Herpetology Notes, volume 8: 329-330 (2015) (published online on 16 June 2015)

Predation on the tropical bullfrog marmorata (Anura: ) by the wandering Ctenus ornatus (Araneae: Ctenidae) in southeastern

Lucas Coutinho Amaral¹,*, Pedro de Souza Castanheira², Sergio Potsch de Carvalho-e-Silva¹ and Renner Luiz Cerqueira Baptista²

Anurans are common preys to some species of tiny middle eyes and two large posterior eyes (Jocqué (Menin et al., 2005). Not only adults (e.g., Barej et al., and Dippenaar-Schoeman, 2006). Ctenids are nocturnal 2005), but also tadpoles are preyed on by spiders (e.g., hunters, running mainly on the leaf litter. They use mainly Folly et al., 2014a; Luiz et al., 2013). The species vibration and visual contact to locate prey, catching and Adenomera marmorata Steindachner, 1867, occurs in killing them with their powerful poison, delivered by the the Atlantic Rain Forest in southeastern Brazil, from fangs of their strong chelicerae (Jocqué and Dippenaar- Rio de Janeiro to Santa Catarina states (Frost, 2015), Schoeman, 2006). Ctenus ornatus (Keyserling, 1877) is and is one of the most abundant species in a large and very common ground spider in the Atlantic the leaf-litter (Heyer et al., 1990; Rocha et al., 2007). It Forest, distributed from Pernambuco state, in Northeast, is mostly a nocturnal frog, but males can also be heard to Goiás state, in the West, both in Brazil, to Misiones, at anytime of the day during rainy days (Izecksohn and Argentina (Brescovit and Simó, 2007). Carvalho-e-Silva, 2001). Males call from chambers The following event was observed during a dug in the ground, where the females lay their eggs herpetological field work at approximately 07:30 pm embedded in foam nests (Izecksohn and Carvalho-e- on 10 August, 2014, at the Centro Marista São José Silva, 2001). The spider family Ctenidae is the only das Paineiras, Mendes municipality, Rio de Janeiro known Brazilian family including State, southeastern Brazil (22°30’48’’S, 43°45’14’’W). members that can harm humans, with a large number of The Centro Marista São José das Paineiras is located medically important bites in Brazil each year (Martins in a relatively well-preserved area, mostly covered by and Bertani, 2007). They can be easily identified by a secondary forest. Its anuran fauna is currently under longitudinal groove on the rear of their carapace and study and has shown to be quite diverse (Folly et al., by the eye formula 4-2-2, with four frontal eyes, two 2014b). While searching the leaf-litter, an adult female of Ctenus ornatus was seen jumping onto an adult A. marmorata, and quickly biting the frog’s dorsum with its chelicerae. The spider soon let the motionless A. marmorata loose, but stayed at approximately 5 cm from its prey until we collected both specimens. The frog died ¹ Laboratório de Anfíbios e Répteis (LAR), Universidade on the way back to Centro Marista headquarters. Both Federal do Rio de Janeiro, Centro de Ciências da Saúde, specimens were collected and deposited as vouchers. Instituto de Biologia, A1-111, Ilha do Fundão, CEP 21941- The spider (prosoma 5.52 mm long; 4.0 mm wide) is 590, Rio de Janeiro/RJ, Brazil housed in the Laboratório de Diversidade de Aracnídeos, ² Laboratório de Diversidade de Aracnídeos (LABAR), Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio Janeiro, Instituto de Biologia, A1-097, Ilha do Fundão, CEP 21941-590, Rio de Janeiro/RJ, Universidade Federal do Rio de Janeiro (UFRJ 0949), Brazil. and the frog (snout-vent length 18.87 mm) is housed in * Corresponding author: [email protected] the Amphibian Collection of Departamento de Zoologia, 330 Lucas Coutinho Amaral et al.

Instituto de Biologia, Universidade Federal do Rio de Jocqué, R., Dippenaar-Schoeman, A.S. (2006): Spider Families Janeiro (ZUFRJ 14937). of the World. Tervuren, Belgium. Musée Royal de l’Afrique Predation of Adenomera marmorata by Ctenus Centrale Press. Luiz, A.M., Pires, T.A., Dimitrov, V., Sawaya, R.J. (2013): medius Keyserling, 1891 was previously reported by Predation on tadpole of Itapotihyla langsdorffii (Anura: Hylidae) Barbo et al. (2009). Despite being the only report of by the semi-aquatic spider Thaumasia sp. (Araneae: Pisauridae) Ctenus species preying on A. marmorata, the authors in the Atlantic Forest, southeastern Brazil. Herpetology Notes have suggested that this behavior was presumably more 6: 451–452. frequent. Our report of another Ctenus species preying Martins, R., Bertani, R. (2007): The non-Amazonian species of on the same anuran species supports their suggestion. the Brazilian wandering spiders of the Perty, The form of attack was similar to the one described 1833 (Araneae: Ctenidae), with the description of a new species. Zootaxa 1526: 1–33. before (Barbo et al., 2009), differing only regarding Menin, M., Rodrigues, D.J., Azevedo, C.S. (2005): Predation on the distance of the spider from the prey. As both by spiders (Arachnida, Araneae) in the Neotropical Ctenus species and the frog A. marmorata are common region. Phyllomedusa 4(1): 39–47. nocturnal in the Atlantic forest, often sharing Rocha, C.F.D., Vrcibradic, D., Kiefer, M.C., Almeida-Gomes, M., the same , predation might be common, albeit Borges-Junior, V.N.T., Siqueira, C.C., Goyannes-Araújo, P., not usually recorded. Knowledge of trophic relations is Fernandes, C.G.A., Rubião, E.C.N., Van Sluys, M. (2007): A an important key to understanding species’ interactions survey of the leaf-litter frog assembly from an Atlantic forest area (Reserva Ecológica de Guapiaçu) in Rio de Janeiro State, with its surroundings. Records of predation in nature are Brazil, with an estimate of frog densities. Tropical Zoology. 20: rare and can be helpful for behavioral and community 99–108. ecology in addition to other studies.

References

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