 |
| Bothrops oligobalius Dal Vechio, Prates, Grazziotin, Graboski & Rodrigues, 2021. |
ABSTRACT
Recent genetic studies have found unclear species boundaries and evidence of undescribed diversity in the poorly studied jararacussu species group within Bothrops. In this contribution, we investigate phenotypic and genetic diversity in the Amazonian snake Bothrops brazili to test previous assertions of unrecognised species diversity within this taxon. Our phylogenetic results and inferences of independently evolving lineages based on molecular data recover two divergent clades within B. brazili, one restricted to areas north and another to areas south of the Amazon River. Phylogenetic relationships between these lineages and other species in the jararacussu species group reveal B. brazili to be paraphyletic, with the northern clade inferred as sister to a clade composed of Atlantic Forest taxa (B. jararacussu, B. muriciensis, B. pirajai). External morphology (number of ventral and subcaudal scales) and colouration patterns (lateral trapezoidal marks) consistently separate the two lineages of B. brazili. We therefore recognise and describe the northern lineage as a new species of Bothrops, improving our knowledge of species diversity within a medically important clade of venomous South American snakes.
KEYWORDS: Amazonia, Amazon River, Bothrops brazili, B. jararacussu, B. pirajai, B. muriciencis, species delimitation
 |
| Figure 2. Bothrops oligobalius sp. nov. from French Guiana. Photo by Maël Dewynter. |
Bothrops oligobalius sp. nov.
Diagnosis:
(1) A robust body species, SVL = 245–805 mm, (2) short tail, TL = 35–113 mm; (3) 23–27
dorsals on the first third of the body; (4) 23–25 dorsals at midbody; (5) 18–21 dorsals on
the last third of the body; (6) 156–164 ventrals in females (median = 160) and 154–159 in
males (median = 156); (7) anal scale not divided; (8) 42–48 paired subcaudals in females
(median = 44.5) and 47–52 in males (median = 48.8); (9) 9–13 lateral trapezoidal marks in
each side (median = 11,01 and 11,7 on the right and left side, respectively); (10) postorbital stripe absent or poorly marked; (11) eight supralabials; (12) 10–12 infralabials;
(13) second supralabial fused to the prelacunal; (14) belly checkered; (15) absence of
vertebral stripe.
 |
| Figure 6. Geographic map of South America showing the distribution of Bothrops oligobalius sp. nov. (yellow) and B. brazili (red). Outlined diamonds and circles represent sites with genetic samples available. Diamonds with an inner dot indicate the type locality of each both species. The Amazonian biome is highlighted in green; the Amazon River is also indicated. Photos: B. oligobalius sp. nov. from French Guiana, by Maël Dewynter; B. brazili from Porto Velho, RO, Brazil, by Francisco Dal Vechio. |
Etymology: The specific name derives from the Greek oligos (few) and balios (spotted, dappled). The
name is a reference to the smaller number of lateral trapezoidal marks on the body
compared to Bothrops brazili, a name now restricted to the populations south of the
Amazon River.
Francisco Dal Vechio, Ivan Prates, Felipe G. Grazziotin, Roberta Graboski and Miguel Trefaut Rodrigues. 2021. Molecular and Phenotypic Data reveal A New Amazonian Species of Pit Vipers (Serpentes: Viperidae: Bothrops). Journal of Natural History. 2415-2437. DOI: 10.1080/00222933.2020.1845835
