Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

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  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

A Decade of Change: Trends in Scorpion Richness, Abundance, and Community Structure in Central Algerian Sahara

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A Decade of Change: Trends in Scorpion Richness, Abundance, and Community Structure in Central Algerian Sahara

Abstract

Understanding long-term temporal dynamics of desert arthropod communities is essential for evaluating ecosystem responses to environmental variability. This study investigates decadal changes (2014–2024) in species richness, abundance, diversity, and assemblage composition of scorpions in the central Algerian Sahara. Annual species abundance data were analyzed using diversity indices and multivariate approaches. Temporal turnover in species composition was assessed using Bray–Curtis dissimilarity, linear regression, and SIMPER analysis to identify species contributing to assemblage change. Species richness increased substantially over the study period, rising from four species in 2014 to eleven species in 2024, but this rise likely reflects improved taxonomic knowledge and more complete inventories rather than a recent ecological colonization. In contrast, total abundance showed strong interannual variability without a clear temporal trend, indicating a decoupling between richness and overall population size. Diversity indices increased progressively, with higher Shannon and Simpson values in later years, reflecting reduced dominance and greater evenness, although both indices reached minimum values in 2019. Temporal β-diversity revealed moderate interannual turnover (mean dissimilarity = 0.22) and a non-significant decline through time, suggesting gradual assemblage reorganization. SIMPER analysis indicated that temporal change was mainly driven by shifts in dominance, particularly the decline of Androctonus amoreuxi and changes in secondary species such as Buthacus samiae and Lissothus chaambi. Overall, scorpion assemblages exhibited increasing richness and diversity with moderate turnover, driven primarily by changes in species dominance rather than widespread species replacement.

Sadine, S. E., Zebsa, R., Bensakhri, Z., Souilem, Z., Rouari, L., Houhamdi, M., & Lira, A. F. (2026). A Decade of Change: Trends in Scorpion Richness, Abundance, and Community Structure in Central Algerian Sahara. Diversity, 18(7), 420. https://doi.org/10.3390/d18070420