Amphidraus caxiuanan Salgado & Ruiz, 2017

Salgado, Alexandre & Ruiz, Gustavo R. S., 2019, Seven new species of Amphidraus Simon, 1900 (Araneae: Salticidae: Euophryini), Zootaxa 4563 (3), pp. 451-481 : 468

Amphidraus caxiuanan Salgado & Ruiz, 2017

Figs 18 A–H, 19C–D, 19F–G, 20

Amphidraus caxiuanan Salgado & Ruiz, 2017: 408 , figs 5A–B, 6A–D (Holotype ♂ from Melgaço, [01°42'24"S, 51°27'34.3"W], Pará, Brazil, 14.IV.2006, J.A.P. Barreiros leg., deposited in MPEG 29052); World Spider Catalog 2018.

Additional material examined. BRAZIL: Pará: 1♂ from Floresta Estadual do Trombetas, Rio Acapu (along about 25 km on the North margin), [01°06'10.10"S, 56°26'04.00"W], Oriximiná, 10–18.X.2014, M.B. Aguiar-Neto et al. leg. ( MPEG 35013 ).

Revised diagnosis. Amphidraus caxiuanan Salgado & Ruiz, 2017 and A. manauara sp. nov. have the embolic disc with one long, prolaterally projected, distal process (dPED) with rounded tip, and one short, ventrally projected ventral process (vPED) ( Figs 17A , 19C ); also, the same pattern of tibial apophyses: the RvTA is short and rounded and the RTA emerges from retrodorsal portion of tibia, being curved and projected to the apex of palp ( Figs 19 E–G); proximal dorso-prolateral portion of cymbium is prominent in both species, and there is a proximal retro-dorsal cavity on cymbium ( Figs 17B , 19B, 19D ). However, Amphidraus caxiuanan can be distinguished by having a longer proximal dorso-prolateral projection of cymbium ( Figs 19B, 19D ) and longer RTA ( Figs 19 E–G). Moreover, the embolus shaft and the embolic filament are longer in proportion to the embolic disc in A. caxiuanan ( Figs 19A, 19C ). The female of A. caxiuanan is still unknown.

Description. See Salgado & Ruiz (2017).

Variation. Based on comparisons between the type specimen of A. caxiuanan from Melgaço, Pará, Brazil, and this new male from Oriximiná, Pará, Brazil (about 550 km from the type locality; Fig. 20 ), we observed several similarities, including in tibial apophyses and especially in the embolic disc, which made us refrain from describing a new species from Oriximiná. That male is herein recognized as being a variant form of A. caxiuanan . Hence, palpal variation within the species is summarized as follows ( Figs 18 B–D, 18F–H, 19C–D, 19F–G): the RTA has a slight ( Figs 18G , 19F ) or accentuated curvature ( Figs 18C , 19G ); the dorso-prolateral, proximal cymbial projection varies in length ( Figs 18D, 18H ); RTA length is also variable ( Figs 18 C–D, 18G–H, 19F–G). However, the proportions of these structures in the male from Oriximiná are intermediate when comparing the holotype of A. caxiuanan and the holotype of A. manauara (whose type locality is about 450 km away from Oriximiná; Fig. 20 ), which could indicate a cline across the Amazon River. Nevertheless, the embolic disc of the male palp of A. manauara is different enough to convince us to describe it as a new species (see diagnoses above).

Distribution. Known only from the state of Pará, Brazil ( Fig. 20 ). It is worth mentioning that, if the specimens from Oriximiná and Melgaço are indeed conspecific, this small species of jumping spider occurs in preserved forests on both margins of the old Amazon River, which is between two and eight kilometers wide in that portion of South America. This provides evidence for the high ability of dispersal present in this species.

Figures

FIGURE 17. Amphidraus manauara sp. nov. A–C left male palp (A ventral; B dorsal; C retrolateral); D epigyne/vulva, cleared, ventral. Abbreviations: cc, cymbial conductor; cd, copulatory duct; co, copulatory opening; Cy, cymbium; dPED, distal process on embolic disc; e, embolus shaft; ed, embolic disc; ef, embolic filament; fd, fertilization duct; gl, gland; po, coupling pocket; RTA, retrolateral tibial apophysis; RvTA, retroventral tibial apophysis; S, spermatheca; T, tegulum; TL, tegular lobe; vPED, ventral process on embolic disc.

FIGURE 18. Morphological variation in Amphidraus caxiuanan Salgado & Ruiz, 2017. A–D holotype from Melgaço, Pará (A male, dorsal; B left palp, ventral; C retrolateral; D dorsal). E–H specimen from Oriximiná, Pará (E male, dorsal; F left palp, ventral; G retrolateral; H dorsal). Abbreviations: cc, cymbial conductor; dPED, distal process on embolic disc; e, embolus shaft; ef, embolic filament; RTA, retrolateral tibial apophysis; RvTA, retroventral tibial apophysis; TL, tegular lobe; vPED, ventral process on embolic disc. Black arrow in D shows dorso-prolateral, proximal cymbial projection.

FIGURE 19. Comparison of male palpal structures in Amphidraus spp. A–B, E left male palp of A. manauara sp. nov. (A ventral; B cymbium, dorsal; E retrolateral, bulb removed). C–D, F–G left male palp of A. caxiuanan Salgado & Ruiz, 2017 (C holotype from Melgaço, ventral; D same, cymbium, dorsal; G same, retrolateral, bulb removed; F specimen from Oriximiná, retrolateral, bulb removed. Abbreviations: Cy, cymbium; RTA, retrolateral tibial apophysis; RvTA, retroventral tibial apophysis; T, tegulum.

FIGURE 20. Map of northern Brazil showing records of Amphidraus caxiuanan and A. manauara. White lines represent the borders of Brazilian states. Map modified from Google Earth ®. Blue line between Manaus and Melgaço represents the Amazon River.