Taxonomic notes on the armored spiders of the families Pacullidae and Tetrablemmidae (Arachnida, Araneae) from Singapore

Abstract Eight species of armored spiders belonging to two families, Pacullidae Simon, 1894 and Tetrablemmidae O. Pickard-Cambridge, 1873, are reported from Singapore. Five species are documented as new to science: Paculla bukittimahensis Lin & Li, sp. n. (male and female), Paculla globosa Lin & Li, sp. n. (male and female), Ablemma malacca Lin & Li, sp. n. (male and female), Singaporemma lenachanae Lin & Li, sp. n. (male and female), and Sulaimania brevis Lin & Li, sp. n. (male). The three known species are Brignoliella besutensis Lin, Li & Jäger, 2012, Brignoliella michaeli Lehtinen, 1981, and Singaporemma singulare Shear, 1978, of which the female of Brignoliella besutensis is described for the first time. For comparison, types of Singaporemma adjacens Lehtinen, 1981 from Vietnam, Singaporemma halongense Lehtinen, 1981 from Vietnam, Singaporemma singulare from Singapore and Sulaimania vigelandi Lehtinen, 1981 from Malaysia are studied and photographed.


Introduction
Tetrablemmids and pacullids are collectively known as armored spiders because their abdomen is characteristically armor-plated with complicated abdominal scuta. Family placement of these haplogyne spiders has gone through a rather tortuous journey. Tetrablemmidae was first established by O. Pickard-Cambridge (1873) with Tetrablemma as its type genus. The family name Pacullidae was first used by Thorell (1898). He had taken the cue from Simon (1889Simon ( , 1894 who had replaced the preoccupied name Phaedima in Phaedimonidae (Thorell 1881) with Paculla, and grouped it, along with Perania and Tetrablemma in Paculleae, but under the family Theridiidae. Roewer (1963) placed Paculla, Tetrablemma, and a few other tetrablemmids under another family, viz., Hadrotarsidae. The family placements of these armored spiders were negated when Levi and Levi (1962) and Levi (1968) transferred them out of Theridiidae and Hadrotarsidae respectively. Believing that they were monophyletic, Brignoli (1973) subsumed Pacullidae (sensu Thorell) under Tetrablemmidae. In an extensive survey of the armored spiders, Shear (1978) pointed out that some of the Paculla described by Simon, Roewer and Brignoli were not the Paculla (sensu Phaedima) as initially conceived by Thorell (1898). More significantly, while agreeing that Pacullidae and Tetrablemmidae were closely related, he argued that more study was needed before the two families were combined. Nevertheless, Lehtinen (1981) decided to incorporate Pacullidae, then with a sole genus Paculla, as a sub-family under Tetrablemmidae. More recently, however, based on target-gene analyses from extensive spider taxa, Wheeler et al. (2016) have restored the family status of Pacullidae and circumscribed Tetrablemmidae, with redefined diagnoses and composition. Here, their family placement in reporting the armored spiders from Singapore are adopted.
According to Murphy and Murphy (2000: 548, fig 59.1-3), Singapore was home to four species of armored spiders. They included Singaporemma singulare Shear, 1978, which was the type species of the genus named after Singapore. The remaining three armored spiders comprised an unidentified species of Paculla collected from Bukit Timah in Singapore, and two species previously described from Malaysia and Vietnam: Brignoliella michaeli Lehtinen, 1981 and Singaporemma halongense Lehtinen, 1981. Our current study suggests that the Singaporemma in Singapore comprise S. singulare and a second Singaporemma not identical to S. halongense, but a new species closely related to it. This study further suggests that the unidentified Paculla referred to by Murphy and Murphy (2000: 370, fig 59.1) is probably one of the two new species of Paculla described in this paper.
Altogether, this paper records a total of eight species of armored spiders in Singapore. They include two new species of Paculla (Pacullidae). Among the Tetrablemmidae described and re-described in this paper are S. singulare, along with a new species each of Ablemma, Singaporemma and Sulaimania. The presence of Brignoliella besutensis Lin, Li & Jäger, 2012 in Singapore was ascertained for the first time, while the presence of B. michaeli was revalidated.

Materials and methods
All specimens were collected from July to August 2015 from various locations in Singapore by sifting leaf litter. Specimens were preserved in 95% ethanol. They were examined and measured under a Leica M205 C stereomicroscope. Further details were studied under an Olympus BX43 compound microscope. Vulvae were removed and treated in lactic acid. To reveal the course of the spermatic duct, the palpal bulbs were treated in lactic acid and mounted in Hoyer's Solution. Photographs were taken with a Canon EOS 60D wide zoom digital camera (8.5 megapixels). The images were combined using Helicon Focus 3.10.3 software (Khmelik et al. 2006).
All measurements are in millimetres. Height of carapace is measured with tubercle. Leg measurements are given in the following sequence: total length (femur, patella, tibia, metatarsus, and tarsus). Abbreviations in figures are as follows: A -anal plate; ALG -anterolateral groove of preanal plate; AT -atrium; AV -anterior ventrolateral plate; EF -epigynal fold; EP -epigynal pit; ep -embolic part of apes of palpal organ; IVP -inner vulval plate; L -lateral plate; LH -lateral horn; MV -median ventrolateral plate; MVB -bridge fragments of MV; P -pulmonary plate; PA -preanal plate; PG -postgenital plate; PLC -posterolateral corner of PA; PMC -posteromedial corner of PA; PV -posterior ventrolateral plate; sd -spermatic duct; sl -subterminal lamella; SR -seminal receptaculum; VD -vulval duct; VS -vulval stem. Abbreviations in text include: AER -anterior eye row; ALE -anterior lateral eye; AME -anterior median eye; PLE -posterior lateral eye. References to figures in the cited papers are listed in lowercase (fig. or figs); figures from this paper are noted with an initial capital (Fig. or Figs).
All types of the new species are deposited in the Lee Kong Chian Natural History Museum, National University of Singapore (LKCNHM). Other material used in the current work are deposited in the Natural History Museum of the Sichuan University (NHMSU) in Chengdu, China; the Zoological Museum of the University of Turku (ZMUT) in Turku, Finland and the American Museum of Natural History in New York, USA (AMNH).
Distribution. Singapore. Etymology. The specific epithet derives from the Latin word "globosus" = globular, drawing attention to the shape of palpal bulb; adjective.

Ablemma malacca
Etymology. The specific epithet refers to the Strait of Malacca, which separates Singapore from the Indonesian island of Sumatra; noun.
Prosoma ( Fig. 13C-D, F, H) as in male; but lack of clypeal horn and cheliceral apophysis, and clypeus lower than in male. Legs also as in male.

Singaporemma lenachanae
Etymology. Patronymic in honour of Dr Lena Chan from the National Biodiversity Centre, Singapore in recognition of her support of this study; noun (name) in genitive case.
Prosoma ( Fig. 16C-D, F, H) as in male, but clypeus slightly lower than in male. Palps distinctly reduced. Legs also as in male.
Prosoma ( Fig. 24C-D, F, H) as in male, except for clypeal area no reticulated, but covered with short setae. Palp reduced. Legs also as in male.
Distribution. Singapore.      Remarks. This species is originally described from Singapore and was designated as the type species of the genus Singaporemma by Shear (1978). Based on the only male specimen available at that time, he had illustrated an embolus of the right palp that was said to be "curving sharply posteriorly" (Shear, 1978: 36, figs 109-110), i.e. bent at right angles at about mid-length. Schwendinger and Košulič (2015) suggested that Shear's description of S. singulare was based on an atypical specimen. They noted that five other Singaporemma male specimens from Singapore, one of them from the type locality itself, all had "essentially straight emboli (only slightly bent ventrad) on both palps". We have since reexamined the holotype of the species and photographed its left palp (Fig. 23A-E). We can now confirm that Shear (1978) had indeed described a deformed embolus. Lehtinen, 1981 Type species. Sulaimania vigelandi Lehtinen, 1981 from Malaysia (see Lehtinen 1981). Etymology. The specific epithet derives from the Latin word "brevis" = short, and refers to the short embolus; adjective.

Sulaimania brevis
Diagnosis. This new species shares certain characteristics of the genus Sulaimania, including eye arrangement, habitus, and the general configuration of the male palp similar to that of the type species, S. vigelandi (see Fig. 28D -E and Lehtinen 1981: 51, figs 126-130, 133). However, it may be distinguished from S. vigelandi by the shorter embolus without a bent embolic end (Fig. 27F-H vs. Fig. 28D-E and Lehtinen 1981: fig. 129), the larger body size, the oblong carapace (Fig. 22A vs. Fig. 28A and Lehtinen 1981: fig. 127), and the sternum with reticular margins (Fig. 22B vs. Fig. 28B).