Megalopsalis caeruleomontium, Taylor, Christopher K., 2013

Taylor, Christopher K., 2013, Further revision of the genus Megalopsalis (Opiliones, Neopilionidae), with the description of seven new species, ZooKeys 328, pp. 59-117 : 78-80

Megalopsalis caeruleomontium sp. n. Figs 10-11

Material examined.

Male holotype. Mt Kembla, Sydney Catchment Authority Reserve, New South Wales, 34°26'33"S, 150°44'24"E, 11-15 December 1998, L. Gibson, pitfall traps (AMS KS63019; measured).

Paratypes. 2 males, 1 female, Blue Mountains road to Ingar picnic area, New South Wales, 33°46'03"S, 150°24'30"E, 3 October 1996, pitfall trap (AMS KS57166, KS57168; all measured); 3 males, Clyde Mountain, 35°33'S, 149°57'E, 24 October 1968, G. B. M[illedge] (AMS KS65018; measured); 3 males, 2 females, Kirkconnell, 28 May 1972, G. S. Hunt (AMS KS21480; 2 females measured); 1 male, Mt Shivering (near pluviometer), E of Oberon, New South Wales, 23 September 1972, G. S. Hunt (AMS KS21484; measured); 4 males, 6 females, Mt Werong (near pluviometer), New South Wales, 3 July 1972, G. S. Hunt (AMS KS23117; 2 males, 5 females measured); 4 males, 3 females, Muogamarra Nature Reserve, Pacific Highway, 0.7 km SE of Bird Gully Swamp, New South Wales, 33°33'42"S, 151°11'15"E, 2-16 December 1999, M. Gray, G. Milledge, H. Smith, pitfall traps (AMS KS62256; 2 females measured); 1 male, hill NE of Oberon, 10 June 1972, G. S. Hunt (AMS KS21483; measured); 1 male, “Scalloway” pool, Geringong, New South Wales, 23 November 1986, G. Wishart, found 'walking on water’ (AMS KS17413, measured).

Diagnosis.

Megalopsalis caeruleomontium differs from other species of Megalopsalis in the presence of setae on the mobile finger of the chelicerae (Fig. 10b). Most males (except the smallest) can also be distinguished by the inflated second segment of the chelicerae (Fig. 10b). Megalopsalis caeruleomontium has a relatively flattened penis compared to other Megalopsalis species except Megalopsalis nigricans ; the glans is rather short, with the sides becoming subparallel distally (Figs 10 d–e).

Description.

MALE (N = 10). Prosoma length 1.17 (0.88-1.46), width 2.34 (1.98-2.50); total body length 3.25 (2.81-3.88). Propeltidium light orange-brown spotted with white and dark brown patches. Anterior propeltidial area pinkish-brown, with diverging dark-brown lines from ocularium to anterior margin, and dark-brown area around short supracheliceral groove on sharply downturned face. Prosoma unarmed. Ocularium bright white with light orange-brown base and behind eyes; postocularium bright white. Mesopeltidium, metapeltidium and first four segments of opisthosoma grey-brown with slightly lighter median band and distinctive transverse row of black setae in lighter spots across each segment. Posterior part of opisthosoma yellow-brown dusted with dark-brown; anal operculum silver. Coxae pinkish-brown with median white areas proximally; venter of opisthosoma grey-brown.

Chelicerae. Segment I 2.26 (0.57-3.26), segment II 3.36 (1.24-4.55). Segment I medium-brown dorsally and on proximal two-thirds laterally, peach-coloured ventrally and distolaterally, white patch at distolateralmost end with ventrolateral medium-brown patch directly underneath it; denticulate dorsally and on ventrolateral and ventromedial edges. Segment II strongly inflated in larger specimens to not inflated in smallest specimens, proximally mottled medium-brown and pink dorsally, medium-brown laterally, peach ventrally; distally pink-cream, fingers yellow-cream; denticulate dorsally and ventrolaterally. Cheliceral fingers bowed apart proximally in larger specimens, less or not bowed in smaller specimens.

Pedipalps. Femur 1.29 (0-1.46), patella 0.55 (0.37-0.64), tibia 0.78 (0.48-0.95), tarsus 1.63 (1.08-1.91). Trochanter and proximalmost part of femur cream; proximal two-thirds of femur medium-brown, then peach band, then light-brown band; patella pink-brown; tibia pink-brown proximally, cream distally; tarsus pink-brown at proximalmost end, remainder cream. No patellar apophysis. Microtrichia on tarsus and distal third of tibia; tooth-comb on claw.

Legs. Femora 4.26 (3.72-4.65), 7.29 (6.50-8.15), 3.97 (3.60-4.25), 5.90 (5.31-6.28); patellae 1.11 (0.91-1.23), 1.26 (1.06-1.44), 1.08 (0.80-1.30), 1.23 (0.97-1.37); tibiae 3.96 (3.31-4.28), 7.35 (6.50-8.00), 3.81 (3.14-4.10), 5.48 (4.67-6.00). Trochanters pinkish-cream, unarmed. Legs I and III medium-brown with cream bands, legs II and IV yellow-brown. Femora denticulate, with larger denticles dorsally than ventrally; fewer denticles dorsally on patellae, remaining segments unarmed.

Penis (Fig. 10 d–e). Tendon long; bristle groups well-developed. Glans in line with shaft; dorsoventrally flattened for entire length with bases of bristle groups (especially left) consequently more ventral than lateral; glans short, sides converging in ventral view. Deep pores.

Spiracle (Fig. 11). Sparse curtain of slender reticulate spines extending only partway across spiracle; terminations of spines multifurcate; dense patch of lace tubercles at lateral corner.

FEMALE (Fig. 10c; N = 10). Prosoma length 1.30 (1.03-1.74), width 2.29 (2.08-2.59); total body length 4.60 (3.88-6.13). Propeltidium medium-grey-brown with dark-brown patches; prosoma unarmed. Ocularium grey-brown, unarmed. Mesopeltidium, metapeltidium and first three segments of opisthosoma medially dark-grey-brown, laterally whitish-grey with dark-brown patches on lateral margins. Posterior part of opisthosoma whitish-grey with mottled dark-brown patches laterally. Coxae light-brown mottled with white proximally followed by central cream band, medium-brown distally darkening to dark-brown pro- and retrolaterally. Mouthparts and genital operculum light tan. Venter of opisthosoma medium-orange-brown densely mottled with silver-white.

Chelicerae. Segment I 0.84 (0.72-0.95), segment II 1.66 (1.49-1.79). Dark orange-brown reticulated with silver dorsally and large silver-white patch distolaterally on first segment; unarmed.

Pedipalps. Femur 1.21 (1.14-1.38), patella 0.55 (0.50-0.59), tibia 0.78 (0.70-0.84), tarsus 1.55 (1.42-1.67). Femur light tan at proximalmost end, remainder medium brown; patella medium brown with small silver patches distolaterally; tibia and tarsus each proximally medium brown, distally light tan silvered dorsally. No apophysis or hypersetose areas; microtrichia over entire length of tibia and tarsus.

Legs. Femora 3.57 (3.38-3.92), 6.30 (5.97-7.23), 3.37 (3.17-3.86), 5.20 (4.94-5.63); patellae 1.10 (1.00-1.15), 1.22 (1.15-1.31), 1.06 (0.95-1.15), 1.18 (1.03-1.26); tibiae 3.40 (3.22-3.76), 6.31 (6.07-6.85), 3.26 (3.06-3.60), 4.84 (4.45-5.06). Trochanters grey-tan mottled with white, unarmed. Legs banded medium brown and light tan, with tan bands overlain by silver from distalmost end of femur to tibia. Femora and patellae with longitudinal rows of small denticles.

Etymology.

From the Latin words caeruleus, blue, and mons, mountain: "of the Blue Mountains", in reference to the distribution of this species.

Comments.

Males of this species vary significantly between the largest and smallest individuals in the development of the chelicerae, from inflated with bowed fingers in the largest specimens to slender with unbowed fingers in the smallest. However, variation appears to be more or less continuous (albeit with large individuals distinctly more numerous than small individuals) without a clear division between morphs.