Pseudocleobis solitarius Maury, 1976

Iuri, Hernán A. & Iglesias, Mónica S., 2022, The genus Pseudocleobis Pocock, 1900 (Solifugae: Ammotrechidae) in transitional Patagonia-Monte deserts, with descriptions of two new species, Zootaxa 5094 (3), pp. 435-460 : 452-457

Pseudocleobis solitarius Maury, 1976

( Figs. 2D–F ; 5 ; 6D, E ; 8C–E ; 9F ; 10F ; 11D ; 12J–L ; 15 . Table 1 , table 2)

Pseudocleobis solitarius: Maury 1976: 87–94 –101, figs.: 24–25; Maury 1983: 172.

Type material (examined). Holotype: ARGENTINA: Río Negro: ♂, Paso Córdoba [39º06’47,46’’S 67º37’34,08’’W], General Roca, I.1961, A. Bachmann coll., (MACN-Ar 6886) ; Paratypes: ARGENTINA: Río Negro: 1♂, General Conesa [40º06’14,71’’S 64º27’30,59’’W], 16.II.1941, M. Birabén coll., (MACN-Ar 6887) .

Other examined material: ARGENTINA: Mendoza: 3♂, 1♀, El Nihuil [35º01’40,53’’S 68º40’20,51’’W], 8.XI.1952, R. Cotta coll., (MACN-Ar 7589) ; Neuquén: 1♂, Arroyito [39º04’09,53’’S 68º33’54,11’’W], 7.I.1986. M. & P. Gentilé coll., (MACN-Ar) ; Río Negro: 1♂, San Antonio Oeste [40º43’48,82’’S 64º56’19,98’’W], 19.I.1994, A. Roig coll., (MACN-Ar) ; 7♂, 11♀, 1 immature, Paso Córdoba, near the Nautical Club “Julio A. Trulls” [39º06’46,16’’S 67º37’12,45’’W], 16–21.I.2015, H.A. Iuri coll., (MACN-Ar) ; 5♂, 2♀, same locality and collector, I-2016, (MACN-Ar) ; 5♂, 1♀, Valcheta , near the abandoned fluorite factory [40°39’58,87”S 66°10’13,84”W], 10– 12.I.2015, H.A. Iuri coll., (MACN-Ar) ; 3♂, Playas Doradas , “sendero del cuis” [41°38’46.55”S 65° 1’27.64”W], 8–10.I.2015, H.A. Iuri coll., (MACN-Ar) .

Material tentatively assigned to P. solitarius : Argentina: San Juan: 1♂, Ichigualasto [30º09’49,70’’S 67º50’32,98’’W], 17.XII.1979, E.A. Maury & A. Roig coll., (MACN-Ar 7590) ; 1♂, Bermejo [31º35’21,68’’S 67º39’32,67’’W], 15.XII.1979, E.A. Maury & A. Roig coll., (MACN-Ar 7591) .

Diagnosis: The flagellum attached at level between FSD and FM teeth ( Fig. 8D ), and the stylet-like fixed finger mucron on males ( Figs. 8C ; 12J ) are characteristic for this species. Pseudocleobis solitarius resembles P. mustersi , in the shape on the flagellum-mucron complex. However, P. mustersi has other unique modifications on the chelicerae such as a bifurcated movable finger mucron. All the others Pseudocleobis examined have a wider shaped flagellum with an attachment ring at level between the FSM and FP teeth or posterior.

Note: The female of P. solitarius has a wide, bell-shaped genital plate with a large oval opening in the middle ( Fig. 10F ). This shape is different from all other described females of Pseudocleobis . However, as the female genital plate has been proved to be uninformative at the species level in some cases (see P. huinca , P. bardensis and P. profanus ), and the females of some species from southern Patagonia are unknown (e.g., P. mustersi , P. levii ) we prefer not mention it as diagnostic for the species.

Redescription: Male: measurements in Table 1 . Color in vivo ( Fig. 2E–F ). Specimens of the population from the type locality possess a whitish body coloration pattern with beige legs.

Color in 96 % ethanol. The pattern in alcohol is quite similar to the live specimens, except that the body turns more whitish and legs turn darker.

Morphology and Chaetotaxy: General body chaetotaxy as described for P. profanus . Fixed finger ( Figs. 8C–D ; 12J ): the fixed finger mucron is much narrower than the movable finger mucron ( Fig. 8C, D ). The FSD smaller than FD and FM, but generally well developed, not vestigial ( Fig. 8D ). The FSM and FM teeth are separated by a short diastema. Movable finger ( Fig. 8C–D ): the movable finger is robust and possesses a wide dorsal crest on the mucron. The three teeth (MM, MSM, MP) are widely separated from each other. Flagellum ( Figs. 8D ; 9F ; 12J ): the flagellum in very narrow ( Fig. 9F ) with small attachment ring placed at level between FSD and FM teeth ( Fig. 8D ). The flagellum reaches almost the tip of mucron ( Figs. 8D ; 12J ). The central portion of the prolateral surface possesses some prominent filaments ( Fig. 12J ). The membrane, in general, is thicker than the flagellum of the other species treated here, and with some flat filaments in the retrolateral surface. The apex has some surface roughness and a few, very small, projections. Pedipalps ( Fig. 15A–C ): chaetotaxy as described for P. profanus sp. nov. except that the spiniform setae are more setiform (thin and undulate), more equally sized (especially those of the tibia), and the clubbed setae were not seen. Leg I ( Fig. 15D–F ): similar to P. profanus , but the clubbed setae ( Fig. 15F ) are less abundant. Opisthosoma: ctenidia: 5-5 on sternite III and 4-4 on sternite IV ( Fig. 15J ).

Female: Measurements in Table 1 . Color in vivo: As in Fig. 2D . Morphology and chaetotaxy similar to male, except by wider propeltidium, wider chelicerae, and more robust body in general ( Fig. 2D ). Pigment pattern similar to males. The spiniform setae of the pedipalps are more spiniform than in males (especially those of the tibia). Genital plate ( Fig. 10F ): the genital plate is relative wide, bell-shaped. There is a large oval opening in the middle, covered distally by two whitish rigid plates. The lateral margins are straight or concave. Short, thick, bifurcated tip setae are placed on the lateral margins.

Variability: Dentition variability on both sexes is detailed in Table 2. A careful examination shows that the dark brown areas on propeltidium and chelicerae of P. huinca , are whitish in the specimens of P. solitarius from Paso Córdoba. That coloration allows to easily distinguishing it from P. huinca (found in sympatry in the type locality). However, specimens of P. solitarius , from other populations (i.e., Playas Doradas and Valcheta), possess some brown pigment similar to P. huinca (also found in sympatry on these localities), so they cannot be easily distinguished by the coloration in these areas.

Distribution: The records of P. solitarius are from the Austral and Septentrional districts of the Monte biogeographic province ( Figs. 1A–B, D ; 5 ). However, we found females of Pseudocleobis with the P. solitarius genital plate shape at the MACN collection, from the Chubut and Santa Cruz districts of the Patagonian biogeographic province. As we could not study males from these localities, these females are included in the distribution map as solitarius shape. The males recorded by Maury (1983) for San Juan province have some slight differences in the shape of cheliceral fingers mucra, and they could belong to a different species. However, due to the scarcity of material, we maintain these here as P. solitarius .

Examined material of Pseudocleobis sp. (females solitarius shape): ARGENTINA: Chubut: 1♀, 15 km S of Los Tamariscos , 19.I.1977, E.A. Maury and Petriccha coll., (MACN-Ar) ; 1♀, Puerto Lobos , 1.II.2016, E.A. Maury coll., (MACN-Ar) ; 1♀, Puerto Lobos, Arroyo Verde , 25–26.I.1975, E.A. Maury, C. Césari and P. Domínguez coll., (MACN-Ar) ; 1♀, Puerto Madryn , XII.1981, P. Goloboff coll., (MACN-Ar) ; 1♀, Telsen , XII.1981, P. Goloboff coll., (MACN-Ar) ; 1♀, Rada Tilly, near Punta del Marqués [45°57’8.33’’S 67°33’7.35’’W], 28–30.I.2015, H.A. Iuri coll., (MACN-Ar) ; Río Negro: 1♀, 5 km of Moligue , 1500 masl, 20.I.1973, (MACN-Ar) ; 1♀, Sierra Grande , near the cemetary [41º36’16.62’’S 65º23’12.77’’W], 19–20.I.2016, H.A. Iuri coll., (MACN-Ar) .

Figures

FIGURE 1. Habitat of some Pseudocleobis Pocock, 1900 species in Río Negro and Neuquén provinces. A. Monte between Pellegrini Lake and Cinco Saltos city (Río Negro province). B. Monte at the base of the mountains in Sierra Grande (Río Negro province). C. Payunia environment from Cuchillo Curá (Neuquén province). D. Monte from Paso Córdoba (Río Negro province).

FIGURE 2. Live specimens of Pseudocleobis huinca (A–C) and Pseudocleobis solitarius (D–F), females (A, D) and males (B, C, E, F) in dorsal (A, B, D, E) and laterofrontal (C, F) views.

FIGURE 5. Known records of Pseudocleobis solitarius and females with P. solitarius genital sternite shape, but not linked with males.

FIGURE 6. Pseudocleobis general characters. A. female chelicera of P. huinca, retrolateral view. B. Male prosoma of P. huinca, dorsal view. C. Female pedipalp of P. huinca, prolateral view (only proventral spiniform setae shown). D. Right basitarsus II of P. solitarius, retrolateral view, proventral distal (PV-d) and subdistal (PV-sd) spiniform setae in orange, retroventral distal spiniform seta (RV-d) in yellow, retrolateral basal (RL-b) and subdistal (RL-sd) spiniform setae in light blue and retrodorsal distal (RD-d) spiniform seta in green. E. Right telotarsus II of P. solitarius, retrolateral view. F. Right telotarsus IV of P. huinca, proventral view.

FIGURE 8. Male chelicera of P. mauryi sp. nov. (A, B) and P. solitarius (C, D) in retrolateral (A, C) and prolateral (B, D) views. E. P. solitarius, female chelicera in retrolateral view. DN: distal notch.

FIGURE 9. Male flagellum, prolateral view. A–B. P. huinca. C. P. profanus sp. nov. D. P. bardensis. E. P. mauryi sp. nov. F. P. solitarius. Scale bars: 200 μm (A, C, E), 250 μm (D, F), 500 μm (B).

FIGURE 10. Female genital sternite. A. P. huinca, female allotype. B. P. bardensis, female allotype. C. P. profanus sp. nov., female from Cinco Saltos, diagonal arrows indicate the small plaques, straight arrows indicate the posterior sclerite. D–E. P. huinca, females from Paso Córdoba with abrasion signs. F. P. solitarius, female from Paso Córdoba. Scale bars: 200 μm (B), 500 μm (A, C–F).

FIGURE 11. Right male chelicera under SEM, prolateral view. A. P. huinca. B. P. profanus sp. nov. C. P. mauryi sp. nov. D. P. solitarius. Scale bars: 1 mm.

FIGURE 12. Right male chelicera under SEM, prolateral view. A–C. P. huinca. D–F. P. profanus sp. nov. G–I. P. mauryi sp. nov. J–L. P. solitarius. A, D, G, J. Fixed finger, detail of flagellum prolateral surface in yellow circle in J. B, E, H, K. Plumose setae (pvd setae), yellow arrows indicate the setae of the second row at the profundal teeth level. C, F, I, L. Stridulatory plate. Scale bars: 10 μm (detail in J), 200 μm (E, G–H, J–L), 250 μm (F, I), 500 μm (A–D).

FIGURE 15. Pseudocleobis solitarius male. A–C. Right pedipalp. A. Telotarsus, retrodorsal view. B. Detail of sensilla ampullacea. C. Tapered seta tip. D–F. Right leg I. D. Apex of telotarsus, apical seta in ligh blue. E. Detail of apical seta. F. Clubbed seta tip. G–I. Right telotarsus IV. G. Detail of pseudosegmentation. H. Terminal tarsomere and arolium. I. Detail of distal seta with comb-like structure. J. Sternites III and IV, filiform ctenidia in light blue. Scale bars: 600 nm (B), 900 nm (C), 2 μm (F), 6 μm (E, I), 60 μm (D, H), 90 μm (G), 200 μm (A, J).

Tables

TABLE 2. Variability report of cheliceral dentition on both sexes of the species Pseudocleobis huinca and Pseudocleobis solitarius. The (+1) indicates an additional denticle, for example MP (+1) MSM = 1 additional denticle between MP and MSM. For more than one modification, these are separated by semicolon (;), for example FSD absent; MP (+1) MSM = FSD absent and 1 additional denticle between MP and MSM. P. huinca ♂

n = 40	Left Chelicera	Right Chelicera
26	normal	normal
4	FSD absent	normal
3	normal	FSD absent
2	FSD absent	FSD absent
2	normal	RFSM (+1) RFM
1	normal	MSM (+1) MM
1	RFSM (+1) RFM	FSD absent
1	FSD absent; MP (+1) MSM	FSD absent
P. huinca ♀
n = 20	Left Chelicera	Right Chelicera
13	normal	normal
2	normal	RFSM (+1) RFM
1	normal	MP (+1) MSM
1	MP (+1) MSM	normal
1	normal	RFM (+1) FP
1	normal	RFP (+1) RFSM
1	FSD (+1) FD	normal
P. solitarius ♂
n = 8	Left Chelicera	Right Chelicera
7	normal	normal
1	PFSM absent	PFSM absent
P. solitarius ♀
n = 8	Left Chelicera	Right Chelicera
3	normal	normal
2	normal	RFP (+1) RFSM
1	(+1) RFSP	normal
1	(+1) RFSP	RFP (+1) RFSM
1	RFSM (+1) RFM; MP (+1) MSM	normal