Sparassidae Research Articles

Newly Discovered Male of Heteropoda Languida Simon, 1887 (Araneae: Sparassidae) in Yunnan, China

Heteropoda spiders are an essential predator in tropical and subtropical areas because they trap and eat insects, cockroaches, and other domestic soft-bodied pests in crops. Pantropical huntsman spiders do not use webs to catch prey, like other stray spiders do. They catch the insects they eat using their powerful chelicerae (jaws) and quick movements. More than 140 individuals belonging to Heteropoda languida Simon, 1887 species, were collected from Xishuangbanna Dai Autonomous Prefecture and brought back to lab, and then stored in 75% ethanol. Among which 36 individuals were males and 104 individuals were females. Our research findings provide previously unknown male of Heteropoda languida Simon, 1887 for the first time, and the female is re-described from Xishuangbanna Dai autonomous prefecture, Yunnan, China. Our results also adding a little knowledge to Heteropoda species distribution, and may help to study the biogeography and dispersal route of Heteropoda spiders. In this paper, we provide the diagnosis, description, illustration, and field photos with distribution map for both males and females.

Six Heteropoda Spiders (Araneae: Sparassidae) from Xishuangbanna Dai Autonomous Prefecture, China

Due to the fact that they catch and consume insect pests, cockroaches, and other domestic soft-bodied pests in crops, Heteropoda spiders are highly important predator in tropical and subtropical regions. As with other vagrant spiders, pantropical huntsman spiders do not use webs to capture prey. Their great speed and strong chelicerae (jaws) are used to capture the insects on which they feed. Venom is also injected into the prey from glands extending from the chelicerae into the cephalothorax. In this study, more than 227 individuals belonging to six Heteropoda spiders were collected from Xishuangbanna Dai Autonomous Prefecture and brought back to lab, and then stored in 75% ethanol. Among which 64 individuals were males and 163 individuals were females. A total of six known species of the genus Heteropoda are described: Heteropoda dagmarae Jäger and Vedel, 2005, H. onoi Jäger, 2008, H. simplex Jäger and Ono, 2000, H. tetrica Thorell, 1897, H. venatoria (Linnaeus, 1767) and H. zuviele Jäger, 2008. Our findings provide new record for H. dagmarae from China, adding more knowledge to Heteropoda species distribution in China, and may help to study the biogeography and dispersal route of Heteropoda species. Our results also provide a little information for the origin and evolution study of Heteropoda genus, because no author has published any molecular phylogenetic study on this genus. We also provide description, illustration, and distribution map for each species in the current paper

Two new huntsman spiders from Xiaolong Mountains in Gansu Province, China (Araneae, Sparassidae)

Two new species of the sparassid genera Pseudopoda Jäger, 2000 and Sinopoda Jäger, 1999 are described from Xiaolong Mountains, Gansu, China: Pseudopoda tricuspidata sp. n. (♂♀) and Sinopoda subcampanacea sp. n. (♂♀). Photos of habitus and genitalia are provided.

Spiders - It’s not the Way we Think

Spiders, eight legged arthropod for many looks creepy or a yekk creature. When we think of spiders, for majority long & thin legged cellar spiders in corner of our room with messy web comes to mind. For some large huntsman spider with large legs in bathrooms & few with little garden may think of web weaving spiders, which have disturbed them for morning walk.

Spider limb regeneration: Cost and benefits

One of the most phenomenal innate powers of organisms is their ability to repair injured or lost body parts better known as regeneration. Regeneration is the natural process of replacing or restoring missing body parts and is a primary attribute of all living organisms. Studying regeneration may be a potential for use in biomedical sciences. Closely associated with regeneration in the arthropods is autotomy an anti-predator behavior in animals. Autotomy is one of the most remarkable features of many arthropods, however, autotomy is not well known in spiders. Also, the cost and benefits of regeneration of lost limbs have not received much attention in recent decades. Understanding the cost-benefits dynamics of regeneration of lost limbs in spiders will undoubtedly increase our understanding of the evolutionary trajectory. Spiders are remarkable for their ability to regenerate limbs with apparent ease during young stages. We used the huntsman spider Heteropoda venatoria as a model to address this. This mini-review also addresses the ecological implications of regeneration for spiders themselves. The study is of great importance because understanding the molecular mechanisms associated with regeneration could be exploited to reconstitute regeneration from constituent parts.

A study on morphometric and sexual dimorphism characteristics of giant huntsman spider in Kandi, sangareddy region of Telangana state, India

A study on morphometric and sexual dimorphism characteristics of giant huntsman spider in Kandi, sangareddy region of Telangana state, India

Taxonomic study on Sinopoda Jäger, 1999 (Araneae, Sparassidae, Heteropodinae), with three new species from Korea.

The genus Sinopoda Jäger, 1999 is a group of huntsman spiders (Araneae: Sparassidae: Heteropodinae), and currently seven species have been reported in Korea. In this study, three new species are described from Korea, Sinopodabigibba sp. nov., Sinopodabogil sp. nov., and Sinopodapantherina sp. nov.; Sinopodajirisanensis Kim & Chae, 2013 is revalidated with neotype designation, and had been formerly synonymized with Sinopodaforcipata (Karsch, 1881). Additionally, all previous records of Sinopodastellatops Jäger & Ono, 2002 and S.forcipata from Korea are deemed misidentifications of S.jirisanensis and S.bogil sp. nov., respectively.

Object-of-Interest Perception in a Reconfigurable Rolling-Crawling Robot.

Cebrenus Rechenburgi, a member of the huntsman spider family have inspired researchers to adopt different locomotion modes in reconfigurable robotic development. Object-of-interest perception is crucial for such a robot to provide fundamental information on the traversed pathways and guide its locomotion mode transformation. Therefore, we present a object-of-interest perception in a reconfigurable rolling-crawling robot and identifying appropriate locomotion modes. We demonstrate it in Scorpio, our in-house developed robot with two locomotion modes: rolling and crawling. We train the locomotion mode recognition framework, named Pyramid Scene Parsing Network (PSPNet), with a self-collected dataset composed of two categories paths, unobstructed paths (e.g., floor) for rolling and obstructed paths (e.g., with person, railing, stairs, static objects and wall) for crawling, respectively. The efficiency of the proposed framework has been validated with evaluation metrics in offline and real-time field trial tests. The experiment results show that the trained model can achieve an mIOU score of 72.28 and 70.63 in offline and online testing, respectively for both environments. The proposed framework’s performance is compared with semantic framework (HRNet and Deeplabv3) where the proposed framework outperforms in terms of mIOU and speed. Furthermore, the experimental results has revealed that the robot’s maneuverability is stable, and the proposed framework can successfully determine the appropriate locomotion modes with enhanced accuracy during complex pathways.

Huntsman spider phylogeny informs evolution of life history, egg sacs, and morphology

Huntsman spiders (Araneae: Sparassidae) are among the most speciose spider families, with a near-worldwide distribution, diverse habitats, equally diverse life histories, and five prolonged subsocial species. Previous molecular phylogenies have focused on individual subfamilies or clades. Here, we provide a phylogenetic inference with broadened sampling from 37 genera and eight of the eleven sparassid subfamilies. We increased taxon sampling by including species not previously sequenced and most available data on GenBank of two mitochondrial (COI, 16S rRNA) and two nuclear (H3, 28S rRNA) genes for a total of 262 ingroup taxa and nine outgroup taxa. Divergence dates were estimated using outgroup fossil taxa suggesting the sparassids evolved ∼ 100 mya (stem age), while the clade containing all subfamilies except Sparianthinae evolved ∼ 90 mya (stem age). Using a stochastic map approach with 40 species, this is the first sparassid phylogeny to incorporate extensive biology and life history data. Correlations of life history traits with solitary, subsocial, and prolonged subsocial behavior are examined using the D-test. Sparassid sociality is associated with life history traits that allow developing spiders to remain in their natal retreat longer (e.g., larger permanent retreats, plastered egg sacs, and ontogenetically delayed foraging), but is unrelated to body size or lifespan. Detailed morphological scoring of the endemic Australian subfamily Deleninae contextualizes existing molecular data, including in the Isopeda-Holconia-Isopedella complex. This study supports the monophyly of many major lineages, including for the first time, the Sparianthinae, but indicates multiple clades (Sparassinae and Eusparassinae) are paraphyletic and need further revision.

Ecological niche modelling and climate change in two species groups of huntsman spider genus Eusparassus in the Western Palearctic

The huntsman spiders’ genus Eusparassus are apex arthropod predators in desert ecosystems of the Afrotropical and Palearctic ecoregions. The Eusparassus dufouri and E. walckenaeri clades are two distinct taxonomic, phylogenetic, and geographic units concerning morphology, molecular phylogeny, and spatial data; but little is known about their ecological niche. We applied the maximum-entropy approach and modelled ecologic niches of these two phylogenetically closely related clades. Ecological niches of the two clades were compared using identity and background tests and two different metrics, the Schooner’s D and Warren’s I. We also predicted the impacts of climate change on the distribution of the two clades. The results of the identity test showed that the ecological niches of the two clades were different in geographic space but were similar in environmental space. While results of the background test revealed that the ecological niches of the two clades were similar in geographic and environmental space. This indicated that “niche conservatism” had an important role over the evolutionary time of allopatric diversification. However, the normalized difference vegetation index vs. topographic heterogeneity had influenced the niches of the dufouri and walckenaeri clades, respectively. The analyses recovered that the two clades’ climatically suitable habitats will increase under future climate (the year 2070). However, since the two clades are characterized by the narrow range of environmental optimum and the accordingly high limits of tolerance, they are vulnerable to climate change.

Night on Earth

Night on Earth

Variation of Two S3b Residues in KV4.1-4.3 Channels Underlies Their Different Modulations by Spider Toxin κ-LhTx-1.

The naturally occurred peptide toxins from animal venoms are valuable pharmacological tools in exploring the structure-function relationships of ion channels. Herein we have identified the peptide toxin κ-LhTx-1 from the venom of spider Pandercetes sp (the Lichen huntsman spider) as a novel selective antagonist of the KV4 family potassium channels. κ-LhTx-1 is a gating-modifier toxin impeded KV4 channels’ voltage sensor activation, and mutation analysis has confirmed its binding site on channels’ S3b region. Interestingly, κ-LhTx-1 differently modulated the gating of KV4 channels, as revealed by toxin inhibiting KV4.2/4.3 with much more stronger voltage-dependence than that for KV4.1. We proposed that κ-LhTx-1 trapped the voltage sensor of KV4.1 in a much more stable resting state than that for KV4.2/4.3 and further explored the underlying mechanism. Swapping the non-conserved S3b segments between KV4.1(280FVPK283) and KV4.3(275VMTN278) fully reversed their voltage-dependence phenotypes in inhibition by κ-LhTx-1, and intensive mutation analysis has identified P282 in KV4.1, D281 in KV4.2 and N278 in KV4.3 being the key residues. Furthermore, the last two residues in this segment of each KV4 channel (P282/K283 in KV4.1, T280/D281 in KV4.2 and T277/N278 in KV4.3) likely worked synergistically as revealed by our combinatorial mutations analysis. The present study has clarified the molecular basis in KV4 channels for their different modulations by κ-LhTx-1, which have advanced our understanding on KV4 channels’ structure features. Moreover, κ-LhTx-1 might be useful in developing anti-arrhythmic drugs given its high affinity, high selectivity and unique action mode in interacting with the KV4.2/4.3 channels.

Description of a new species of Thelcticopis Karsch (Araneae, Sparassidae) from Guangxi Province, China.

BackgroundDue to its special ways of hiding and lifestyle, Thelcticopis is a type of spider that is very difficult to collect. In 2018, we collected two huntsman spiders in Guangxi. After comparison with other Thelcticopis species, such as anterior median eye larger than other eyes, they were found to belong to the genus of Thelcticopis.New informationCurrently, four Thelcticopis species are reported from China, T. severa (L. Koch, 1875), T. zhengi Liu, Li & Jäger, 2010, T. dahanensis Zhu & Zhong, 2020 and T. unciformis Zhu & Zhong, 2020. They are mainly distributed in the tropical or subtropical areas of China (Fujian, Guangdong, Guangxi, Hainan, Hongkong, Hunan, Taiwan, Yunnan and Zhejiang). In this paper, we diagnose and describe a new species, Thelcticopis pinmini sp. nov., which was collected from Guangxi Province, China.

Size-related increase in inducible mechanical variability of major ampullate silk in a huntsman spider (Araneae: Sparassidae).

Most spiders use major ampullate silk (MAS) to perform many functions across their lifetimes, including prey capture, vibratory signal detection, and safety/dragline. To accommodate their various needs, adult spiders can use inducible variability to tailor MAS with specific mechanical properties. However, it is currently unknown whether this inducible mechanical variability develops gradually or remains consistent across spider size. Supercontraction -a process by which "native-state" silk fibers axially shrink when exposed to water or high humidity-can be used to reveal the extent of inducible variability in MAS. Supercontraction removes some processing effects that occur during the spinning of the solid fiber from its liquid precursor by allowing a native-state MAS fiber to return to a low energy "ground-state". Here, we examined the relative extent of inducible variability of MAS across spider size by assessing supercontraction properties and the difference between ground- and native-state MAS tensile properties using silk from the huntsman spider Heteropoda venatoria (Sparassidae). Stiffness of forcibly pulled native-state silk increased by 200% with spider size. After exposure to 90% RH and subsequent supercontraction, axial shrinkage of native-state silk fibers increased by 15% in larger spiders. Supercontracted, ground-state fibers demonstrated a 200% increase in extensibility across spider size. Our results indicate a gradual increase in inducible variability of MAS mechanical properties across spider size potentially caused by shifts in internal processing or chemical composition. These findings imply both development of inducible variability and changes in use of MAS as a safety line or aiding jumps across a spider's lifetime.

Enigmatic “love bites” and an indirect mating plug: revision of Thunberga Jäger, 2020 with description of new species (Araneae: Sparassidae: Heteropodinae)

The huntsman spider genus ThunbergaJäger, 2020 is revised. Twenty-five species are described for the first time: Thunberga alienaspec. nov. (♂), T. befotakaspec. nov. (♂), T. boyanslatspec. nov. (♀), T. calaspec. nov. (♀), T. conductorspec. nov. (♂, ♀), T. darainaspec. nov. (♂, ♀), T. elongataspec. nov. (♀), T. gosuraspec. nov. (♀), T. jaerviispec. nov. (♀), T. jyotispec. nov. (♀), T. mafiraspec. nov. (♂, ♀), T. malalaspec. nov. (♂, ♀), T. mamaspec. nov. (♂, ♀), T. matomaspec. nov. (♀), T. millotispec. nov. (♂), T. paulyispec. nov. (♂, ♀), T. panusilemspec. nov. (♀), T. platnickispec. nov. (♂, ♀), T. rothorumspec. nov. (♂), T. rugosaspec. nov. (♀), T. samsagalaspec. nov. (♂), T. soruagspec. nov. (♀), T. v-insignitaspec. nov. (♀), T. wasserthalispec. nov. (♀), T. woodaespec. nov. (♂, ♀). The male of T. greta is described for the first time. One species is transferred to Thunberga: T. laterifusca (Strand, 1908) comb. nov. (from Eusparassus), it is considered a nomen dubium. The distribution range of the genus includes now Madagascar with adjacent islands and Mayotte. Photos of living spiders are shown for the first time revealing a possible new diagnostic character: a small white patch in front of the fovea. Another new diagnostic character is a distal V- to U-shaped field of bristles situated ventrally on metatarsus IV, the metatarsus III exhibits ventro-distally a short to very stout bristle embedded in a scopula. Metatarsi I and II possess only scopula without bristles distally. In the female genitalia, plugs were observed not only at the copulatory openings, but in few cases also at the unpaired anterior pocket, the first known case within the Entelegynae that structures other than the copulatory openings are plugged. Externally recognisable mating plugs to various degrees were found in twelve out of twenty-three species known from females. Sixteen of these exhibited paired scars at the dorsal prosoma. It is hypothesized that males grab the females with their chelicerae and cause small punctuations in the cuticle (so-called “love bites”). Morphological and possible behavioural characters of Thunberga species are discussed.

Effects on running speed of changes in sexual size dimorphism at maturity on in the cursorial huntsman spider, Delena cancerides (Sparassidae).

Running speed is a measure of whole-organism performance reflecting relative fitness. For spiders, increased speed translates into enhanced prey capture, mating success and reduced predation risk. In male spiders, leg length increases dramatically with the molt to sexual maturity. To determine how changes in leg length and body mass with sexual maturity influence running performance, we compared allometric and kinematic changes in a species without extreme size sexual dimorphism (SSD): male and female Delena cancerides (Sparassidae) during their penultimate and adult instars. Spiders in each age-sex class were filmed running in the lab, and body morphometrics, maximum velocity, body lengths per second, acceleration, stride length and stride frequency were compared. At maturity, females increase in overall size, whereas male's leg length increases over 30% with little associated increase in body mass or overall size. Adult male legs are similar in length to those of the adult females and maximum velocity did not differ between age-sex classes. However, both male age-classes have higher velocity scaled as body lengths per second than females, due to their lighter mass. Thus, for sparassids spiders without large SSD, lower mass and longer legs translate into lower energetic costs of running distances for males.

Five new Sinopoda species (Araneae, Sparassidae) from China and Thailand.

Five new species of the huntsman spider genus Sinopoda Jäger, 1999 are described: S. hongruii Wang & Li, sp. nov. (♂♀, forest in Anhui, China), S. jiangzhou Wang & Li, sp. nov. (♂♀, cave in Guangxi, China), S. saiyok Wang & Li, sp. nov. (♀, cave in Kanchanaburi, Thailand), S. yanjin Wang & Li, sp. nov. (♀, forest in Yunnan, China), and S. yanzi Wang & Li, sp. nov. (♂♀, cave in Hunan, China). A distribution map of the new species is provided.

An Afrotropic element at the north-western periphery of the Oriental Region: Pseudomicrommata mokranica sp. nov. (Araneae: Sparassidae)

The surprising discovery of a new species of grass huntsman spider, Pseudomicrommata mokranica sp. nov. (♂♀), belonging to “the African clade”, is reported and described from south-eastern Iran, more than 4000 km away from the nearest recorded locality of the genus in Kenya. Similar vicariant occurrences of other sparassid taxa in Africa and Asia are discussed.

Having a live huntsman spider on a rubber hand does not modulate the rubber-hand illusion in a top-down manner.

The rubber-hand illusion is an illusion where a person embodies a rubber hand as if it were their own. After embodiment, many studies have threatened the false hand and measured physiological responses to the threat for the purposes of verification. For the first time, we tested if embodiment of the false hand could be modulated with a fearful stimulus already present prior to the elicitation of the illusion. This was done by having a live huntsman spider placed on top of the false hand for the entire duration of testing. We also examined if the procedure could change implicit attitudes towards spiders. The results revealed that the embodiment of the false hand with the fearful stimulus on top of it occurred as strongly as when the latter was not there, suggesting that the top-down processing of fearful stimuli is not strong enough to influence bottom-up processes. However, implicit attitudes towards spiders did not change.

Forty-seven new species of Sinopoda from Asia with a considerable extension of the distribution range to the South and description of a new species group (Sparassidae: Heteropodinae).

Up to current knowledge, the spider genus Sinopoda Jäger, 1999 is distributed in South-, East- and Southeast-Asia. New material treated in this paper include new records from Brunei, India, Indonesia, Thailand and Vietnam. Forty-seven new Sinopoda species are described: S. aenyk spec. nov. (female; Laos), S. arboricola spec. nov. (male, female; Malaysia), S. assamensis spec. nov. (female; India), S. bifurca spec. nov. (male, female; China), S. bispina spec. nov. (male; Myanmar), S. caeca spec. nov. (female; Laos), S. chiangmaiensis spec. nov. (male, female; Thailand), S. cornuta spec. nov. (male, female; Indonesia), S. deminutiva spec. nov. (male; Laos), S. emei spec. nov. (female; China), S. empat spec. nov. (male; Malaysia), S. flexura spec. nov. (female; Indochina), S. hainan spec. nov. (male; China), S. hanya spec. nov. (male; Malaysia), S. incisura spec. nov. (female; China), S. inthanon spec. nov. (male; Thailand), S. kalaw spec. nov. (female; Myanmar), S. kambaiti spec. nov. (male; Myanmar), S. kamouk spec. nov. (female; Laos), S. kieo spec. nov. (female; Laos), S. kinabalu spec. nov. (male; Malaysia), S. konglor spec. nov. (female; Laos), S. kyee spec. nov. (female; Myanmar), S. lebar spec. nov. (female; Indonesia), S. longicymbialis spec. nov. (male, female; Thailand), S. lot spec. nov. (female; Thailand), S. maculata spec. nov. (female; Malaysia), S. mat spec. nov. (female; Vietnam), S. matang spec. nov. (male, female; Malaysia), S. nanphagu spec. nov. (female; Myanmar), S. parva spec. nov. (male; Malaysia), S. phathai spec. nov. (female; Thailand), S. phiset spec. nov. (female; Thailand), S. phom spec. nov. (male, female; Thailand), S. reinholdae spec. nov. (female; Malaysia), S. rotunda spec. nov. (female; China), S. ruam spec. nov. (female; Thailand), S. silvicola spec. nov. (male, female; China), S. sulawesia spec. nov. (male, female; Indonesia), S. tawau spec. nov. (female; Malaysia), S. thieu spec. nov. (female; Vietnam), S. tibang spec. nov. (female; Indonesia), S. tilmanni spec. nov. (male, female; Malaysia), S. tralinh spec. nov. (female; Vietnam), S. tuber spec. nov. (female; Malaysia), S. unicolor spec. nov. (female; Thailand) and S. wayala spec. nov. (female; China). The female of S. exspectata Jäger Ono, 2001 and the males of S. scurion Jäger, 2012 and S. steineri Jäger, 2012 are described for the first time. Males of S. tengchongensis Fu Zhu, 2008 and S. triangula Liu et al., 2008 and females of S. crassa Liu et al., 2008 and S. licenti (Schenkel, 1953) are redescribed. In addition to the okinawana-group, a second species-group is diagnosed, the chiangmaiensis-group, which includes S. chiangmaiensis spec. nov., S. lot spec. nov. and S. phathai spec. nov. All three species occur in north-western Thailand. Twenty new species are described from caves, some of which have distinct cave adaptations: S. caeca spec. nov. is the second known eyeless huntsman spider, S. kamouk spec. nov. has two remnants of eyes without pigments, S. empat spec. nov. has four remnants of eyes without pigmentation and S. tralinh spec. nov. has all eight eyes but without pigments. All other new species herein described have eight functional eyes.