Venom Variation as a Window into the Ecology and Evolution of Snakes

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  Venom Variation as a Window into the Ecology and Evolution of Snakes Abstract Snake venoms are complex biochemical systems that function primarily in prey subjugation and defense, yet their composition varies extensively across individuals, populations, species, and environments. This variation provides a powerful framework for investigating ecological and evolutionary processes. Here, we offer a forward-looking synthesis of snake venom diversity that proposes new research directions and highlights how venom variation can illuminate eco-evolutionary dynamics across biological scales. We review evidence for ten key contexts in which venom variation arises, including within-population differences, sexual dimorphism, geographic structuring, ontogenetic shifts, seasonal changes, interspecific divergence, hybridization, convergent evolution, prey specificity, and venom resistance. Together, these processes demonstrate that venom phenotypes are shaped by interacting selective pressures...

A regenerated chelicera in an African tarantula, Anoploscelus lesserti Laurent, 1946 (Araneae: Theraphosidae)

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A regenerated chelicera in an African tarantula, Anoploscelus lesserti Laurent, 1946 (Araneae: Theraphosidae)

Abstract

An adult male of Anoploscelus lesserti Laurent, 1946 from Burundi, deposited in the Royal Museum for Central Africa (RMCA) with a regenerated right chelicera is illustrated and discussed. Simultaneously, this constitutes the first record of the genus Anoploscelus Pocock, 1897 for Burundi. 

In early 2023, whilst working in the collections at the Royal Museum for Central Africa (RMCA), we discovered a male of Anoploscelus lesserti Laurent, 1946 from Burundi with cheliceral regeneration. Simultaneously, this constitutes the first record of the genus Anoploscelus Pocock, 1897 in Burundi. The specimen is readily assigned to Anoploscelus owing to the incrassate femur III, transverse fovea, and palpal bulb morphology (Fig. 1). The specimen (BE_RMCA_ARA.Ara.247722) has the following data: Mt. Ruvubu, Muremera, Cibitoke Province, Burundi (3°6′40″S, 30°22′23″E), 20/08/2016. A revision of the genus should be forthcoming (R. Gallon pers. comm.), and for this reason we do not provide full detailed measurements (e.g. the description format used by the senior author in her taxonomic contributions on theraphosids) of the specimen. However, to quantify the identification of the male and separate it from the type species, we provide here a diagnosis, and describe the palpal bulb (keels follow the terminology of Bertani, 2000) in this genus.

Many thanks to Danni Sherwood for providing me with this paper.

Sherwood, Danniella, Rudy Jocqué, and Arnaud Henrard. "A regenerated chelicera in an African tarantula, Anoploscelus lesserti Laurent, 1946 (Araneae: Theraphosidae)", Animal Taxonomy and Ecology (published online ahead of print 2024), doi: https://doi.org/10.1556/1777.2024.00051