A New Species of the Spider Genus Parabatinga Polotow and Brescovit, 2009 (Araneae: Ctenidae), from the Brazilian Amazonia

: Parabatinga danielae sp. n. is described and illustrated based on material collected in caves of the Caraj á s region, state of Par á , Brazilian Amazonia. With the inclusion of the second species in the genus, we propose here a new diagnosis for Parabatinga and its type species, P. brevipes (Keyserling, 1891).


Introduction
The Neotropical genus Parabatinga was proposed by Polotow and Brescovit in 2009 [1] to include only one species, P. brevipes (Keyserling, 1891) [2]. This species is widely distributed in South America, and it can be found in the Brazilian Cerrado, grasslands in Uruguay and Argentina, and a few Andine localities in Bolivia and Colombia. Because of its wide distributional range, this species was described under twelve different names over the course of fifty years (from 1891to 1941World Spider Catalog, 2022 [3]). The synonymies were discovered through the painstaking work of visiting collections and examining type specimens around the world, and these results were published by Polotow and Brescovit in 2009 [1].
This monotypic genus was distinguished from other Ctenidae by males with the dorsal branch of RTA with a hyaline tip, an embolus with a distal hyaline projection, and a median apophysis with a prolateral laminar process, as well as females with a spermathecae that is oval and dorsally projected (Polotow and Brescovit, 2009: figs. 16C,D and 17A-D [1]).
The aim of this work is to add the description of a second species, Parabatinga danielae sp. n., found in the state of Pará, Brazil, exclusively from cave areas in the Carajás region. In addition, we present a new generic diagnosis for the genus Parabatinga, an emended diagnosis of P. brevipes, and discuss the putative synapomorphies of the species.
The morphological terms follow those used by Polotow and Brescovit, 2009 [1]. The descriptions and measurements were performed using a LEICA 165C stereomicroscope. Photographs were taken with a Leica DFC 500 digital camera on a Leica MZ16A stereomicroscope. Focal-range images were made using Leica Application Suite software, version 2.5.0. All measurements are in millimeters. Female genitalia were excised with a sharp needle, digested using one tablet of enzymatic eye lens cleaner (Ultrazyme enzymatic cleaner) into 5 mL distilled water for 24 h, and photographs were taken using Hoyer's microscope slides (Krantz and Walter, 2009 [4]). For scanning electron microscopy (SEM) images, body parts were dehydrated in a graded series of ethanol washes (80% to 100%), dried by critical point, mounted on metal stubs using adhesive copper tape and nail polish for fixation, and covered with gold. SEM images were taken with a FEI Quanta 250 scanning electron microscope at the Laboratório de Biologia Celular of Instituto Butantan, São Paulo, Brazil. Maps were produced using GPS Track Maker-PRO and edited in GIMP v2.8.14 and Inkscape v0.48.4. Graphics and tables were made in Microsoft Office Excel 2013.
Study area: The caves where the spiders were found are located in the ferruginous outcrops in the Carajás region in southeastern Pará state, in the eastern region of the Amazon Forest in Brazil. These caves are in and around the National Carajas Forest (FLONA de Carajás), which covers approximately 411,000 hectares. This region consists of a mosaic of protected areas forming a continuous area of 1.31 million hectares of preserved forest (Rolim et al. 2006 [5]), surrounded by pastures that replaced the original forest (Martins et al. 2012 [6]; Carmo and Jacobi 2013 [7]). The material cited here was collected in caves that are located in areas of mining interest in the municipalities of Parauapebas, Canaã dos Carajás, and Curionópolis.
region. Both were observed in illuminated areas as well as in twilight regions of the cavities. The female of Parabatinga danielae sp. n. selects the subterranean environment and fixes the egg sac to the cavity wall ( Figure 6A,B), as observed in other cave-dwelling Ctenid species, such as Ctenus fasciatus Mello-Leitão, 1943 [8] (Cizauskas et al., 2022 [9]). The morphological characteristics observed in the evaluated specimens suggest that these spiders are able to complete their life cycle in hypogean habitats, since, no specimens have been sampled outside the cave environment.

Discussion
Ctenids males, specially from the subfamily Cteninae, exhibit a number of leg modifications, such as metatarsus IV sinuous (Höfer et al., 1994 [10]; Brescovit and Simó, 2007 [11]; Polotow and Brescovit, 2018 [12]; Hazzi et al., 2018 [13]) and modified spines distributed in different legs and leg segments (Polotow and Brescovit, 2007 [14]; Polotow and Brescovit, 2013 [15]; Pereira et al., 2020 [16]). The only change detected in the legs of Parabatinga danielae sp. n. was the presence of a ventral process on coxa IV ( Figure 1B,C). This structure can be found in Isoctenus species such as I. coxalis (F.O.Pickard-Cambridge, 1902 [17]) and I. areia Polotow and Brescovit,[1], among others (Polotow et al., 2005 [18]; Polotow and Brescovit,[1]).This discussion leads us to a reformulation of the diagnosis, with the inclusion of this character in coxa IV, for gender diagnosis. Both the function of these modified spines and the ventral apophysis of the coxa are still enigmatic in Cteninae males. They could be used as a sexual display or even as auxiliary structures to hold the female during copulation, but no studies exist about it. Parabatinga danielae sp. n. was found inside caves, a generally dimly lit environment, and a visual display in copulation seems to be unlikely in this habitat type. Probably the function of these projections on the coxae could help to keep the female immobile during copulation, but this should be tested, as despite the Ctenidae being a highly diverse family, little is known about the reproductive activities of its species.