A peer-reviewed version of this preprint was published in PeerJ on 31 October 2017.

View the peer-reviewed version (peerj.com/articles/3972), which is the preferred citable publication unless you specifically need to cite this preprint.

Mammola S, Michalik P, Hebets EA, Isaia M. 2017. Record breaking achievements by spiders and the scientists who study them. PeerJ 5:e3972 https://doi.org/10.7717/peerj.3972 Spider World Records: a resource for using organismal biology as a hook for science learning

Stefano Mammola Corresp., 1, 2 , Peter Michalik 3 , Eileen A Hebets 4, 5 , Marco Isaia Corresp. 2, 6

1 Department of Life Sciences and Systems Biology, University of Turin, Italy 2 IUCN SSC Spider & Scorpion Specialist Group, Torino, Italy 3 Zoologisches Institut und Museum, Ernst-Moritz-Arndt Universität Greifswald, Greifswald, Germany 4 Division of Invertebrate Zoology, American Museum of Natural History, New York, USA 5 School of Biological Sciences, University of Nebraska - Lincoln, Lincoln, United States 6 Department of Life Sciences and Systems Biology, University of Turin, Torino, Italy

Corresponding Authors: Stefano Mammola, Marco Isaia Email address: [email protected], [email protected]

The public reputation of spiders is that they are deadly poisonous, brown and nondescript, and hairy and ugly. There are tales describing how they lay eggs in human skin, frequent toilet seats in airports, and crawl into your mouth when you are sleeping. Misinformation about spiders in the popular media and on the World Wide Web is rampant, leading to distorted perceptions and negative feelings about spiders. Despite these negative feelings, however, spiders offer intrigue and mystery and can be used to effectively engage even arachnophobic individuals. As such, we contend that spider biology can be a convincing hook for engaging people of all ages in science-related learning. Towards this end, and in order to provide an enthusiastic knowledge base for spider-related learning, we provide essential information about spider biology followed by a compilation of Spider World Records. We choose a world-record style format, as it is known to be an effective tool of engaging youth and adults alike. We group our records into the categories of Taxonomy, Morphology/Physiology and Ecology/Behaviour. We further reported on curiosities and clarify fake news about these underappreciated animals. Our contribution is specifically aimed to raise public awareness and attractiveness of spiders, meanwhile providing the first official knowledge base for world spider records.

PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.3028v1 | CC BY 4.0 Open Access | rec: 15 Jun 2017, publ: 15 Jun 2017 1 Spider World Records: a resource for using organismal biology as a hook

2 for science learning

3

4 Stefano Mammola1,2,*, Peter Michalik3,4, Eileen Hebets5 & Marco Isaia1,2,**

5

6 1. Laboratory of Terrestrial Ecosystems, Department of Life Sciences and Systems Biology, University of

7 Torino, Torino, Italy

8 2. IUCN SSC Spider & Scorpion Specialist Group, Torino, Italy

9 3. Zoologisches Institut und Museum, Ernst-Moritz-Arndt-Universität, Greifswald, Germany

10 4. Research Associate, Division of Invertebrate Zoology, American Museum of Natural History, New York,

11 USA

12 5. School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, USA

13 * corresponding author: [email protected]

14 ** corresponding author: [email protected]

15

16 Keyword: Araneae, Extremes, Misinformation, Science education, Urban legends,

17 Arachnophobia, Spider biology

18

19 20 Abstract

21 The public reputation of spiders is that they are deadly poisonous, brown and

22 nondescript, and hairy and ugly. There are tales describing how they lay eggs in human

23 skin, frequent toilet seats in airports, and crawl into your mouth when you are sleeping.

24 Misinformation about spiders in the popular media and on the World Wide Web is

25 rampant, leading to distorted perceptions and negative feelings about spiders. Despite

26 these negative feelings, however, spiders offer intrigue and mystery and can be used to

27 effectively engage even arachnophobic individuals. As such, we contend that spider

28 biology can be a convincing hook for engaging people of all ages in science-related

29 learning. Towards this end, and in order to provide an enthusiastic knowledge base for

30 spider-related learning, we provide essential information about spider biology followed

31 by a compilation of Spider World Records. We choose a world-record style format, as it

32 is known to be an effective tool of engaging youth and adults alike. We group our

33 records into the categories of Taxonomy, Morphology/Physiology and

34 Ecology/Behaviour. We further reported on curiosities and clarify fake news about these

35 underappreciated animals. Our contribution is specifically aimed to raise public

36 awareness and attractiveness of spiders, meanwhile providing the first official

37 knowledge base for world spider records. 38 INTRODUCTION

39 There exists a growing trend for youth and adults alike to be increasingly physically

40 inactive and associated with this, to spend less and less time outdoors (Guthold et al.,

41 2010; Hallal et al., 2012; Schaefer et al., 2014; Tremblay et al., 2014). As a result, in

42 most urban settings—where the majority of human populations now reside (54% in

43 2014; United Nation, 2014)—people are losing their connection with their natural

44 environment and with the organisms they share it with. Despite this, human curiosity

45 and intrigue with animals persists, especially in youth. Some of the first words that

46 children learn or noises children make are often animal-specific, as suggested by the

47 multiple “first words” books for babies and toddlers (e.g., Priddy, 2004; Machell, 2005).

48 Similarly, animal-related children’s books presumably facilitate early reading due in

49 large part to their ability to retain a child’s interest and attention—see the multiple Eric

50 Carle books on animals, e.g. "The Very Hungry Caterpillar", "The Very Busy Spider",

51 "Brown Bear, Brown Bear, What do you See?". Even among adults, animals are a

52 useful tool for attracting attention, as evidenced by the numerous viral videos focused

53 on cats, dogs, and other animals (e.g. Try to stay SERIOUS – The most popular CAT

54 videos had 17,465,589 views on YouTube as of June 2 2017). Following from these

55 observations, we propose that organismal biology can be an extraordinarily useful tool

56 for engaging people of all ages in science-related learning. We strongly maintain,

57 however, that the organism-specific toolset needs to be based upon accurate scientific

58 data.

59 Though an individual’s daily experience(s) with their environment and the

60 organisms within may be decreasing (on average), the daily accessibility of "science"- 61 related facts and stories is ever-increasing. The quality of these “facts” and stories,

62 however, can be quite variable. The (often) readily and easily accessible internet as well

63 as associated social media venues enable the rapid spread of evidence-based

64 information. While such easy access to science and related stories can be helpful for

65 increasing interest and enthusiasm for science, if the information is not accurate it can

66 do far more harm than good. For organisms that are particularly effective at capturing

67 the public’s attention and imagination —e.g. spiders and their relatives—misinformation

68 is unfortunately quite common.

69 Spiders, and arachnids in general, are animals that can simultaneously instill

70 both terror and intrigue, making it extraordinarily easy to engage even the most bio-

71 phobic individual into arachnid-based discussions and activities. Arachnids tend to

72 generate polar opposite reactions from people, scientists and non-scientists alike. They

73 are either loved or feared (and “hated”), with few individuals feeling ambivalence

74 towards them (Hillyard, 1994; Mulkens, de Jong & Merckelbach, 1996; Woody, McLean

75 & Klassen, 2005; Rinck & Becker, 2007; Knight, 2008). Even the fear of spiders though

76 can enhance science learning, as spider-phobic individuals in particular have been

77 shown to demonstrate preferential recall to spider-relevant information (Smith-Janik &

78 Teachman, 2008). Because arachnids are able to evoke strong reactions, they provide

79 an excellent opportunity for engaging youth in science learning.

80 In addition to leveraging a charismatic group of organisms like arachnids for

81 science engagement, we take advantage of the reality that youth often tend to think in

82 extremes. Indeed, for people of all ages, the entire range of superlatives exerts a

83 powerful spell on human curiosity. Scientists are no exception, as they are similarly 84 attracted by formidable species and extreme biological discoveries (e.g., Watson &

85 Walker, 2004; Glaw et al., 2012; Sendra & Reboleira, 2012; Wilson et al., 2012;

86 Andersen et al., 2015; Klug et al., 2015). Additionally, the excitement of scientists often

87 coincides with the public’s interest, as evidenced by a recent paper by McClain et al.

88 (2015) focusing on the largest-sized species occurring in the ocean. In only a few

89 months, this paper received impressive attention from scientists as well as the media,

90 both in term of visualizations, citations and altmetric score—i.e. a measure of the

91 attention that research outputs receive online in social media, traditional media and

92 reference managers (999 Altmetric score as of 2 June, 2017).

93 To facilitate the use of spider biology for increasing public engagement and

94 interest in science, we assemble data from peer-reviewed scientific literature about

95 spider records and spider-related curiosities. We present our findings in a world-record

96 style format, as this is known to be an effective means of engaging youth and adults

97 alike. The Guinness World Records' website (www.guinnessworldrecords.com), for

98 example, reports an impressive variety of records from very ordinary ones such as the

99 highest peak or the deeper abyss to weird and peculiar ones such as the heaviest birth

100 or the fastest delivery of a cricket ball. Numerous spider-related world records have

101 similarly already been claimed in peer-review scientific papers (e.g., Jäger, 2001;

102 Kunter & Coddington, 2009; Agnarsson, Kuntner & Blackledge, 2010; Lepore et al.,

103 2012; Smithers & Whitehouse, 2016). Officially, spiders hold 51 world records—

104 although only 12 of them are true biological records (Guinness World Records, 2017a–l)

105 and the remaining are related to Spider-Man and other non-biological topics. Here, we

106 build off of records in the scientific literature to provide an accessible resource for what 107 we consider the most interesting and exciting spider world records. We do not intend

108 this to be an exhaustive list, but more of a “highlights”. This information will not only be

109 useful for educators aiming to increasing interest and enthusiasm for animals, but also

110 for scientists studying arachnids (arachnologists), as a source of ideas for future

111 research avenues.

112 We begin our synthesis with a brief introduction to spiders. Next, we present the

113 Spider World Records in four distinct sections. I - Taxonomy, arachnology and

114 arachnologists: encompasses records related to the history of the science of

115 arachnology, and the taxonomy and nomenclature of living and fossil spiders. II -

116 Morphology and physiology: includes records related to spider morphology and

117 physiology (the latter referring mostly to venom and silk). III - Ecology and behaviour:

118 comprises records related to the behaviour of spiders (e.g. courtship, hunting

119 strategies), to their ecology and habitat preferences, and to their conservation status

120 and rarity. IV – Curiosities: includes a few records that are not strictly biological.

121

122 A BRIEF INTRODUCTION TO SPIDERS

123 Spiders (Araneae) belong to the class Arachnida together with ten other orders:

124 scorpions (Scorpiones), harvestmen (Opiliones), pseudoscorpions (Pseudoscorpiones),

125 windscorpions (Solifugae), mites and ticks (“Acari”), micro-whip scorpions (Palpigradi),

126 hooded tickspiders (Ricinulei), tailless whipscorpions (Amblypygi), and shorttailed

127 whipscorpions and whipscorpions (Uropygi)—common names based on Breene et al.

128 (2003). All spiders are hypothesized to have descended from a common ancestor (i.e.

129 they represent a monophyletic group; Garrison et al., 2016; Wheeler et al., 2016) and 130 the group encompasses more than 46,700 extant species, distributed among 4,059

131 genera and 113 families (WSC, 2017). They are considered to be one of the most

132 successful groups of organism in terms of their long evolutionary history and diverse

133 ecological impacts—they are distributed in virtually all terrestrial ecosystems and play a

134 key role as generalist carnivorous predators (Turnbull, 1973; Foelix, 2011). Indeed, a

135 recent study by Nyffeler & Birkhofer (2017) estimated that the global spider community

136 consumes between 400 and 800 million tons of prey annually—an enormous amount

137 and a finding which drew impressive media attention around the world, resulting in

138 headlines such as “Spiders outdo humans and whales as they chop through 800 million

139 tons of prey a year” in the UK based newspaper “The Telegraph”.

140 In terms of body form (i.e. anatomy), a spider is divided in two parts: (i) the

141 prosoma and (ii) the opisthosoma. These two body parts (i.e. tagma) are joined by a

142 narrow stalk called a pedicel. The prosoma is relatively hard and carries six pair of

143 appendages: the chelicerae, the pedipalps, and four pair of walking legs. The chelicerae

144 function in spider feeding and venom injection takes place through their fangs. So far,

145 only two spider families, hackled orbweavers (Uloboridae) and Holarchaeidae, are

146 known to lack venom glands connected to their fangs. Just behind the chelicerae are

147 the pedipalps—the first pair of appendages behind the mouth. The pedipalps of adult

148 males are modified into copulatory organs and facilitate the transfer of sperm to mature

149 females. The four pair of walking legs are located just behind the pedipalps. All walking

150 legs originate from the first body part, or prosoma, unlike the way they are sometimes

151 portrayed in spider merchandise—e.g. attached to a single body part or inaccurately

152 originating from the second body part. In addition to the six pair of appendages, the 153 eyes are also located on the prosoma. Most spiders possess eight eyes, but in some

154 species this number may be reduced or eyes may be entirely lacking (see Spider World

155 Records).

156 The second body part—the opisthosoma or abdomen—is soft, expandable, and

157 shows high variation in shape and pattern among species (Figure 1). The abdomen of

158 spiders houses the respiratory structures, the heart, most of the digestive system, the

159 excretory system, silk producing system, and the reproductive system. In addition to

160 these internal systems, the genital openings are located on the underside (i.e. ventral

161 surface) and are barely visible in mature males and immatures. In females, the genital

162 opening can be covered by a hardened (i.e. sclerotized) structure, the so-called

163 epigyne. At the back end (i.e. posterior) of the abdomen most spiders have their

164 spinnerets, which are used for producing silk. Depending upon the species, a single

165 spider can possess up to eight different silk glands, each extruding a distinct type of silk.

166 Silk is deployed in almost every aspect of a spider’s life—from web construction to egg

167 protection (Foelix, 2011).

168 Understanding the basic body form of spiders empowers students of all ages to

169 acquaint themselves with biological diversity that they encounter daily. For example, it

170 enables them to readily distinguish insects (three body parts and six legs) from

171 arachnids (two body parts and eight legs). It also provides them a foundation from which

172 they can ask more in-depth questions and embark on their own research to answer

173 newly inspired curiosities. How is a spider heart similar to and/or different from a human

174 heart? What does spider excreta look like? Why? Do spiders have blood? How exactly

175 do male spiders use their pedipalps to transfer sperm to female spiders? How do 176 spiders eat? Do spiders take bites out of prey like many other predators? Are there any

177 spiders that live and work together peacefully?

178 In addition to providing an increased awareness of the basic form and function of

179 these abundant and omnipresent animals to which all youth can relate (i.e. spiders), our

180 goal is to share some incredible facts and stories relating to both spiders and the

181 scientists who study them (i.e. arachnologists). In the next section, we highlight select

182 spider world records as a means of demonstrating how spider natural history and

183 behavior can inspire the learning of physics (through properties of silk or walking upside

184 down), chemistry (through studies of venom or digestive enzymes), agriculture and food

185 (through the use of spiders as biocontrol agents), and many more topics that relate

186 directly to educational learning objectives—e.g. the Next Generation Science Standards

187 in the USA (https://www.nextgenscience.org/). More specifically, we have next

188 compiled a series of spider world records that we hope will serve as entry points into

189 some of the incredible stories that spiders, and the scientists who study them, have to

190 offer.

191

192

193 194 METHODS

195 We began the compilation of the Spider World Records by verifying and including all

196 available biological records on spiders reported in the Guinness World Record website

197 (see Guinness World Records, 2017a–l). Wherever we observed discrepancies

198 between the information found in the official Guinness World Record and those found in

199 the scientific literature, we detailed it in the explanation of the relative record (see, e.g.,

200 "Smallest adult male spider"). A thorough search of the available literature was than

201 conducted to track further documentations of extremes in spider biology. This included

202 finding peer-reviewed international articles by means of literature searches engines—

203 Web of Sciences, Google Scholar, etc.—but also personal communications with

204 arachnologists and other scientists conducting research on the topics under evaluation.

205 Most records related to taxonomy were compiled exploring the online catalog of spiders

206 (World Spider Catalog—WSC, 2017), including updated species counts and all literature

207 on spider taxonomy from 1757 to date. 208 SPIDER WORLD RECORDS

209 We have organized our compiled world records into four general categories: I.

210 Taxonomy, arachnology, and arachnologists; II. Morphology and physiology; III. Ecology

211 and behaviour; and IV. Curiosities.

212 I. Taxonomy, arachnology and arachnologists

213 (a) Largest spider family – Jumping spiders, Family Saltidicae. The largest spider

214 family is Salticidae with 5,950 species currently described, distributed in 625

215 genera (WSC, 2017; see also Guinness World Records, 2017a).

216 (b) Smallest spider family – Shared by three families. The smallest families of

217 spiders are Huttoniidae, Sinopimoidae, and Trogloraptoridae, all of which include

218 one single species—Huttonia palpimanoides, Sinopimoa bicolor, and

219 Trogloraptor marchingtoni, respectively. H. palpimanoides is endemic to New

220 Zealand (Paquin, Vink & Dupérré, 2010), S. bicolor is restricted to rainforest in

221 China (Li & Wunderlich, 2008), while T. marchingtoni was discovered in few

222 caves in southwestern Oregon, USA (Griswold, Audisio & Ledford, 2012).

223 (c) First listed spider alphabetically – Abacoproeces molestus Thaler (Linyphiidae).

224 Abacoproeces molestus is the first spider species listed alphabetically in the

225 World Spider Catalog (WSC, 2017), while Zyuzicosa zeravshanica Logunov

226 (Lycosidae) is the last.

227 (d) Longest scientific name – Acanthoscurria hirsutissimasterni Schmidt

228 (Theraphosidae). This spider’s name has thirty-three characters. Names with

229 thirty-two characters are more common, such as Alloclubionoides 230 wolchulsanensis (Linyphiidae), Anophthalmoonops thoracotermitis (Oonopidae),

231 Mecysmauchenioides nordenskjoldi (Mecysmaucheniidae), Megalepthyphantes

232 pseudocollinus (Linyphiidae), and Troglohyphantes typhlonetiformis

233 (Linyphiidae).

234 (e) Shortest scientific name – Gea eff Levi (Araneidae). This spider has only six

235 characters in its name. Names with seven characters are found in the genus Ero

236 (Mimetidae) and Copa (Corinnidae).

237 (f) First described fossil – An amber spider. Although the earliest report of a fossil

238 spider ("Spinnenstein/Sternstein/Siegstein") in European literature can be found

239 in Schwenckfeld (1603), Kundmann (1737: plate XII, Fig. 13) illustrated and

240 described the first amber spider. See Selden & Penney (2010) for further details.

241 (g) First spider(s) ever described in binomial nomenclature – Shared by 68 species.

242 The record for the first spider ever described in binomial nomenclature is shared

243 by 68 species described by Carl Alexander Clerck in 1757 (see WSC, 2017).

244 Actually, some of them are nowadays considered nomen dubia or have been

245 synonymized, leaving the total to 53 currently valid species (see WSC, 2017).

246 These species own a second record, being among the first animals ever

247 described using the binomial system of nomenclature (see also "First

248 arachnologist in history"). (Figure 2a)

249 (h) First arachnologist in history – Carl Alexander Clerck (1709–1865). Although

250 reports about spiders can be found in very old writings such as those of Aristotle

251 and Pliny, according to Bonnet (1955) the father of the modern arachnology was

252 Carl Alexander Clerck, author of the first book on spiders using the binomial 253 system of nomenclature, Svenska Spindlar (Clerck, 1757). His book was

254 published only one year before the seminal "Systema Naturae" of Carl von Linné

255 (Linneaus, 1758), which marks the beginning of the binomial system of

256 nomenclature. In order to consider Clerck´s spider descriptions valid under the

257 system of zoological nomenclature, his work is deemed to be published on 1

258 January 1758, which is regulated in the International Code of Zoological

259 Nomenclature (Article 3.1; ICZN 1999).

260 (i) Most prolific arachnologist – Eugène Simon (1848-1924). In terms of

261 publications, the most prolific arachnologist was the French naturalist Eugène

262 Louis Simon. Over his life, he authored more than 270 spider-related scientific

263 works, and he described (or revised the status) of 5,633 species—although some

264 of them were later synonymized or considered nomen dubia (WSC, 2017).

265 (Figure 2b)

266 (j) First catalogue of spiders – 1942. Carl Friedrich Roewer (1881–1963) own the

267 record for publishing the first catalogue of spiders, i.e. the first volume of "Katalog

268 der Araneae von 1758 bis 1940", published in 1942. It included the list of spider

269 species, synonyms and references published from 1758 to 1940. This

270 remarkable publication provided the baseline, together with the competing

271 catalog of Bonnet (1955, 1956, 1957, 1958, 1959) for further implementations

272 (e.g., Brignoli, 1983; Platnick, 1989; 1993; 1998), up to the complete online

273 taxonomic catalogues of spiders developed in the last decades (Platnick, 2000–

274 2014; WSC, 2017; see also World Spider Catalog Archive, 2014–2017). 275 (k) Longest publication on spiders – Bibliographia Araneorum. With 6,481 pages, the

276 longest publication on spiders is the Bibliographia Araneorum (Bonnet, 1955,

277 1956, 1957, 1958, 1959), representing the culmination of 40 years of work of the

278 arachnologist Pierre Bonnet (1897–1990).

279 (l) First congress of Arachnology – Germany, 1960. The first scientific

280 arachnological meeting was held at the University of Bonn (Germany) in 1960. It

281 was organized by Ernst Kullmann (1931–1996). According to the congress photo,

282 at least 18 arachnologists attended this meeting (Kraus, 1999). (Figure 2c)

283 (m) Most attendees at a congress of arachnology – 365. With 365 participants, the

284 20th International Congress of Arachnology (2–9 July 2016, Golden, Colorado,

285 USA) was the largest arachnological congress ever held. It was organized by

286 Paula Cushing (Denver, USA). (Figure 2d)

287 (n) Oldest fossil spider – ~300 MYA. The oldest known true spiders date back to the

288 Carboniferous age, around 300 Myr ago. Most likely, specimens of Palaeothele

289 montceauensis (Selden) (Mesothelae) are the earliest described fossil species,

290 from the Upper Carboniferous (Stephanian) of Montceau-Ies-Mines, France

291 (Selden, 1996).

292 (o) Oldest fossil spider in amber – 125–135MYA. The oldest described amber spider

293 (125–135 Myr ago) is an undetermined Linyphiinae, preserved in a small piece of

294 Lebanese amber (Penney & Selden, 2002; Guinness World Records, 2017k).

295 This fossil specimen is also the oldest linyphiid spider known to date.

296 (p) Oldest recorded spider silk – 140MYA. Although spiders are known to produce

297 silk since the Mid-Devonian (410 Myr ago), the oldest spider silk record dates 298 back to the Earliest Cretaceous (~140 Myr ago). The silk is preserved in a piece

299 of amber, which was found within alluvial soils of the Ashdown Formation,

300 Hastings (Brasier, Cotton & Yenney, 2009; Guinness World Records, 2017i).

301 (q) Oldest web with entrapped prey – 110MYA. The oldest web with entrapped prey

302 is preserved in a cylindrical stalactitic mass of amber, dating back to Early

303 Cretaceous (around 110 Myr ago). The fossil sample was discovered in San Just

304 (Spain), and contains 26 strands of sticky silk entrapping a beetle, a parasitic

305 wasp, a mite and a fly (Peñalver, Grimaldi & Delclòs, 2006; Guinness World

306 Records, 2017l).

307 (r) First entire genome sequenced – 2014. In 2014, the entire genome—the

308 complete set of genetic material in an organism—of the African social velvet

309 spider Stegodyphus mimosarum Pavesi (Eresidae) was sequenced for the first

310 time by Sanggaard et al. (2014). In the same study, the author published the first

311 draft assembly of the genome of the mygalomorph spider Acanthoscurria

312 geniculata (C.L. Koch) (Theraphosidae). The estimate genome size for S.

313 mimosarum is 2.55 GB, whereas for A. geniculata is 6.5 GB. 314

315 II. Morphology and physiology

316 (a) Largest fossil spider – Mongolarachne jurassica (Selden, Shih & Ren)

317 (Mongolarachnidae). With a body length of ~2.5 cm and first legs of nearly 6 cm,

318 M. jurassica from Middle Jurassic (~165 Myr ago) found in the strata of

319 Daohugou in Inner Mongolia is the largest known fossil spider know to date

320 (Selden, Shih & Ren, 2011, 2013).

321 (b) Largest living spiders – Theraphosa blondi (Latreille) (Theraphosidae) and

322 Heteropoda maxima Jäger (Sparassidae). The Goliath bird-eater, T. blondi is

323 possibly the largest known spider by mass. According to Guinness World

324 Records (2017b), a single reared individual reached a leg span of 28 cm and a

325 weight of 170 g. H. maxima (Sparassidae), discovered from caves in Laos, is

326 possibly the largest known spider by leg span—up to 30 cm; Jäger (2001). With a

327 total body length up to 39.7 mm and a leg span of over 10 cm, females of

328 Nephila komaci Kuntner & Coddington (Nephilidae) are the largest known orb-

329 weaver spiders (Kuntner & Coddington, 2009). (Figure 3a, 3b)

330 (c) Smallest adult female spider – Anapistula ataecina Cardoso & Scharff

331 (Symphytognathidae). The record for the smallest adult female spider goes to

332 one specimen of the type series of A. ataecina, with a body length of 0.43 mm.

333 The species was discovered in the Frade cave system (Portugal); the male is still

334 unknown (Cardoso & Scharff, 2009). 335 (d) Smallest adult male spider – Patu digua Forster & Platnick (Symphytognathidae).

336 With a total length of about 0.37 mm (not including the chelicerae), P. digua is

337 the smallest adult male spider ever described (Forster & Platnick, 1977). Instead,

338 the Guinness World Records (2017d) reports the congeneric P. marplesi Forster

339 as the smallest spider (0.3 mm). However, according to the original description,

340 the male holotype of P. marplesi has a prosoma length of 0.22 mm, and an

341 abdomen of 0.21 mm (Forster, 1959)—in contrast to 0.15 mm and 0.25 mm

342 (prosoma and abdomen, respectively) in the holotype of P. digua (Forster &

343 Platnick, 1977). Intra-specific variability in the body size is possibly at the base of

344 this discrepancy. It is also worth noticing, that there are other spiders of similar

345 size for which only the female is described (WSC, 2017)—see, e.g., "Smallest

346 adult female spider".

347 (e) Most legs – Ten. In insects, the expression domain of the Hox gene

348 Antennapedia (Antp) controls the expression of legs. Khadjeh et al. (2012) used

349 RNA inference to down-regulate this gene in the spider Achaearanea

350 tepidariorum (C. L. Koch) (Araneae), giving rise to a 10-legged phenotype, which

351 is, therefore, the spider with the highest number of legs.

352 (f) Best diurnal eyesight – Jumping spiders and wolf spiders. Despite the majority of

353 spiders possess eight eyes, most species are known to have poor eyesight

354 (Foelix, 2011). This is especially true in web-spinning spiders, relying mostly on

355 vibrational cues for foraging and mating, rather than on visual perception. Two

356 notable exceptions are found in jumping spiders (Salticidae) and wolf spiders

357 (Lycosidae), being mostly diurnal active ground dwellers. Spiders from both 358 families possess enlarged eyes and a pronounced visual acuity, used in foraging

359 and mating.

360 (g) Best nocturnal eyesight – Net-casting spiders, family Deinopidae. The best

361 nocturnal eyesight documented to date is found in the net-casting spiders

362 (Deinopis spp.). They possess enlarged posterior median eyes that are reported

363 to be 2,000 times more sensitive to light than human eyes, thus appearing

364 physiologically designed for detecting movement at night (Blest & Land, 1977). It

365 has been suggested that these visual cues are fundamental to net-casting

366 spiders for capturing cursorial prey items (Stafstrom & Hebets, 2016). (Figure 3c)

367 (h) Highest number of eyes – Eight. The highest number of eyes in spider is eight, as

368 found in countless species. An anecdotic record is held by Troglohyphantes

369 polyophthalmus Joseph (Linyphiidae), which possesses sixteen eyes according

370 to the original description—as emphasized by the specific epithet (Joseph, 1881).

371 However, this species was described on a specimen killed in the early stage of

372 moulting, so that the number of eyes appeared doubled.

373 (i) Least number of eyes – Zero. The first eyeless spider ever described is Stalita

374 taenaria Schiödte (Dysderidae) from the Postojnska cave in Slovenia (Schiödte,

375 1847). S. taenaria shares the record for the less number of eyes (zero) with more

376 than 1,000 anophthalmic spider species inhabiting caves and other subterranean

377 habitats around the world (Mammola & Isaia, 2017). (Figure 3d)

378 (j) Largest web (area) – 2.8 meters square. The Darwin's bark spider, Caerostris

379 darwini Kuntner & Agnarsson (Araneidae) spins a web whose surface ranges

380 from 900 to 28,000 cm2. The largest measured web in this species was about 2.8 381 m2, being therefore the largest orb web ever measured (Kuntner & Agnarsson,

382 2010; see also Guinness World Records, 2017f). Prior to the discovery of this

383 species, the record was held by representatives of the genus Nephila

384 (Nephilidae), capable to spun orb webs of more than 1 m diameter (Kuntner &

385 Coddington, 2009). (Figure 3e, 3f)

386 (k) Largest web (dimension) – 25 meters. The anchor lines of the web of Darwin's

387 bark spider, Caerostris darwini Kuntner & Agnarsson (Araneidae), are capable of

388 bridging over 25 m, being the longest web among all spiders (Kuntner &

389 Agnarsson, 2010; Gregorič et al., 2011; see also Guinness World Records,

390 2017g).

391 (l) Strongest silk – 520 MJ/m3. The Darwin's bark spider, Caerostris darwini Kuntner

392 & Agnarsson (Araneidae), produces the toughest known spider silk—see also

393 "Largest web". Tensile testing has shown that certain threads may reach the

394 toughness of 520 MJ/m3 (average= 350 MJ/m3). The silk of C. darwini is

395 therefore over 10 times tougher than Kevlar® (Agnarsson, Kuntner & Blackledge,

396 2010; see also Guinness World Records, 2017e). (Figure 3e)

397 (m) Strongest cocoon silk - Maximum stress = 0.64 GPa and strain = 751%. The

398 record for the most stretchable egg sac silk goes to the stalk silk of the cocoon of

399 Meta menardi (Latreille) (Tetragnathidae), for which tensile testing pointed out a

400 maximum stress and strain of 0.64 GPa and 751%, respectively (Lepore et al.,

401 2011). On the other hand, the toughness of the egg case silk threads recorded to

402 date (G= 193 MJm−3) is spun by the hermit spider Nephilengys cruentata

403 (Fabricius) (Nephilidae) (Alam et al., 2016). 404 (n) Highest number of eggs – >3,000. The number of eggs laid by spiders is highly

405 variable depending on species and female body mass (Marshall & Gittleman,

406 1994). For example, Robinson & Robinson (1976) reported more than 2,400

407 eggs for a species of Nephila (Nephilidae). The same authors estimated that for

408 other species one female may produce as many as 3,000 eggs in multiple egg

409 sacs. According to available evidences, Nephila pilipes (Fabricius) is possibly the

410 spider capable to lay the highest number of eggs per clutch. In this species, the

411 egg sac usually contains more than 3,000 eggs (Higgins, 2002). Higgins

412 observed how female fecundity—number of eggs laid per clutch—is a function of

413 pre-laying female mass (see Higgins 2002: p. 382). The mass of the largest

414 female sampled by Higgins was 6.9 g and so, it is possible to estimate that the

415 clutch size of this female should be equivalent to 9,724 eggs.

416 (o) Least number of eggs – One. In Telema tenella (Simon) (Telemidae), a European

417 cave-dwelling spider, the lowest number of eggs found in a single eggsac is one

418 (Sic!) (Juberthie, 1985). The tendency to lay small numbers of eggs is a well-

419 known adaptation to hypogean habitats. Studies on subterranean spiders are

420 however scarce: it appears likely that T. tenella shares this record with other

421 cave species for which the number of eggs/cocoon was never quantified

422 (Mammola & Isaia, 2017).

423 (p) Longest life span – ~40 years. In spiders, data about lifespan in the wild are

424 extremely scarce. It was assumed that the enigmatic Tasmanian Cave Spider,

425 Hickmania troglodytes, reaches a life-span of several decades (Doran et

426 al.1999). The longest longevity reported is found in Theraphosidae in captivity, 427 with certain species having a life expectancy of 30–40 years (Schultz & Schultz,

428 1999, Ibler et al. 2014).

429 (q) Longest sperm – 0.65 mm. The longest known spider sperm by far is

430 reported for the goblin spider Neoxyphinus termitophilus (Bristowe) (Oonopidae).

431 With approximately 0.65 mm, one sperm measures around 1/3 of the body length

432 of this spider (Lipke & Michalik, 2015). The sperm is transferred coiled and

433 encapsulated in groups resembling the so-called synspermia, which have a

434 diameter of approximately 0.07 mm in this species. The longest transfer form

435 (0.08 mm) is held by another goblin spider, Orchestina spp. (Lipke & Michalik,

436 2015).

437 (r) Most extreme sexual size dimorphism – Females weighing 125 times that of

438 males. Sexual size dimorphism is a morphological syndrome in which conspecific

439 male and female sizes differ significantly. Among terrestrial animals, the most

440 extreme female-biased gigantism is found in orb weaving spiders (Foellmer &

441 Moya-Laraño 2007). Golden orb weaving spiders (Nephilidae) are the most

442 extremely sexually size dimorphic. Female on average can be up to 125 heavier

443 than mating males (Kuntner et al., 2012). (Figure 3g)

444 (s) Most unusual sexual size dimorphism – Males larger than females. In most web-

445 building spiders, females are larger than males. The water spider Argyroneta

446 aquatica (Clerck) (Cybaeidae) is one of the few spiders in which males are larger

447 than females, possibly showing the most extreme male-biased sexual size

448 dimorphism among spiders (Schütz & Taborsky. 2003; 2005; Seymour & Hetz, 449 2011). It has been suggested that larger males should have mobility advantages

450 over smaller ones when moving under water (Schütz & Taborsky. 2003).

451 (t) Fastest spider – Cebrennus rechenbergi Jäger (Sparassidae). The flic-flac

452 behavior of the Maroccan flic-flac spider C. rechenbergi is possibly the fastest

453 locomotory behavior documented for spiders (for a description see Jäger, 2014:

454 p. 350, f. 152–161). It was interpreted as a last resort escaping behavior, by

455 which the speed of the spider—2 m/s according to estimations—can increase up

456 to two times the normal running speed. This striking behavior has also inspired

457 the construction of a robot with similar motional elements (King, 2013).

458 (u) Fastest predatory strike – Zearchaea sp (Mecysmaucheniidae). The fastest

459 predatory strike in spiders was documented in the family Mecysmaucheniidae.

460 This family currently comprises 25 described species of tiny ground-dwelling

461 spiders distributed in New Zealand and southern South America, that rely on

462 active hunting to prey capture. By means of high-speed video calculations, Wood

463 et al. (2016) documented the speed of the power-amplified predatory strikes in

464 14 species belonging to this family. The fastest was a species in the genus

465 Zearchaea, capable of striking with a speed of 0.00012 s and releasing a power

466 output of 60000 W/Kg (mean values of 3 recording events).

467 (v) Most venomous to humans – Funnel-web spiders (Hexathelidae). In general,

468 only very few spider taxa are known for a potent venom—e.g. widow spiders

469 causing latrodectism and recluse spiders can cause severe skin lesions and

470 systemic effects. Wandering spiders of the South American genus Phoneutria

471 are known to be very poisonous by transferring large quantities of a strong 472 neurotoxin during a single bite. However, it is important to emphasize that

473 verified bites from other spider species cause only minor and transient effects

474 (Vetter and Isbister 2008). Funnel-web spiders are considered to be the most

475 dangerous spiders—to humans—in the world (White, 2000; Isbister et al., 2005).

476 Within the family, the most venomous spider is possibly the Sydney funnel-web

477 spider male, Atrax robustus O. Pickard-Cambridge. In this species, just 0.2

478 mg/kg of the venom of the male is lethal for humans (Guinness World Records,

479 2017c). On the other hand, according to literature reviews (Isbister et al., 2005),

480 the tree-dwelling Australian funnel web spider Hadronyche cerberea L. Koch has

481 the highest rate of severe envenomations (75%), in contrast to 17% in A.

482 robustus. Since the development of antidotes against funnel spider

483 envenomation, no fatal bites have been reported (Nentwig & Kuhn-Nentwig

484 2013b).

485 (w) Least venomous – Shared by two families. Least venomous spiders are

486 representative of the family Uloboridae and Holarchaeidae, by having secondarily

487 reduced their venom glands. Uloboridae have evolved an alternatively hunting

488 strategy: they wrap their prey in silk, cover it in regurgitated digestive enzymes

489 and toxins and then ingest the liquified body (Weng, Barrantes & Eberhard,

490 2006). On the other hand, Holarchaeidae entirely lacks openings of the poison

491 glands (Kuhn-Nentwig, Stöcklin & Nentwig, 2011; Nentwig & Kuhn-Nentwig,

492 2013a). 493

494 III. Ecology and behavior

495 (a) Best ballooners – Most spiders. Many spiders, especially small species or

496 immature stages, disperse by releasing one or more silk threads to catch the

497 wind (the so-called ballooning behaviour). Airborne dispersal is particularly

498 widespread amongst higher Entelegyne spiders (Bell et al., 2005). Distances

499 travelled by spider ballooners can reach >1,000 km, as testified by sailors who

500 reported spiders caught in their ships in the middle of oceans (Bell et al., 2005).

501 Possibly, the longest distance covered with ballooning is 3,200 km, as reported

502 by Gressit (1965) for an unidentified linyphiid spider. (Figure 4a)

503 (b) Best sailers – Fishing spiders (Pisauridae). The ability to walk on water has

504 evolved independently among over 1,200 species of vertebrates and

505 invertebrates (Bush & Hu, 2006). In spiders, spiders in many families are capable

506 of locomotion on the surface of water (Suter, 2013). Most likely the best sailers

507 are the adults of fishing spiders Dolomedes spp. (Pisauridae), capable of moving

508 across water surfaces taking advantage of wind currents (Suter, 1999). More

509 recently, it was demonstrated that ballooning linyphiids and tetragnathids may

510 also display sailing-related behaviours, as specific responses to landing on water

511 surfaces after ballooning (Hayashi et al., 2015)—see also "Best ballooners".

512 (Figure 4b)

513 (c) Highest altitude – >6,000 meters. A male specimen of Euophrys omnisuperstes

514 Wanless (Salticidae) was collected at an altitude of ca. 5,900 m a.s.l. during an

515 expedition in Mount Makalu (Nepal/China). Immature specimens collected by 516 Major Kingston at an altitude of ca. 6,700 m in Mount Everest (Nepal/China) were

517 tentatively attributed to same species (Wanless, 1975). Therefore, most likely E.

518 omnisuperstes owns the record of the spider dwelling at the highest altitude.

519 (d) Largest prey – Fish, toads, birds, bats. Websites are full of stories and videos

520 about spiders foraging on any kind of vertebrate animals. Although we

521 acknowledge that some of them are truly impressive, we remain skeptical and

522 rely on scientific literature. Accordingly, we report four scientifically documented

523 cases of vertebrate prey:

524 - The largest fish captured by a spider is a goldfish Carassius auratus

525 (Cyprinidae) of ~9 cm length of presumably 15 g weight. It was captured

526 by a pisaurid spider in a garden pond in Sydney (Nyffeler & Pusey, 2014).

527 However, under the assumption that the largest wandering spider, the

528 ctenid Ancylometes rufus (Walckenaer) weighing up to 7 g, is as effective

529 in overpowering oversized prey as the smaller-sized pisaurids, fish of up

530 to 30 g might conceivably be killed in the wild (Nyffeler & Pusey, 2014).

531 - The largest amphibians captured by spiders are possibly toads. Menin and

532 colleagues (2005) reported the predation of an individual of Theraphosa

533 blondi (84.12 mm) (see "Largest living spiders") on a juvenile Bufo

534 marinus (Bufonidae) of 90.52 mm length.

535 - According to Brooks (2012), the largest bird found wrapped in a spider orb

536 web is a laughing dove Streptopelia senegalensis (Columbidae) of 80 g

537 (wing chord of 138 mm). 538 - The largest bat found wrapped in a spider web is a Gould’s wattled bat,

539 Chalinolobus gouldii (Vespertilionidae), weighing around 15 g (estimated

540 value). It was captured by an unidentified web-building spider (Nyffeler &

541 Knörnschild, 2013).

542 (e) Shortest Mating – <1 second. Given the wealth of literature and observations it is

543 not easy to decide about the shortest mating. However, we think that mating of

544 certain wasp spiders (Argiope spp.), the one-palped spider Tidarren argo

545 Knoflach & van Harten (Theridiidae) and the dark fishing spider Dolomedes

546 tenebrosus (Hentz) (Pisauridae) can be considered the shortest, when

547 considering mating as an interaction of two conscious partners. In these species,

548 the male dies almost immediately after the insertion of his copulatory organ—

549 spontaneous death—and is usually cannibalized by the female afterwards

550 (Foellmer & Fairbairn, 2003; Knoflach & Van Harten, 2001; Schwartz, Wagner &

551 Hebets, 2013). (Figure 4c)

552 (f) Longest mating – >18 hours. Due to the paucity of information, we were unable

553 to establish an absolute winner for this category. However, Troglohyphantes

554 spiders (Linyphiidae) represents suitable candidates. In certain species, a

555 protracted mating lasting >18 hours was documented by Deeleman-Reinhold

556 (1978). (Figure 4d)

557 (g) Most elaborate courtship – Jumping spiders, Salticidae. With a certain

558 degree of subjectivity, the mating dance of peacock spiders Maratus spp.

559 (Salticidae), can be listed among the most elaborate and beautiful courtship

560 displays in arthropods (Girard, Kasumovic & Elias, 2011) attracting much 561 attention especially in the social media—e.g. the videos about the courtship

562 displays of different species of Maratus in the Peacockspiderman YouTube

563 channel had cumulatively more than 12 million views as of June 2 2017. (Figure

564 4e)

565 (h) Most endangered – Shared by 36 species. Thirty-six species of spiders are listed

566 in the 'critically endangered' IUCN category (IUCN, 2015), being therefore the

567 most endangered species of spiders. Habitat changes and deterioration

568 represent the major threats for these species. Some endangered Theraphosidae

569 are also frequently commercialized as pets (see "Most wanted as pet"). However,

570 it is worth noticing that only a minor part of the extant spider species has been

571 evaluated against IUCN criteria (Cardoso et al., 2011).

572 (i) Most wanted as pet – Tarantulas. As far as we are aware, the Gooty sapphire

573 Poecilotheria metallica Pocock (Theraphosidae) is among the most

574 commercialized spider species. According to IUCN (2015), P. metallica is

575 considered 'critically endangered', not only for the degradation of its natural

576 habitat, but also due to its indiscriminate collection by pet traders. Since 2002,

577 reports of advertised P. metallica exported illegally from India and put on sale on

578 the internet have been documented (Molur, Daniel & Siliwal, 2016).

579 (j) Most peaceful – Social spiders. The vast majority of spiders conduct a solitary

580 lifestyle, and generally display an aggressive behavior even toward conspecifics.

581 However, a reduced number of species have evolved different forms of group

582 living lifestyles (Lubin & Bilde, 2007). Two main forms of sociality has arisen in

583 spiders: i) cooperative species ("social" sensu Lubin & Bilde, 2007) live in 584 family group territories wherein they share communal nests and capture webs,

585 which ‐they inhabit together cooperating in foraging and raising young; ii) colonial

586 species (territorial permanent social’’ sensu Avilés, 1997) occur in aggregations,

587 but individuals in the colony ‐ generally forage and feed alone and there is no

588 maternal care beyond the egg stage. Among these two group living styles,

589 coloniality is the most common form, being reported in at least 12 families

590 (Whitehouse & Lubin, 2005). Social spiders are rarer, being found in at least six

591 families: Agelenidae, Dictynidae, Eresidae, Oxyopidae, Theridiidae, Thomisidae

592 (Lubin & Bilde, 2007). Genus Anelosimus (Theridiidae) shows the highest

593 number of group-living species.

594 (k) Rarest – Unclear. In lack of detailed information about biology, ecology, range of

595 distribution, and population size of the different species, rarity is extremely

596 difficult to define from a biological viewpoint (Gaston, 1994). It is therefore

597 challenging to assess which is the rarest spider species in the world. As an

598 example, Smithers & Whitehouse (2016) suggested Nothophantes horridus

599 Merrett & Stivens (Linyphiidae) as the rarest spider in the world, being recorded

600 exclusively from two abandoned limestone quarries near Plymouth, covering a

601 surface of circa 0.1 km2 (Cardoso & Hilton-Taylor, 2015). However, the reputation

602 of "rarest spiders" is possibly shared by numerous spiders described on the base

603 of a single specimen, and never recorded thereafter (see WSC, 2017).

604 (l) Strangest habitat – Underwater. Spiders are well-known to be ubiquitous in

605 terrestrial ecosystem (Foelix, 2011). In our opinion, the diving bell spider

606 Argyroneta aquatica (Clerck) (Cybaeidae) owns the record of the most peculiar 607 habitat, being the only known spiders living a wholly aquatic life. A. aquatica

608 possesses specific adaptations to breathe in immersion, being therefore able to

609 hunt, to consume prey, to moult, to deposit eggs and to copulate underwater

610 (e.g., Seymour & Hetz, 2011; Mammola, Cavalcante & Isaia, 2016). On the other

611 hand, there are other species that are able to conduct a partially aquatic life,

612 such as Desis marina (Hector) (Desidae), inhabiting intertidal habitats (e.g.,

613 McQueen & McLay, 1983). (Figure 4f)

614 (m)Strangest diet – Leaf tips. Spiders are renowned to be carnivorous. Being the

615 only spider—mostly—herbivorous, Bagheera kiplingi Peckham & Peckham

616 (Saticidae), distributed from Mexico to Costa Rica, owns the record for the

617 strangest diet. From behavioral observations and stable-isotope analysis,

618 Meehan et al. (2009) showed that the diet of this spider predominantly comprises

619 specialized leaf tips, the so-called Beltian food bodies. There are other spider

620 species occasionally feeding on vegetal products (e.g. pollen), with at least 95

621 reports documented in literature (Nyffeler, Olson & Symondson, 2016). (Figure

622 4g)

623 (n) Best mother – matriphagy. Providing offspring with food is thought to be the

624 most important form of parental care. Possibly, the most 'unusual and extreme

625 form of care' (Evans, Wallis & Elgar, 1995) is called matriphagy, in which the

626 mother sacrifices herself to feed her offspring. This peculiar form of parental care

627 has evolved at least in six spider families (Schneider, 1996).

628 (o) Best father – Dolomedes tenebrosus (Hentz, 1844) (Pisauridae). In numerous

629 spiders, females eat their mating partner just after the copula (see "Shortest 630 Mating"). Such self-sacrifice is evolutionary advantageous if being eaten

631 sufficiently increases offspring number or fitness (paternal effort hypothesis) or,

632 either, the fertilization success. Recent experiments conducted by Schwartz,

633 Wagner & Hebets (2016) on the dark fishing spider, D. tenebrosus, demonstrated

634 an impact of male consumption on offspring size and overall survival—indicating

635 that self-sacrifice behavior should be adaptive.

636 (p) Best date – Nuptial gifts in Pisaura mirabilis (Clerck) (Pisauridae). "Nuptial gifts"

637 are nutrients that males of a number of species—especially Arthropods—offer to

638 females prior to, during, or shortly after copulation (Gwynne, 2008). In spiders,

639 nuptial gifts have been documented in various forms as e.g. glandular secretion

640 or wrapped prey items. The most spectacular is reported for P. mirabilis (e.g.,

641 Van Hasselt, 1884; but see Itakura, 1993 for a possible other species), as it

642 consists of large prey items wrapped up in silk by the male (Prokop & Maxwell,

643 2012). The male offers his gift during courtship and, while the female is feeding

644 on it, he successfully mates with her.

645 (q) Most creative prey capture – Bolas spiders. Bolas spiders (Araneae,

646 Mastophorini) have evolved a unique hunting tactic that combines chemical

647 mimicry—mimics pheromone blends to attract the prey—with a bola-like weapon,

648 which consist of a silk thread ending with a droplet of adhesive glue that the

649 spider swing to catch its flying prey (Yeargan, 1994).

650 (r) Best thieves – Kleptoparasites. In spiders, best thieves are kleptoparasites, i.e.

651 spiders regularly stealing food from the web of other spider species.

652 Kleptoparasites generally do not build webs, but exploit other spiders’ web for 653 any of their activity. To date, kleptoparasitism has been documented in five

654 spider families—Theridiidae, Dictynidae, Salticidae, Symphytognathidae and

655 Mysmenidae (Vollrath, 1987). (Figure 4h) 656

657 IV. Curiosities

658 (a) The longest journey – Into space. In 1973, two females of Araneus diadematus

659 Clerck (Araneidae) were sent into space on the Skylab 3 mission to the US

660 Skylab space station (Witt et al., 1976). They are the first spiders that travelled in

661 space (Guinness World Records, 2017h). Witt et al. (1976) observed that web

662 spun in space had modified features—unusual distribution of radial angles, low

663 number of turning points—indicating a deviation from earth webs, which was

664 attributed to the absence of gravity.

665 (b) Most delicious – Personal preference. It is difficult to assess which is the

666 most delicious species of spider, as flavour is rather subjective and a matter of

667 gourmets (see also "Most eaten by humans"). It is worth noting, however, that in

668 some countries, spiders are considered a food delicacy. As an example, in

669 Cambodia and Thailand Haplopelma albostriatum (Simon) (Theraphosidae) is

670 served fried as street food (Ray, 2002), but also sold canned with salt. A few

671 species in Thailand are also used to flavour vodka and whiskey. In Venezuela,

672 the jungle tribe Piaroa commonly eat Theraphosa blondi roasted.

673 (c) Most eaten by humans – Many. Likely, the most eaten spiders are eaten

674 accidentally. In many countries, the legal limits governing the presence of

675 arthropods in processed foods are indeed large enough so that over time a large

676 amount of spider parts is ingested (see, e.g., CFSAN, 1998).

677 (d) Most feared – Indiscriminate. Countless species of spiders terrify the public alike.

678 With a prevalence rate ranging from 3.5 to 6.1 % of the population (Jacobi, 2004; 679 Schmitt & Müri, 2009), "arachnophobia" is indeed documented to be the most

680 common phobia related to animals (Hofmann, Alpers & Pauli, 2009).

681 (e) Most iconic spider – Spiderman. Arachnid symbolism is found through human

682 history (Melic, 2002). Possibly, the most famous, successful and iconic character

683 inspired by arachnids is Spider-Man, the famous Marvel superhero created by

684 Stan Lee and Steve Ditko in 1962. However, it is worth noticing that according to

685 a recent survey (Da-Silva et al., 2014) there are at least 123 other comics’

686 characters inspired to Arachnids in the Comics literature.

687

688 DISCUSSION

689 We provide an initial list of spider world records, categorized into the general topics of

690 taxonomy and the history of arachnology, morphology and physiology, and ecology and

691 behaviour. We add a fourth grouping that encompasses topical spider curiosities that do

692 not fit neatly into the aforementioned categories. Throughout this list we provide multiple

693 fun facts that we suspect will intrigue readers of all ages. For example, we highlight the

694 largest and smallest spiders, the largest prey eaten, the fastest runners, the highest

695 fliers, the species with the longest sperm, the most venomous spider species, and many

696 more. These facts are reminiscent of those found in the National Geographic Weird but

697 true! series, of which there are currently 26 available books; a sure indication of public

698 interest. We hope that our compilation will similarly inspire science educators to

699 embrace the biology of spiders for engaging their students in science learning.

700 As a means of making both the science and the scientists more accessible, we

701 provide historical information on the arachnologists who study spiders. Our list also 702 encompasses the evolutionary history of spiders through mentions of the oldest fossil

703 spider, the oldest spider in amber, the oldest recorded spider silk. By reviewing this list

704 readers can ascertain that early spiders did not build webs, despite having the capacity

705 for producing silk. Inspired research could explore the initial functions of spider silk and

706 the evolutionary history of its use. Similarly, our records regarding the physical

707 properties of spider silk hint at an astounding biomaterial. With some imagination, we

708 suspect that science educators can bring their students into creative discussions and

709 research surrounding potential translational innovations associated with spider silk.

710 We importantly note that our list is far from being exhaustive. We also

711 acknowledge that there may be records that were missed, as they may be hidden in old

712 papers or in contributions written in languages unspoken by the authors. In spite of the

713 biases inherent in a compilation such as we provide, we hope that this contribution will

714 provide a useful tool for finding specific answers about many curiosities concerning

715 spiders, meanwhile challenging scientists to find new world spider records.

716 One might notice the timing of many of our world records, with many of them

717 indicating research published since 2010. This accurately reflects the relative infancy of

718 arachnology; relative to other organismal systems such as mammals, birds, or even

719 insects. By some estimates, arachnologists have described only one third of the spider

720 species worldwide (Agnarsson, Coddington & Kuntner, 2013); and even among the

721 described species, basic information about their biology and natural history remain

722 unknown. Indeed, our knowledge of spiders is still in its early stages and with the

723 expected future discoveries of thousands of new species and novel observations of

724 species already known to science will surely come new records and new curiosities. 725 Our hope in putting together this initial list is that it will inspire a new generation of

726 scientists to take notice of spiders and their relatives and to engage in their own

727 observations and conduct their own research. Arachnids offer unparalleled opportunities

728 for community science projects, but we need local educators and scientists to lead the

729 charge. Finally, in order to transform this overview in a community-driven knowledge

730 base, we will implement this list in the website of the International Society of

731 Arachnology (www.arachnology.org).

732

733 ACKNOWLEDGMENTS

734 Many thanks to all friends and colleagues who posed to us bizarre questions about

735 spiders, stimulating the idea for this paper. Rebecca Wilson, Yael Lubin, Theo Blick,

736 Jens Runge, Philippe Vernon, Cecilia Ruffino, Filippo Milano, Raquel Galindo, and

737 Silvia Grilli provided information and/or suggested some of the records listed herein. We

738 thank Irene Frigo for the help in creating the layout of figure 1. We are grateful to Matjaz

739 Kuntner, Peter Jäger, Barbara Knoflach-Thaler, Riccardo Cavalcante, Francesco

740 Tommasinelli, Fulvio Gasparo, Adam Fletcher, Steve Le Roux, Olaf Craasmann,

741 Maximilian Paradiz, Nicky Bay, Patrick Coin, and Pieceoflace photography for sharing

742 their photos of spiders.

743

744 Competing interests

745 We have no competing interests.

746 747 LITERATURE CITED

748 Agnarsson I, Coddington JA, Kuntner M (2013) Systematics—progress in the study of spider diversity and

749 evolution. In: Penney D, ed. Spider research in the 21st century: trends and perspectives.

750 Manchester: Siri Scientific Press, 58-111.

751

752 Agnarsson I, Kuntner M, Blackledge TA (2010) Bioprospecting finds the toughest biological material:

753 extraordinary silk from a giant riverine orb spider. PLoS ONE 5(9):e11234. doi:

754 10.1371/journal.pone.0011234

755

756 Alam P, Otieno D, Nuhamunada M, Anyango R, Odoyo J, Odhiambo J, Onyango K (2016) The toughest

757 recorded spider egg case silks are woven into composites with tear-resistant architectures.

758 Materials Science and Engineering: C 69:195-199. doi:10.1016/j.msec.2016.06.063 759

760 Andersen T, Baranov V, Hagenlund LK, Ivković M, Kvifte GM, Pavlek M (2016) Blind flight? A new

761 troglobiotic Orthoclad (Diptera, Chironomidae) from the Lukina Jama–Trojama Cave in Croatia.

762 PLoS ONE 11(4):e0152884. doi:10.1371/journal.pone.0152884

763

764 Avilés, L. (1997) Causes and consequences of cooperation and permanent sociality in spiders. In Crespi

765 B & Choe J., ed. ‘The Evolution of Social Behavior in Insects and Arachnids.‐ Cambridge University

766 Press, 476-498.

767

768 Bell JR, Bohan DA, Shaw EM, Weyman GS (2005) Ballooning dispersal using silk: world fauna,

769 phylogenies, genetics and models. Bulletin of entomological research 95(02):69-114.

770 doi:10.1079/BER2004350

771 772 Blest AD, Land MF (1977) The physiological optics of Dinopis subrufus L. Koch: a fish-lens in a spider.

773 Proceedings of the Royal Society of London B: Biological Sciences 196(1123): 197-222.

774 doi:10.1098/rspb.1977.0037

775

776 Bonnet P (1955) Bibliographia araneorum. Toulouse 2(1):1-918.

777

778 Bonnet P (1956) Bibliographia araneorum. Toulouse 2(2):919-1926. 779

780 Bonnet P (1957) Bibliographia araneorum. Toulouse 2(3):1927-3026. 781

782 Bonnet P (1958) Bibliographia araneorum. Toulouse 2(4):3027-4230. 783

784 Bonnet P (1959) Bibliographia araneorum. Toulouse 2(5):4231-5058. 785

786 Brasier M, Cotton L, Yenney I (2009) First report of amber with spider webs and microbial inclusions from

787 the earliest Cretaceous (c. 140 Ma) of Hastings, Sussex. Journal of the Geological Society

788 166(6):989-997.

789

790 Breene RG, Allen Dean D, Edwards GB, Hebert B, Levi HV, Manning G, McWest K, Sorkin L (2003).

791 Common Names of Arachnids (5th Edition). American Arachnological Society. ISBN 1-929427-11-5 792

793 Brignoli PM (1983) A catalogue of the Araneae described between 1940 and 1981. Manchester University

794 Press.

795

796 Brooks DM (2012) Birds caught in spider webs: a synthesis of patterns. The Wilson Journal of Ornithology

797 124(2):345-353. doi:10.1676/11-148.1 798

799 Bush JW, Hu DL (2006) Walking on water: biolocomotion at the interface. Annual Review of Fluid

800 Mechanics 38, 339-369. doi:10.1146/annurev.fluid. 38.050304

801

802 Cardoso P, Hilton-Taylor C (2015) Nothophantes horridus. The IUCN Red List of Threatened Species

803 2015: e.T70560176A7056021. doi:10.2305/IUCN.UK.2015- 1.RLTS.T70560176A70560214.en 804

805 Cardoso P, Scharff N (2009) First record of the spider family Symphytognathidae in Europe and

806 description of Anapistula ataecina sp. n. (Araneae). Zootaxa 2246:45–57.

807 doi:10.5281/zenodo.190697

808

809 Cardoso P, Borges PV, Triantis K, Ferrández M, Martín J (2011) Adapting the IUCN Red List criteria for

810 invertebrates. Biological Conservation 144(10):2432 2440. doi:10.1016/j.biocon.2011.06.020

‐ 811

812 CFSAN—Center for Food Safety and Applied Nutrition (1998) The food defect action levels: levels of

813 natural or unavoidable defects in foods that present no health hazards for humans. U.S.

814 Department of Agriculture. Online at: http://vm.cfsan.fda.gov/~dms/dalbook.html. Accessed: 13

815 April 2016. 816

817 Da-Silva ER, Coelho LBN, Campos TRM, Carelli A, Miranda GS, Santos ELS, Silva TBNR, Passos MIS

818 (2014) Marvel and DC characters inspired by arachnids. The Comics Grid: Journal of Comics

819 Scholarship 4(1):1-14. doi:10.5334/cg.aw

820

821 Deeleman-Reinhold CL (1978) Revision of the cave-dwelling and related spiders of the genus

822 Troglohyphantes Joseph (Linyphiidae), with special reference to the Jugoslav species. Opera

823 Academia Scientiarum et Artium Slovenica (Classis IV) Ljubljana 23(6):1-221. 824

825 Doran NE, Kiernan K, Swain R, Richardson AMM (1999) Hickmania troglodytes, the Tasmanian cave

826 spider, and its potential role in cave management. Journal of Insect Conservation 3:257-262.

827 doi:10.1023/A:1009677531343 828

829 Evans TA, Wallis EJ, Elgar MA (1995) Making a meal of mother. Nature 376(6538):299-299.

830 doi:10.1038/376299a0

831

832 Foelix RF (2011) Biology of Spiders (3rd ed.). Oxford University Press, New York.

833

834 Foellmer MW, Fairbairn DJ (2003) Spontaneous male death during copulation in an orb-weaving spider.

835 Proceedings of the Royal Society of London B: Biological Sciences 270(2):183-185.

836 doi:10.1098/rsbl.2003.0042

837

838 Foellmer MW, Moya-Laraño J (2007) Sexual size dimorphism in spiders: patterns and processes. In: Sex,

839 size and gender roles: Evolutionary studies of sexual size dimorphism. In: Fairbairn DJ,

840 Blanckenhorn WU, Szekely T, ed.). Oxford University Press, New York, 71–81.

841

842 Forster RR (1959) The spiders of the family Symphytognathidae. Transactions and Proceedings of the

843 Royal Society of New Zealand 86:269-329.

844

845 Forster RR, Platnick NI (1977) A review of the spider family Symphytognathidae (Arachnida, Araneae).

846 American Museum Novitates 2619:1-29.

847 848 Garrison NL, Rodriguez J, Agnarsson I, Coddington JA, Griswold CE, Hamilton CA, Hedin M, Kocot KM,

849 Ledford JM, Bond JE (2016) Spider phylogenomics: untangling the Spider Tree of Life. PeerJ

850 4:e1719. doi:10.7717/peerj.1719 851 852

853 Gaston KJ (1994) Rarity. Chapman and Hall, London.

854

855 Girard MB, Kasumovic MM, Elias DO (2011) Multi-codal courtship in the peacock ppider, Maratus volans

856 (O.P.-Cambridge, 1874). PLoS ONE 6(9):e25390. doi:10.1371/journal.pone.0025390

857

858 Glaw F, Köhler J, Townsend TM, Vences M (2012) Rivaling the world's smallest reptiles: Discovery of

859 miniaturized and microendemic new species of leaf chameleons (Brookesia) from northern

860 Madagascar. PLoS ONE 7(2):e31314. doi:10.1371/journal.pone.0031314

861

862 Gregorič M, Agnarsson I, Blackledge TA, Kuntner M (2011) How did the spider cross the river?

863 Behavioral adaptations for river-bridging webs in Caerostris darwini (Araneae: Araneidae). PLoS

864 ONE 6(10): e26847. doi:10.1371/journal.pone.0026847

865

866

867 Gressitt JL (1965) Biogeography and ecology of land arthropods of Antarctica. In: van Miegham J, van

868 Oye P, ed. Biology and ecology of Anarctica. Monographiae Biologicae 15. W. Holland, Junk, 431–

869 490.

870 871 Griswold CE, Audisio T, Ledford JM (2012) An extraordinary new family of spiders from caves in the

872 Pacific Northwest (Araneae, Trogloraptoridae, new family). ZooKeys 215:77-102.

873 doi:10.3897/zookeys.215.3547

874

875 Guinness World Records (2017a). Largest spider family. Online at:

876 http://www.guinnessworldrecords.com/world-records/largest-spider-family. Accessed: 8 June 2017

877

878 Guinness World Records (2017b). Largest spider. Online at:

879 http://www.guinnessworldrecords.com/world-records/largest-spider. Accessed: 8 June 2017

880

881 Guinness World Records (2017c). Most venomous spider. Online at:

882 http://www.guinnessworldrecords.com/world-records/most-venomous-spider. Accessed: 8 June 2017

883

884 Guinness World Records (2017d). Smallest spider. Online at:

885 http://www.guinnessworldrecords.com/world-records/smallest-spider. Accessed: 8 June 2017

886

887 Guinness World Records (2017e). Strongest spider web. Online at:

888 http://www.guinnessworldrecords.com/world-records/strongest-spider-web. Accessed: 8 June 2017

889

890 Guinness World Records (2017f). Largest cobwebs. Online at:

891 http://www.guinnessworldrecords.com/world-records/largest-cobwebs. Accessed: 8 June 2017

892

893 Guinness World Records (2017g). Longest cobwebs. Online at:

894 http://www.guinnessworldrecords.com/world-records/longest-cobwebs. Accessed: 8 June 2017 895

896 Guinness World Records (2017h). First spider web in space. Online at:

897 http://www.guinnessworldrecords.com/world-records/first-spider-web-in-space. Accessed: 8 June 2017

898

899 Guinness World Records (2017i). Oldest spider silk. Online at:

900 http://www.guinnessworldrecords.com/world-records/oldest-spider-silk. Accessed: 8 June 2017

901

902 Guinness World Records (2017j). Oldest spider gossamer. Online at:

903 http://www.guinnessworldrecords.com/world-records/oldest-spider-gossamer. Accessed: 8 June 2017

904

905 Guinness World Records (2017k). Oldest spider in amber. Online at:

906 http://www.guinnessworldrecords.com/world-records/oldest-spider-in-amber. Accessed: 8 June 2017

907

908 Guinness World Records (2017l). Oldest spider web with trapped prey. Online at:

909 http://www.guinnessworldrecords.com/world-records/oldest-spider-web-with-trapped-prey. Accessed: 8

910 June 2017

911

912 Guthold R, Cowan MJ, Autenrieth CS, Kann L, Riley LM (2010) Physical activity and sedentary behavior

913 among schoolchildren: a 34-country comparison. The Journal of pediatrics 157(1):43-49.

914 doi:10.1016/j.jpeds.2010.01.019

915

916 Gwynne DT (2008) Sexual conflict over nuptial gifts in insects. Annual Review of Entomology 53:83-101.

917 doi:10.1146/annurev.ento.53.103106.093423

918 919 Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U, Lancet Physical Activity Series

920 Working Group (2012) Global physical activity levels: surveillance progress, pitfalls, and prospects.

921 The Lancet 380(9838):247-257. doi:10.1016/S0140-6736(12)60646-1

922

923 Hayashi M, Bakkali M, Hyde A, Goodacre SL (2015) Sail or sink: novel behavioural adaptations on water

924 in aerially dispersing species. BMC evolutionary biology 15(1):118. doi:10.1186/s12862-015-0402-5

925

926 Higgins L (2002) Female gigantism in a New Guinea population of the spider Nephila maculata. Oikos

927 99(2):377-385. doi.10.1034/j.1600-0706.2002.990220 928

929 Hillyard PD (1994) The book of the spider: from arachnophobia to the love of spiders. Random House

930 Incorporated.

931

932 Hofmann SG, Alpers GW, Pauli P (2009) Phenomenology of panic disorder, social anxiety disorder, and

933 specific phobia. In: Antony MM, Stein MB, Ed. Oxford handbook of anxiety and related disorders.

934 Oxford University Press, New York, 34-46.

935

936 Isbister G, Gray M, Balit C, Raven R, Stokes B, Porges K, Turner E, White J, Fisher M (2005) Funnel-web

937 spider bite: a systematic review of recorded clinical cases. Medical journal of Australia 182(8):407-

938 411.

939

940 Itakura Y (1993) The life history and nuptial feeding of a nursery web spider, Pisaura lama.

941 Insectarium 30:88-93. 942 943 944 IUCN (2015) The IUCN Red List of Threatened Species (Version 2015-4). Online at: www.iucnredlist.org.

945 Accessed 14 May 2016

946

947 Jacobi F, Wittchen H-U, Hölting C, Höfler M, Pfister H, Müller N, Lieb R (2004) Prevalence, co-morbidity

948 and correlates of mental disorders in the general population: results from the German Health

949 Interview and Examination Survey (GHS). Psychological Medicine 34, 597−611.

950 doi:10.1017/S0033291703001399

951

952 Jäger P (2001) A new species of Heteropoda (Araneae: Sparassidae: Heteropodinae) from Laos — the

953 largest huntsman spider? Zoosystema 23:461-465.

954

955 Jäger P (2014) Cebrennus Simon, 1880 (Araneae: Sparassidae): a revisionary up-date with the

956 description of four new species and an updated identification key for all species. Zootaxa

957 3790(2):319-356. doi:10.11646/zootaxa.3790.2.4

958

959 Joseph G (1881) Erfahrgungen im wissenschaftlichen Sammeln und Beobachten der den Krainer

960 Tropfsteingrotten eigenen Arthropoden. Berliner Entomologische Zeitschrift 25:233-282.

961

962 Juberthie C (1985) Cycle vital de Telema tenella dans la Grotte-Laboratoire de Moulis et strategies de

963 reproduction chez les Araignees cavernicoles. Memoires de Biospéologie 12(7):77-89. 964

965 Khadjeh S, Turetzek N, Pechmann M, Schwager EE, Wimmer EA, Damen WG, Prpic NM (2012)

966 Divergent role of the Hox gene Antennapedia in spiders is responsible for the convergent evolution

967 of abdominal limb repression. Proceedings of the National Academy of Sciences 109(13):4921-

968 4926. doi:10.1073/pnas.1116421109 969

970 King RS (2013) BiLBIQ: a biologically inspired robot with walking and rolling locomotion. (2nd Volume).

971 Springer, Verlag, Berlin, Heidelberg. doi:10.1007/978-3-642-34682-8

972

973 Klug C, De Baets K, Kröger B, Bell MA, Korn D, Payne JL (2015) Normal giants? Temporal and latitudinal

974 shifts of Palaeozoic marine invertebrate gigantism and global change. Lethaia 48(2):267-288.

975 doi:10.1111/let.12104 976

977 Knight AJ (2008) “Bats, snakes and spiders, Oh my!” How aesthetic and negativistic attitudes, and other

978 concepts predict support for species protection. Journal of Environmental Psychology 28(1):94-103.

979 doi:10.1016/j.jenvp.2007.10.001

980

981 Knoflach B, Harten A (2001) Tidarren argo sp. nov. (Araneae: Theridiidae) and its exceptional copulatory

982 behaviour: emasculation, male palpal organ as a mating plug and sexual cannibalism. Journal of

983 Zoology 254(4):449-459. doi:10.1017/S0952836901000954

984

985 Kraus O (1999) Historic overview of past congressses of arachnology and of the Centre International de

986 Documentation Arachnologique (C.I.D.A.). Journal of Arachnology 27: 3-6.

987

988 Kuhn-Nentwig L, Stöcklin R, Nentwig W (2011) Venom composition and strategies in spiders: is

989 everything possible? Advances in Insect Physiology 40:1-86. doi:10.1016/B978-0-12-387668-

990 3.00001-5 991

992 Kundmann JC (1737) Rariora naturae et artis, item in re medica, oder Seltenheiten der Natur und Kunst

993 des Kundmannischen Naturalien Cabinets, wie auch in der Artzeney-Wissenschaft. Breslau &

994 Leipzig. 995

996 Kuntner M, Coddington JA (2009) Discovery of the largest orbweaving spider species: the evolution of

997 gigantism in Nephila. PLoS ONE 4(10):e7516. doi:10.1371/journal.pone.0007516

998

999 Kuntner M, Agnarsson I (2010). Web gigantism in Darwin's bark spider, a new species from Madagascar

1000 (Araneidae: Caerostris). Journal of Arachnology 38(2):346-356. doi:10.1636/B09-113.1

1001

1002 Kuntner M, Zhang S, Gregorič M, Li D (2012) Nephila female gigantism attained through post-maturity

1003 molting. Journal of Arachnology 40(3):345-347. doi:10.1636/B12-03.1

1004

1005 Lepore E, Marchioro A, Isaia M, Buehler MJ, Pugno NM (2012) Evidence of the most stretchable egg sac

1006 silk stalk, of the European Spider of the Year Meta menardi. PLoS ONE 7(2):e30500.

1007 doi:10.1371/journal.pone.0030500

1008

1009 Li SQ, Wunderlich J (2008) Sinopimoidae, a new spider family from China (Arachnida, Araneae). Acta

1010 Zootaxonomica Sinica 33:1-6.

1011

1012 Lipke E, Michalik P (2015) Evolutionary morphology of the male reproductive system and spermatozoa of

1013 goblin spiders (Oonopidae, Araneae). Bulletin of the American Museum of Natural History 906:1-

1014 72. doi:10.1206/906.1

1015

1016 Lubin Y & Bilde T (2007) The evolution of sociality in spiders. Advances in the Study of Behavior 37:83-

1017 145. doi:10.1016/S0065-3454(07)37003-4

1018 1019 Mammola S, Cavalcante R, Isaia M (2016) Ecological preference of the diving bell spider Argyroneta

1020 aquatica in a resurgence of the Po plain (Northern Italy) (Araneae: Cybaeidae). Fragmenta

1021 entomologica 48(1):9-16. doi:10.4081/fe.2016.158

1022

1023 Mammola S, Isaia M (2017) Spiders in caves. Proceedings of the Royal Society of London B: Biological

1024 Sciences 284:20170193. doi:10.1098/rspb.2017.0193

1025

1026 Marshall SD, Gittleman JL (1994) Clutch size in spiders: is more better? Functional Ecology 118-124.

1027 doi:10.2307/2390120

1028

1029 McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, Dove ADM, Gaskins LC, Helm RR,

1030 Hochberg FG, Lee FB, Marshall A, McMurray SE, Schanche C, Stone SN, Thaler AD. (2015) Sizing

1031 ocean giants: patterns of intraspecific size variation in marine megafauna. PeerJ 3:e715.

1032 doi:10.7717/peerj.715

1033

1034 Machell D (2005) First words. Make Believe Ideas, Hertz, UK

1035

1036 McQueen DJ, McLay CL (1983) How does the intertidal spider Desis marina (Hector) remain under water

1037 for such a long time? New Zealand journal of zoology 10(4):383-391.

1038 doi:10.1080/03014223.1983.10423933

1039

1040 Melic A (2002) De madre araña a demonio escorpión: Arácnidos en la mitología. Revista Iberica de

1041 Aracnologia 5:112-124.

1042 1043 Menin M, de Jesus Rodrigues D, de Azevedo CS (2005) Predation on amphibians by spiders (Arachnida,

1044 Araneae) in the Neotropical region. Phyllomedusa: Journal of Herpetology 4(1):39-47.

1045 doi:10.11606/issn.2316-9079.v4i1p39-47

1046

1047 Meehan CJ, Olson EJ, Reudink MW, Kyser TK, Curry RL (2009) Herbivory in a spider through

1048 exploitation of an ant–plant mutualism. Current Biology 19(19):892-893.

1049 doi:10.1016/j.cub.2009.08.049

1050

1051 Molur S, Daniel BA, Siliwal M (2008) Poecilotheria metallica. The IUCN Red List of Threatened Species

1052 2008:e.T63563A12681959. doi:10.2305/IUCN.UK.2008.RLTS.T63563A12681959.en. 1053

1054 Mulkens SA, de Jong PJ, Merckelbach H (1996) Disgust and spider phobia. Journal of abnormal

1055 psychology 105(3):464-468. doi:10.1037/0021-843X.105.3.464

1056

1057 Nentwig W, Kuhn-Nentwig L (2013a). Main components of spider venoms. In: Nentwig W, ed. Spider

1058 ecophysiology. Springer, Berlin, 191-202. 1059

1060 Nentwig W, Kuhn-Nentwig L (2013b). Spider venoms potentially lethal to humans. n: Nentwig W, ed..

1061 Spider ecophysiology. Springer, Berlin, 253-264. 1062

1063 Nyffeler M, Knörnschild M (2013) Bat predation by spiders. PLoS ONE 8(3):e58120.

1064 doi:10.1371/journal.pone.0058120

1065

1066 Nyffeler M, Pusey BJ (2014) Fish predation by semi-aquatic spiders: a global pattern. PLoS ONE

1067 9(6):e99459. doi:10.1371/journal.pone.0099459

1068 1069 Nyffeler M, Birkhofer K (2017) An estimated 400–800 million tons of prey are annually killed by the global

1070 spider community. The Science of Nature 104(3-4):30. doi:10.1007/s00114-017-1440-1

1071

1072 Nyffeler M, Olson EJ, Symondson WO (2016) Plant-eating by spiders. Journal of Arachnology 44(1):15-

1073 27. doi:10.1636/P15-45.1

1074

1075 Paquin P, Vink CJ, Dupérré N (2010) Spiders of New Zealand: Annotated Family Key & Species.

1076 Manaaki Whenua Press. 1077

1078 Peñalver E, Grimaldi DA, Delclòs X (2006) Early Cretaceous spider web with its prey. Science

1079 312(5781):1761-1761. doi:10.1126/science.1126628

1080

1081 Penney D, Selden PA (2002) The oldest linyphiid spider, in lower Cretaceous Lebanese amber (Araneae,

1082 Linyphiidae, Linyphiinae). Journal of Arachnology 30(3):487-493.

1083

1084 Platnick NI (1989) Advances in Spider Taxonomy 1981-1987: a supplement to Brignoli's A Catalogue of

1085 the Araneae described between 1940 and 1981. Manchester University Press.

1086

1087 Platnick NI (1993) Advances in spider taxonomy 1988-1991, with synonymies and transfers 1940-1980.

1088 The New York Entomological Society, New York.

1089

1090 Platnick NI (1998) Advances in spider taxonomy 1992-1995 with redescriptions 1940-1980. New York

1091 Entomological Society, New York.

1092 1093 Platnick NI (2000–2014) Archive of the World Spider Catalog by Norman I. Platnick. American Museum of

1094 Natural History. Online at: http://www.wsc.nmbe.ch/archive/. Accessed: 09 Jan 2017. 1095

1096 Priddy R, (2004) My Little Word Book. St Martin's press, New York.

1097

1098 Prokop P, Maxwell MR (2012) Gift carrying in the spider Pisaura mirabilis: nuptial gift contents in nature

1099 and effects on male running speed and fighting success. Animal Behaviour 83(6):1395-1399.

1100 doi:10.1016/j.anbehav.2012.03.007 1101

1102 Ray N (2002) Lonely Planet Cambodia. Lonely Planet Publications. 1103

1104 Rinck M, Becker ES (2007) Approach and avoidance in fear of spiders. Journal of behavior therapy and

1105 experimental psychiatry 38(2):105-120. doi:10.1007/s10826-010-9402-7 1106

1107 Robinson MH, Robinson B (1976) The ecology and behavior of Nephila maculata: a supplement.

1108 Smithsonian Institution Press.

1109

1110 Roewer CF (1942). Katalog der Araneae von 1758 bis 1940. Bremen 1:1-1040. 1111

1112 Roewer CF (1955). Katalog der Araneae von 1758 bis 1940, bzw. 1954. Bruxelles 2:1-1751.

1113

1114 Sanggaard KW, Bechsgaard JS, Fang X, Duan J, Dyrlund TF, Gupta V, Jiang X, Cheng L, Fan D, Feng

1115 Y, Han L, Huang Z, Wu Z, Liao L, Settepani V, Thøgersen IB, Vanthournout B, Wang T, Zhu Y,

1116 Funch P, Enghild JJ, Schauser L, Andersen SU, Villesen P, Schierup MH, Bilde T, Wang J (2014)

1117 Spider genomes provide insight into composition and evolution of venom and silk. Nature

1118 communications 5:3765. doi:10.1038/ncomms4765 1119

1120 Schaefer L, Plotnikoff RC, Majumdar SR, Mollard R, Woo M, Sadman R, Rinaldi RL, Boulé N, Torrance B,

1121 Ball GD, Veugelers P, Wozny P, McCargar L, Downs S, Lewanczuk R, Gleddie D, McGavock J

1122 (2014) Outdoor time is associated with physical activity, sedentary time, and cardiorespiratory

1123 fitness in youth. The Journal of pediatrics,165(3), 516-521. doi:10.1016/j.jpeds.2014.05.029

1124

1125 Schiödte JC (1847) Forelöbig Beretning om Untersögelser om den underjordiske Fauna i Hulerme i Krain

1126 og Istrien. Oversigt over det Kongelige Danske Videnskabernes Selskabs Forhandlinger 1847:75-

1127 81. 1128

1129 Schmitt WJ, Müri RM (2009) Neurobiologie der Spinnenphobie. Schweizer Archiv für Neurologie

1130 160(8):352–355.

1131

1132 Schneider JM (1996) Differential mortality and relative maternal investment in different life stages in

1133 Stegodyphus lineatus (Araneae, Eresidae). Journal of Arachnology 24(2):148-154

1134

1135 Schultz SA, Schultz, MJ (1998) The Tarantula Keeper's Guide. Barron's Educational Series, ISBN

1136 0764100769.

1137

1138 Schütz D, Taborsky M (2003) Adaptations to an aquatic life may be responsible for the reversed sexual

1139 size dimorphism in the water spider, Argyroneta aquatica. Evolutionary Ecology Research 5:105-

1140 117.

1141 1142 Schütz D, Taborsky M (2005). Mate choice and sexual conflict in the size dimorphic water spider

1143 Argyroneta aquatica (Araneae, Argyronetidae). Journal of Arachnology 33: 767–775.

1144 doi:10.1636/S03-56.1

1145

1146 Schwartz SK, Wagner WE, Hebets EA (2013) Spontaneous male death and monogyny in the dark fishing

1147 spider. Biology letters 9(4):20130113. doi:10.1098/rsbl.2013.0113

1148

1149 Schwartz SK, Wagner WE, Hebets EA (2016) Males can benefit from sexual cannibalism facilitated by

1150 self-sacrifice. Current Biology 26(20):2794-2799. doi:10.1016/j.cub.2016.08.010

1151

1152 Schwenckfeld C (1603) Therio-trophium Silesiae, in quo Animalium, hoc est, Quadrupedum, Reptilium,

1153 Avium, Piscium, Insectorum natura, vis et usus sex libris perstringuntur. Alberti, Lignicii.

1154

1155 Selden PA (1996) First fossil mesothele spider, from the Carboniferous of France. Revue Suisse de

1156 Zoologie 2:585–596.

1157

1158 Selden PA, Penney D (2010) Fossil spiders. Biological Reviews 85(1):171-206. doi:10.1111/j.1469-

1159 185X.2009.00099

1160

1161 Selden PA, Shih C, Ren D (2011) A golden orb-weaver spider (Araneae: Nephilidae: Nephila) from the

1162 Middle Jurassic of China. Biology letters 7(5):775-778. doi:10.1098/rsbl.2011.0228

1163

1164 Selden PA, Shih C, Ren D (2013). A giant spider from the Jurassic of China reveals greater diversity of

1165 the orbicularian stem group. Naturwissenschaften 100(12):1171-1181. doi:10.1007/s00114-013-

1166 1121-7 1167

1168 Sendra A, Reboleira ASPS (2012) The world deepest subterranean community – Krubera-Voronja Cave

1169 (Western Caucasus). International Journal of Speleology 41(2):221-230. doi:10.10070.5038/1827-

1170 806X.41.2.9

1171

1172 Seymour RS, Hetz SK (2011) The diving bell and the spider: the physical gill of Argyroneta aquatica.

1173 Journal of Experimental Biology 214: 2175-2181. doi:10.1242/jeb.056093 1174

1175 Smithers P. & Whitehouse A. (2016) Nothophantes horridus, Possibly the Rarest Spider in the World; a

1176 brief history. Newsl. Br. arachnol. Soc., 135: 4-5.

1177

1178 Smith-Janik S, Teachman BA (2008) Impact of priming on explicit memory in spider fear. Cognitive

1179 Therapy and Research 32:291-302.

1180

1181 Stafstrom JA, Hebets EA (2016) Nocturnal foraging enhanced by enlarged secondary eyes in a net-

1182 casting spider. Biology letters 12(5):20160152. doi:10.1098/rsbl.2016.0152

1183

1184 Suter RB (1999) Cheap transport for fishing spiders (Araneae, Pisauridae): the physics of sailing on the

1185 water surface. Journal of Arachnology 27:489-96. 1186

1187 Suter RB (2013) Spider locomotion on the water surface: biomechanics and diversity. Journal of

1188 Arachnology 41(2):93-101: doi:10.1636/M13-14 1189

1190 Tremblay MS, Gray CE, Akinroye K, Harrington DM, Katzmarzyk PT, Lambert EV, Liukkonen J, Maddison

1191 R, Ocansey RT, Onywera VO, Prista A, Reilly JJ, Rodríguez Martínez MP, Sarmiento Duenas OL, 1192 Standage M, Tomkinson G (2014) Physical activity of children: a global matrix of grades comparing

1193 15 countries. Journal of physical activity and health 11(1):113-125. doi:10.1123/jpah.2014-0177

1194

1195 Turnbull AL (1973) Ecology of the true spiders (Araneomorphae). Annual Review of Entomology 18: 305-

1196 348. doi:10.1146/annurev.en.18.010173.001513 1197

1198 United Nations (2014) World Urbanization Prospects: The 2014 Revision, Highlights (ST/ESA/SER.A/352)

1199

1200 Van Hasselt AWM (1884). Waarnemingen omtrent anomaliën van de geslachtsdrift bij spinnen-mares.

1201 Tijdschrift voor Entomologie 27:197-206.

1202

1203 Vetter RS, Isbister GK (2008) Medical aspects of spider bites. Annual Review of Entomology 53, 409-429.

1204 doi:10.1146/annurev.ento.53.103106.093503

1205

1206 Vollrath F (1987) Kleptobiosis in spiders. In: Nentwig W, ed. Ecophysiology of Spiders Nentwig Springer-

1207 Verlag, Berlin, 274-286.

1208

1209 Wanless FR (1975) Spiders of the family Salticidae from the upper slopes of Everest and Makalu. Bulletin

1210 of the British Arachnological Society 3:132-136.

1211

1212 Watson W, Walker HJ (2004). The world's smallest vertebrate, Schindleria brevipinguis, a new

1213 paedomorphic species in the family Schindleriidae (Perciformes: Gobioidei). Records of the

1214 Australian Museum 56(2):139-142. doi: 10.3853/j.0067-1975.56.2004.1429

1215 1216 Weng JL, Barrantes G, Eberhard WG (2006) Feeding by Philoponella vicina (Araneae, Uloboridae) and

1217 how uloborid spiders lost their venom glands. Canadian Journal of Zoology 84:1752–1762.

1218 doi:10.1007:10.1139/Z06-149 1219

1220 Wheeler WH, Coddington JA, Crowley LM, Dimitrov D, Goloboff PA, Griswold CE, Hormiga G, Prendini L,

1221 Ramírez MJ, Sierwald P, Almeida-Silva LM, Álvarez-Padilla F, Arnedo MA, Benavides Silva LR,

1222 Benjamin SP, Bond JE, Grismado CJ, Hasan E, Hedin M, Izquierdo MA, Labarque FM, Ledford J,

1223 Lopardo L, Maddison WP, Miller JA, Piacentini LN, Platnick NI, Polotow D, Silva-Dávila D, Scharff

1224 N, Szűts T, Ubick D, Vink CJ, Wood HM, Zhang JX (2017) The spider tree of life: phylogeny of

1225 Araneae based on target-gene analyses from an extensive taxon sampling. Cladistics.

1226 doi:10.1111/cla.12182 upload pdf 1227

1228 White J (2000) Bites and stings from venomous animals: a global overview. Therapeutic drug monitoring

1229 22(1):65-68. doi:10.1097/00007691-200002000-00014

1230

1231 Whitehouse MEA & Lubin Y (2005) The functions of societies and the evolution of group living: Spider

1232 societies as a test case. Biological Reviews 80:1–15. doi:10.1017/S1464793104006694

1233

1234 Wilson JB, Peet RK, Dengler J, Pärtel M (2012) Plant species richness: the world records. Journal of

1235 vegetation Science 23(4):796-802. doi:10.1111/j.1654-1103.2012.01400

1236

1237 Witt PN, Scarboro MB, Daniels R, Peakall DB, Gause RL (1976) Spider web-building in outer space:

1238 evaluation of records from the Skylab spider experiment. Journal of Arachnology 4:115-124.

1239 1240 Wood HM, Parkinson DY, Griswold CE, Gillespie RG, Elias DO (2016) Repeated evolution of power- 1241 amplified predatory strikes in trap-jaw spiders. Current Biology 26(8):1057-1061. 1242 doi:10.1016/j.cub.2016.02.029 1243

1244 Woody SR, McLean C, Klassen T (2005) Disgust as a motivator of avoidance of spiders. Journal of

1245 anxiety disorders 19(4):461-475. doi:10.1016/j.janxdis.2004.04.002

1246

1247 World Spider Catalog (2017). World Spider Catalog (Version 17.5). Natural History Museum Bern. Online

1248 at: http://wsc.nmbe.ch. Accessed: 09 Jan 2017

1249

1250 World spider Catalog Archive (2014–2017) Archive of the World Spider Catalog. Museum of Natural

1251 History Bern. Online at http://wsc.nmbe.ch/archive. Accessed: 09 Jan 2017

1252

1253 Yeargan KV (1994) Biology of Bolas Spiders. Annual Review of Entomology 39:81-99.

1254 doi:10.1146/annurev.en.39.010194.000501

1255 Figure 1(on next page)

General anatomy of a spider and variation in body forms.

Dorsal view of a spider showing its general organization and variation in its appearance exemplified by few representative of the 113 known spider families. THERIIDIIDAE PHOLCIDAE

THOMISIDAE ARANEIDAE

Leg I

Chelicerae

Leg II

Pedipalp

Eyes Prosoma (Cephalothorax) Pedicel Opisthosoma Leg III (Abdomen)

Leg IV

Spinneret SPARASSIDAE SALTICIDAE

THERAPHOSIDAE ATYPIDAE Figure 2(on next page)

Taxonomy, arachnology and arachnologists. a) Original illustrations of some of the first spiders described in binomial nomenclature (Modified from Clerck, 1757); b) Eugène Louis Simon (1848–1924), the most prolific arachnologist in history (Photo credit: en.wikipedia.org); c) The first Congress of Arachnology in history at the University of Bonn (Germany) in 1960 (Modified from Kraus, 1999); d) The largest congress of Arachnology (2–9 July 2016, Golden, Colorado, USA) (Photo credit: Congress Organizing committee). c

a b d Figure 3(on next page)

Morphology and physiology. a) The Goliath bird-eater, Theraphosa blondi (Theraphosidae), the largest known spider by mass (Photo credit: Steve Le Roux); b) Heteropoda maxima (Sparassidae), the largest known spider by leg span, in its typical ambushing position (Photo credit: Peter Jäger); c) The enlarged posterior median eyes of a net-casting spider ( Deinopis sp., Deinopidae) viewed under ultraviolet light (Photo credit: Nicky Bay) d) Stalita taenaria (Dysderidae), the first eyeless spider ever described (Photo credit: Fulvio Gasparo); e) The Darwin's bark spider, Caerostris darwini (Araneidae), produces the toughest known spider silk (Photo credit: Matjaz

Kunter); f) The web of the Darwin's bark spider can reach an area of 2.8 m 2 , being therefore the largest orb web ever measured (Photo credit: Matjaz Kunter); g) Golden orb weaving spiders (Nephilidae) exemplify the most extreme male-biased sexual size dimorphism in spiders. The white arrow points at the male (Photo credit: Matjaz Kunter). a ab

ac

ad f ag

♂

ae Figure 4(on next page)

Ecology and behavior. a) A ballooning spider—numerous spiders can disperse through the air by releasing one silk threads to catch the wind (Photo credit: Pieceoflace photography); b) A fishing spider, Dolomedes spp. (Pisauridae), capable of effective locomotion on the surface of water (Photo credit: Olaf Craasmann); c) A male and female of the one-palped spider Tidarren argo (Theridiidae) during the copula: in this species, the male dies almost immediately after the insertion of his copulatory organ and is usually cannibalized by the female afterwards (Photo credit: Barbara Knoflach-Thaler); d) A cave-dwelling spider of the genus Troglohyphantes. In some species, a protracted mating lasting >18 hours was observed (Photo credit: Francesco

Tommasinelli); e) A male of Maratus elephans (Salticidae) performing its courtship display (Photo credit: Adam Fletcher); f) The water spider, Argyroneta aquatica (Cybaeidae), the only known spiders living a wholly aquatic life (Photo credit: Riccardo Cavalcante); g) Bagheera kiplingi (Salticidae), the only known spider with a mostly herbivorous diet—it predominantly consumes specialized leaf tips of Acacia (Photo credit: Maximilian Paradiz); h) A kleptoparasitic spider (Theridiidae: cf. Neospintharus sp.; arrow) dwelling in the web of a Northern Black Widow, Latrodectus variolus (Theridiidae) (Photo credit: Patrick Coin). a b

♂

♀ c d

e f

g h