Herpetology Notes, volume 10: 647-650 (2017) (published online on 10 November 2017)

Predation of the snake Tantilla melanocephala (Squamata: Colubridae) by the spider Latrodectus geometricus (Araneae: Theridiidae) in Central Brazil

Clarisse R. Rocha1,*, Paulo César Motta2, Alexandre S. Portella3, Marcus Saboya1 and Reuber Brandão1,3

There are several field observations of predation Brazil (Motta, 2014). This species is the largest theridiid on vertebrates by large or medium-sized cursorial spider in the Brazilian cerrado biome, with females spiders in the families Ctenidae, Lycosidae, Pisauridae, varying from 0.7–1.2 cm in length and possessing a Sparassidae, Theraphosidae, and Trechaleidae (e.g., beige to black brown globose abdomen (depending Menin et al., 2005; Maffei et al., 2010; Nyffeler on local luminosity; Motta, 2014). This species can be and Pusey, 2014). On the other hand, predation on identified easily by having characteristic dorsal spots vertebrates by orbicular web spiders (Nephilidae and and ventrally an orange or reddish hourglass mark, and Araneidae) seems to be less common (Nyffeler and also by its spiked egg sacs. Knörnschild, 2013), whereas predation by small spiders These spiders live in a small, cone-shaped silk using diffuse webs is apparently rare (Werger, 1978; retreat from which they build an irregular, framed web Garb et al., 2004). Herein we report the first record of (Benjamin and Zschokke, 2003). Generally at night, a brown widow spider, Latrodectus geometricus C.L. brown widows extrude diffuse threads impregnated Koch, 1841 (Theridiidae), preying on a neotropical with glue droplets at their terminal ends onto the snake Tantilla melanocephala (Linnaeus, 1758). substrate (Lamoral, 1968; Foelix, 2011). Prey animals Latrodectus geometricus is widespread in Africa and become glued to the threads at a touch and, while the Americas (mainly Central and South America) and trying to wrestle free, neighbouring trapping threads has been introduced to some others countries around are contacted and the prey becomes progressively more the world (Levi, 1959; Garb et al., 2004); it is generally entangled, capturing the prey (Levi, 1959; Garb et considered to be of little medical importance (Vetter al., 2004; Foelix, 2011). Latrodectus geometricus is a and Isbister, 2008; Almeida et al., 2009). The species generalist that can feed on a wide range of animals, but is commonly found in urban habitats around houses, it mainly consumes insects and other ground-dwelling buildings, gardens, and other anthropogenically- arthropods, including spiders, scorpions, and centipedes modified areas, such as agricultural plots (e.g., Lamoral, (Rossi and Godoy, 2005; Lira and Costa, 2014; Rosa et 1968; Anderson, 1972), but it also occurs in natural al., 2016). environments like cerrado (open savannah) in Central Tantilla melanocephala is a small (19–25 cm in total length) snake with a large range in the Neotropics, occurring from Guatemala to northern Argentina and Uruguay (Santos-Costa et al., 2006) and showing both 1 Centro de Estudos do Cerrado na Chapada dos Veadeiros, diurnal and nocturnal habits. This snake is found in Universidade de Brasília, Alto Paraíso, 73770-000 Goiás, many localities in the cerrado, but at low abundance Brazil (Marques and Puorto, 1998; França and Araújo, 2006; 2 Laboratório de Aracnídeos, Departamento de Zoologia, Braz and França, 2016). Tantilla melanocephala feeds Universidade de Brasília, Brasília, 70910-900 Distrito on centipedes (Myriapoda: Chilopoda), which are Federal, Brazil immobilized and killed, and ingested always beginning 3 Laboratório de Fauna e Unidades de Conservação, Departamento de Engenharia Florestal, Universidade de Brasília, Brasília, with the head (Marques and Puorto, 1998; Oliveira, 70910-900 Distrito Federal, Brazil 2016). These snakes commonly use soil debris, termite * Corresponding author e-mail: [email protected] mounds, or fallen logs as shelters in cerrado habitats 648 Clarisse R. Rocha et al.

ground (Fig. 1). The spider progressively enveloped the snake by its head and body, coiling it (Fig. 2). After three days, the spider discarded the snake, which was dried and covered by silk. The snake showed damaged tissues close to the cloaca, the place that spider was observed feeding on it. Remains of food prey (crickets, cockroaches, moths) were also observed in the same web. The specimens were collected and the Tantilla melanocephala was deposited in the herpetology collection, of the Universidade de Brasília, Brazil (accession number CHUNB 76031) and the Latrodectus geometricus was deposited in the arachnid collection at the same institution (accession number DZUB 8806). This predatory encounter could be considered a serendipitous and perhaps random event, but it deserves consideration because of the disproportionate size of predator (spider total length 11 mm) and prey (snake snout-vent length 152 mm, total length 192 mm), with the spider about 18 times smaller than the snake (Fig. 3). Although rare, vertebrate predation events by Latrodectus have been reported in the literature before (e.g., Werger, 1978; Wilson, 1991; Garb et al., 2004). However, there are many more informal reports of

Figure 1. Beginning of the predation process by a brown widow spider (Latrodectus geometricus) on a black-headed snake (Tantilla melanocephala) in Brazil.

and have relatively low fecundity, with a clutch size of 1–3 eggs (Marques and Puorto 1998; Santos-Costa et al., 2006). On 29 January 2017 we found an adult male Tantilla melanocephala entangled in the threads of a Latrodectus geometricus web, outside of a rural house, close to native cerrado vegetation, near Chapada dos Veadeiros National Park (Alto Paraíso de Goiás, Goiás State, Brazil). The spider’s shelter was located inside an isolated bathroom of the house, near the pipe leading to a sink, about 60 cm above ground level. When first Figure 2. A black-headed snake (Tantilla melanocephala) sighted, the dead snake was glued to threads attached entangled in the threads of a brown widow spider (Latrodectus to its posterior end and slightly suspended above the geometricus) web in Brazil. Predation of the snake Tantilla melanocephala by Latrodectus geometricus 649

Figure 3. Size comparison of predator (Tantilla melanocephala) and prey (Latrodectus geometricus).

vertebrate predation by black and brown widows, biogeography, and invasion history. Molecular Phylogenetics including predation on snakes, available on the Internet and Evolution 31: 1127–1142. (e.g., at http://www.spiderzrule.com/spidersnake.htm). Garb, J.E., Hayashi, C.Y. (2013): Molecular evolution of a- It is interesting to consider that, based on the potent Latrotoxin, the exceptionally potent vertebrate neurotoxin in black widow spider venom. Molecular Biology and Evolution neurotoxic and myotoxic effects of L. geometricus 30: 999–1014. toxin in vertebrates (Reyes-Lugo et al., 2009) and the Lamoral, B.H. (1968): On the nest and web structure of Latrodectus high toxicity of Latrodectus venom in general (Garb in South Africa, and some observations on body colouration and Hayashi, 2013), predation on vertebrates by black of L. geometricus (Araneae: Theridiidae). Annals of the Natal and brown widows is probably not uncommon. As a Museum 20: 1–14. consequence, local monitoring of the potential impact of Levi, H.W. (1959): The spider genus Latrodectus (Araneae, brown widow on native vertebrate fauna, as a result of Theridiidae). Transactions of the American Microscopical spider colonization in new habitats, should be relevant. Society 78: 7–43. Lira, A.F.A., Costa, A.A. (2014): First record of a brown widow spider Latrodectus geometricus Koch, 1841 (Araneae, Acknowledgements. We thank Walace Cavalcante for some Theridiidae) feeding [on a] scorpion (Scorpiones, Bothriuridae) photographs and logistic support. in a Brazilian Atlantic forest. Brazilian Journal of Biology 74: 1011–1011. References Maffei, F., Ubaid, F.K., Jim, J. (2010): Predation of herps by Almeida, R.A.M.B., Ferreira-Junior, R.S., Chaves, C.R., Barraviera, spiders (Araneae) in the Brazilian Cerrado. Herpetology Notes B. (2009): Envenomation caused by Latrodectus geometricus 3: 167–170. in São Paulo state, Brazil: a case report. Journal of Venomous Marques, O.A.V., Puorto, G. (1998): Feeding, reproduction Animals and Toxins including Tropical Diseases 15: 562–571. and growth in the crowned snake Tantilla melanocephala Anderson, M.P. (1972): Notes on the brown widow spider, (Colubridae), from southeastern Brazil. Amphibia-Reptilia 19: Latrodectus geometricus (Araneae: Theridiidae) in Brazil. The 311–318. Great Lakes Entomologist 5: 115–118. Menin, M., Rodrigues, D.J., Azevedo, C.S. (2005): Predation on Benjamin, S.P., Zschokke, S. (2003): Webs of theridiid spiders: amphibians by spiders (Arachnida, Araneae) in the Neotropical construction, structure and evolution. Biological Journal of the region. Phyllomedusa 4: 39–47. Linnean Society 78: 293–305. Motta, P. C. (2014): Aracnídeos do Cerrado. Rio de Janeiro, Brasil, Braz, V.S., França, F.G.R. (2016): Wild vertebrate roadkill in the Editora Technical Books. Chapada dos Veadeiros National Park, Central Brazil. Biota Nyffeler, M., Knörnschild, M. (2013): Bat predation by spiders. Neotropica 16: 1–11. PLOS ONE 8: e58120. Foelix, R.F. (2011): Biology of Spiders, Third Edition. New York, Nyffeler, M., Pusey, B.J. (2014): Fish predation by semi-aquatic USA, Oxford University Press. spiders: a global pattern. PLOS ONE 9: 1–21. França, F.G., Araújo, A.F. (2006): The conservation status of Oliveira, F.A. (2016): Variação geográfica na ecologia de Tantilla snakes in central Brazil. South American Journal of Herpetology melanocephala (Serpentes: Colubridae) em áreas de Caatinga 1: 25–36. e Floresta Atlântica no Nordeste na região Neotropical. Garb, J.E., Gonzáles, A., Gillespie, R.G. (2004): The black widow Unpublished M.Sc. Thesis, Programa de Pós-graduação em spider genus Latrodectus (Araneae: Theridiidae): phylogeny, Ecologia e Monitoramento Ambiental, João Pessoa, Brazil. 650 Clarisse R. Rocha et al.

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Accepted by Hinrich Kaiser