Synotaxus jaraguari, Souza & Brescovit & Araujo, 2017

Souza, Lucas Henrique Bonfim, Brescovit, Antonio Domingos & Araujo, Douglas, 2017, A new species of Synotaxus and the first chromosomal study on Synotaxidae, presenting a rare XY sex chromosome system in spiders (Araneae, Araneoidea), Zootaxa 4303 (1), pp. 140-150 : 141-142

Synotaxus jaraguari new species

Figs 1–7

Types. Holotype male from Furnas do Dionísio (20°10'25.83"S 54°34'40.46"W), Jaraguari , Mato Grosso do Sul, Brazil, 14/XI/2015, D. Araujo coll., deposited in IBSP 167041 . Paratype: one female from Toca do Ouriço (20°8′34″S 54°35′6″W), Jaraguari , Mato Grosso do Sul, Brazil, 19/V/2016, L.H.B Souza coll. ( IBSP 168350 ).

Additional material examined. Brazil. Mato Grosso do Sul: Jaraguari , Furnas do Dionísio (20°10'25.83"S 54°34'40.46"W), 1♂, 14/XI/2015, D. Araujo coll. ( IBSP 167036) ; 1♂, 14/XI/2015, D. Araujo coll. (IBSP 167043; SEM); 1♀ juv., 17/III/2016 (IBSP 168346); 4♀ 1♂ juv. 6 juv. (IBSP 168347; IBSP 168343; IBSP 168351; IBSP 168354; IBSP 168344; IBSP 168365; IBSP 168367; IBSP 168345; IBSP 168348; IBSP 168353; IBSP 168349), all collected in 07/VII/2016, by L.H.B. Souza coll.; Toca do Ouriço (20°06'04.73"S 54°33'46.23"W), 1♀, 19/V/2016, L.H.B. Souza coll. ( IBSP 168352).

Etymology. The specific epithet is a noun in apposition taken from the type-locality.

Diagnosis. Synotaxus jaraguari n. sp. ( Fig. 1 ) resembles S. monocerus , S. itabaiana and S. siolli by the presence of a distinctive horn in the male ocular area ( Fig. 2 A–D, Agnarsson 2003: fig. 3F–G). The males of S. jaraguari differs from these species by the shorter prongs in the patellar apophysis ( Fig. 3 B) and by the rounded base of TTA ( Figs. 2 E–F, 3A). Females have lateral atria on the epigynum, similar to that of Synotaxus itabaiana (see Santos & Rheims 2005: fig. 17), but differ from this latter species by the anterior median border directed posteriorly ( Fig. 4 C) and by the large accessory sacs connected posteriorly to the spermathecae ( Fig. 4 D).

Description. Male (IBSP 167041). Coloration: carapace yellow cream, lateral borders and large setae black, with border of the ocular median area black. Chelicerae white with teeth orange. Endites, labium and sternum white. Legs yellowish white and abdomen white. Ocular area overhanging clypeus, with one elongated and curved horn between the anterior median eyes ( Figs 2 A–D). Legs thin, with numerous setae. Abdomen elongated and pointed posteriorly, scarcely covered with setae. Carapace 1.3 long, 1.05 wide. Patella-tibia I length 5.0, II 3.0, III 1.2, IV 2.5. Abdomen used for cytogenetic study, partly destroyed. Paracymbium short with truncated apex, median apophysis large and rounded, TTA rounded distally ( Figs 2 E–F, 3A–D, 4A–B).

Female (paratype IBSP 168350). Coloration as in male, except distal area of tibia and metatarsus I–II darker. Body shape and pilosity as in male. Ocular area anteriorly triangular in dorsal view, with a small and slender curved macrosetae. Carapace 1.3 long, 1.0 wide. Patella-tibia I length 4.2, II 2.5, III 1.0, IV 2.4. Abdomen as in male. Copulatory ducts inconspicuous or apparently absent. Accessory sacs large and rounded. Spermathecae globose. Fertilization ducts long, originating from base of spermathecae ( Figs 4 C–D).

Distribution. Known only from the type locality in the state of Mato Grosso do Sul, Brazil.

Figures

FIGURE 1. Female specimen of Synotaxus jaraguari n. sp., dorsal view. Scale bar, 4 mm.

FIGURE 2. Synotaxus jaraguari n. sp. A – D, Male. A, Carapace, frontal view. B, Lateral view. C, Horn, detail, frontal view. D, Lateral view. E – F, Palp. E, Ventral view. F, Theridioid tegular apophysis, detail. Abbreviations: E, embolus; TTA, Theridioid tegular apophysis.

FIGURE 3. Synotaxus jaraguari n. sp., male palp. A, Theridioid tegular apophysis, lateral view. B – D, Paracymbium and patelar apophysis. B, Lateral view. C, Ventro-lateral view. D, Detail, ventral view. Abbreviations: C, Cymbium; PA, Patellar apophysis; PC, Paracymbium; PP, Patellar projection, TTA, Theridioid tegular apophysis.

FIGURE 4. Synotaxus jaraguari n. sp. A. Male palp, ventral view. B, Ditto, retrolateral view. C, Epigynum, ventral view. D, Female internal genitalia, dorsal view. Abbreviations: AB, Anterior border of epigynum; AS, Accessory sac; MA, Median apophysis; PA, Patellar apophysis; PC, Paracymbium; PP, Patellar projection, TTA, Theridioid tegular apophysis; FD, Fertilization ducts; SP, Spermathecae. Scale bar, 0.5 mm.

FIGURE 5. Mitotic telocentric chromosomes of Synotaxus jaraguari n. sp. A, Spermatogonial metaphase 2 n ♂ = 22 + XY. B – C, Oogonial metaphases. B, 2 n ♀ = 22 + XX. C. 2 n ♀ = 26. Scale bar, 5 µm.

FIGURE 6. Chromosomes of Synotaxus jaraguari n. sp., male. A – C, Giemsa stained. D, Silver nitrate impregnation. A – B, Diplotenes, with 11 autosomal bivalents + XY, showing the achiasmatic association between X and Y (A, photo and inset) and its early segregation (B). C, Metaphase II with n = 12. D, Spermatogonial metaphase, with 2 n ♂ = 24, highlighting the Nucleolar Organizer Regions (arrows). Scale bar, 5 µm.

FIGURE 7. Scheme showing hypothetical origin of the karyotype 2 n ♂ = 22 + XY, found in Synotaxus jaraguari n. sp.