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Biology subjects

Elias, D. O.

Publications and source records attributed to Elias, D. O..

3 recordsLinked to original sources

Takeoff dynamics are stereotyped across jumping spiders

Jumping is a challenging locomotive mode, requiring rapid force generation and precise coordination of multiple limbs. Many animals meet this challenge using elastic mechanisms that store and rapidly release energy. Jumping spiders (Salticidae), however, rely on a semi-hydraulic system that constrains how their legs can generate propulsion. Much about how these spiders reliably generate jumps within these mechanical constraints remains unknown. Here, we analyze 46 individuals spanning 14 genera and significant morphological diversity and show that this physically constrained system is coupled to a remarkably stereotyped coordination strategy. Whole-body kinematics and novel graph-based analyses of inter-limb coordination reveal a stereotyped two-stage takeoff sequence: a "swing" driven by extension of the fourth legs, followed by a rapid "fling" by the third legs that generates propulsion for takeoff. We further demonstrate that this pattern is preserved beyond Amazonian species, persisting in salticids from North America and Australia. Our results suggest that physical and biomechanical constraints may canalize locomotor evolution toward a common dynamical solution.

animal behavior and cognition↗

Timing matters: age-dependent female receptivity and preference patterns

The timing of reproductive processes can influence how mating interactions shape reproductive strategies. We examined how female age correlates with receptivity and preference in the jumping spider Habronattus formosus, a system characterized by elaborate male courtship and strong female choice. To test how receptivity changes across the post-maturation period, we paired females of different ages with males and quantified male courtship displays and mating outcomes. Females were not receptive immediately after maturation and instead exhibited receptivity primarily 2-3 weeks after maturation. We further found that the full male courtship predicted mating success in older females, whereas only the second stage of the courtship predicted success in younger females. The delay in female receptivity is consistent with expectations for strong female choice systems, where females may have a greater opportunity to evaluate male courtship before mating. These results highlight the importance of age-dependent changes in female reproductive state and suggest that the timing of receptivity may shape how different components of male courtship influence mating success.

animal behavior and cognition↗

The return to water in ancestral Xenopus was accompanied by a novel mechanisms for producing and shaping vocal signals

Species-specific vocal signals allow listeners to locate potential mates. During the tetrapod transition from water to land, lungs replaced gills, allowing expiration to drive sound production. Several groups, e.g. cetaceans and some frogs, then returned to water. Here we explore how air-driven sound production changed upon re-entry and how essential acoustic information on species identity was preserved in the secondarily aquatic frog Xenopus. We filmed movements of cartilage and muscles during evoked sound production in isolated larynges. Our results refute the current theory for Xenopus vocalization, cavitation, and instead favor sound production by mechanical excitation of laryngeal resonance modes following rapid separation of laryngeal arytenoid discs. The resulting frequency resonance modes (dyads) are intrinsic to the larynx rather than due to neuromuscular control. We show that dyads are a distinctive acoustic signature across species. While dyad component frequencies overlap across species, their ratio is shared within each Xenopus clade and thus provide information on species identity, potentially facilitating both conspecific localization and ancient species divergence.

zoology↗