Deceptive communication in asymmetric fights of the stomatopod crustacean Gonodactylus bredini

Abstract

When fighting for ownership of cavities, newly moulted stomatopods, Gonodactylus bredini, bluffed opponents by producing meral spread threat displays, even though their soft condition prevented them from delivering or withstanding blows. Newly moulted stomatopods adjusted the frequency of bluffing according to the relative size of their opponent, apparently in response to the risk of probing. Newly moulted residents were more likely to threaten and less likely to flee when facing intruders that were 15% smaller than when facing intruders that were the same size or 15% larger. Bluffs by residents inhibited escalation by intruders and increased the probability of successful cavity defence. This effect was strongest when the intruder was smaller than the resident. When stomatopods fought twice in the laboratory, they often modified their fighting behaviour according to the nature of their first encounter. However, no evidence was found that intruders developed scepticism towards the meral spread threat display after successfully evicting a bluffing resident. Furthermore, newly moulted animals did not decrease their use of the bluff following unsuccessful attempts to deter intruders. © 1990.