Seasonal Variation in Whole-Body Elemental Concentrations and Excreta Production of a Riparian Orb-Weaving Spider (Larinioides cornutus)

Posted by
  Seasonal Variation in Whole-Body Elemental Concentrations and Excreta Production of a Riparian Orb-Weaving Spider (Larinioides cornutus) ABSTRACT Predators influence nutrient cycling by assimilating elements from their prey and returning nutrients to ecosystems via excretion and discarded prey remains. However, seasonal variation in the contribution of predators to nutrient cycling remains poorly understood, particularly for terrestrial arthropod predators such as spiders. We examined temporal variation in whole-body elemental concentrations, excreta C and N concentrations, and cumulative excreta output in a riparian orb-weaving spider ( Larinioides cornutus ) across the growing season of 2024. Adult females were collected across seven sampling periods spanning mid-June to early October, and whole-body concentrations of macronutrients (carbon [C], nitrogen [N], phosphorus [P]) and multiple trace elements were quantified. Whole-body N and P concentrations, and several trace elemen...

Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest interior spider

Posted by

 


Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest interior spider

Abstract

Quaternary climate oscillations significantly influenced the configuration of the Brazilian Atlantic Forest. In this study, mitochondrial DNA analysis of Enoploctenus cyclothorax (Bertkau, 1880) was conducted to investigate potential cryptic diversity within populations across the state of Paraná, Brazil. Two divergent genetic lineages were identified based on genetic distances, haplotype network, and phylogenetic inference. A phylogeographical break separates the lineages into two geographic regions; one lineage is found exclusively in the eastern region and the other is found mainly in the northern and western regions of the state. The coalescence tree estimates the divergence time between 1.8 million years and 500 000 years ago, period marked by glaciation, suggesting historical forest fragmentation as a potential isolating mechanism. These findings support the hypothesis of independently evolving units within E. cyclothorax, possibly representing cryptic species, though broader sampling and integrative approaches are necessary for taxonomic validation.
Mariana Costa Terra, Antonio Domingos Brescovit, Ana Lúcia Dias, Matheus Pires Rincão, and Renata da Rosa. 2025. Cryptic diversity identified by DNA barcoding reveals the impact of pleistocene climate oscillations on a forest interior spider. Genome. 68: 1-12. https://doi.org/10.1139/gen-2025-0028