A new species of Erythrolamprus from the oceanic island of Tobago (Squamata, Dipsadidae).

John C Murphy,Gilson A Rivas,Amaël Borzée,Renoir J Auguste,Stevland P Charles,Alvin L Braswell,Michael J Jowers,Richard M Lehtinen

doi:10.3897/zookeys.817.30811

Abstract

Tobago is a small island on the southeast edge of the Caribbean Plate with a continental flora and fauna. Using DNA sequences from Genbank, new sequences, and morphological data from the snakes Erythrolamprusepinephalus, E.melanotus, E.reginae, and E.zweifeli, the species status of specimens of a Tobago snake previously considered to be Erythrolamprusreginae was assessed. Erythrolampruszweifeli, long considered a subspecies of E.reginae, was found to be a northern Venezuela-Trinidad endemic and the sister to E.reginae. The trans-Andean species E.epinephalus is shown to be non-monophyletic while the Costa Rican lineage of E.epinephalus is weakly supported as the sister to the Tobago population. The Tobago Erythrolamprus is described as a distinct taxon based upon five specimens from four localities in lower montane rainforest. Much of the new species range includes the Main Ridge Forest Reserve of Tobago, the oldest protected forest in the Western Hemisphere. All known locations fall within a 400-ha area, and its total geographic distribution is likely to be less than 4,566 ha. The restricted distribution of this new snake makes it a likely candidate for threatened status. The new species also becomes another biogeographic link between northern Venezuela and Tobago.

Highlights

The Cordillera de Costa (CC) is a sky island archipelago that extends 925 km in an east-west orientation from western Venezuela, across the Northern Range of Trinidad to the island of Tobago
Tobago is at the eastern edge of the CC sky island complex and is slightly more than 300 km2, and its highest peak is about 576 m above sea level (ASL)
Eight of the 16 species occur on the Guyana Shield and seven species of Erythrolamprus are recognized on Trinidad and Tobago: E. aesculapii (Linnaeus, 1758); E. bizona Jan 1863; E. cobellus (Linnaeus, 1758); E. melanotus (Shaw, 1802), E. ocellatus Peters, 1868; E. zweifeli (Roze, 1959); and E. reginae (Linnaeus, 1758) (Murphy et al 2018)

Summary

Introduction

The Cordillera de Costa (CC) is a sky island archipelago that extends 925 km in an east-west orientation from western Venezuela, across the Northern Range of Trinidad to the island of Tobago. Eight of the 16 species occur on the Guyana Shield and seven species of Erythrolamprus are recognized on Trinidad and Tobago: E. aesculapii (Linnaeus, 1758); E. bizona Jan 1863; E. cobellus (Linnaeus, 1758); E. melanotus (Shaw, 1802), E. ocellatus Peters, 1868; E. zweifeli (Roze, 1959); and E. reginae (Linnaeus, 1758) (Murphy et al 2018). Both E. aesculapii and E. bizona are coral snake mimics, and each is known from a single specimen from Trinidad (but better known from elsewhere in their ranges). We examine the genetic divergence and morphology of a Tobago snake, previously considered part of the E. reginae group, in an attempt to understand its phylogenetic relationship to other Erythrolamprus and the biogeography in northeastern South America

Materials and methods

Discussion

Findings

D2 D3 V