Corasoides stellaris, 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 : 53-62
treatment provided by
Corasoides stellaris sp. nov.
Other material examined. 1 juvenile, same data as holotype, discarded after electrophoretic work GoogleMaps .
Diagnosis. The length and width of the epigyne of this species are almost equal, unlike the dimensions of the epigynes of closely related C. angusi sp. nov. and C. nimbus sp. nov. In addition C. stellaris sp. nov. can be distinguished from these two latter species by the width of the lateral extension of the scape that is well over half the width of the epigyne ( Fig. 31a View Figure 31 ). Corasoides stellaris sp. nov. can also be distinguished by the number and configuration of the insemination ducts and the presence in C. stellaris sp. nov. of a large, curved diverticulum at the site of entry into the seminal receptacle ( Fig. 31b–d View Figure 31 ).
Description. Medium to large spider. Carapace. Pale basic pattern. Abdomen. Basic generic pattern but with dorsolateral stripes reduced to the anterior quarter of the abdomen ( Fig. 30a View Figure 30 ).
Female ( Figs 30 View Figure 30 , 31 View Figure 31 ). CL 5.7, CW 4.6, AL 6.6, AW 4.9, HW 2.9, EpGW 1.8, MOQL 0.83, MOQAW 0.72, MOQPW 0.89, SL 2.7, SW 2.5, ML 1.8, MW 1.2, LL 1.1, LW 0.9, ChelL 2.8, ChelW 0.94, clypeus height 0.5. Cephalothorax ( Fig. 30 View Figure 30 ). Sternum roughly broad as wide with long but blunt point. Labium basally notched. Maxillae broad. Chelicerae. Robust ( Figs 30b View Figure 30 , 31e View Figure 31 ). Teeth: retromarginal 5, promarginal 3(4), evenly spaced but uneven in size ( Fig. 30c View Figure 30 ). No ridges between margins. Leg lengths:
I II III IV Palp femur 10.0 9.0 7.1 9.8 6.9
patella 2.3 2.1 1.8 1.9 2.0
tibia 10.0 6.9 5.4 8.0 3.9 metatarsus 10.9 8.0 8.0 11.6 —
tarsus 5.0 4.9 3.3 4.0 4.0
total 38.2 30.9 25.5 35.3 16.8
Spination. Leg I: femur d1,3,3,1,2,2; tibia v1,1; metatarsus d2 v1,1,1,1,1. Leg II: femur d2,1,3,1,3,3,2; tibia v1,2; metatarsus d1,1 v2; Leg III: femur d3,2,2,2,2, p1,1,1,1; tibia d1,1,2 v1,2,2; metatarsus d1,1,1,1,1,1,2 v1,2,2,3. Leg IV: femur d2,1,1,1,1,2,1,1; tibia d1,1,1,3; metatarsus d1,1,2,2,4 v1,2,1,2,2; palp: femur d1,1,3; patella d1,1; tibia d1,1; tarsus several. Three trichobothria on 1st tarsus. Abdomen. Anterior lateral spinnerets with tail of small spigots. Epigyne ( Fig. 31a View Figure 31 ). Length almost equal to width. Anterior and lateral portions covered with long, posteriorly directed hairs. Genital openings near transverse midline, scape stalk much narrower than diameter of one genital opening. Lateral extensions of scape long and wide, continuing beyond margin of genital openings. Insemination ducts mostly anterior to seminal receptacles, proceeding anteriorly from genital openings and with at least four bends. Large, curved diverticulum at site of entry into each spermatheca. This diverticulum is an extension of the insemination duct beyond its entry into the spermatheca ( Fig. 31 View Figure 31 b-d).
Remarks. This species is sympatric with C. cowanae sp. nov. The juvenile mentioned in Other material examined, was collected 2 m from the holotype collection site. This specimen, which was too large to be C. cowanae sp. nov., was tentatively identified as C. stellaris sp. nov. and results from allozyme electrophoresis work (Humphrey, 2010) confirmed this identification.
Habitat. Both specimens were collected from horizontal sheet webs under an overhanging earthen embankment by the side of a creek in an area of cleared rainforest. The retreat was in a natural crevice in the embankment.
Distribution. Known only from holotype location, south east slope of Mt Akric, 15 km north west of Tabubil, Western Province, Papua New Guinea ( Fig. 31f View Figure 31 ).
Etymology. From the Latin, stella, a star, suggestive of the type locality in the Star Mountains, Papua New Guinea.
3♀♀, Lamington NP, Nagarigoon, Rainforest , 28°42'S 153°30'E, 08 Apr. 1976, Queensland Museum Party, QM S14686 View Materials ( QM) GoogleMaps . — NEW SOUTH WALES 1♀, KS.71545 ; 2♀♀, 1♂, KS.71546; 2♀♀, KS.71547, same data as holotype GoogleMaps ; 1♂, Mt Nardi , 28°33'S 153°17'E, 22 Dec. 1991, M. Humphrey, KS.71548 GoogleMaps ; 1♂, same data, KS.98073 GoogleMaps ; 3♂♂, Mt Nardi, Nightcap NP, NSW, 28°33'S 153°20'E, 03 Oct. 1991, KS.71549 GoogleMaps ; 3♀♀, same data, KS.71550 GoogleMaps ; 1♂, same data, KS.71551 GoogleMaps ; 1♀, same data, KS.71557 GoogleMaps ; 1♂, 1♀, Mt Nardi , 28°33'S 153°17'E, 3 Oct 1991, KS.71552 GoogleMaps ; 1♀, hatched from material, 14 Feb. 1992, died 24 Feb 1993, KS.71553; 1♀, Border Ranges NP, 28°20'S 153°05'E, 29 Sept 1991 KS.71554 GoogleMaps ; 1♂, same data, KS.71555 GoogleMaps ; 1♀, Mt Nardi, Nightcap NP, 28°33'S 153°20'E, 30 Oct. 1991, M. Humphrey, KS.71556 GoogleMaps ; 1♀, Minion Falls, NE NSW, 28.612°S 153.390°E, May 2005,M. Humphrey & M. S. Moulds, KS.98070 ( AM) GoogleMaps . 1♂, Whian Whian SF, 28°41'S 153°19'E, 12.ix.1976, R. J. Raven, QM S14688 View Materials ( QM) GoogleMaps .
Other material examined. — QUEENSLAND 1♀, 1 pen ♂, Lamington NP, O’Reillys, Rainforest , 28°14'S 153°08'E, 22 Jun 1973, R. J. Raven, QM S14674 View Materials ; 1 pen GoogleMaps ♂, Lamington Plateau , rainforest, 28°19'S 153°04'E, 13 Apr. 1974, R. J. Raven, QM S14681 View Materials ( QM) GoogleMaps . — NEW SOUTH WALES 1♀, Border Ranges NP, 28°20'S 153°05'E, 29 Sept 1991 GoogleMaps ; 5 juv., 03 Oct 1991; 2 pen ♂♂, 30 Oct 1991; 1♀, Mt Nardi , Nightcap NP, 28°33'S 153°20'E, 03 Oct. 1991, M. Humphrey GoogleMaps ; 1 juv., Wiangaree SF, 28°23'S 153°06'E, 16 Nov 1974, KS.3566 GoogleMaps ; 1♀, Wiangaree SF, 28°23'S 153°06'E, 16 Nov 1974, KS.4898 ( AM) GoogleMaps ; 1 juv., Mt Warning , 28°25'S 153°17'E, 03 Dec. 1974, R. J. Raven, QM S14690 View Materials GoogleMaps ; 1 juv., Nothofagus Mtn, 12 km N Woodenbong, Rainforest , 28°17'S 152°37'E, 4–6 Feb. 1982, G. Monteith, D. Yeates, QM S14671 View Materials ( QM) GoogleMaps .
Diagnosis. Distinguished from other Australian species by the absence of a retroventral tibial apophysis in the male.
Humphrey: Revision of Corasoides spiders 55
lateral from centre; (d) internal genitalia, ventral; (e) carapace, lateral; (f) distribution
Retrolateral apophysis with basal section broader than its height. Female epigyne twice as wide as long with the genital atria occupying most of the width. Long, finger-like diverticulum at site of entry of insemination ducts.
Description. Medium to large spider. Carapace. Full pattern for genus. Abdomen. Basic pattern with dorsolateral stripe extending to at least two thirds length of abdomen ( Fig. 33a View Figure 33 ).
Male ( Figs 32 View Figure 32 , 33a,e–g View Figure 33 , 34a View Figure 34 ). CL 5.6 (4.4–6.6), CW 4.4 (3.7–4.5), AL 5.5, AW 3.1, HW 2.7, EpGW 1.6, MOQL 0.88, MOQAW 0.69, MOQPW 0.75, SL 2.6, SW 2.4, ML 2.4, MW1.1, LL 1.3, LW 0.6, ChelL 3.8 (2.8–5.6), ChelW 1.4 (1.1–1.9), clypeus height 0.4. Cephalothorax. Sternum longer than wide, distinct point distally ( Fig. 33e View Figure 33 ). Labium notched basally, barely rebordered. Chelicerae. Long, often curved or bent in males ( Fig. 32d View Figure 32 ). Cheliceral teeth: retromarginal 6, promarginal 3; evenly spaced, uneven size ( Fig. 33f View Figure 33 ) Transverse ridges present between teeth margins. Leg lengths:
I II III IV Palp femur 11.9 4.7 8.3 11.3 4.8
patella 2.5 2.1 0.9 2.0 1.3
tibia 11.8 8.3 3.3 9.3 1.3 metatarsus 13.8 10.8 4.8 14.0 —
tarsus 2.1 3.3 2.6 3.0 4.4
total 42.1 33.8 28.9 39.5 11.6
Spination. Leg I: femur d3,2,2,2,1,3,3,2; tibia v2,2,2,2; metatarsus v2,2,1,1,2,2 p1,1 r1. Leg II: femur d3,2,2,3,3,1,3,3; tibia v2,2,2,3; metatarsus d1,2 v1,1,2,2. Leg III: femur d3,2,2,1,3,1,3 p1,1,1,1; tibia d1,2,1 v2,2,2,2; metatarsus d2,2,2,2 v1,2,2,2,2. Leg IV: femur d1,2,2,2,1,1,1,3; tibia d1,1,1,1,1,2 v2,2,2,2; metatarsus d2,1,2,1,2,1,22 v2,2,2,1,2; Palp: femur d1,1,1,1,1; tarsus several. Male palp. Digitiform portion of cymbium long and curved, cymbium length approximately 4 times diameter of bulb. Retroventral apophysis absent. Ventral apophysis spout-like, rebordered prolaterally. Retrolateral apophysis with wide basal section. Spine-like process of apophysis originates from retrolateral corner of the basal section and curves towards bulb finishing near the opposite side of the base ( Figs 32 View Figure 32 e-g). Embolus arises basally. Conductor stalked, appearing wide at base. Conductor tip straight, untwisted, cone-shaped, without ridges, pointing antero-retrolaterally. Trichobothria on cymbium: single row of 5 on dorsum, decreasing in size basally. Abdomen. Tail of small spigots on anterior lateral spinnerets.
Female ( Figs 33b–d View Figure 33 , 34b View Figure 34 ), similar to male. CL 5.3 (4.9–6.6), CW 4.3 (3.6–4.1), AL 8.5, AW 4.1, HW 2.8, EpGW 1.6, MOQL 0.81, MOQAW 0.69, MOQPW 0.81, SL 3.0, SW 2.7, ML 2.2, MW 1.3, LL1.3, LW 1.1, ChelL 3.3 (2.6–3.4),
ChelW 1.4 (1.1–1.6), clypeus height 0.5. Chelicerae. Teeth: retromarginal 6, evenly sized and spaced; promarginal 4. Leg lengths:
I II III IV Palp femur 9.8 8.1 7.0 9.4 3.4
patella 2.4 2.0 7.0 1.9 1.4
tibia 8.9 6.8 1.6 7.0 1.9 metatarsus 10.6 8.4 5.6 11.8 —
tarsus 3.8 2.4 8.0 2.9 2.8
total 35.4 27.7 1.9 33.0 9.5
Spination. Leg I: femur d3,4,2,1,3,3,3,3; tibia v2,2,2,2; metatarsus v2,2,2. Leg II: femur d3,4,3,3,1,3; tibia v2,2,2,2 p1,1 r1; metatarsus v2,2,2p1,1. Leg III: d3,4,2,3,3 p1,1,1; tibia d1,1 v2,2,1,2 p1,1,1 r1; metatarsus d1,2,2,2 v1,1,1,1,2 p1,1,1. Leg IV: femur d1,2,1,2,4,3; tibia d1,1 v2,1,1,1,2 p1,1,1 r1; metatarsus d1,1,1,2,2 v2,2,2,2. Palp: femur d1,1,1,1,1; tibia d1; tarsus several. Trichobothria on 1st tarsus: one row of 5. Epigyne ( Figs 33b View Figure 33 , 34b View Figure 34 ). Width twice length.Atria of genital openings occupying almost all width. Almost hairless except for sparse row on anterior of scape directed towards genital atria. Small projection midline at posterior end of scape. Scape stalk very narrow, less than one-quarter of width of a genital atrium. Lateral extension of scape short, approximately half diameter of a genital atrium. Initiation of insemination ducts posterior, entering below spermathecae. Insemination ducts weakly convoluted (2 bends). Long, finger-like diverticula at site of entry into spermathecae ( Fig. 33c,d View Figure 33 ).
Habitat. Warm temperate/sub-tropical rainforest. Webs commonly found extending from crevices in tree trunks, epiphytes, fallen logs and other debris, 0.2–2.0 m from the ground, especially where there is a slight break in the tree canopy.
Distribution. Rainforest region in vicinity of Cunningham’s Gap, Lamington National Park, MacPherson Ranges, Queensland and Border Ranges National Park, Mt Warning National Park and south to Nightcap National Park, Mt Nardi and Terania Creek, New South Wales ( Fig. 33g View Figure 33 ).
Etymology. Named after the type location (nominative in apposition), Terania Creek, New South Wales.
Phylogenetic relationships were determined by cladistic analyses using morphological characters supplemented by behavioural, chromosomal and ecological attributes.
All analyses were carried out using the computer program PAUP*, version 4.0b2 ( Swofford, 1998), employing an heuristic search using default settings. Trees were printed via CLADOS version 1.2 ( Nixon, 1992). Characters were optimized using the default setting that favoured parallel developments over reversals (DELTRAN). All characters have been given equal weighting and all except one 5-tiered morphological character (character 18) have been treated as unordered. Missing data or inappropriate data are indicated by “?”.
Two outgroups were selected, Cambridgea fasciata Koch, 1872 and Inola subtilis Davies, 1982 . Inola subtilis was chosen following the results of electrophoretic work ( Humphrey, 2015). Cambridgea fasciata was chosen because of its morphological similarity to Corasoides and the taxonomic placing of Cambridgea near Corasoides by Forster & Wilton (1973) and Davies (1988).
The following characters and character states were used in the analysis. The data matrix from these characters is shown in Table 1. Web
Character 0. Weave pattern: (0) irregular; (1) regular, square to rectangular.
Character 1. Ventral extension of chelicerae (at least in male): (0) well beyond level of labium; (1) equal to or marginally beyond labium.
Character 2. Two pairs of prominent cheliceral bristles
(at least in male): (0) absent: (1) present. [Note. These bristles are sited on the upper half of the chelicerae and usually cross each other in front of and between the two chelicerae ( Fig. 13d View Figure 13 ).]
Character 3. Size of two pairs of prominent cheliceral bristles in character 2: (0) normal, prominent, crossing; (1) prominent but reduced, not or barely crossing. [Note. Female Corasoides tend to have larger numbers of hairs and smaller cheliceral bristles than males. In species where the cheliceral bristles are reduced in the male, the usually prominent bristles of the females are often almost the same size and robustness as other bristles on the chelicerae.]
Character 4. Serrations on fangs: (0) present; (1) absent. [Note. In some species serration is not obvious and its detection is compounded by the false absence in some specimens, caused, presumably, by wear and tear.]
Character 5. Form of fangs: (0) short, curved; (1) long: (2) short, angular, chunky.
Character 6. Prominence of boss: (0) prominent; (1) reduced.
Character 7. Relative number of promarginal and retromarginal teeth: (0) equal; (1) more promarginal; (2) more retromarginal.
Character 8. Presence of enlarged prolateral cheliceral teeth in adult males: (0) absent; (1) present. [Note. This attribute may not be displayed to full extent in all specimens.]
Character 9. Cheliceral grooves: (0) absent; (1) present. [Note. Cheliceral grooves are transversely placed between the rows of cheliceral teeth.]
Character 10. Length of cephalothorax: (0) greater than 3 mm; (1) less then 3 mm.
Character 11. Banding on legs: (0) banded; (1) not banded. [Note. Faint banding on any part of the legs is scored (0). In faded alcohol specimens banding can usually still be seen on the femora of leg IV.
Character 12. Spines on patella of leg III, at least in male: (0) absent; (1) present. [Note. In some specimens the patella spine(s) may be reduced to large bristles. Character 13. Tail of pyriform spigots prolaterally on anterior lateral spinnerets: (0) absent; (1) present ( Fig. 3b,c View Figure 3 )
Female genital morphology
Character 14. Presence of beak on epigyne: (0) absent; (1) present. [Note. Beak is ventral projection anterior to scape, as an extension to the ridge anterior to the genital openings ( Figs 16e,g View Figure 16 , 23c,f View Figure 23 ).]
Character 15. Lateral extension of scape: (0) present; (1) absent.
Character 16. Plugging of female epigyne during mating: (0) plugged; (1) not plugged. [Note. Although this could be described as a behavioural character, it is observed as a physical state of the female genitalia. A single plugged female scores (0) for a species. To be scored (1) at least five adult females in the vicinity of adult males must be unplugged. Otherwise is scored as (?).]
Character 17. Diverticula at junction of insemination ducts and spermathecae: (0) absent; (1) present.
Character 18. Number of bends in insemination ducts: (0) 0; (1) 1–2; (2) 3–4; (3) 5–7; (4) 8+. [Note. A bend is scored for a change in direction of at least 90 degrees.]
Character 19. Diameter of insemination ducts: (0) uniform thickness throughout length; (1) at least twice the thickness in the initial section as in the remainder ( Fig. 31d View Figure 31 ). [Note. The length of the initial section is at least the length of the diameter of the spermathecae.]
Character 20. General position of loops of insemination ducts with respect to spermathecae: (0) central, between spermathecae; (1) anterior; (2) evenly looped around spermathecae. [Note. General position of loops of insemination ducts with respect to spermathecae is associated to some extent with character 18. It is useful really only for those species with numerous bends in the insemination ducts as it defines the position of these extra bends. Where insemination ducts are simple, they generally lie between the spermathecae and this is the case with both outgroups. Corasoides angusi sp. nov. is scored “?” because the insemination ducts are as much anterior as between the spermathecae and as such is intermediate in state.]
Male papal morphology
Character 21. Bristled retroventral apophysis: (0) absent; (1) present.
Character 22. Retrolateral apophysis: (0) absent; (1) present.
Character 23. Retrolateral apophysis morphology: (0) does not taper to point; (1) tapers to point.
scored as “?”. Note that numbering of characters begins with zero.
Character 24. Pit on retrolateral apophysis ( Fig. 29b View Figure 29 ): (0) absent; (1) present.
Character 25. Direction of retrolateral apophysis: (0) straight in direction of palp; (1) bending towards bulb and then towards base of apophysis (hooked); (2) bending away from bulb, then crossing over ventrally to point obliquely towards the bulb and the base of the apophysis; (3) bending away from bulb; (4) bending towards bulb from far end of base and then pointing dorsally.
Character 26. Conductor morphology: (0) not T-shaped; (1) T-shaped. [Note. The conductors of C. australis
are less so. The T-shape is caused by a pair of lobes that enclose the embolus and guide it to the tip of the conductor and are extended basally and prolaterally. These lobes are present, although reduced basally and prolaterally in C. mouldsi sp. nov. and C. occidentalis sp. nov. but are still scored as “1”. A small, similar looking lobe on C. terania sp. nov. is not homologous, being single rather than paired, part of the stalk and not a member of the pair of lobes which guide the embolus into the tip of the conductor.]
Character 27. Degrees of arc through which embolus sweeps from origin to tip: (0) embolus originates centrally; (1) roughly 90 (60–120) degrees; (2) roughly 180 (130–190) degrees; (3) greater than 180 (200+) degrees. [Note. Although this appears to be a continuous character, the states do not overlap. These states define the length of the embolus as well as its position of origin. A centrally originating embolus (as in the genus Inola ) does not sweep in an arc around the bulb of the cymbium but travels roughly ventrally to the conductor.]
Character 28. Retrodorsal tibial apophysis on male palp: (0) present; (1) absent. [Note. This apophysis is not as obvious, erect or complex as the other male papal apophyses in Corasoides .]
Character 29. 2n chromosome number: (0) not equal to 31; (1) equal to 31. [Note. 2n of the outgroup Inola is 28 (Tio & Humphrey, 2010).]
Character 30. Number and type of sex chromosomes: (0) XX; (1) XXX. [Note. Inola state (XX) is from Tio and Humphrey (2010).]
Character 31. Burrowed retreat of adults: (0) absent; (1) present. [Note. Specimens of some species may be found with retreats in the ground, but these are not scored “1” unless they have been actively dug by the spider.]
Character 32. Cohabitation of male with penultimate female prior to mating: (0) present; (1) absent.
Character 33. Ability to inhabit outside rainforest: (0) absent; (1) present. [Note. Corasoides motumae inhabits both rainforest and wet sclerophyll and is scored (1).]
Character 34. Inability to inhabit below 1500 m in altitude. (0) absent; (1) present.
Of the 35 characters, 29 were based on morphology, two related to karyotype, two to behaviour and two were ecological. Of the 29 morphological characters, seven were based on female genitalia and eight on the male papal organ while four of the remainder were at least partially gender dependent. Chromosomal characters and states were taken from Humphrey (in press). Behavioural and ecological characters and states are the author’s personal observations.
The following characters are often used in cladistical work on spiders but have not been used for the following reasons.
Colour and pattern. The colour of the head and anterior portion of the carapace provides an autapomorphy and quick and easy identification for Corasoides motumae sp. nov., it being the only species to be dark to black. It is the only colour pattern in Corasoides , other than banding in the legs, which does not overlap specifically. In general, colour and pattern are unreliable in Coraso ides. A species often has a wide natural variation which may not be appreciated unless a large number of representatives, from throughout the distribution, is examined. This variation is also extended by age, sex, time from moulting and preservation conditions. This is very obvious in the abdominal pattern which, although typical of the genus, varies from pronounced to obscure. The smaller Papua New Guinea species have a reduced pattern consisting of a double row of spots but again this can be faint or nonexistent in preserved specimens.
Number of cheliceral teeth. There is insufficient variation between species in promarginal teeth and too much intraspecific variation causing overlap of states for retromarginal teeth. The number of cheliceral teeth sometimes varied from one side of a specimen to the other. However, the relative number of retromarginal to promarginal teeth was useable, character 7.
Relationships of leg lengths to body lengths. Whether as absolute values or ratios, the states for leg length overlap between species. Leg length relationships are also dependent upon age, gender and degree of sexual development and legs are also subject to regeneration.
Number of trichobothria on legs and cymbium. The number and pattern of trichobothria on Corasoides is often difficult to ascertain and the numbers vary between specimens. Lehtinen (1978) argues that trichobothria number is allometric, related to leg size and gender.
Length of cymbium. The extreme length of the digitiform portion of the cymbium in C. occidentalis sp. nov. is characteristic for that species. However, intraspecific variation in other species of Corasoides (probably related to degree of secondary sexual development) negates the use of this character.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.