Data and code for manuscript "Weapon regeneration can promote unreliable signalling when reduced strength goes undetected"

Using the crayfish <i>Cherax destructor</i>, we experimentally removed one chela from 40 individuals and compared them with 40 intact controls after 12 months of regeneration. We measured weapon morphology, claw strength, body growth, swimming performance and contest outcomes.

We found that regenerated chelae were smaller, more slender and weaker for their size, revealing a mismatch between signal size and actual fighting ability, with few detectable costs to growth or swimming. In contests, weapon size alone predicted success when interactions were resolved through signalling, while both size and strength mattered once fights escalated. Our results suggest that unreliable signals can persist when receivers cannot detect reduced performance and only occasionally test signals through escalation.</p>