Aquatic adaptations in a Neotropical coral snake: A study of morphological convergence

Abstract

Micrurus surinamensis is an aquatic member of the genus Micrurus. This species is known for its highly specialized venom and distinctive diet, mostly made of aquatic vertebrates. Here, we explore both external (head and body) and skull shape morphologies in M. surinamensis, comparing it with two terrestrial species of the genus (M. lemniscatus and M. spixii) and to aquatic and terrestrial species of distantly related groups. We use both traditional and geometric morphometrics to determine whether the presence of similar traits in head shape morphology is rather the result of adaptive convergences between M. surinamensis and other aquatic species, or whether it is the product of phylogenetic conservatism within the genus. Results from both traditional and geometric morphometrics show that M. surinamensis can be considered convergent with aquatic species, mainly in the skull shape. Micrurus surinamensis differs from the two terrestrial species of Micrurus by having a wider head, smaller distance between nostrils, and a long tail. Geometric morphometric analysis shows that despite having an extremely conserved skull and mandible shape, M. surinamensis shows a longer supratemporal and quadrate bones than in terrestrial Micrurus, indicating a larger gape for this species. A more kinetic skull combined with a larger gape would allow M. surinamensis to feed on fish, which represent larger and wider prey that contrast with the elongate prey, which compose the main diet of species in the genus Micrurus. Our results illustrate the importance of both phylogenetic conservatism and adaptation in shaping species morphology.

Coevolution of Snake Venom Toxic Activities and Diet: Evidence that Ecological Generalism Favours Toxicological Diversity

“…Specific types of activities can differ for a given type of prey, but dietary generalism promotes the evolution of diverse functional activities of snake venoms. Future work investigating this pattern in more detail, including links with documented ecological influences on venom complexity such as climate [12] or ecomorphological coadaptations to particular prey types [57,58] is likely to be fruitful, and we believe our current manuscript provides a new perspective to direct such studies.…”

Phylogeography of West Indies Coral snakes (Micrurus): Island colonisation and banding patterns

“…Hence, New World coral snakes seem to lack the long‐distance dispersal capabilities of other snakes (e.g. Boidae, Bothrops ) to colonise offshore islands, even though some species have morphological adaptations to swimming and are considered aquatic or semi‐aquatic (Silva et al, ). The presence of the same M. diutius haplotypes in Trinidad and Guyana is somehow surprising as it implies very recent isolation on Trinidad or isolation through sea level rise.…”

DIMORFISMO SEXUAL, REPRODUCCIÓN Y BIOLOGÍA ALIMENTARIA DE Helicops angulatus (LINNAEUS, 1758) (COLUBRIDAE: HYDROPSINI) EN LA AMAZONIA ORIENTAL, BRASIL

“…The elongated body and the absence of limbs make the snakes agile and capable of occupying a great diversity of microhabitats, being able to prey on a wide variety of items. In addition, the kinetic head allows the ingestion of relatively large prey (Greene, 1983;Cundall and Greene, 2000;Santos et al, 2016;Silva et al, 2017a). Some taxa differ in their habits, especially when it comes to breeding and feeding activity (Pizzatto, Jordão and Marques, 2008;Alencar, Gaiarsa and Martins, 2013;Silva, Oliveira, Nascimento, Machado and Prudente, 2017b).…”