A morphological and molecular study of Hydrodynastes gigas (Serpentes, Dipsadidae), a widespread species from South America

Priscila S Carvalho; Hussam Zaher; Nelson J da Silva Jr; Diego J Santana

doi:10.7717/peerj.10073

A morphological and molecular study of Hydrodynastes gigas (Serpentes, Dipsadidae), a widespread species from South America

PeerJ. 2020 Nov 25:8:e10073. doi: 10.7717/peerj.10073. eCollection 2020.

Authors

Priscila S Carvalho^{1

2}, Hussam Zaher³, Nelson J da Silva Jr⁴, Diego J Santana¹

Affiliations

¹ Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
² Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista, São José do Rio preto, São Paulo, Brazil.
³ Museu de Zoologia da Universidade de São Paulo, São Paulo, São Paulo, Brazil.
⁴ Escola de Ciências Médicas, Farmacêuticas e Biomédicas, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás, Brazil.

Abstract

Background: Studies with integrative approaches (based on different lines of evidence) are fundamental for understanding the diversity of organisms. Different data sources can improve the understanding of the taxonomy and evolution of snakes. We used this integrative approach to verify the taxonomic status of Hydrodynastes gigas (Duméril, Bibron & Duméril, 1854), given its wide distribution throughout South America, including the validity of the recently described Hydrodynastes melanogigas Franco, Fernandes & Bentim, 2007.

Methods: We performed a phylogenetic analysis of Bayesian Inference with mtDNA 16S and Cytb, and nuDNA Cmos and NT3 concatenated (1,902 bp). In addition, we performed traditional morphometric analyses, meristic, hemipenis morphology and coloration pattern of H. gigas and H. melanogigas.

Results: According to molecular and morphological characters, H. gigas is widely distributed throughout South America. We found no evidence to support that H. gigas and H. melanogigas species are distinct lineages, therefore, H. melanogigas is a junior synonym of H. gigas. Thus, the melanic pattern of H. melanogigas is the result of a polymorphism of H. gigas. Melanic populations of H. gigas can be found in the Tocantins-Araguaia basin.

Keywords: Biodiversity; Integrative taxonomy; Melanism; Neotropical region; Polymorphism; Squamata; Synonymization; Watersheds; Xenodontinae.

Grants and funding

This work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES Finance Code 001), Universidade Federal de Mato Grosso do Sul – UFMS/MEC – Brasil, CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) provided research fellowships (311492/2017-7 and 309950/2018-0) and this research was supported by grant 2011/50206-9 to Hussam Zaher. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.