Dishonest signals of strength in male slender crayfish (Cherax dispar) during agonistic encounters

Robbie S. Wilson, Michael Angilletta, Rob S. James, Carlos Navas, Frank Seebacher

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

Many animals resolve disputes without combat by displaying signals of potential strength during threatening displays. Presumably, competitors use each other's displays to assess their relative strengths, and current theory predicts that these signals of strength should generally be honest. We tested this prediction by investigating the relationships among morphology, performance, and social dominance in males of the slender crayfish Cherax dispar. Crayfish routinely use their enlarged front claws (chelae) for both intimidation and fighting, making this species ideal for studying the honesty of weapon size. We evaluated five competing models relating morphological and physiological traits to dominance during paired competitive bouts. Based on the best model, larger chelae clearly resulted in greater dominance; however, chela strength had no bearing on dominance. Thus, displays of chela size were dishonest signals of strength, and the enlarged chelae of males seemingly function more for intimidation than for fighting. In addition, an analysis of the performance of isolated chela muscle showed that muscle from male crayfish produced only half the force that muscle from female crayfish produced (236.6 ± 26.4 vs. 459.5 ± 71.6 kN m-2), suggesting that males invest more in developing larger chelae than they do in producing high-quality chela muscle. From our studies of crayfish, we believe dishonest signaling could play a greater role in territorial disputes than previously imagined.

Original languageEnglish (US)
Pages (from-to)284-291
Number of pages8
JournalAmerican Naturalist
Volume170
Issue number2
DOIs
StatePublished - Aug 2007
Externally publishedYes

Fingerprint

Cherax
crayfish
muscle
dominance (genetics)
muscles
fighting
territorial dispute
social dominance
weapon
claws
prediction
Chela
animal
animals

Keywords

  • Chela strength
  • Dominance
  • Signaling
  • Weapon size

ASJC Scopus subject areas

  • Ecology

Cite this

Dishonest signals of strength in male slender crayfish (Cherax dispar) during agonistic encounters. / Wilson, Robbie S.; Angilletta, Michael; James, Rob S.; Navas, Carlos; Seebacher, Frank.

In: American Naturalist, Vol. 170, No. 2, 08.2007, p. 284-291.

Research output: Contribution to journalArticle

Wilson, Robbie S. ; Angilletta, Michael ; James, Rob S. ; Navas, Carlos ; Seebacher, Frank. / Dishonest signals of strength in male slender crayfish (Cherax dispar) during agonistic encounters. In: American Naturalist. 2007 ; Vol. 170, No. 2. pp. 284-291.
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