Sex-specific life-history strategies among immature jumping spiders: Differences in body parameters and behavior

Abstract

Selection forces often generate sex-specific differences in various traits closely related to fitness. While in adult spiders (Araneae), sexes often differ in colouration, body size, antipredator or foraging behaviour, such sex-related differences are less pronounced amongst immatures. However, sex-specific life-history strategies may also be adaptive for immatures. Thus, we hypothesized that, among spiders, immature individuals show different life-history strategies that are expressed as sex-specific differences in body parameters and behavioural features, and also in their relationships. We used immature individuals of a protandrous jumping spider, Carrhotus xanthogramma, and examined sex-related differences. Results showed that males have higher mass and larger prosoma than females. Males were more active and more risk-tolerant than females. Male activity increased with time, and larger males tended to capture the prey faster than small ones, while females showed no such patterns. However, females reacted to the threatening abiotic stimuli more with the increasing number of test sessions. In both males and females, individuals with better body condition tended to be more risk-averse. Spiders showed no sex-specific differences in inter-individual behavioural consistency and in intra-individual behavioural variation in the measured behavioural traits. Finally, we also found evidence for behavioural syndromes (i.e. correlation between different behaviours), where in males only the activity correlated with the risk-taking behaviour, but in females all the measured behavioural traits were involved. The present study demonstrates that C. xanthogramma sexes follow different life-history strategies even before attaining maturity.

Urbanization increases fluctuating asymmetry and affects behavioral traits of a common grasshopper

“…Growing literature indicates that females and males differ in the mean levels of behavioral expression (Schuett et al, 2010) and repeatability of behavioral traits (Bell et al, 2009). Although a meta‐analysis has already shown that personality and traits are not sex‐dependent in most of the animals (Harrison et al, 2021), there may be sex‐specific differences with respect to certain traits in some species (e.g., sex‐specific dispersal, Han & Dingemanse, 2017; Li & Kokko, 2019; Trochet et al, 2016; exploration and aggression, Kralj‐Fišer et al, 2019, 2021; activity and risk‐taking behavior, Mezőfi et al, 2022), leading to the evolution of sex‐specific genetic architecture behind such traits (Lande, 1980). In addition, responses to environmental stress may be sex‐dependent.…”