The good, the bad and the boa: An unexpected new species of a true boa revealed by morphological and molecular evidence

PLoS One. 2024 Apr 17;19(4):e0298159. doi: 10.1371/journal.pone.0298159. eCollection 2024.

Abstract

Snakes of the genus Boa are outstanding elements of the New World biota with a broad sociological influence on pop culture. Historically, several taxa have been recognized in the past 300 years, being mostly described in the early days of binomial nomenclature. As a rule, these taxa were recognized based on a suite of phenotypic characters mainly those from the external morphology. However, there is a huge disagreement with respect to the current taxonomy and available molecular phylogenies. In order to reconcile both lines of evidence, we investigate the phylogenetic reconstruction (using mitochondrial and nuclear genes) of the genus in parallel to the detailed study of some phenotypic systems from a geographically representative sample of the cis-Andean mainland Boa constrictor. We used cyt-b only (744bp) from 73 samples, and cyt-b, ND4, NTF3, and ODC partial sequences (in a total of 2305 bp) from 35 samples, comprising nine currently recognized taxa (species or subspecies), to infer phylogenetic relationships of boas. Topologies recovered along all the analyses and genetic distances obtained allied to a unique combination of morphological traits (colouration, pholidosis, meristic, morphometric, and male genitalia features) allowed us to recognize B. constrictor lato sensu, B. nebulosa, B. occidentalis, B. orophias and a distinct lineage from the eastern coast of Brazil, which we describe here as a new species, diagnosing it from the previously recognized taxa. Finally, we discuss the minimally necessary changes in the taxonomy of Boa constrictor complex; the value of some usually disregarded phenotypic character system; and we highlight the urgency of continuing environmental policy to preserve one of the most impacted Brazilian hotspots, the Atlantic Forest, which represents an ecoregion full of endemism.

MeSH terms

  • Animals
  • Boidae* / genetics
  • Brazil
  • Lepidoptera*
  • Male
  • Mitochondria / genetics
  • Phylogeny

Grants and funding

RCG: Conselho Nacional de Desenvolvimento Científico e Tecnológico [https://www.gov.br/cnpq/pt-br], Grant/Award Number: 142370/2014-2; Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico [https://www.funcap.ce.gov.br/], Grant/Award Number: 06319627/2021; LCBL: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [https://www.gov.br/capes/pt-br], Grant/Award Number: 51652900268; PP Conselho Nacional de Desenvolvimento Científico e Tecnológico [https://www.gov.br/cnpq/pt-br], Grant/Award Number: 309560/2018-7; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro [https://www.faperj.br/], Grant/Award Number: E- 26/202.737/2018; MJJS Fundação de Amparo à Pesquisa do Estado de São Paulo [https://fapesp.br/], Grant/Award Number: #14/02885-2. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.