Gymnophiona (caecilians) is the least known Amphibia order, which can be related with the predominant fossoriality of most species (Nussbaum and Wilkinson, 1989; Gower and Wilkinson 2005). Typhlonectidae (Taylor, 1968) includes the semi-aquatic and aquatic caecilians of South America from five known genera (Wilkinson and Nussbaum, 2006; Wilkinson et al., 2011; Maciel, 2016): Atretochoana (Nussbaum & Wilkinson, 1995), Chthonerpeton (Peters, 1880), Nectocaecilia (Taylor, 1968), Potamotyphlus (Taylor, 1968) and Typhlonectes (Peters, 1880). The genus Chthonerpeton currently includes eight species, seven of which are present in Brazil (Napoli et al., 2015). Only one species of the genus, Chthonerpeton braestrupi (Taylor, 1968), is registered for the state of Rio de Janeiro (Dorigo et al., 2018), although the taxonomy of the Chthonerpeton from this region is still in review and might soon result in a new species (Maciel, 2016).

Erythrolamprus miliaris (Linnaeus, 1758) is a dipsadid snake widely distributed throughout South America, occurring in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela (Wallach et al., 2014; Nogueira et al., 2020). It is considered as a common species in southeastern

Brazil (Gans, 1964; Dixon, 1983). Presenting diurnal and nocturnal habits, it is a generalist species associated with humid environments (Marques et al., 2001). Its diet covers a wide variety of amphibians and fishes, although lizards, snakes and even a mammal have already been registered as prey for this species (Araujo, 1985; Marques and Souza, 1993; Palmuti et al., 2009; Vrcibradic et al., 2012; Batista et al., 2019). A recent overview by van den Burg (2020) shows that 77% of its diet is based primarily on amphibians, but a single record for Gymnophiona was found.

As individuals of the same species generally acquire similar resources to survive and reproduce, intraspecific competition may alter their reproductive success (Rinkevick and Loya, 1985; Begon et al., 2007). Although intraspecific interactions can occur indirectly, intraspecific competition usually occurs directly between individuals that defend territories (Begon et al., 2007). Predation of Chthonerpeton viviparum Parker & Wettstein, 1929 by E. miliaris has already been reported in the literature (Albolea, 1998; Chicarino et al., 1998; Marques and Sazima, 2004). However, here we include a novel prey species to the list (van den Burg, 2020) and report the first intraspecific competition event of two individuals of E. miliaris for one individual of Chthonerpeton aff. braestrupi.

On 20 December 2019, we found two Erythrolamprus miliaris simultaneously preying on a single caecilian while performing fieldwork in a Restinga area, in the Reserva Particular do Patrimônio Natural (RPPN) Caruara, in the municipality of São João da Barra, Rio de Janeiro State, Brazil. The snakes were located in a puddle on a dirt road at the edge of a flooded area, while disputing and trying to swallow the prey from opposite ends (Fig. 1). The dispute generated lacerations in the caecilian which exposed eggs in its final third of the body, allowing to determine the individual as a female. We observed the event for five minutes, until

Herpetology Notes, volume 14: 945-947 (2021) (published online on 29 June 2021)

“Lady and the Tramp”: Chthonerpeton aff. braestrupi (Gymnophiona: Typhlonectidae) as prey of two Erythrolamprus miliaris (Serpentes: Dipsadidae)

Letícia Leitão-Martins*,¹, Lucas Rosado Mendonça², Carlos Henrique De-Oliveira-Nogueira³, Hender Lélis Rezende Maciel¹, and Leonardo Serafim da Silveira¹

¹ Núcleo de Estudos e Pesquisas em Animais Selvagens, Laboratório de Morfologia e Patologia Animal, Universidade Estadual do Norte Fluminense, Av. Alberto Lamego, 2000, 28013-602 Campos dos Goytacazes, Rio de Janeiro, Brazil.

2 Departamento de Biologia, Programa de Pós-graduação em Zoologia, Av. Gen. Rodrigo Otávio Jordão Ramos 6200, 69080-900 Manaus, Amazonas, Brazil. ³ Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Cidade Universitária, 79002-970 Campo Grande, Mato Grosso do Sul, Brazil.

* Corresponding author. E-mail: leticia.leitao97@gmail.com

© 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0.

Letícia Leitão-Martins et al.946

the moment when one of the snakes halted its predation attempt. Both snakes were collected, with the caecilian still in the mouth of one of the snakes, which eventually was released in the collection bag. All individuals were deposited in the herpetological collection of the Núcleo de Estudos e Pesquisas em Animais Selvagens (NEPAS) of the Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF) under the vouchers: HNF 850: E. miliaris, male, snout-vent length (SVL) = 59.8 cm; HNF 851: E. miliaris, female, SVL = 66.3 cm; HNF 849: C. aff. braestrupi, female, SVL = 32.4 cm. After sexing both snakes, we found that it was the male that first released the caecilian. The caecilian was identified by the Gymnophiona specialist Adriano Maciel based on the number of primary annuli and the position of the tentacles.

Predation records of Chthonerpeton aff. braestrupi are rare. The species is preyed upon by the coral snake Micrurus corallinus (Merrem, 1820) (Gonzales et al., 2018). Since Erythrolamprus miliaris has a generalist diet and is known to prey Chthonerpeton viviparum Parker & Wettstein, 1929, (Albolea, 1998; Chicarino et

al., 1998; Marques and Sazima 2004), our record is not surprising. However, we highlight the dispute between two individuals of the same species and of different sexes over a poorly studied species. Intraspecific competition events might be difficult to observe in fieldwork, but it has been registered for some snakes (Himes 2003; Flores et al., 2010; Escalona, 2012), and might indicate a shortage of resources in the region (Begon et al., 2007). Such competition can drive ecological variations, forcing them to seek new resources, acquire greater sexual dimorphism, or even provoke speciation (Bolnick 2004; Svanback and Bolnick, 2006).

This record expands our knowledge on natural history and trophic relationships of Erythtrolamprus miliaris and Chthonerpeton aff. braestrupi; on the other hand, it highlights the scarcity of basic ecological data for neotropical caecilians.

Acknowledgement. We thank the project “Herpetofauna do Norte Fluminense” (ICMBio/SISBIO capture permit # 72011-1) for allowing the fieldwork. We are grateful to Adriano Maciel for helping us with the identification of the caecilian and suggestions for the improvement of the manuscript. We would like to thank

Figure 1. Predation attempt of two Erythrolamprus miliaris individuals (arrows) on a single Chthonerpeton aff. braestrupi in the RPPN Fazenda Caruara, São João da Barra, Rio de Janeiro State, Brazil. Photo by Carlos Henrique de Oliveira Nogueira.

the managers of RPPN Fazenda Caruara for their authorisation and support for conducting research in the area.

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Chthonerpeton aff. braestrupi as prey of two Erythrolamprus miliaris 947

Accepted by Renato C. Nali