A review of the spider genus Sinanapis, with the description of a new species from Tibet (Araneae, Anapidae)

Abstract The genus Sinanapis Wunderlich & Song, 1995 is reviewed in this paper. The material of all three known species was reexamined and photographed resulting in a new species, Sinanapismedogensesp. n. (♂, ♀) being described from Tibet, China. A key is provided for the genus, as well as species diagnoses, illustrations, and distribution maps for all four species of Sinanapis.


Introduction
According to the World Spider Catalog (2018), 223 extant species in 58 genera are documented in the family Anapidae Simon, 1895, including eleven species in seven genera from China. This family is chiefly distributed in the tropical and southern temperate regions (Lin and Li 2012).
The Sinanapis was originally erected by Wunderlich and Song (1995) as a monotypic genus based on S. crassitarsa Wunderlich & Song, 1995 from Xishuangbanna in Yunnan of China. Currently Sinanapis comprises three valid species distributed in southern China, Vietnam and Laos: S. crassitarsa Wunderlich & Song, 1995, S. longituba Lin & Li, 2012, and S. wuyi Jin & Zhang, 2013 Sinanapis the genus with the highest number of species within the family Anapidae in China. The genus was previously known in China from Yunnan to Fujian Provinces only.
While studying material from Tibet, we recognized several specimens belonging to Anapidae. Detailed study of these specimens reveals that they belong to an undescribed species of Sinanapis, a genus previously unknown in Tibet. The goal of this paper is to provide detailed description of the new species and to conduct a comprehensive review of the genus Sinanapis.

Materials and methods
Specimens were examined and measured with a Leica M205 C stereomicroscope. Further details were studied with an Olympus BX43 compound microscope. Male and female copulatory organs were examined after they were dissected and detached from the bodies. Epigyne were removed and treated with lactic acid before photographed. All type specimens were preserved in 95% ethanol. Photos were taken with a Canon EOS 60D wide zoom digital camera (8.5 megapixels) mounted on an Olympus BX43 stereomicroscope. The images were montaged using Helicon Focus 3.10 (Khmelik et al. 2006) image stacking software.
All measurements are in millimeters. Leg measurements are given in the following sequence: total length (femur, patella, tibia, metatarsus, and tarsus). Abbreviations in figures or text are as follows: ALE anterior lateral eyes; AME anterior median eyes; BA basal patellar apophysis on palp; BC book lung covers; CD copulatory ducts; Cu cusps on leg I; Cy cymbium; CO copulatory opening; DA dorsal patellar apophysis on palp; DP dentigerous patellar process on palp; Em embolus; Remarks. This genus gender is considered as masculine at its establishment by Wunderlich and Song (1995). But it was later corrected to feminine by World Spider Catalog (2018).  Diagnosis. Sinanapis crassitarsa may be distinguished from the other two species except S. medogense sp. n. by having a rasper-like dentigerous patellar process and the absence of anterior median eyes (Figs 1D,2C,D). In contrast, the other two species lack the dentigerous patellar process, and the anterior median eyes are present (Figs 3G, 4A, 9D). It may be distinguished from S. medogense sp. n. by the wide, laminar basal patellar apophysis, and the dentigerous patellar process is as large as the dorsal patellar apophysis ( Figure 2B-D, F). In contrast, S. medogense sp. n. has a narrow, tubular basal patellar apophysis, and its dentigerous patellar process is smaller than dorsal patellar apophysis ( Figure 6A, B, F-I).
Distribution. China (Yunnan), Laos, and Vietnam.   Diagnosis. The male of S. longituba can be distinguished from S. crassitarsa and S. medogense sp. n. by the presence of anterior median eyes ( Figure 3G), lacking in two latter species (Figs 1D, 5G), and by the absence of a rasper-like dentigerous process ( Figure 3A, B), whereas the dentigerous process is present in the other two species (Figs 2C, 6H). It differs from S. wuyi by the robust leg I in both sexes (Figs 3A-D, 4C, D), as against the normal leg I seen in S. wuyi ( Figure 8A, B, D, E). It further differs from S. wuyi by having a very long basal patellar apophysis, 3 times longer than palpal femur ( Figure 4A, B), while the basal patellar apophysis is shorter than the palpal femur in S. wuyi ( Figure 9A, B). The female of S. longituba can be distinguished from that of the congeners by the larger copulatory openings and the longer copulatory ducts around the spermathecae ( Figure 4G, H). On the other hand, the copulatory openings are smaller in S. medogense sp. n. (Figure 7G, I) and S. wuyi ( Figure 9E, F) and their shorter copulatory ducts do not around the spermathecae.

Sinanapis longituba
Description. See Figs 3A Etymology. The specific name derives from the type locality; adjective. Diagnosis. The male of this new species can be distinguished from that of S. longituba and S. wuyi by the lack of anterior median eyes and having a rasper-like dentigerous process (Figs 5G, 6G, H). In the case of the two latter species, the anterior median eyes are present, and the rasper-like dentigerous patellar process is absent (Figs 3G, 4A, 9D;Yuan and Peng, 2014: figs 7, 9). It also differs from S. crassitarsa by having a tubular basal apophysis, and a smaller dentigerous process ( Figure 6A, B, G-I). In S. crassitarsus, the basal apophysis is laminar, and the dentigerous process is larger (Figure 2A-D, F). The female of the new species differs from S. longituba by having shorter copulatory ducts, each coiling with less than two loops next to the spermatheca ( Figure 7I). In S. longituba, each copulatory coil around the spermatheca in more than two loops ( Figure 4H). S. medogense further differs from S. wuyi by the absence of anterior median eyes, and by having a white pattern on the abdomen ( Figure 5C, F  Palp ( Figure 6A-I): Trochanter very long, subequal to 2/3 of femur length. Femur distally swollen approx. 2 times wider than proximally. Patella, complex, each modified with four apophyses ( Figure 6H): basal apophysis long horned, almost as long as patella; two dorsal apophyses, one crooked and fingerlike, and another rasper-  like dentigerous process ( Figure 6I); a lateral apophysis straight, finger-shaped, protruded. Tibia with a dorsal apophysis and a dorsal trichobothrium ( Figure 6F-H). Cymbium bowl-shaped, as wide as long, covered with sparse long setae. Bulb simple, cone-shaped, tegulum smooth and flat, without any apophysis. Embolus long, strongly sclerotized, started at the middle margin of bulb, and ends in the above of subcentral bulb, coiled almost into two loops, distally tapering ( Figure 6A, E).
Female ( Epigyne ( Figure 7G-I): Epigyne sclerotized, almost rectangular, about 2 times wider than booklung cover, vulva visible through the translucent integument; copulatory openings large, sub-rounded, closed to the epigynal posteromargin. Spermatheca globular, each with a width equal to 2/3 of the breadth of booklung cover, separated by a gap measuring around its own diameter; copulatory ducts coiled the base of spermathecae, starting near the rebordered epigynal posteromargin, and ended at the posterolateral margins of spermathecae; fertilization ducts short, and thin, connected with the bases of the spermathecae.
Distribution. Known only from the type locality. Diagnosis. The male of S. wuyi can be distinguished from these of S. crassitarsa and S. medogense sp. n. by the lack of a rasper-like dentigerous patellar process on the palp, and by having anterior median eyes ( Figure 9D; Yuan and Peng 2014: figs 7, 9). In the other two species, the dentigerous patellar process is present, and the anterior median eyes are absent (Figs 1D, 2C, 5G, 6H). It differs from S. longituba by having a shorter basal apophysis not exceeding the palpal femoral length, and the shorter copulatory ducts not coiled around the spermathecae ( Figure 9A-F). One the other hand, in S. longituba, the very long basal apophysis exceed the at least 3 times the length of the palpal femur, and the lengthy copulatory ducts coil around the spermathecae (Figure 4A