FIRST RECORD OF A DEFENSIVE BEHAVIOR IN Microcaecilia nicefori (GYMNOPHIONA: SIPHONOPIDAE) PROVOKED BY THE SNAKEBITE OF Micrurus dumerilii (SERPENTES: ELAPIDAE)

Abstract

We here report the first dynamic event of predation and defensive behavior in Microcaecilia nicefori provoked by Micrurus dumerilii in Armero, Tolima, Colombia, and we also provide a compendium of all the available literature records of caecilians being preyed upon by snakes in the Neotropic.

Resistance Is Not Futile: Widespread Convergent Evolution of Resistance to Alpha-Neurotoxic Snake Venoms in Caecilians (Amphibia: Gymnophiona)

“…The motif also evolved independently on different continents: once in Africa (in the genus Schistometopum), three times in America (in the genera Rhinatrema, Caecilia, and Typhlonectes), and four times in Asia (once in the genera Gegeneophis and Chikila and twice at different positions in the genus Ichthyophis). These numbers are roughly consistent with the reports of the elapid predation on caecilians in Asia and America ( [7][8][9][10][11][57][58][59][60] sensu lato) and the apparent lack thereof in Africa. The motifs at positions 187-189 all have an isoleucine (I) or valine (V) as the second residue; meanwhile, those at position 189-191 share an evolutionarily conserved tyrosine (Y) residue.…”

“…Although many caecilians may produce skin poisons too, there is remarkably little evidence [6]. Caecilians are found in the diets of many semi-fossorial venomous snakes [7][8][9][10][11][12]. Therefore, they might be under particularly strong pressure to evolve a resistance to snake venom.…”

“…This first reported evidence of toxin resistance in caecilians is intriguing because of their physical characteristics and ecological niche. Most caecilians are fossorial (except for the South American family Typhlonectidae, which is secondarily aquatic), legless, worm-like amphibians [55,56]; therefore, they are thought to be vulnerable to sympatric fossorialhunting elapids across their ranges, particularly in the Americas (e.g., Leptomicrurus and Micrurus) [7][8][9][10][11] and Asia (e.g., Bungarus, Calliophis, Naja, and Sinomicrurus) [57][58][59][60].…”

“…Caecilian diversification patterns and their current distribution reflect a Pangaean origin with subsequent Gondwanan radiation [61][62][63]. Elapid snakes are the dominant venomous snake predators in the fossorial niche and have been documented as preying on caecilians [7][8][9][10][11]. We hypothesized that caecilians are therefore under strong selective pressure to evolve resistance to elapid venom.…”

First record of predation on a Red-tailed Coralsnake (Micrurus mipartitus) by an Antioquian Coralsnake (Micrurus dumerilii antioquensis)

“…The natural history of M. d. antioquensis has been poorly studied, and only one instance of predation (on a Thompson's Caecilian, Caecilia thompsoni) has been documented (Herrera-Lopera et al 2018). However, other subspecies of M. dumerilii are known to eat snakes (Vera-Pérez et al 2019), and small vertebrates such as swamp eels, lizards (Roze 1996), andcaecilians (Fernández-Roldán andGómez-Sánchez 2021).…”