (SMTD-Crustac-S109), Palawan, Taytay, Poblacion, Manguao , Mechico Creek , temporary tributary N coast, degraded primary forest, boulders, gravel, sand, CPOM, c. 20 m asl, 10°46'37"N, 119°33'14"E (119), coll. H. Freitag, 4 Nov.2007 ; 2 males (29.0 by 21.4 mm, 23.6 by 17.8 mm) (SMTD-Crustac-S110), Palawan, Taytay, Poblacion, Manguao , small waterfall, W coast, secondary forest, c. 20 m asl, 10°46'07"N, 119°31'40"E (14), coll. H. Freitag, 15 Sep.2008 ; 1 female (28.2 by 21.4 mm) (SMTD- Crustac-S111), Palawan, Taytay, Manguao tributary W Sinangalit Stream, residual pool, rocks & leaves, c. 20 m asl, c. 10°46'46"N, 119°31'05"E (73b), coll. A. Norte, 28 Sep.2008 ; 1 male (31.2 by 24.2 mm), 1 ov. female (26.9 by 20.8 mm) ( ZRC 2010.0341 ), dump site, secondary forest, rocks, sand, CPOM, fall & pool, c. 50 m asl, c. 11°12'N, 119°26"E (113b), coll. H. Freitag, 15 Oct.1994 ; 1 male (23.6 by 18.0 mm) ( ZRC 2010.0342 ), Palawan, El Nido, Pasadeña, Sitio Kalanpinay, Bulalacao Falls , degraded primary forest, rocks, gravel, c. 100 m asl, 11°13'18"N, 119°27'52"E, coll. H. Freitag, 15 Oct.1994 .

Other material. — 1 juv. male (13.3 by 10.2 mm) (SMTD-Crustac- S114), Palawan, Taytay, Poblacion, Manguao, W spring Enolbong Creek , temporary mountain tributary N coast, primary forest, rocks, gravel, CPOM, c. 20 m asl, 10°46'40"N, 119°32'19"E, coll. H. Freitag, 5 Nov.2008 .

Diagnosis. — Carapace ( Figs. 8A, B ) c. 1.31–1.40 times as broad as wide, moderately high; anterior-lateral branchial regions swollen; cervical grooves moderately deep; suborbital margin ventrally dilated, not oblique; epigastric cristae slightly projected over postorbital cristae; mesogastric cristae conspicuous and rather high; progastric, mesogastric, cardiac and intestinal regions convex; medio-posterior carapace margin slightly convex in dorsal view.

Male abdominal somites ( Fig. 8C ) moderately broad; telson c. 1.2 as broad as long; sixth abdominal somite c. 1.6–1.9 times as broad as long; telson c. 1.1–1.2 times as long as sixth abdominal somite in males, approximately of same length in females ( Fig. 8D ).

Mandible with deep incision opposite of palp incertation; terminal segment of palp rather short and broad, evenly tapering towards apex. Second maxilliped ( Fig. 9B ) exopod rather flat, partly membranous, lateral margin broadly indented at about half length; propodus distinctly longer than broad, outer distal margin of carpus protrudingly dilated. Third maxilliped ( Fig. 9A ) with dactylus about 1/5 longer than carpus; propodus about 1/5 shorter than carpus; merus more than 2/3 as long as broad, margins slightly curved, edges rather sharp.

Larger cheliped in adult males broad; dactylus at least half as broad as chela length.

G1 ( Fig. 9 D–H) stout, sinuously bent; distal part of terminal segment hook-like curly and attenuate, twisted towards ventral side; tip perpendicularly contorted from the longitudinal axis; base of terminal segment dilated, broader than distal subterminal segment, sub-proximally inflated; collar distinctly, but not cuneatly protruding dorsally; ventral collar region conspicuously broadly notched. G2 with flagellum c. 0.4–0.5 times as long as basal segment; enlarged proximal portion of basal segment rather broad and subtriangular ( Fig. 9C ).

Remarks. — The species is best distinguished from other representatives of the genus by the G1 that combines characters of I. magnum, new species, and I. palawanense , new species, but is unique in the attenuate, hook-like curly tip of the terminal segment (versus straight or subclavate to hamulose tip in the other species). Externally, it can be distinguished by the somewhat inflated carapace (progastric, mesogastric, cardiac and intestinal regions convex versus slightly convex or almost flat; branchial region swollen versus more or less convex in all other species). Furthermore, it varies respectively from the abovementioned species by the broad carapace (1.31–1.40 times as broad as wide versus 1.23–1.29 in I. magnum, new species), the more conspicuous and slightly higher mesogastric cristae and the slenderer male sixth abdominal somite (≤1.9 times as broad as wide versus ≥ 1.9 in I. palawanense , new species).

The G1 and G 2 in juvenile male specimens ( Fig. 9G, H ) are straighter and less sinuously curved. Their distal part of the G1 terminal segment is relatively broader and stouter, already distinctly curly, but not yet hook-like and the G1 collar is less developed and less protruding.

Etymology. — Named after Johann Christian Freitag, Schwerin, Germany

Distribution. — Northern Palawan Island

Figures

Fig. 8. Insulamon johannchristiani, new species. Paratype male (31.0 by 23.9 mm) from Lake Manguao catchment (63a): A, dorsal view; B, frontal view; C, ventral view. D, paratype female (34.8 by 25.7 mm) from Villa Libertad (113b), 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.