Experiments with claw models explain the function of the waving display ofIlyoplax pusilla(Brachyura: Dotillidae).
Males of the dotillid crab,Ilyoplax pusilla, perform waving displays during the reproductive season. Unlike many fiddler crabs (genusUca), however, the function of the waving display is unclear for this species. Experiments using waving and static claw models over short (10 cm) and long (25 cm) distances were conducted to investigate responses by wandering females to artificial waving signals. In long-distance choice experiments, presuming undirected waving to unseen females as broadcast waving, females were equally likely to approach the waving and static claw sections during the non-reproductive season, but significantly more females (65 %) chose the waving claw section during the reproductive season. In short-distance choice experiments, presuming directed courtship waving toward a particular female, there was no significant difference between the waving and static claw models during the non-reproductive season, but significantly more females (88 %) chose the waving claw during the reproductive season. These results suggest that one function of the waving display ofI. pusillais mate attraction and that waving from a short distance is more effective.
grid.274841.c0000000106606749Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555 Japan.
Daichi
D
Izumi
grid.274841.c0000000106606749Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555 Japan.
Yoko
Y
Kawano
grid.274841.c0000000106606749Aitsu Marine Station, Center for Marine Environment Studies, Kumamoto University, Matsushima, Kami-Amakusa, Kumamoto 861-6102 Japan.
Yasuhisa
Y
Henmi
Claw model; Dotillid crab; Female choice; Ilyoplax pusilla; Signal function; Waving display