Cosmopelma decoratum Simon 1889
Creators: name: Mori, Andre
name: Bertani, Rogerio
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Barychelidae
Cosmopelma
Cosmopelma decoratum

description: Cosmopelma decoratum Simon, 1889
(Figs 1–19, 36–37, 39–41. Tables 1–2)
Cosmopelma decoratum Simon, 1889: 217; 1892:128; Petrunkevitch, 1911: 54; Mello-Leitão, 1923: 123; Roewer, 1942: 220.
Diagnosis. Females of C. decoratum can be distinguished by the absence of the D-shaped base of the spermathecae and the non-spiralled stalks connected to the receptacles (Figs 36–37); males can be distinguished by the presence of cuspules on the maxillae (Fig. 13), the absence of a megaspine on the tibiae I (Fig. 16), and the thin, long and mostly straight embolus (Figs 17–18).
Type material. Holotype female, Brazil, State of Bahia, “Rio Salobro, now Santa Luzia (15°26'00.9"S, 39°19'44.0"W), Gounelle col., MNHN AR8756 B.102, examined.
Other material examined. BRAZIL: Bahia: Uruçuca, Fazenda Almada (14°35'44.6"S, 39°17'08.0"W), 1 male, November 1977, J. Santos (CEPLAC 3793); 1 female, same date and collector (CEPLAC 3780); 12 females, 2 immatures, Fazenda Santa Teresa (14°35'44.6"S, 39°17'08.0"W), no futher data, (MNRJ 12919, R2955).
Redescription. Female. MNRJ 12919. Carapace 3.48 long, 3.06 wide. Abdomen 3.45 long, 2.61 wide. Total length 6.9. Carapace: Surface smooth. Thoracic striae faint, shallow. Caput slightly raised. Fovea short, shallow, slightly procurved. Eight eyes on reduced and low tubercle, 0.20 high, 0.91 wide, 0.45 long. Clypeus, 0.29 wide. MOQ 0.92 wide, 0.32 long. Anterior eye row slightly procurved, posterior slightly recurved. AME, 0.15; ALE, 0.14; PME, 0.08; PLE, 0.16. Eye interspaces: AME-AME, 0.15; AME-ALE, 0.08; ALE-ALE, 0.61; PME-PLE, 0.04; PME-PME, 0.38; ALE-PLE, 0.02. Chelicerae: 1.53 long with very fine setae on pro- and retrolateral side. Seven teeth on promargin. Fangs pale at base, darkening distally, becoming light brown hue. Rastellum absent, distal edge with 8 dark thick setae. Labium: 0.25 long, 0.64 wide, with one row of fine setae anteriorly. Cuspules absent. Labiosternal groove shallow, flat, with pair of sigilla. Maxillae: 0.96 long in front, 1.42 behind, 0.74 wide, with 31 spiky cuspules ventrally on inner angle of both maxillae. Maxillary heel rounded, anterior lobe indistinct. Fine setae throughout surface, without dense patches. Lyra absent. Coxa I: 12 spiky cuspules ventrally on inner mound. Sternum: 1.74 long, 1.62 wide. Fine setae throughout surface, without dense patches. Three pairs of faint sigilla, circular, close to coxae of legs I, II and III, one diameter from sternum margin. Booklungs: semi-circular, with elliptical aperture; booklung combs not evident.
Legs: formula IV I II III. Measurements in Table 1. Spines: leg I: fe 0, pa 0, ti r1-1-1, me v2 -0-1(ap), ta 0; leg II: fe 0, pa 0, ti v1-2 -1, me v2 -0-1(ap), ta 0. Leg III: fe 0, pa 0, ti 0, me p0-0-1, v1 -0-2(ap), ta 0. Leg IV: fe 0, pa 0, ti 0, me v0-0-2(ap), ta 0; palp: fe 0, pa v0-1-0, ti v2-2 -2, ta 0. Preening combs absent. Few (4–7) clavate trichobothria on tarsi of all legs and palps, median-positioned. Claws: palpal claw without teeth, slightly longer than claw tuft. Paired claws without teeth on other legs, slightly longer than claw tuft. Claw tufts: dense on all legs and palp, slightly separated in two symmetrical parts. Scopulae: undivided, dense on tarsi of palp, metatarsi and tarsi of legs I and II, less dense on tarsi of legs III and IV.
Spermathecae: two, with thin base, from which two receptacles branch; external receptacle large, rounded, connected by thick short stalk; internal receptacle thin, rod-shaped, connected by thin short stalk; stalks of inner receptacles very sclerotized.
Spinnerets: PMS short, triangular, 0.33 long, 0.16 wide. Basal, middle, and apical segments of PLS 0.48 long, 0.41 wide, 0.14 long, 0.33 wide; 0.20 long, 0.23 wide, respectively; apical segment triangular with two pale bands: one basal and one apical. All segments covered by fine setae.
Color pattern: chelicerae and carapace light brown, legs bicolored, with alternating pale and brown bands, abdomen dorsally bicolored, with distinctive symmetric pattern of pale and brown areas: 3 anterior pairs of bands separated by brown area in middle and 3 posterior bands undivided; ventrally pale.
Description. Male. CEPLAC 3793. All characters as in female except: carapace 3.47 long, 3.23 wide. Abdomen 3.37 long, 2.38 wide. Total length 7.58. Eye tubercle 0.30 high, 0.84 wide, 0.44 long. Clypeus 0.18. MOQ 0.84 wide, 0.28 long. AME 0.20, ALE 0.15, PME 0.12, PLE 0.08. Eye interspaces: AME–AME, 0.17; AME–ALE, 0.07; ALE–ALE, 0.62; PME–PLE, 0.03; PME–PME, 0.69; ALE–PLE, 0.08. Chelicerae 1.06 long. Labium 0.19 long, 0.57 wide, without cuspules. Maxillae 0.94 long in front, 1.23 long behind, 0.44 wide, with 8 thin cuspules ventrally on inner angle. Coxae I: cuspules absent. Sternum: 1.87 long, 1.57 wide.
Legs: Formula IV I II III. Measurements in Table 2. Spines: leg I: fe 0, pa 0, ti r0-1-1, me v0-0-1, ta 0; leg II: fe 0, pa 0, ti v0-2-1, me r1-0-1(ap), ta 0. Leg III: fe 0, pa 0, ti 0, me p0-0-2 (1ap), r0-0-2(1ap), ta 0. Leg IV: fe 0, pa 0, ti, me, ta missing on both sides; palp: fe 0, pa 0, ti 0, ta 0. Scopulae entire on all tarsi of legs, absent on other segments. Tibial apophysis on leg I absent, with two regular spines instead.
Palp: bulb piriform. Embolus short, thin, mostly straight but a little curved at end. Several dark parallel keels around bulb surface. Duct gradually tapering, coiled twice on prolateral face.
Spinnerets: PMS 0.19 long, 0.11 wide. Basal, middle, and apical segments of PLS 0.46 long, 0.37 wide, 0.33 long, 0.30 wide; 0.14 long, 0.14 wide, respectively.
Distribution. Santa Luzia and Uruçuca, in the State of Bahia, Brazil.
Discussion. Cosmopelma decoratum was first described only from a very distinctive female (Figs 1–3) which displayed unusual cuspules on the maxillae and the coxae I (Fig. 2). Newly examined material from the Uruçuca municipality, including 12 females and 1 male, proved to be new records of C. decoratum. The redescription was based on a well-preserved female (Figs 4–10) whose spermathecae matched those of the holotype, albeit with minor difference in the thickness of the receptacles (Fig. 37). Such differences could be due to the preservation or positioning of the spermathecae, given how certain variations are seen even between the spermathecae in the same specimen, or also likely due to intraspecific variation, given how other spermathecae from the same group of the Uruçuca spiders also showed some variation in the thickness of the receptacles.
Additionally, a male (although not in good condition) is described (Figs 11–19) for the first time. Nevertheless, the diagnostic characters of Cosmopelma in this male are preserved, and important structures such as the bulbs (Figs 17–18) are visible.
description: Published as part of Mori, Andre & Bertani, Rogerio, 2016, On the genus Cosmopelma Simon, 1889 (Araneae, Barychelidae), pp. 520-534 in Zootaxa 4137 (4) on pages 522-526, DOI: 10.11646/zootaxa.4137.4.4, http://zenodo.org/record/267111