Charinus vulgaris, Miranda, Gustavo Silva De & Giupponi, Alessandro Ponce De Leão, 2011

Miranda, Gustavo Silva De & Giupponi, Alessandro Ponce De Leão, 2011, A new synanthropic species of Charinus Simon, 1892 from Brazilian Amazonia and notes on the genus (Arachnida: Amblypygi: Charinidae), Zootaxa 2980, pp. 61-68 : 62-64

Charinus vulgaris sp. n.

( Figs 1–10 )

Etymology. The epithet “ vulgaris ” is from Latin vulgaris (“ordinary, common”) in reference of the microhabitats where the specimens were collected.

Type material. Female holotype: BRAZIL: Rondônia: Porto Velho, Bairros São João Bosco, Rio Madeira e Santo Antônio, II-2011, Miranda, G.S. leg. ( MNRJ 09106). Female paratypes: BRAZIL: Rondônia: Porto Velho, Bairros São João Bosco, Rio Madeira e Santo Antônio, XII-2009 MNRJ 0 9104, 3 juveniles, and II-2011, Miranda, G.S. leg. (11 adults and 6 juveniles, MNRJ 09105; 1 adult and 1 juvenile IBSP 226). Male unknown.

Diagnosis. Charinus vulgaris differs from all Brazilian species by its cushion-like gonopods, with an apical sharp edge that partially covers the seminal receptacle atrium. All other Brazilian species have a conical gonopod with an apical sucker-like prehensile structure. C. vulgaris lacks the median eye tubercle. The sternum is tri-segmented, with second and third pieces rounded and convex. Pedipalp femur has three spines on dorsal and two on ventral margins; dorsal margin of pedipalp tibia with four spines and ventral margin with two spines; pedipalp basitarsus dorsally with two spines (proximal spine less than half the length of distal one); on ventral with one spine; pedipalp distitarsus with two spines dorsally. Leg tibia I with 22 (21–25) articles. Leg IV: basitibia with 3 pseudoarticles; distitibia with number of trichobothria varying between 16 and 17.

Description of female holotype. Carapace ( Fig. 1 ): flattened, wider than long (ratio a little less 3/4); anterior depression (in place of the absent median eye tubercle), from which starts a thin median furrow that reaches around the anterior area of the pair of lateral humps situated behind the lateral eye. Anterior margin with 6 small setae.

Corners of antero-lateral margin extending downwards in a wide, rounded boss. Many tiny tubercles, more densely distributed in the frontal area. Tubercles arranged in lines and spots, irradiating from the fovea and interspersed with smooth areas. 3 pairs of deep furrows and a very deep, triangular fovea. 1st pair of furrows placed just behind the lateral boss and not reaching the middle line. 3 lateral pairs of depressions (first one placed over the 1st pair of furrows). Lateral eyes present with little pigmentation. Frontal process well developed, a little longer than wide, with blunt, thickened apex.

Sternum ( Fig. 3 ): tri-segmented, all segments sclerotized and convex. Tritosternum with a round basis and projected anteriorly in a small blunt tubercle, with 2 apical, 2 medial and 2 basal setae. Middle piece rounded, convex, with 2 setae and a few setulae. Third piece also rounded and convex, but smaller and with smaller setae than the second piece. Sternites separated from each other by the diameter of the third piece.

Abdomen: oblong, with almost indistinguishable punctuations, finer than in the carapace.

Chelicera: Cheliceral furrow ( Fig.7 ) with 4 internal teeth, the distal one bifid, the distal cusp bigger than the second one. Basal tooth twice as long than the others and much stouter. Teeth length (from tip to basis) IV>Ia>Ib=II>III. Claw with 4 subequal denticles.

Pedipalp: Trochanter: with ventral spiniform apophysis with 11 subequal setiferous tubercles and with a blunt tip pointed forwards. Femur ( Figs.4–5 ): 3 dorsal spines all of nearly equal lengths; 2 ventral spines, the distal two thirds length of the proximal. Tibia ( Figs. 4–5 ): 4 dorsal spines (II>III>IV>I). Spine I with one setae of about ½ its length. Spines II and III with 2 setae at the end of the basal third. One setiferous tubercle between the spines II–III, and III–IV; one small setiferous tubercle after the fourth spine. 2 ventral spines, the distal twice as long as the proximal, the basal placed at the middle third and the distal at the beginning of the distal third. Basitarsus ( Figs. 4–5 ): 2 dorsal spines in the middle of the article, the basal spine about 1/3 the length of distal one; 3 small setiferous tubercle in the base of the distal spine and 2 setiferous tubercle in the base of the proximal one. 1 ventral spine at the distal half, around 2/3 the article length. Distitarsus ( Figs. 4–5 ): long, with 2 curved dorsal spines at the basal half, the distal larger, reaching almost 1/3 the article length. Cleaning organ about ½ the article length. Claw ( Figs. 4–5 ): long, with an acute, curved tip.

In Figure 11 , taken in vivo, it is possible to see two yellowish-brown circles on the tibia of both pedipalps. Only after the pictures were taken, these spots were noticed, so it could not be checked if it is present in all specimens. It is not seen in preserved animals.

Legs: All densely setose. Femur length I>III>IV>II. Tibia I with 22 (21–25) articles. Tarsus (basitarsus+distitarsus) I with 38 (37-42) articles. Leg IV ( Fig. 6 ): Basitibia: 3 pseudo-articles, one trichobothrium at first and two at the last pseudo-article. Distitibia: 4 (3 in some specimens) basal and 13 distal trichobothria. Basitibia-distitibia length BT1>DT>BT3=BT4>BT2. Basitarsus / distitarsus ratio 7/4, distitarsus tetramerous.

Measurements. Females (n=6): Cephalothorax: Length: 3.0 mm (2.5–3.7), Width: 4.2 mm (3.3–5.5). Abdomen: 5.0 mm (3.9–6.2). Pedipalp: Femur 2.8 mm (1.6–3.5), Tibia 2.9 mm (1.6–3.6), Basitarsus 1.2 mm (0.9–1.7), Distitarsus 0.7 mm (0.5–0.9), Tarsal claw 0.9 mm (0.5–1.5).

Color pattern (in alcohol): Chelicerae, pedipalps and carapace yellowish. Legs lighter colored. Abdomen pale yellow. Live animals have color pattern similar to the preserved ones ( Fig. 11 ).

Genitalia ( Figs. 8–10 ): Posterior margin of genital operculum rounded, slightly concave medially, with few setae. The dorsal side the genital operculum carries two rounded, cushion-like gonopods; the gonopods are concave with the atrium of the seminal receptacle large and located in the posterior border; both gonopods touch in the midline where some cuticular pores are present. The posterior border of the gonopod has an apical sharp edge, which partially covers the atrium of the seminal receptacle; this apical sharp edge resembles a claw that probably pulls the sperm package into the seminal receptacle.

Natural history. The specimens were first collected in July 2009 at São João Bosco neighborhood, in Porto Velho city (8° 45ʹ 43ʺ S, 63° 54ʹ 14ʺ W), Rondônia state, north of Brazil. At this time of the year the city has high temperature (30ºC to 34ºC), low humidity, and the pluviosity is extremely reduced (20 mm /month). Rondônia has an intense urbanization rate (68.8%) (PRDA, 2010), and the city of Porto Velho is very busy, with little traces of the original forest. In the first collect, the individuals were encountered in the backyards of residences, in a deforested place with accumulated wreckage and garbage. Only juveniles were captured after a daytime and nocturnal search. A second collect effort was made in February 2011, when the temperature is lower (17º C a 23°C), the humidity is higher, and the rain is intense (approximately 3000 mm /month). At this time, only a diurnal search was performed at scrapyards ( Fig. 12 ) at Rio Madeira and Santo Antônio neighborhood. Both juveniles and adults were encountered, including females with eggs and offspring. The places where Charinus vulgaris was encountered were full of garbage and accumulated wreckage, such as stones, pipes, bricks, plastics items, tiles and debris.

Figures

FIGURES 1 – 7. Charinus vulgaris sp. nov. (female holotype). 1. Cephalotorax. 2. Latero-frontal view of the anterior carapace margin with the six setae and the frontal process. 3. Sternum. 4. Right pedipalp ventral view. 5. Right pedipalp dorsal view. 6. Arrangement of trichobothria on fourth basitibial segment and distibiae of left leg IV. 7. Left chelicerae (female paratype). Scale bars 1.0 mm.

FIGURES 8 – 10. Charinus vulgaris sp. nov. (female paratypes). 8. Gonopods dorsal view. 9. Gonopods dorsal view. The atrium of the seminal receptacle can be seen. 10. Gonopods view from behind.

FIGURES 11 – 12. Charinus vulgaris sp. nov. 11. Living female with offspring. 12. One of the scrapyards from where Charinus vulgaris were collected.