Crayfish Size Ceiling from Museum Data

A continental‑scale survey of museum and field specimens reveals an ~80 mm upper size limit for North American crayfish, despite indeterminate growth; researchers argue the ceiling likely reflects physiological and life‑history constraints (molting vulnerability, locomotor/burrowing mechanics) rather than simple climatic or evolutionary trends. The pattern was identified by aggregating measurements from collections and comparing species/ecological modes, then testing common macroecological rules and ruling them out. — Demonstrates how low‑cost, museum‑based datasets can detect macroecological limits and guide mechanistic hypotheses with implications for life‑history theory, conservation priorities, and how we interpret size trends across regions.