﻿Meotipa species (Araneae, Theridiidae) from China

﻿Abstract In an ongoing effort to expand knowledge of the Chinese cobweb spider fauna (Theridiidae), the genus Meotipa Simon, 1894 is reviewed. Two new species are described, Meotipapseudopicturatasp. nov., Meotipastriatasp. nov., and five known species are redescribed: Meotipaargyrodiformis (Yaginuma, 1952), Meotipapulcherrima (Mello-Leitão, 1917), Meotipapicturata Simon, 1895, Meotipaspiniventris (O. Pickard-Cambridge, 1869), and Meotipavesiculosa Simon, 1895.


Introduction
Meotipa Simon, 1895 is an enigmatic and taxonomically poorly understood theridiid genus, in part because it was synonymized with the much larger and more widespread genus Chrysso by Levi (1962) until being resurrected by Deeleman-Reinhold (2009). Meotipa are long-legged theridiid spiders bearing a conspicuous synapomorphic feature: flattened black spines on the abdomen and/or legs (Deeleman-Reinhold 2009). However, some Chrysso species also have obvious spines on the abdomen which are often sharp or needle-like (Kulkarni et al. 2017), such as Chrysso lingchuanensis Zhu & Zhang, 1992 known from China. Their relationship needs further research based on more evidence, such as molecular data. Meotipa contains 18 known species (World Spider Catalog 2021) that are quite common in gardens and secondary forests across the tropics in Asia (Deeleman-Reinhold 2009; Kulkarni et al. 2017). Nine Meotipa species are known from China: M. argyrodiformis (Yaginuma, 1952), Meotipa capacifaba Li, Liu, Xu & Yin, 2020, Meotipa luoqiae Lin & Li, 2021, Meotipa menglun Lin & Li, 2021, M. picturata Simon, 1895, M. pulcherrima (Mello-Leitão, 1917, M. spiniventris (O. Pickard-Cambridge, 1869), M. vesiculosa Simon, 1895, and Meotipa zhengguoi Lin & Li, 2021. In the past two years, a series of surveys for Chinese theridiid spiders were conducted by the colleagues of Hubei University in China and yielded numerous new species. This is our second paper on Chinese cobweb spiders with the aim to review the Chinese Meotipa spiders and includes two new species, one new record for Hunan, and four known species .

Materials and methods
In the field, we collected cobweb spiders by using visual searching and beating vegetation. We attempted to take photographs of every species, alive, in the field, and webs of all species encountered in web were photographed. All specimens were preserved in 99% ethanol and examined with an Olympus SZX16 stereomicroscope; details were further investigated with an Olympus BX51 compound microscope. Male palps and female genitalia were examined and their photographs taken after dissection from the spider bodies. The epigynum was cleared with Proteinase K. Habitus and photographs were obtained using a Leica 205C digital microscope. We added some key marginal lines for genitalia photographs using the Apple pencil (2 nd generation) and edited the photographs in Adobe Photoshop 2020. Leg measurements are shown as: total length (femur, patella, tibia, metatarsus, tarsus). The terminology used in text and figure legends, and palpal homologies follow Agnarsson (2004a) and Agnarsson et al. (2007a). Geographical co-ordinates were recorded in decimal degrees. All measurements are given in millimeters. All specimens are deposited in the Centre for Behavioural Ecology and Evolution, College of Life Sciences, Hubei University, Wuhan, China (CBEE). The abbreviations used in this paper are as follows:

ALE
anterior lateral eyes; AME anterior median eyes; C conductor; CD copulatory duct;  Fig. 2A-H) in: having the abdomen pointed to a tubercle posteriorly (Fig. 1B), lacking obvious copulatory openings, and having a spoon-shaped conductor in the male palp. However, it can be distinguished from the latter by the following combination of characters: (1) the abdomen extends beyond spinnerets ~ 3/4 of total abdomen length in M. argyrodiformis ( Fig. 1A), but less than half in M. pulcherrima ( Fig Description. Female. Total length 5.20; Prosoma length 1.20, width (at middle) 0.81, height (at middle) 0.88; Opisthosoma length 4.05, width (at middle) 1.97, height (at middle) 2.46; Eye diameters: ALE 0.07, AME 0.07, PLE 0.07, PME 0.07; Eye interdistances: AME-AME 0.05, ALE-ALE 0.15, PLE-ALE contiguous, PLE-PLE 0.22, PME-PME 0.07, PME-PLE 0.07, AME-ALE 0.  2.80, 0.59, 2.69, 2.43, 0.76]. Carapace rather ovate with V-shaped longitudinal fovea, cephalic area short and narrow, thoracic area widest between coxae II and III (Fig. 1A). Eyes in two rows with black or pale brown ring, strongly recurved (Fig. 1B); anterior eye row curved, shorter than the straight posterior eye row. Sternum yellow, longer than wide, lateral margins slightly indented. Labium contiguous to the sternum, yellow with a brown, rounded to slightly triangular, apical margin (Fig. 1C). Chelicerae vertical, yellow with pale brown fang. Yellow legs long and slender with or without gray bands and bearing a few dark brown short spines, tibiae with two dorsal spines in legs I, II and IV, and one in leg III, tarsus three-clawed with 5-7 teeth in the superior claws. Leg formula 1423. Pedipalp yellow and length ~ 2/3 carapace, single-clawed, with many short hairs; tibia laterally with a lanceolate spine. Abdomen pale yellowish, anterior portion overhangs the carapace, approximately triangular in lateral view, dorsum with red cardiac marking and several transverse reddish brown bands laterally. Posterior area of ventral abdomen with deep red stripes, pointed posteriorly, with six black and medially broad setae with sharp ends, and ventrally projected spinnerets (Fig. 1B). Epigynum forming a triangular atrium, without obvious copulatory openings (Fig. 1D); two round spermathecae can be clearly seen in ventral view (Fig. 1E); copulatory ducts long, narrow, almost straight; fertilization ducts short, close to copulatory ducts, and both of them are located at the directly below spermathecae (Fig. 1F); spermathecae round, slightly separate from each other (Fig. 1H).
Remarks. Although we did not examine the female holotype of M. pulcherrima, the triangular abdomen with caudal region extending upwardly beyond spinnerets, the short and swollen copulatory ducts, and the sphere-shaped spermathecae all indicate our specimens belong to M. pulcherrima according to the original, albeit simple illustrations by Mello-Leitão (1917: 86, figs 7, 8) and detailed illustrations by Zhu et al. (1992: 23, fig. 3A-D) and Yoshida (2003: 126, figs 337, 341, 342).We also note some slight differences in our specimens against the original illustrations of Brazilian specimens by Mello-Leitão (1917). The specimens we collected only has half of the abdomen extending beyond the spinnerets (Fig. 2B), but the specimens from Brazil have 2/3 of abdomen extending beyond them (see Mello-Leitão 1917: 86, fig . 7). Meanwhile, the shadow of the copulatory ducts and the fertilization ducts can be seen from the ventral view of epigynum, and the shadows on both sides look like two tadpoles in atrium, with fertilization ducts resembling their tails and copulatory ducts resembling their heads. The shadows of the specimen from Brazil in 1917 resemble two tadpoles swimming towards the middle of the atrium (see Mello-Leitão 1917: 86, fig. 8), but the shadows of our specimen resemble two tadpoles swimming to the sides of the atrium (Fig. 2C). However, the tails of tadpoles in the Brazilian specimens may be the spermathecae instead of the fertilization ducts according to the original illustrations. In addition, the posterior margin of atrium has a tongue-shaped protrusion medially in our individuals, but not in the Brazilian specimens. Diagnosis. Meotipa picturata is similar to M. sahyadri (Kulkarni et al. 2017: figs 1-38) in having a deep round atrium, the presence of rod-shaped projection with distinct oval openings distally in the median of the atrium (Fig. 3D). It can be distinguished from the latter by the following combination of characters: (1) the rodshaped projection with three openings in this species (Fig. 3D), but two openings in M. sahyadri (see Kulkarni et al. 2017: figs 19, 22); (2) the distal shape of rodshaped projection is flat, quadrangular in M. picturata (Fig. 3E), but triangular in M. sahyadri (see Kulkarni et al. 2017: figs 19, 21); (3) the copulatory ducts curve outward in M. picturata (Fig. 3F), but curve inward in M. sahyadri (see Kulkarni et al. 2017: fig. 18); (4) the end of copulatory ducts enter into the spermathecae ventrally in M. picturata (Fig. 3E), but laterally in M. sahyadri (see Kulkarni et al. 2017: fig. 18).
Male. Not collected. Distribution. China (Yunnan). New country and province record (Fig. 10).   of characters: (1) the carapace has a central black band, opisthosoma with four median yellow and white patches, and four or five lanceolate spines posteriorly in M. spiniventris (Fig. 4A), but carapace without any marking, opisthosoma with a median black patch and 12-15 lanceolate spines posteriorly in M. multuma (see Murthappa et al. 2017: fig. 3A-C); (2) copulatory ducts short, extending to the lateral part of spermathecae (Fig. 4E) and fertilization ducts short in M. spiniventris (Fig. 4F, H), but the copulatory ducts are long and convoluted around spermathecae and fertilization ducts longer, twisted in M. multuma (see Murthappa et al. 2017: figs 3D, E, 4E, F); (3) the tip of the conductor is uniquely strongly sclerotized and twisted in M. spiniventris (Fig. 5C).

Meotipa vesiculosa
Description. Female. Cephalothorax pale yellow with a red-brown central stripe; cephalic area relatively long and broad; clypeus narrow, bulged out. Eyes in two rows and nearly uniform in size, strongly recurved; AME separation is greater than AME-ALE, and PE are arranged at almost equal distances; AME black, PME eyes pearly white (Fig. 6A). Sternum deep yellow, triangular, lateral margins slightly indented. Labium contiguous with the sternum, brown, triangular. Chelicera vertical, deep yellow with red fang (Fig. 6B). Legs yellowish white with small hairs and bearing a few dark short spines, the end of tibiae with a black ring in each legs and femur of all legs have small black spots. Leg formula 1423. Pedipalp yellowish white, single-clawed, with many short hairs; tibia with a black ring on the extreme and bearing a lanceolate spine  (D-H). Abbreviations: CO = copulatory opening, CD = copulatory duct, FD = fertilization duct, S = spermathecae. laterally (Fig. 6A, B). Opisthosoma approximately triangular laterally, dorsally provided with numerous white and black spots, posterior region extending downwardly towards spinnerets. Two pairs of dorsolateral abdominal humps, black distally ( Fig. 6A-C). Atrium large, with a clear herringbone structure medially (Fig. 6D). Copulatory ducts and fertilization ducts short and both of them extending into spermathecae at the same position (Fig. 6H). Spermathecae large, oval-shaped (Fig. 6G).
Male. Not collected. Distribution. China (Fujian; Guangxi; Hunan; Taiwan; Yunnan, newly recorded), Vietnam to Japan, Philippines, Indonesia.  Kulkarni et al. 2017: figs 1-38) in having a deep round atrium, and having the copulatory ducts openings in the atrium (Fig. 7E). It can be distinguished from the latter two by the following combination of characters: (1) The tip of rod-shaped projection is narrower than its basal part in this new species, but wide in M. picturata (see Murthappa et al. 2017: fig. 4C) and M. sahyadri (see Kulkarni et al. 2017: fig. 21) ; (2) the ends of the copulatory ducts are curved and enter the spermathecae ventrally in M. pseudopicturata sp. nov. (Fig. 7F), and laterally in M. picturata (see Murthappa et al. 2017: figs 1J, 4D) and M. sahyadri (see Kulkarni et al. 2017: fig. 18); (3) fertilization ducts relatively short, proximal part confronting without curve in M. pseudopicturata sp. nov. (Fig. 7H), but relatively long, proximal part confronting with an apical curve in M. picturata (see Murthappa et al. 2017: fig. 4D) and M. sahyadri (see Kulkarni et al. 2017: fig. 18). In addition, M. pseudopicturata sp. nov. can be distinguished from other Meotipa species by the long and triangular opisthosoma which extends beyond spinnerets ~ 3/4 of total abdomen length, with blunt end curved ventrally.

Discussion
Meotipa Simon, 1895 is a relatively small genus of the family Theridiidae, totaling 20 species globally including two new species reported here. Most species are distributed in East Asia (eleven species in China, three species in Japan and Korea), Southeast Asia (eight species in Brunei, Indonesia, Laos, Malaysia, Myanmar, Thailand, and Vietnam), and South Asia (five species in India). Only M. pulcherrima is found outside Asia: it is widely distributed in tropical Africa and is presumed to have been introduced to Papua New Guinea, China, Korea, Japan, and the Pacific islands, and the Americas, including its type locality in Brazil (see Note under M. pulcherrima). Meotipa spiders prefer to inhabit the underside of leaves typically decorated by lichens and fungi. Against this background, the black, white, and red patterns on the body and the brushes of black scale-like spines on legs and abdomen blur their outline and enhance their disguise (Deeleman-Reinhold 2009). Therefore, these long-legged spiny theridiids are difficult to find and collect in the wild. Given the broad distribution of Meotipa in Asia spanning many poorly sampled areas where taxonomic expertise is lacking, it is likely that many species await discovery and thus further taxonomical work focused on this genus is needed.
It is difficult to speculate on Meotipa interrelationships without a phylogeny, but some morphological observation may serve to indicate certain relationships: 1. Abdomen bearing two pairs of humps on dorso-lateral sides is only present in M. impatiens, M. ultapani, and M. vesiculosa However, whether these characters actually reflect relationships remains to be seen upon the systematic collection of phylogenetic data. In addition, we must consider that the two new species (only female) covered in the current paper were collected from same region (Mengla County, Xishuangbanna Dai Autonomous Prefecture) with three known species (only males of M. luoqiae, M. menglun, M. zhengguoi) recently reported (Lin et al. 2021), but we are sure that they do not match with each other based on the following reasons: 1. the habitus of our new species (M. pseudopicturata sp. nov. and M. striata sp. nov.) are significantly different from the males of the three known species (Figs 7A-C, 8A-C); 2. the male of M. pseudopicturata sp. nov. should be similar to M. picturata and M. sahyadri according to our above hypothesis about Meotipa interrelationships, but none of these three species is similar; 3. the female of M. striata sp. nov. is similar to M. spiniventris (Figs 4A-H, 5A-H) and M. capacifaba (see Li et al. 2020: figs 1A-J, 2A-E, 3A-E) in having two conspicuous copulatory openings; therefore, we speculate that its male should be similar to M. spiniventris (Figs 4A-H, 5A-H) and M. capacifaba in having a straight embolus covered completely by conductor, but the embolus is not covered by the conductor in these three species (M. luoqiae, M. menglun, and M. zhengguoi; see Lin et al. 2021: figs 47-52).
Meotipa clearly belongs to the subfamily Theridiinae based both on molecular phylogenetic data (Liu et al. 2016), and clear morphological synapomorphies, in particular the complete absence of the colulus and the hooded paracymbium (Agnarsson 2004a). The exact position of Meotipa within Theridiinae is less certain: Deeleman-Reinhold (2009) resurrected Meotipa from Chrysso mainly based on the presence of flattened black spines on the abdomen and/or legs, and the cutinized conductor in the male palp. However, the genus Chrysso seems to be polyphyletic (Liu et al. 2016). Deeleman-Reinhold (2009) speculated that the Chrysso species distributed in Southeast Asia are more closely related to Theridion and Achaearanea than they are to the type species Chrysso albomaculata from the Americas (Deeleman-Reinhold, 2009). We do not see any evidence of the close relationship between Theridion and Meotipa (but note that Agnarsson et al. (2007b) included an undetermined Meotipa species from Malaysia but its placement as sister to Theridion was poorly supported). However, the type of Achaearanea, A. trapezoidalis, shares certain characteristics such as abdomen shape with many species of Chrysso. The study of Liu et al. (2016) included one unnamed Meotipa species, placing it on a long branch as sister to two Yunohamella species: Y. lyricus (Walckenaer, 1841) and Y. palmgreni (Marusik & Tsellarius, 1986) according to recent research (Marusik and Logunov, 2017). We infer that Meotipa may instead belong to the "Chrysso clade" of Arnedo et al. (2007), given the similarities between Meotipa and Chrysso. Such speculations need to be tested through innovative phylogenetic analyses aimed to anchor Meotipa to the theridiid tree of life.