Acanthoctenus Keyserling, 1877

Arizala, Stephany, Labarque, Facundo Martín & Polotow, Daniele, 2021, Revision of the Neotropical spider genus Acanthoctenus (Araneae: Ctenidae Acanthocteninae), Zootaxa 4920 (1), pp. 1-55 : 6-12

publication ID	https://doi.org/ 10.11646/zootaxa.4920.1.1
publication LSID	lsid:zoobank.org:pub:89E38EAD-A8D2-4ED9-A7D0-8C388A785E61
DOI	https://doi.org/10.5281/zenodo.4497849
persistent identifier	https://treatment.plazi.org/id/F73887DC-E926-9669-43F7-F8E8FAC8AA5B
treatment provided by	Plazi
scientific name	Acanthoctenus Keyserling, 1877
status

Treatment

Genus Acanthoctenus Keyserling, 1877 View in CoL View at ENA

Acanthoctenus Keyserling, 1877: 693 View in CoL , plate 8, fig. 60. Type species Acanthoctenus spiniger Keyserling, 1877 View in CoL , designated by Simon (1892: 229).— Simon 1893: 430.—F.O. Pickard-Cambridge 1897: 101.— Dahl, 1901b: 186.—F.O. Pickard-Cambridge 1902: 354.— Tullgren 1905: 19.— Kraus 1955: 51.— Simon 1906: 288.— Strand 1909: 402.— Petrunkevitch 1925: 95.—Mello-Leit„o 1936: 181.— Reimoser 1939: 364.—Mello-Leit„o 1945: 256.— Soares & Soares 1946: 53.— Caporiacco 1947: 28, 1948: 684, 1955: 290.— Chickering 1960: 81.— Lehtinen 1967: 208.— Forster & Wilton 1973: 293.—Griswold 1993: 3.— Bosselaers 2002: 141.— Silva-Dávila 2003: 3.— Griswold et al. 2005: 17.— Polotow & Brescovit 2008: 706, 2012: 40, 2014: 334.— Ramirez 2014: 28.— Polotow et al. 2015: 134.— World Spider Catalog 2020.

Paracantheis Kraus, 1955: 51 . Type species Paracantheis virginea Kraus, 1955 by original designation.— Lehtinen 1967: 256 (Syn).— World Spider Catalog 2020.

Diagnosis. Acanthoctenus species resemble other Acanthocteninae as Nothroctenus and Viracucha by the presence of a cribellum and calamistrum ( Figs 5E, F View FIGURE 5 ; 6E View FIGURE 6 ), three retromarginal teeth on the chelicerae ( Fig. 5A View FIGURE 5 ; Polotow & Brescovit 2014: char. 64) and the distal pair of spines on tibia I distant from the apical margin of tibia ( Polotow & Brescovit 2014: char. 73). Males resemble those of Nothroctenus and Viracucha by the palp with swollen patella ( Polotow & Brescovit 2014: char. 1, fig. 5a), retrolateral cymbial process ( Fig. 8A View FIGURE 8 ; Polotow & Brescovit 2014: char. 16, fig. 5A; Silva-Dávila 2003: fig. 19c–d), and curved papal tibia ( Fig. 11C View FIGURE 11 ; Polotow & Brescovit 2014: fig. 5a). Males of Acanthoctenus can be distinguished from those genera by the short and cylindrical embolus ( Fig. 8B View FIGURE 8 ) and by the elongated and thin median apophysis with an apical hook ( Fig. 8B View FIGURE 8 ) whereas the males of Nothroctenus ( Silva-Dávila 2003: fig. 19c) and Viracucha ( Polotow & Brescovit 2014: fig. 5a) have embolus with a laminated base and median apophysis reduced or massive, respectively. Furthermore, males can be distinguished from Nothroctenus by the absence of a folded spermatic duct ( Fig. 11C View FIGURE 11 ), present in the latter ( Dias & Brescovit 2004: figs 7–8). Females resemble those of Nothroctenus ( Dias & Brescovit 2004: fig. 9) and Viracucha ( Lehtinen 1967: fig. 415) by the lack of lateral projections on the epigynum ( Fig. 9A View FIGURE 9 ; Polotow & Brescovit 2014: char. 52). Females of Acanthoctenus can be distinguished from Nothroctenus ( Lehtinen, 1967: fig. 417; Dias & Brescovit 2004: fig. 9) and Viracucha ( Lehtinen 1967: fig. 415) by their large atrium ( Figs. 13C View FIGURE 13 , 16C View FIGURE 16 ; Lehtinen, 1967: fig. 414), reduce or absent in the other genera, respectively, and from Nothroctenus by the shorter copulatory ducts ( Fig. 9B View FIGURE 9 ), elongated and convoluted in the latter ( Dias & Brescovit 2004: fig. 10).

Description. Small to medium-sized cribellate spiders. Total body length (males and females) 7.26–16.20. Carapace piriform, light brown with a wide longitudinal stripe of lighter coloration (from light brown to beige) from ocular area to the posterior border; thoracic groove longitudinal and located in the posterior third ( Figs 1A View FIGURE 1 , 3A View FIGURE 3 , 4 View FIGURE 4 A–B, 11A, 13A, 15A, 17A, 20A, 22A, 24A, 27A, 30A, 31A, 33A, 36A, 38A, 40A, 42A, 44A, 46A, 48A). Carapace profile higher at the ocular area ( Figs 1B View FIGURE 1 , 3B View FIGURE 3 ). Clypeus with long dark bristles ( Fig. 13B View FIGURE 13 , 15C View FIGURE 15 ). Ctenid eye pattern 2-4-2, with the anterior and posterior row recurved in dorsal view ( Figs 4B View FIGURE 4 , 5B View FIGURE 5 , 13B View FIGURE 13 ). Eyes round, except oval anterior lateral eyes, mounted over black mounds ( Figs 5B View FIGURE 5 , 13B View FIGURE 13 , 20C View FIGURE 20 ), with grade-shaped tapetum (barely shown in Fig. 22C View FIGURE 22 ). Anteriorly with a dark band with two lateral stripes of white setae extending from the anterior border of the carapace to the anterior median eyes ( Figs 1C View FIGURE 1 , 3C View FIGURE 3 , 13B View FIGURE 13 , 15C View FIGURE 15 , 20C View FIGURE 20 , 22C View FIGURE 22 , 24C View FIGURE 24 , 27C View FIGURE 27 , 30B View FIGURE 30 , 36C View FIGURE 36 , 38C View FIGURE 38 , 40C View FIGURE 40 , 42C View FIGURE 42 , 44C View FIGURE 44 , 46C View FIGURE 46 , 48C View FIGURE 48 ). Chelicerae with a large boss ( Fig. 40C View FIGURE 40 ), thickened setae next to the fang base ( Fig. 5A View FIGURE 5 ), three promarginal teeth, median largest, three retromarginal teeth, basal smaller, and without intermaginal denticles ( Figs 5A View FIGURE 5 , 22B View FIGURE 22 ). Chilum divided ( Fig. 15C View FIGURE 15 ). Long endites and labium short in relation to the size of the endites; light brown sternum, oval, not extending between legs IV ( Figs 11B View FIGURE 11 , 15B View FIGURE 15 , 17B View FIGURE 17 , 20B View FIGURE 20 , 22B View FIGURE 22 , 24B View FIGURE 24 , 27B View FIGURE 27 , 31B View FIGURE 31 , 33B View FIGURE 33 , 36B View FIGURE 36 , 38B View FIGURE 38 , 40B View FIGURE 40 , 42B View FIGURE 42 , 44B View FIGURE 44 , 46B View FIGURE 46 , 48B View FIGURE 48 ). Leg formula 1423 in males, female leg formula is variable and is described for each species. Shallow trochanteral notch ( Fig. 15B View FIGURE 15 ). Legs usually longer in males than females. Spination: ventral surfaces of tibia I-II with nine pairs of spines and metatarsus I-II with five pairs of spines, except A. remotus (tibia I with seven pairs, tibia II with six pairs and metatarsus I-II with three pairs of spines). All legs in males and females with a patch of tenant setae (claw tufts) arising from a movable plate (claw tuft plate) ( Fig. 6C View FIGURE 6 ). Third small tarsal claw present on each leg tarsus ( Fig. 6D View FIGURE 6 , arrow). Trichobothria bases with four transversal grooves on proximal hood ( Fig. 6A View FIGURE 6 ). Distal capsulated tarsal organ with a drop-shaped opening ( Fig. 6B View FIGURE 6 ). Calamistrum oval with several rows of setae ( Fig. 6E View FIGURE 6 ). Pedicel divided ( Fig. 5C View FIGURE 5 ). Opisthosoma oval with tufts of elongated white setae in two longitudinal rows ( Figs 1A View FIGURE 1 , 4B View FIGURE 4 , 5D View FIGURE 5 ). Cribellum divided into two fields of strobilate spigots that are clumped in short, longitudinal linear rows ( Fig. 5 View FIGURE 5 E–F; Griswold et al. 2005: figs 97a, 115a), larger in females than males. Six spinnerets, ALS, and PLS two-segmented ( Fig. 7A, C View FIGURE 7 ), PMS one-segmented ( Fig. 7B View FIGURE 7 ). The ALS has a bare margin, a two large MAP, and several PI spigots interspersed with tartipores ( Fig. 7A View FIGURE 7 ; Griswold et al. 2005: figs 115b, 116b, 117a). The PMS has a pair of mAP spigots with a tartipore in between and many small AC spigots interspersed with three large CY spigots; without paracribellar spigots ( Fig. 7B View FIGURE 7 ; Griswold et al. 2005: figs 115c–e, 116d, 117d). The PLS has several AC spigots and an apical anterior MS ( Fig. 7C View FIGURE 7 ; Griswold et al. 2005: figs 115d, 116c, 117b–c). The silks used for the construction of egg sacs and shelters are irregular ( Fig. 7 View FIGURE 7 D–F). Males lack epiandrous spigots. Male palp: patella swelled ( Fig. 11A, D View FIGURE 11 ); tibia curved with only one tibial projection (RTA) ( Figs 11C, D View FIGURE 11 , 12 View FIGURE 12 A–B); conical RTA; cymbium longer than tibia and with a basal retrolateral projection ( Figs 11C View FIGURE 11 , 12A View FIGURE 12 ); subtegulum prolateral, partially visible behind embolus; tegulum suboval with a central hyaline area where the median apophysis emerges ( Figs 11C View FIGURE 11 , 12A View FIGURE 12 ); embolus emerging prolaterally, flexibly attached to the tegulum, cylindrical, with a larger base tapering distally ( Fig. 8A View FIGURE 8 ); median apophysis elongated and scoop-shaped, with a subtriangular distal projection ( Fig. 8 View FIGURE 8 A–B); conductor apical and hyaline ( Figs 8 View FIGURE 8 A–B, 12B); some species with modified setae distally on the cymbium ( Fig. 8 View FIGURE 8 C–D). Female genitalia: epigynum divided into the median and lateral sectors ( Figs 9A View FIGURE 9 , 12C View FIGURE 12 ); median sector suboval, subpentagonal, or subrectangular, longitudinally elongated, extending or not into the atrium, partially covered by the lateral sectors ( Figs 9A View FIGURE 9 , 12C View FIGURE 12 , 14A View FIGURE 14 , 17C View FIGURE 17 ); lateral sectors large, anteriorly straight or curved, forming an angle between 30° and 90° with the median sector longitudinal axis, partially transparent, spermathecae visible through transparency ( Figs 14A View FIGURE 14 , 17C View FIGURE 17 , 18A View FIGURE 18 , 20D View FIGURE 20 ); copulatory opening small, connected to the lateral sector ( Figs 14A View FIGURE 14 , 16C View FIGURE 16 , 19A View FIGURE 19 , 21A View FIGURE 21 , 23C View FIGURE 23 ); copulatory ducts sinuous, first half bordered by the lateral sectors, strongly or slightly S-shaped (left side) ( Figs 12D View FIGURE 12 , 14B View FIGURE 14 , 16D View FIGURE 16 , 18B View FIGURE 18 21B View FIGURE 21 ); head of spermathecae quote-shaped, with apical glandular openings ( Figs 12D View FIGURE 12 , 14B View FIGURE 14 , 18B View FIGURE 18 , 21B View FIGURE 21 ); the base of spermathecae scalloped ( Figs 12D View FIGURE 12 , 14B View FIGURE 14 , 18B View FIGURE 18 , 21B View FIGURE 21 ); fertilization ducts short, tubular and sclerotized, emerging from the base of spermathecae ( Figs 9B View FIGURE 9 , 14B View FIGURE 14 , 21B View FIGURE 21 , 25B View FIGURE 25 ).