Iracema horrida Schmidt 1994, comb. nov.
Creators: name: Bertani, Rogério
name: Carla-Da-Silva, Silvia
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Gymnotiformes
Rhamphichthyidae
Iracema
Iracema horrida

description: Iracema horrida (Schmidt 1994) comb. nov.
Figs. 1–5, 10.
Paraphysa horrida Schmidt, 1994: 2, fig. 1 (Holotype female, SMF 38040, examined). ­Platnick (2003).
Diagnosis. Iracema horrida can be distinguished from Iracema cabocla by the larger size, presence of types III and IV of urticating hairs in both sexes and the number of labial cuspules (5 to 16).
Description. Male (IBSP 10120, Manaus, Amazonas, Brazil, Maria E. E. S. Oliveira leg., January, 1991). — Total length excluding chelicerae: 43.9. Carapace: length 22.5, width 20.1. Eye tubercle: length 2.5, width 3.1. Labium: length 3.9, width 4.4. Sternum: length 10.9, width: 9.3. Cephalic region low, hardly distinguishable. Thoracic striae moderately deep. Fovea short, deep and straight. Chelicerae without rastellum, basal segments with 9­9 teeth on promargins. Clypeus absent. Anterior eye row procurved, posterior slightly recurved. Anterior median eyes larger than lateral eyes. Anterior and posterior lateral eyes with similar size. Posterior median eyes about a half of the diameter of the posterior lateral eyes. Labium with 12 cuspules on its anterior half. Maxilla subrectangular, anterior lobe distinctly produced into a conical process, inner part bearing numerous cuspules (more than 50). Labiosternal suture broad. Sigilla: anterior pair not distinctly recognizable; all other pairs well recognizable; situated one diameter from margin, fourth pair twice the diameter of second. Posterior median spinnerets with one article, short; posterior lateral spinnerets with three articles, basal article shorter than median, both shorter than the digitiform apical article. Claw tufts present; superior tarsal claws with a few very small teeth. Tarsi I–IV scopulate, IV with some spiniform setae; metatarsi I scopulate over 2/5 of its length, II scopulate over 1/3, III and IV scopulate only apically. Femur IV without retrolateral scopula. Stridulatory setae absent. Coxae and maxillae having many short spiniform setae on prolateral and retrolateral faces, reaching ventral margin (Fig. 5). Marginal areas of labium and sternum covered by very small spiniform setae. Legs: I femur 20.6, patella 10.5, tibia 18.6, metatarsus 18.1, tarsus 10.8, total 78.6, II 19.8, 9.7, 16.1, 17.4, 9.4, 72.4, III 17.5, 8.6, 14.2, 16.9, 9.7, 66.9, IV 21.3, 9.1, 19.0, 27.2, 10.0, 86.6. Leg spination: tarsi lacking spines. Palpal femur 0, patella 0, tibia v0­1­0, p0­1­1; leg I femur p0­0­1, patella 0, tibia v1­2 ­0, p1­0­0, r1­0­0, metatarsus v0­0­2(ap); II femur p0­2­1, r0­2­0, patella p2, tibia v2­2 ­1(ap), p1­1­0, r1­0­0, metatarsus v1­3 ­2(ap), p1­0­1, r0­0­1(ap); III femur p0­0­1, r0­2­1, patella 0; tibia v2­1 ­3(ap), p2­1­0, r1­1­0, metatarsus v2­2 ­4(3ap), p1­1­1(ap), r1­1­1; IV femur p0­1­1, r0­2­1, patella 0, tibia v3­1 ­2(ap), p2­2­0, r3­1­1, metatarsus v10 (3ap), p1­1­0, r1­4­1. Male spur of palpal tibia (Fig. 3) with two straight branches originating independently from raised bases. Retrolateral branch longer than prolateral, tapers abruptly to distal part. Both branches bearing a narrow spine contiguous to each branch on internal face. Metatarsus I slightly bent at basal part, when flexed it passes between two tibial spur's branches. Male palpal bulb (Figs. 1, 2) with large subtegulum. Bulb piriform, prolateral superior and prolateral inferior keels present. Prolateral inferior dislocated, originating on the retrolateral side; having very small denticles on its distal portion. Carapace covered by orange hairs, sternum and coxae dark, with long orange hairs (Fig. 10). Urticating hairs of types III and IV present, type III on the central area of dorsal opisthosoma, type IV surrounding that area. Opisthosoma longer than wide, black. Legs narrow, black, rings and longitudinal stripes on patellae and tibiae poorly defined.
Female (IBSP 10124, Manaus, Fucada, km 38 BR 174, Amazonas, Brazil, Francisco A. Neo leg., 07, January, 1987) — Total length excluding chelicerae: 52.5. Carapace: length 26.9, width 24.0. Eye tubercle: length 2.7, width 3.6. Labium: length 3.8, width 5.2. Sternum: length 11.6, width: 15.8. All characters as in male, except: cephalic region high; basal segments of chelicerae with 9­10 teeth on promargins; anterior median eyes same size as posterior lateral and anterior lateral eyes; labium with 16 cuspules on its anterior half. Legs: I femur 20.1, patella 11.6, tibia 16.8, metatarsus 14.3, tarsus 7.8, total 70.6, II 18.5, 10.7, 14.1, 13.8, 7.8, 64.9, III 16.0, 8.8, 12.3, 15.4, 6.8, 59.3, IV 19.6, 9.2, 16.6, 21.2, 8.4, 75.0. Leg spination: tarsi lacking spines. Palpal femur p0­0­1, patella 0, tibia v2­3 ­5(4 ap), p1­0­0, r1­0­0; legs I femur p0­0­1, patella 0, tibia v1­1 ­3ap, p0­2­0, r1­0­0, metatarsus v1­2 ­2ap; II femur p0­2­2, d0­1­0, patella 0, tibia v3­2 ­3ap, p1­1­0, r1­0­0, metatarsus v2­1 ­2ap, p0­1­1; III femur p0­2­0, d0­2­2, patella 0; tibia v2­2 ­2ap, p1­1­0, r1­1­0, metatarsus v2­3 ­5(3ap), p0­1­1, r0­2­1; IV femur p0­0­1, r0­0­1, patella 0, tibia v2­2 ­2ap, p1­2­ 0, r1­1­0, metatarsus v8 (2ap), p2­1­1, r3­2­1. Two spermathecae (Fig. 4) heavily sclerotized at their distal part; slightly sclerotized, with folds on the proximal part.
Additional material examined. Brazil, Amazonas: Presidente Figueiredo, Usina Hidrelétrica de Balbina, Equipe de Resgate de Fauna leg., 10 November, 1987, 1 female (IBSP 10116), 20 November, 1987, 2 females (IBSP 10122, IBSP 10126), 08 December, 1987, 2 immature males (IBSP 8540, IBSP 10123), 2 females (IBSP 10125, IBSP 10127), 24 February, 1988, 1 immature male (IBSP 10115); P. E. Vanzolini leg., July, 1988, 1 female (IBSP 4932); Manaus, Fucada, km 38 BR174, F. A. Neo leg., 23 March, 1987, 2 immature males (IBSP 10118, IBSP 10119), 1 male (IBSP 10117); Manaus, Caracaraí, km 30 INPA, H. Hoefer leg., 10 June, 1987, 1 female (IBSP 10121). Roraima: Apiaú, G. Skuk leg., 1 female, alive at the Laboratório de Artrópodes of the Instituto Butantan.
Distribution. Brazil: States of Amazonas and Roraima. Venezuela: Territorio Federal Amazonas, Rio Siapo (R.C. West, pers. comm. 2003).
Discussion. The discovery of the male of the species formerly described as Paraphysa horrida Schmidt, 1994 showed that this species is closely related to Iracema cabocla Pérez­Miles, 2000. The similarity in the morphology of male palpal bulbs (Figs. 1, 2, 6, 7), in male tibial spur (Figs. 3, 8) and of spermathecae (Figs. 4, 9) is striking, as well as the presence of many short spiniform setae in both species (Fig. 5) on prolateral and retrolateral sides of the maxillae and coxae. Both species have a reduced number of labial cuspules, though in I. cabocla the number is extremely low, 3 or 0 contrasting with 5 to 16 in I. horrida. This difference is here considered as a diagnostic characters.
Pérez­Miles (2000) presented a cladistic analysis including his new genus Iracema, in which it appeared as a sister group of Cyriocosmus. The clade Cyriocosmus + Iracema was in a politomy with Grammostola + Paraphysa + (Homoeomma + Plesiopelma) which have as a synapomorphy the presence of type IV of urticating hairs. Iracema was distinguished from Grammostola Simon, 1892 by the absence of stridulatory hairs, from Plesiopelma Pocock, 1901 by the absence of a nodule on the male metatarsus I, from Homoeomma Ausserer, 1871 by the absence of a digitiform apophysis on the male palpal bulb, and from Paraphysa Simon, 1892 by the absence of a process on the retrolateral face of palpal tibia, the very reduced number of labial cuspules (3, being more than 10 in Paraphysa) and by the divided tarsal scopulae (Pérez­Miles 2000).
However, although Iracema can be easily distinguished from almost all the genera by the characters presented above (Pérez­Miles 2000), the inclusion of the species I. horrida in that genus showed that it can not be easily distinguished from Paraphysa by the characters presented by the author. The number of cuspules found on I. horrida, between 5 and 16, overlaps with that found on Paraphysa (more than 10). Furthermore, another character used to distinguish between Paraphysa and Iracema, the presence of a division on tarsal scopula in Iracema, is not present in I. horrida. Because this character is closely related with size (Pérez­Miles 1994) it is very probable that the absence in I. horrida is due to its larger size. Concerning the presence of a process on the retrolateral face of palpal tibia, also used as a diagnostic character, the examination of this structure showed that it is distinct from the process found in genera like Acanthoscurria Ausserer, 1871 and Cyriocosmus in which an acute projection is readily visible.
Additionally, metatarsus I of Iracema spp. males closes between the tibial spurs (Figs. 3, 8), whereas in Paraphysa scrofa (= P. manicata), the type species of the genus, it touches the retrolateral side of the retrolateral branch when flexed. Also, both sexes of Iracema spp. have many short spiniform setae (Fig. 5) on prolateral and retrolateral faces of the maxilla and coxae. These characters should be seen as apomorphies of the genus Iracema.
description: Published as part of Bertani, Rogério & Carla-Da-Silva, Silvia, 2003, Notes on the genus Iracema Pérez­Miles, 2000 with the first description of the male of I. horrida (Schmidt, 1994) (Araneae: Theraphosidae), pp. 1-8 in Zootaxa 362 on pages 2-7, DOI: 10.5281/zenodo.156799