Herpetology Notes, volume 12: 1197-1200 (2019) (published online on 08 December 2019)

Cases of melanism in indica indica Laurenti, 1768 (Serpentes: Dipsadidae: Dipsadini) in northern and northeastern Brazil

Renato Augusto Martins1,*, Ingrid Scheeffer2, Luiz Carlos Batista Turci3, Reginaldo Assêncio Machado3, and Paulo Sérgio Bernarde3

Melanism is the term used to define a congenital individual from predation due to the camouflage increase of melanin in the skin, fur, feathers and scales that the dark colour gives to the , (2) assisting caused by homozygosis in a Mendelian recessive the thermoregulation process, giving the individual gene (Trullas et al., 2007). This feature is known to be greater speed in reaching the ideal temperature, and, associated with the physiology and behaviour of some consequently (3) reaching the ideal metabolic levels. organisms (Roulin and Ducrest, 2011). In , the In addition, it is important to note that, in order to deeper layer of epithelial cells is responsible to produce achieve the optimal temperature and to reach the ideal melanin, and darker skin tones come from the deposition metabolic levels, it also protects the sensitive regions of this pigment by these cells. Among the genes acting of the body from excessive radiation, and changes on phenotypic expression, is the MC1R or MSH-R gene some intraspecific interactions during reproductive (Melanocyte Stimulating Hormone Receptor), which communication (see Andrén and Nilson, 1981, Clusella- has a relation with melanin production in melanocytes Trullas et al., 2007). and which is involved in the expression of phenotypic The Dipsas, currently comprises 14 melanic and non-melanic forms of several vertebrates, widely distributed throughout Brazil, but the populations such as mammals, birds and reptiles (Rosenblum et al., of D. indica can be observed in the northern region of 2004). the Amazon forest, in parts of the Atlantic Forest, and The environmental factor of melanism is considered Cerrado of the Northeast, Midwest and Southeastern of fundamental importance for individuals in nature, Brazil (Freitas, 2015, Costa and Bérnils, 2018, Arteaga since it represents a possible advantage or disadvantage et al., 2018). Known as the golden-drop , it can in certain situations (Matthews et al., 2016). Especially reach the maximum length of approximately 710 mm in the case of reptiles, melanism may have several to the males and 1030 mm to the females (Duellman, important functions, among them: (1) protecting the 1978, Dixon and Soini, 1986). It has large eyes with a vertical pupil and presents a different head colour from the body colour, with a greyish brown head with dark brown spots and bordered of white on the internal, prefrontal, parietal, frontal and supralabial shields. The 1 Programa de Pós-Graduação em Conservação de Fauna, back of the body is brown with wider greyish spots Universidade Federal de São Carlos - UFSCar, Centro de Ciências Biológicas e da Saúde, Rodovia Washington Luiz, towards the vertebral line. Each dorsal spot has a small km 235, Jardim Guanabara, São Carlos, São Paulo State, spot of a light colour, ventrally, in the base (Figure 1a; 13565905, Brazil. Argôlo, 2004). Juvenile individuals often have patterns 2 Programa de Pós-Graduação em Perícia Ambiental, Serviço with a greyish head and body, or brownish body patterns Nacional de Aprendizagem Comercial – SENAC, Campus with dark brown spots e.g. as reported by Martins & Jabaquara, Avenida do Café, 298, Jabaquara, São Paulo, São Oliveira (1998), and registered during this study in Paulo State, 04311000, Brazil. the Amazonian region, in Alto Alegre dos Parecis, 3 Laboratório de Herpetologia, Centro Multidisciplinar, Campus Floresta, Universidade Federal do Acre, Cruzeiro do Sul, Rondônia (Figure 1b and 1c). Herein, we report three Acre State, 69980000, Brazil. cases of melanism in indica Laurenti, * Corresponding author. E-mail: [email protected] 1768, in northern and northeastern Brazil. 1198 Renato Augusto Martins et al.

Figure 1. Colour in living specimens of Dipsas i. indica. Normal coloration at Teixeira de Freitas, Bahia (A), and Alto Alegre dos Parecis, Rondônia (B and C); melanic coloration in Teixeira de Freitas, Bahia (D); Porto Velho, Rondônia (E); Reserva Extrativista Riozinho da Liberdade, Acre (F). Photos by Renato A. Martins (A and D), Luiz C. B. Turci (B, C and E), and Paulo S. Bernarde (F).

(1) On 28 April 2015 at 16:00h, a melanic specimen of same place. It was juvenile with a total length of Dipsas indica indica (Figure 1d) was recorded by approximately 200 mm and was entirely black an active search in a fragment of Atlantic Forest colored, with the gular region and the first third of located in the municipality of Teixeira de Freitas, the body with small gray spots. Bahia (UTM 24K 416776.93E 8030213.22S, (2) On 2 February 2010, an adult melanic specimen datum WGS84). The specimen was found sleeping (Figure 1e) was registered during a fauna rescue inside a folded leaf (Cyclanthaceae), which was by the right margin of Madeira river, nearby the approximately 8 cm above the ground level, the Teotônio Waterfall, in Porto Velho, Rondônia (UTM specimen was photographed and remained in the 20L 380800.73E 9019684.24S; datum WGS84). Cases of melanism in Dipsas indica indica in northern and northeastern Brazil 1199

The specimen was recorded by the afternoon. References

(3) On 24 May 2008 at 20:30h, an adult melanic Andrén, C, Nilson, G (1981): Reproductive success and risk of specimen (Figure 1f) was observed during predation in normal and melanistic colour morphs of the adder, a herpetofauna survey study in the Reserva Vipera berus. Biological Journal of the Linnean Society 15: Extrativista Riozinho da Liberdade, Acre (UTM 235–246. 18M 822290.47E 9119476.36S; datum WGS84). Argôlo, AJS (2004): As serpentes dos cacauais do Sudeste da The specimen was foraging upon the vegetation, Bahia. Primeira edição. Editus, Ilhéus. BA: 260 p. 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Accepted by Martin Jansen