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 new endemic genus of tarantula (Theraphosidae, Ischnocolinae) from southern Peru

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A new endemic genus of tarantula (Theraphosidae, Ischnocolinae) from southern Peru

We propose establishing a new genus of mygalomorph spiders in the family Theraphosidae Thorell, 1869, from the Province Calca, Department of Cusco, Peru. The monotypic genus Allpamayu n. gen. with its type species Allpamayu suyuwixsa n. gen, n. sp. is described. Allpamayu n. gen. differs from the known Ischnocolinae Simon, 1892 by the following unique combination of characters: abdomen with stripes, labium with a low number of cuspules, and clavate trichobothria on tarsi forming two parallel rows along half of tarsus length. Additional characters are palpal bulb of males with two keels, metatarsal ventral tumescence on the first pair of legs, cymbium with long erected setae, spermathecae of females with large subquadrate receptacles and a short wide duct oriented laterally and pointing upwards carrying two to three rounded lobes.

BERATZ M., FERRETTI N. E., CHAPARRO J. C., OCHOA J. A., ALLEN J. P. & WEST R. C. 2026. — A new endemic genus of tarantula (Theraphosidae, Ischnocolinae) from southern Peru. Zoosystema 48 (9): 273-286. https://doi.org/10.5252/zoosystema2026v48a9. http://zoosystema.com/48/9