Corasoides occidentalis, Humphrey, 2017

Humphrey, Margaret, 2017, A Revision and Cladistic Analysis of the Genus Corasoides Butler (Araneae: Desidae) with Descriptions of Nine New Species, Records of the Australian Museum 69 (1), pp. 15-64: 48-53

publication ID

http://doi.org/ 10.3853/j.2201-4349.69.2017.1671

persistent identifier

http://treatment.plazi.org/id/03B387B7-3665-FFB9-3B80-F982FDBEF91C

treatment provided by

Felipe

scientific name

Corasoides occidentalis
status

sp. nov.

Corasoides occidentalis   sp. nov.

Figs 19a View Figure 19 , 26–29 View Figure 26 View Figure 27 View Figure 28 View Figure 29

Holotype ♂, Yallingup , Western Australia, 33°42'S 115°02'E, 02 Oct. 1993, M. Humphrey, KS.71658 ( AM) GoogleMaps   . Paratypes as follows, all Western Australia   : 6♂♂, Yallingup , 33°42'S 115°02'E, 02 Oct. 1993, M. Humphrey, KS.71674 ( AM) GoogleMaps   ; 1♂, Yallingup , 33°42'S 115°02'E, 02 Oct. 1993, M. Humphrey GoogleMaps   ; 1♂, 2♀♀, Yallingup , 33°42'S 115°02'E, 02 Oct. 1993, M. Humphrey, KS.71670 ( AM) GoogleMaps   ; 1♂, Cervantes , 30°30'S 115°04'E, 06 Oct. 1993, M. Moulds, KS.71675 GoogleMaps   ; 1♂, 1♀, Nannup , 33°59'S 115°45'E, 02 Oct. 1993, MM, KS.71672 GoogleMaps   ; 1♂, 1♀, Fitzgerald River NP, 33°55'S 120°10'E, 29 Sept.1993,M. Humphrey, KS.71673 GoogleMaps   ; 1♂, Jewel Cave , 34°05'S 115°06'E, 02 Oct. 1993, M. Humphrey, KS.71681 GoogleMaps   ; 2♂♂, Kalbarri NP, 27°40'S 114°22'E, 09 Oct. 1993, M. Humphrey, KS.71679 GoogleMaps   ; 3♂♂, 2♀♀, Stokes River NP, 33°50'S 121°08'E, 13 Oct.1993, M. Humphrey, KS.71678 GoogleMaps   ; 1♂, 1♀, Stirling Ranges NP, 34°22'S 118°08'E, 30 Sept. 1993, M. Humphrey, KS.71676 GoogleMaps   ; 3♂♂ 2♀♀, Corrigin , 32°20'S 117°52'E, 10 Oct. 1993 M. Humphrey, KS.71677 GoogleMaps   ; 2♀♀, Gelorup , 33°23'S 115°39'E, 03 Oct. 1993, M. Humphrey, KS.71680 GoogleMaps   ; 3♂♂, Gelorup , 33°23'S 115°39'E, 03 Oct.1993, M. Humphrey, KS.71671 and KS.71684 GoogleMaps   ; 1♂, Glen Forrest , 31°55'S 116°04'E Oct. 1993, M. Humphrey, KS.71682 GoogleMaps   ; 1♂, Toodyay , 31°33'S 116°28'E, 04 Oct. 1993, M.Humphrey, KS.1683 ( AM) GoogleMaps   . 1♂, Cannington Bot Res. , 32°01'S 115°58'E, Dec. 1986, W.Humphreys et al., 92/31 GoogleMaps   ; 1♀, Gordon River at Albany H’way crossing, 34°17'S 117°30'E, 10 Nov. 1990, A. F. Longbottom 19/40 GoogleMaps   ; 1♂, Gelorup Rise (lot 101), 33°45'S 115°38'E, 14 Oct. 1991, K. Longbottom GoogleMaps   ; 1♂, Bold Park , 31°57'S 115°46'E, 20 Dec. 1988, Jiang Wang Gao 92/26 GoogleMaps   ; 1♂, 6.5 km NW of Meelup , 33°33'30"S 115°01'00"E, 25 Oct. 1985, G. A. Harold, 92/47 GoogleMaps   ; 1♀, Bold Park , 31°57'07"S 115°45'30"E, 15 Mar 1987, W. Humphreys et al., 92/24 GoogleMaps   ; 1♀, 15 km E of Mount Barker , 34°40'S 117°31'E, 22 Feb. 1990, M. S. Harvey & M. E. Blosfelds, 92/49 GoogleMaps   ; 1♂, Jandakot , 32°06'S 115°52'E, 31 Dec. 1981, S. R. Robinson, 92/16 GoogleMaps   ; 1♂, Naval Base , 32°12'S 115°47'E, 19 Dec. 1971, E. L. Joll, 92/18 GoogleMaps   ; 1♂, 9.6 km E of Green Head , 30°04'S 114°58'E, Dec 1971, (no collector), 19/13 GoogleMaps   ; 1♀, Kallaroo , 31°47'28"S 115°44'28"E, T. C. Connolly, 92/14 GoogleMaps   ; 1♀, Cape Naturaliste , 33°32'S 115°00'E, 12 Nov. 1979, G. B. Muir, 92/2 GoogleMaps   ; 1♂, Albany (37 Parker St ), 35°00'S 117°53'E, ... Apr. 1964, A. Twaddle, 92/1 GoogleMaps   ; 1♂, Stirling Range NP 6.8 km S of Bull Knoll , 34°29'S 118°15'E, 18 Oct. 1989, G. Friend, G. Hall & D. Mitchell, 92/23 GoogleMaps   ; 1♂, Glen Forrest , 31°55'S 116°06'E, 09 Dec. 1974, E. Postmus, 92/11 GoogleMaps   ; 1♂, 1♀, Chesapeake Rd & Gardener Rd junction, 34°46 S 116°10'E, 01 May 1990, M. S. Harvey & J. M. Waldock, 92/34-35; 1♂, Parmelia , 32°15'S 115°47'E, 27 Dec. 1989, A. E. de Jong, 92/19 GoogleMaps   ; 1♂, Gelorup Rise , 33°23'S 115°38'E, 11 Dec. 1990, K. Longbottom, 92/3 GoogleMaps   ; 1♀, Mt Cooke , 32°25'S 116°18'E, 17 Feb. 1991, M. S. Harvey, 92/53 GoogleMaps   ; 1♂, Perth Airport , 31°55'24"S 115°58'40"E, Dec. 1986, W. Humphreys et al., 92/58 GoogleMaps   ; 1♂, 6 km at 15° from Mullalloo Beach, 31°47'S 115°44'E, 10 Sept. 1978, A. Chapman & R. How, 85/13; male, Salter’s Point , 31 Oct. 1987, M. Koch, 88/49 GoogleMaps   ; 1♂, Augusta , 1.5 km NE of, 34°18'15"S 115°10'15"E, 30 Nov. 1985, G. A. Harold, 92/21 ( WAM) GoogleMaps   .

Other material examined all Western Australia. 2 juv., Cape le Grande , 34°00'S 122°00'E, 01 Sept. 1993, M. Humphrey GoogleMaps   ; 1♂, palps of another male, 2♀♀, Glen Forrest , 31°55'S 116°06'E, 04 Oct. 1993, M. Humphrey, KS.71685 GoogleMaps   ; 2 juv, Toodyay , 31°33'S 116°28'E, 04 Oct. 1993, M. Humphrey GoogleMaps   ; 3♀♀, Yallingup , 33°42'S 115°02'E, 02 Oct. 1993, M. Humphrey GoogleMaps   ; 3♂♂ and pair male palps, Gelorup , 33°23'S 115°39'E, 03 Oct. 1993, M. Humphrey GoogleMaps   ; 4 juv., Kalbarri NP, 27°40'S 114°22'E, 09 Oct. 1993, M. Humphrey GoogleMaps   ; 1♀ abdomen, 3 juv., Corrigin , 32°20'S 117°52'E, 10 Oct. 1993, M. Humphrey GoogleMaps   ; 3 juv, pair male palps, Jewel Cave , 34°05'S 115°06'E, 02 Oct. 1993, M. Humphrey GoogleMaps   ; 3 juv, Stirling Ranges NP, 34°22'S 118°08'E, 30 Sept. 1993, M. Humphrey GoogleMaps   ; 1 juv, Stokes River NP, 32°35'S 134°08'E, 13 Oct. 1993, M. Humphrey GoogleMaps   ; 1 juv., Fitzgerald River NP, 34°05'S 120°35'E, 29 Sept. 1993, M. Humphrey ( AM) GoogleMaps   . 1♀, E King River , 34°45'6"S 117°55'9"E, D. Hirst, ARA5322 DH2536 ( SAM) GoogleMaps   . 1♂, Gelorup Rise , 33°23'12"S 115°38'43"E, 25 Nov. 1990, A. F. Longbottom, 19/10 GoogleMaps   ; 1♀, Cervantes , 30°30'S 115°04'E, 14 Jan.1977, K. Zwanenburg, 19/33 GoogleMaps   ; 1♂, Cannington Bot Res , 32°01'29"S 115°58'57"E, 27 Jan. 1987, W. Humphreys et al., 92/32 GoogleMaps   ; 1♀, Chinocup Reserve 6.4 km E of Pingrup, 33°32'S 118°24'E, 14 Feb. 1972, W. H. Butler, 92/36 GoogleMaps   ; 1♂, Gelorup , 33°23'12"S 115°38'43"E, 25 Nov. 1990, A.F. Longbottom, 19/10 ( WAM) GoogleMaps   .

Diagnosis. The male can be distinguished from other Australian species by the very long cymbium, which is up to six times as long as the diameter of the bulb and also by the presence on the conductor tip of a flange which sweeps around it about 180° ( Figs 26a–c,e,f View Figure 26 , 28a–d View Figure 28 ). The female can be distinguished by the lateral profile of the epigyne in which the scape protrudes at almost 90° ( Fig. 27g View Figure 27 ).

Description. Medium to large spider. Carapace. Light tan. Dark tan on chelicerae and head region, extending posteriorly to fovea and then diverging to either side of petiole area. Dark brown edging to carapace except in petiole region. Abdominal pattern. Similar to basic pattern but with central stripe wide and almost merging with row of spots.

Male ( Figs 19a View Figure 19 , 26 View Figure 26 , 27a–d,f View Figure 27 , 28 View Figure 28 , 29 View Figure 29 ). CL 6.7 (3.1–6.8), CW 5.3 (2.5–5.3), AL 6.0, AW 4.0, HW 2.9, EpGW 1.8, MOQL 0.73, MOQAW 0.61, MOQPW 0.70, SL 3.5, SW 2.7, ML 2.9, MW 2.4, LL 1.5, LW 1.2, ChelL 5.6 (3.0–5.8), ChelW 1.9 (1.1–1.9), clypeus height 0.85 (1.3), clypeus concave.

Cephalothorax. Sternum longer than wide, moderate point posteriorly. Labium longer than wide, basally notched. Chelicerae. Prominent pair of cheliceral bristles reduced, not crossing in front. Cheliceral teeth: retromarginal 5, promarginal 3 plus one undersized; evenly spaced and of near equal size. Transverse ridges present between teeth margins. Fangs slightly shorter than other Corasoides   and with serrations. Leg lengths:

I II III IV Palp femur 9.4 7.9 6.4 9.1 5.7

patella 2.3 2.3 1.9 2.0 1.4

tibia 9.5 7.4 5.1 7.5 1.0 metatarsus 10.0 7.9 7.5 10.8 —

tarsus 3.6 2.8 2.1 2.9 6.4

total 34.8 28.1 23.0 32.5 14.5

Spination. Leg I: femur d2,2,2,1,1,1,1,2,3; tibia v1,1; metatarsus v2,2,2. Leg II: femur d3,3,1,3,3,3; tibia v1,1 p1; metatarsus v1,1,2 p1,1 r1. Leg III: femur d3,3,3,3,3; tibia d1,1,1,2 p1; metatarsus; d1,1,1,1,1,2 v2,2,2 p1,1. Leg IV: femur; 1,1,1,3,2,1,3; tibia; d1 p1 r1,1; metatarsus; d1,1,1,2,2,2, v1,1,1,1,1,1,2 p1,1 r1. Palp: femur; d1,2,3; patella: d1; tibia; p1; tarsus several. Male palp. Digitiform portion very long, cymbium length up to six times diameter of papal bulb but as little as four times in some small males. Bristled retroventral tibial apophysis present. Ventral apophysis partially membranous. Retrolateral apophysis long, tapering, curving and twisting slightly away from palp retrolaterally, reversing slightly and with final spinelike portion inclining towards base of cymbium for up to one third its own length, the medial section becoming more bent in specimens from north to south ( Figs 29a–d View Figure 29 ). Conductor stalked with wide base. Conductor tip sclerotized, smooth, with sclerotized, semicircular flange around ventral/

(d) Albany, WA.

prolateral side for about 180° ( Fig. 26a–c,e,f View Figure 26 ). Embolus long, spine-like, arising basally. Single row of 6 trichobothria on cymbium of specimens from type locality but 4–7 according to locality and size of specimen. Abdomen. Tail of spigots present on anterior lateral spinnerets.

Female ( Fig. 27e–h View Figure 27 ), similar to male. CL 6.0 (6.8), CW 4.3 (5.1), AL 6.1, AW 3.4, HW 3.3, EpGW 1.5, MOQL

0.82, MOQAW 0.61, MOQPW 0.73, SL 3.0, SW 2.4, ML 2.3, MW 1.1, LL 1.3, LW 1.1, ChelL 2.9 (4.5), ChelW 1.7 (2.3), clypeus height 0.8. Chelicerae. Prominent pair of cheliceral bristles may or may not be reduced. Other bristles on chelicerae may be as long and almost equally robust. Cheliceral teeth: retromarginal 5, promarginal 3(4). Transverse ridges present between teeth margins. Leg lengths:

I II III IV Palp femur 7.0 6.0 4.9 6.9 3.6 patella 2.3 2.3 1.6 2.0 1.1 tibia 6.3 5.0 4.0 5.9 2.1 metatarsus 7.1 5.6 5.6 7.8 — tarsus 2.9 1.8 1.8 2.4 2.9 total 25.5 20.6 17.9 24.8 9.8

Trichobothria on first tarsus, 6, increasing in length distally. Spination. Leg I: femur d1,3,3,3,3; tibia v1,2 p1; metatarsus d2 v2,2,2 p1,1. Leg II: femur d1,3,3,3,3; tibia v1,1,2 p1; metatarsus d1,1,2 v2,2,2 p1,1. Leg III: femur d2,3,3,1,3,3; tibia d1,1 v1,2,2 p1 r1,1; metatarsus d1,2,2,2, v2,2,2. Leg IV: femur d1,1,1,1,1,1,3; tibia v2,2,2p1 r1,1; metatarsus d1,1,1,1,2 v1,1,1,1,1,2. Palp: femur d1,1,1,1,3 p1; patella d1; tibia d1 p1. Epigyne ( Fig. 27f View Figure 27 ). Width almost twice length. Long hairs directed posteriorly from anterior and sides. Scape protruding ventrally at almost 90° ( Fig. 27g View Figure 27 ). Lateral extension of scape extending to lateral margins of genital atria. Genital openings situated in posterior half of epigyne. Spermathecae large. Insemination ducts weakly convoluted (one full bend) with posteriorly directed diverticula where insemination ducts join spermathecae ( Fig. 27e,g View Figure 27 ).

Habitat. Heathland, woodland, dry and wet sclerophyll forest.

Distribution. Coastal western and south western Western Australia, from Kalbarri National Park to Cape Le Grande and inland as far as Corrigin ( Fig. 27h View Figure 27 ), following Thornthwaite’s (1948) humid and sub-humid zones.

Remarks. Corasoides occidentalis   varies in size and morphology over its distribution. Small males become more common north of Cervantes, east of Fitzgerald River National Park and in general with increasing aridity and distance from the coast. The length of the cymbium and the number of trichobothria on it appears to vary directly according to the size of the specimen. Figure 26g View Figure 26 shows the number of cymbial trichobothria decreasing from six or seven on the mid west coast of their distribution surrounded by a band of four or five and reducing to two or three trichobothria on the southern coast where males tend to reach their smallest size.

The width of the epigyne also varies. The width is greatest in the Glen Forrest and west coast areas and decreases eastward and inland in a geographical variation similar to that of the cymbial trichobothria.

The only observed discrete difference in morphology was the presence of a bifurcate tip to the retrolateral apophysis in some specimens from Glen Forrest ( Fig. 19a View Figure 19 ). All other differences in morphology, particularly with respect to the conductor tip ( Fig. 28a–d View Figure 28 ) and the height and twisting of the retrolateral apophysis ( Fig. 29a–d View Figure 29 ) were due to individual variation or were continuous geographically. A distinct pit with an inner structure is present beneath the tip of the retrolateral apophysis in specimens from Stirling Ranges ( Fig. 29b View Figure 29 ) but is absent in specimens from Perth, Gelorup and Albany ( Fig. 29a,c View Figure 29 ). A less clearly defined pit structure is present in specimens from Glen Forrest. Similarly, a protrusion or crest on the outer final bend of the retrolateral apophysis ( Fig. 29d View Figure 29 ) is present on specimens from Albany and to a lesser extent from Gelorup ( Fig. 29c View Figure 29 ) but appears to be absent from specimens from other regions.

This species is sympatric with C. australis   in some areas, e.g., Toodyay, Corrigin and some areas between Greenough and Cervantes.

Etymology. From the Latin, occidentalis   , meaning “of the falling sun” or “of the west” and referring to the western distribution in Australia of this species.

AM

Australian Museum

WAM

Western Australian Museum

SAM

South African Museum

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Desidae

Genus

Corasoides