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

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.

Biogeographical patterns of amphibians and reptiles in the northernmost coastal montane complex of South America

“…As suggested by Jowers et al [ 45 ], such relationships suggest a Pliocene “land bridge” connection between Tobago and central Venezuela in the past to explain the presence of the glass frog Hyalinobatrachium orientale on Tobago and northeastern Venezuela as it is likely with the ground snake Atractus cf fuliginosus . Another snake, the Tobago Stream Snake, Erythrolamprus pseudoreginae is known only from Tobago, but again its closest relatives are present in north-central Venezuela [ 31 ], not nearby Trinidad.…”

“…The range is oriented in an east-west direction with elevations that range up to 1250 m (Cerro Humo). The Paria Range forms a major segment of Venezuela’s Coastal Range (“Cordillera de La Costa”: CC), a chain of mountains extending eastward from the Andes for about 925 km into Trinidad [ 31 ].…”

“…In northern Venezuela, the Venezuelan Coastal Range or Cordillera de la Costa (CC) is a mountain range that extends 780 km (63,000 km 2 ) in an east-west orientation. If the outliers of the Venezuelan Isla de Margarita, Trinidad’s Northern Range, the Main Ridge on the island of Tobago, and the Sierra Nevada de Santa Marta, all of which are associated with the adjacent Caribbean region, are also included, the east-west distance of this coastal montane complex increases to about 1500 km [ 31 ] ( Fig 1 ). The CC’s high elevation peaks are patchy and therefore many areas of upper elevation with moist forest are isolated from the lower, drier topography that surrounds river valleys, and saltwater barriers [ 32 , 33 ] ( Fig 2 ).…”

Spiders (Arachnida: Araneae) feeding on snakes (Reptilia: Squamata)

“…Furthermore, because mygalomorph species show wide intraspecific variation in body size, it was usually not possible for this spider group to operate with an assumed species-specific body length value based on arachnology books. In very few cases, where exclusively snout-vent length data for snakes were available, those were converted to total length data, using conversion factors taken from the literature (Boada et al 2005;Brust 2013;Mirtschin et al 2017;Murphy et al 2019).…”

Ecology, conservation status, and phylogenetic placement of endemic Pristimantis frogs (Anura: Craugastoridae) in Trinidad and Tobago and genetic affinities to northern Venezuela

“…Interestingly, some of the Tobago endemics seem to be more closely related to species of the Venezuelan coastal montane complex than to Trinidad. Some examples include Tobago's dendrobatid Mannophryne olmonae (Manzanilla et al, 2009), the Tobago glass frog, Hyalinobatrachium orientale (Jowers et al, 2015), the Tobago stream snake, Erythrolamprus pseudoreginae (Murphy et al, 2019) and the fossorial Hallowell's ground snake Atractus fuliginosus (Jowers et al, 2021). Despite some of these species having members of the same genus in Trinidad, they are not closely related to them, suggesting that colonization of Tobago did not happen through a stepping-stone process from Trinidad.…”