Spiders in motion: demonstrating adaptation, structure-function relationships, and trade-offs in invertebrates

Area of Science:

• Zoology
• Biomechanics
• Ecology

Background:

• Animal physiology is shaped by evolutionary history and structural constraints.
• Invertebrate locomotion offers observable examples of adaptation and structure-function relationships.
• Spiders provide a model system for investigating locomotory adaptations and trade-offs.

Purpose of the Study:

• To investigate adaptation, structure-function relationships, and trade-offs in spider locomotion.
• To allow students to engage in hands-on, inquiry-based learning about animal performance.
• To compare burst and endurance performance across different spider families and ecological niches.

Main Methods:

• Students measured burst and endurance performance in various spider families.
• An inexpensive runway apparatus was utilized for locomotion experiments.
• Experiments were designed to allow for variations, including temperature effects on ectotherms.

Main Results:

• Web-dwelling spiders showed reduced performance on complex terrestrial terrain compared to ground-dwelling spiders.
• A trade-off between burst performance and endurance was observed in spiders.
• High variation in performance underscored the need for multiple trials and statistical analysis.

Conclusions:

• Spider locomotion is a clear example of evolutionary adaptation and physiological trade-offs.
• Hands-on experiments with spiders can effectively teach core biological concepts.
• The experimental design is adaptable for various research questions and educational levels.