The chromosome-level genome of Mesobuthus martensii provides insights into its evolution and the diversity of venom peptides

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  The chromosome-level genome of Mesobuthus martensii provides insights into its evolution and the diversity of venom peptides Abstract Mesobuthus martensii , the source species of the traditional Chinese medicine “Quanxie”, has long been utilized for its therapeutic properties. Venom peptides are recognized as the major active molecular basis of these pharmacological activities. Despite this, their development as therapeutic agents remains poorly explored. In this study, we performed an integrated multi-omics investigation to systematically explore the venom peptides of Mesobuthus martensii . We generated a chromosome-level genome assembly of Mesobuthus martensii using third-generation sequencing technologies, yielding a genome size of 1.08 Gb with a contig N50 of 46.46 Mb. Integrated genomic and transcriptomic analyses led to the identification of 51 putative novel venom peptide candidates. From the broader venom peptide set, five lysine- and arginine-rich candidates were select...

If you are hidden, how will I know what you feel?: the role of tarantula burrows in buffering the external climatic conditions

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If you are hidden, how will I know what you feel?: the role of tarantula burrows in buffering the external climatic conditions

Abstract

Context

Thermal refuges, such as burrows, play a crucial role in the survival of ectothermic species by buffering environmental temperature fluctuations. The burrowing tarantula Grammostola vachoni inhabits rocky outcrops in central grassland of Argentina. Considering the importance of refuges for ectotherms, the significant differences between microhabitat and external environmental conditions, and the limited information available on tarantula habitats, understanding microclimate variations within burrows is crucial.

Aims

We investigated the temperature and humidity dynamics inside the burrows of G. vachoni in relation to the surrounding environment. We characterized microhabitat temperature and humidity in adjacent habitats, evaluated the stability of environmental conditions inside and outside the burrow, and analyzed these findings in relation to the known thermal limits of the species.

Methods

We conducted the study in the Ventania System (Argentina), measuring temperature and humidity throughout an entire year. Environmental parameters were recorded using a HOBO data logger, whereas burrow parameters were measured using iButton data loggers placed inside burrows occupied by adult females of G. vachoni. We also analyzed the stability of environmental and burrow conditions, the distribution of extreme temperatures, humidity variability, and the rates of cooling and heating.

Key results

We found that burrows exhibit greater thermal and hydric stability than the external environment, with temperatures inside remaining above 0°C during winter. Cooling and heating rates inside the burrows were slower, which allowed the spiders to avoid rapid and harmful temperature fluctuations. Humidity levels inside the burrows were consistently higher than outside, particularly during the warmer months.

Conclusions

Our results highlighted the importance of monitoring microhabitat conditions not only during the species’ activity periods, because burrows play a determinant role in other phases of the life cycle. Whereas burrows provide some level of thermal refuge, the increasing frequency and intensity of heatwaves could challenge the species’ thermal resilience. The fact that burrow temperatures can exceed both optimal temperature and critical thermal maximum, particularly in the warmer months, raises concerns about the suitability of these refuges in the face of climate change.

Implications

Understanding these microhabitat conditions is essential to grasp the fine-scale relationship between the organism and its environment.

Schwerdt Leonela, Ferretti Nelson, de Villalobos Ana Elena (2025) If you are hidden, how will I know what you feel?: the role of tarantula burrows in buffering the external climatic conditions. Wildlife Research 52, WR24202.

https://doi.org/10.1071/WR24202