Herpetology Notes, volume 11: 445-448 (2018) (published online on 24 May 2018) Brachydactyly in the toad Rhinella granulosa (Bufonidae) from the Caatinga of Brazil: a rare case with all limbs affected Larissa L. Correia1,2, João P. F. A. Almeida1, Barnagleison S. Lisboa3 and Filipe A. C. Nascimento3,4,* Amphibians are unique among tetrapods due to toads and frogs (e.g. Flyaks and Borkin, 2003; Guerra their biphasic life cycle and permeable skin. These and Aráoz, 2016; Silva-Soares and Mônico, 2017). features make them sensitive to potentially dangerous While conducting a survey of Rhinella granulosa exogenous factors that can affect their development (Spix, 1824) specimens deposited in the herpetological and generate body malformations. However, some collection of the Museu de História Natural of the endogenous factors, such as gene mutations, can also Universidade Federal de Alagoas, we found a specimen be the cause of some malformations (e.g. Droin et (MUFAL 8138) with bilateral brachydactyly on the fore- al., 1970; Droin, 1992). Although common in natural and hindlimbs. We used x-ray photographs taken using populations reaching a prevalence rate of 2–5% (Lunde a dental x-ray machine Dabi Atlante Spectro II in order and Johnson, 2012), these abnormalities might affect to confirm the malformation and verify the limb bone individual fitness and thus contribute to the reduction of arrangement. Specimen identification was confirmed amphibian populations (Johnson et al., 2003). based on the diagnosis of Narvaes and Rodrigues (2009), Most cases of malformations in amphibians affect the which reviewed the taxonomy of Rhinella granulosa appendicular skeleton, mainly the bones of the limbs species group. The toad was collected on August 6, (Reeves et al., 2008; Hassine et al., 2011). Brachydactyly 1998 at Alagoas Farm, Ecological Station of Xingó is characterized by a reduction in the number of (limits -9.417° to -9.667°S, -37.750° to -38.083°W), phalanges, while the metacarpal (or metatarsal) bones municipality of Piranhas, Alagoas State, northeastern remain present, which cause a notable shortening of Brazil, a region situated within the morphoclimatic the digits (Meteyer, 2000; Rothschild et al., 2012). This domain of the Caatinga (Ab’Saber, 1977). It is an adult condition has been recorded in many amphibians, both male that measures 48.7 mm in snout-vent length, which in salamanders (e.g. Bassarukin and Borkin, 1984) and is within the normal range of males of R. granulosa (31.4 to 62.4 mm; Narvaes and Rodrigues, 2009). Digits of fore- and hindlimbs of the specimen were noticeably shortened when compared to digits of normal conspecifics (Fig. 1). The x-rays showed that the forelimb 1 Laboratório de Biologia Integrativa, Setor de Biodiversidade, digits were formed only of the metacarpals, with missing Instituto de Ciências Biológicas e da Saúde, Universidade phalanges, and a small, clear distal punctuation on digits Federal de Alagoas. Av. Lourival Melo Mota, s/n, CEP II-IV, which could be remnants of the phalanges or other 57072–970, Maceió, Alagoas, Brazil. type of calcification. In turn, the digits in the hindlimbs 2 Programa de Pós-Graduação em Biologia Animal, Centro de Ciências Biológicas, Universidade Federal de Pernambuco. were composed of the metatarsals and, at least in the Avenida Professor Nelson Chaves, s/nº, CEP 50670-420, digits II-V, by shortened proximal phalanges (Fig. 2). Recife, Pernambuco, Brazil. The remaining phalanges were absent and all the other 3 Setor de Zoologia, Museu de História Natural, Universidade limb bones were apparently normal. Federal de Alagoas. Praça Afrânio Jorge, s/n, CEP 57010– According to Johnson et al. (2010), the frequency 020, Maceió, Alagoas, Brazil. of malformations in late larval stages and juveniles 4 Programa de Pós-Graduação em Zoologia, Instituto de is higher than in adult anurans, presumably because Ciências Biológicas, Universidade Federal de Minas Gerais. Av. Antônio Carlos, 6627, CEP 31270–901, Belo Horizonte, malformations may increase the likelihood of Minas Gerais, Brazil. predation and reduce their ability to capture preys, * Corresponding author. E-mail: [email protected] which consequently decreases the chance of survival 446 Larissa L. Correia et al. Figure 1. (A) dorsal and ventral views of the male specimen of Rhinella granulosa (MUFAL 8138) with brachydactyly in all limbs. (B) dorsal and ventral views of a normal male (MUFAL 5943) of the same species for comparative purpose. Scale bar = 20 mm. in the adult stage (Goodman and Johnson, 2011). Rodrigues, 2009; Pereyra et al., 2016), brachydactyly However, herein we report brachydactyly in an adult was only recorded in one out of 13 currently known of R. granulosa, which suggests that it was not a lethal species: R. fernandezae (Peltzer et al., 2011; Agostini et condition for the specimen. Abnormalities in limbs are al., 2013). However, these and other studies describing known to affect semi-aquatic or terrestrial species less this malformation in several anuran species reported it severely than species with climbing habits (Agostini only in one or two limbs and, less often, along with some et al., 2013). Because species with terrestrial habits do other type of malformation (e.g. Machado et al., 2010; not demand much of its digits compared to species with Modak et al., 2013; Brouard and Smith, 2014). To our arboreal habits, perhaps the lifestyle of R. granulosa knowledge, this is the first documented case of bilateral have substantially contributed to its survivorship. brachydactyly in all digits of hind- and forelimbs in Within Rhinella granulosa species group (Narvaes and anurans. Brachydactyly in the toad Rhinella granulosa from the Caatinga of Brazil 447 Hedgehog and Hox genes) are known to cause limb malformations in tetrapods (Johnson et al., 2003; Sanz- Ezquerro and Tickle, 2003; Jones et al., 2013), including anurans (e.g. Droin and Fischberg, 1980). Furthermore, brachydactyly is also known to be caused by exogenous factors, such as viruses or parasites (Johnson et al., 2002; Schothoefer et al., 2003), UV-B exposure (Muto, 1969; 1970), environmental contamination (Agostini et al., 2013), or even the synergistic interaction of some or all these factors. Although we believe that there is a low probability of brachydactyly in all limbs to be caused by trauma, at this time we cannot safely determine a potential cause for the observed malformation. In Brazilian biomes, there are only a few studies at the population level testing the influence of exogenous factors as potential causes of malformations in anurans (e.g. Toledo and Ribeiro, 2009; Schuch et al., 2015), and virtually none investigating the influence of endogenous factors. Thus, we reinforce the importance of population level studies, especially in biomes under fragmentation processes since it may lead to an increase of consanguineous mating (Williams et al., 2008), as well as a higher exposure of amphibian species to exogenous agents due to the proximity of these areas to urbanized regions. Acknowledgements. We are grateful to Igor Juny Nascimento and Anna Ludmilla Nascimento for helping with the radiographs, and Adriano Maciel for providing a pre-peer review of the manuscript. This research was partially funded by FAPEAL ( 2002.08.110-02). References Ab’Saber, A.N. (1977): Domínios morfoclimáticos na América do Sul: primeira aproximação. Geomorfologia 52: 1–21. Agostini, M.G., Kacoliris, F., Demetrio, P., Natale, G.S., Bonetto, C., Ronco, A.E. (2013): Abnormalities in amphibian populations inhabiting agroecosystems in northeastern Buenos Figure 2. (A) above, detail of the left manus with brachydactyly Aires Province, Argentina. Diseases of Aquatic �rganisms 104: in ventral view of Rhinella granulosa (MUFAL 8183); below, 163–171. the same in a radiographic image. (B) detail of the left manus Bassarukin, A.M., Borkin, L.J. (1984): Distribution, ecology and of normal specimen (MUFAL 5943), for comparative purpose. morphological variability of the Siberian salamander, Hynobius (C) and (D), detail of the left pes of the same specimens of A keyserlingii of the Sakhalin Island. Proceedings of the Zoological and B, respectively. Not to scale. Institute Russian Academy of Science 124: 12–54. Brouard, J.P., Smith, P. (2014): Elachistocleis bicolor (Amphibia: Anura: Microhylidae) and Eupemphix nattereri (Amphibia: Anura: Leiuperidae): Morphological abnormalities from Reserva Natural Laguna Blanca, Paraguay. Herpetologia Brasileira 3: The causes of brachydactyly are difficult to clarify and 85–87. are not fully understood in anurans. Some mutations Droin, A, Fischberg, M. (1980): Abnormal limbs (ABL), a recessive in genes (endogenous factors) involved in digit mutation affecting the tadpoles of Xenopus laevis. Experientia development and specifications (such as the BmP, FgF 36: 1286–1288. 448 Larissa L. Correia et al. Droin, A. (1992): The developmental mutants of Xenopus. The Muto, Y. (1969): Anomalies in the hindlimb skeletons of the toad International Journal of Developmental Biology 36: 455–464. larvae reared at a high temperature. Congenital Anomalies 9: Droin, D., Uehling, V., Reynaud, J. (1970): Une mutation letale, 61–72. recessive, “bt” (bent tail) chez Xenopus laevis. Revue Suisse de Muto, Y. (1970): Development of the hindlimb skeleton and its Zoologie 77: 596–602. anomalies induced by cultivation at a high temperature in the Flyaks, N.L., Borkin, L.J. (2003): Morphological abnormalities toad larvae. Bulletin of Aichi University of Education 19: 43– and heavy metal concentrations in anurans of contaminated 53. areas, eastern Ukraine. Applied Herpetology 1: 229–264. Narvaes, P., Rodrigues, M.T. (2009): Taxonomic revision of Rhinella Goodman, B.A., Johnson, P.T. (2011): Disease and the extended granulosa species group (Amphibia, Anura, Bufonidae), with a phenotype: parasites control host performance and survival description of a new species. Arquivos de Zoologia 40: 1–73. through induced changes in body plan. PLoS �ne 6: 1–10. Peltzer, P.M., Lajmanovich, R.C., Sanchez, L.C., Attademo, A.M., Hassine, J.B., de Buffrénil, V., Nouira, S. (2011): First record Junges, C.M., Bionda, C.L., Martino, A.L., Bassó, A.