I. Akagawa et al., Female mate choice through spawning parade formed by male-male competitionin filefish Rudarius ercodes, J ETHOL, 16(2), 1998, pp. 105-113
In the small filefish Rudarius ercodes inhabiting temperate seaweed beds, 2
-10 males follow a gravid female, in a line until spawning early in the mor
ning. Formation of the spawning parade and change of male order were invest
igated in a large aquarium. Males competed for the position nearest to the
female during the parade, while the female controlled the parade by her swi
mming speed and course. During the parade, male members and their order cha
nged frequently. The male order in the parade was related with the intensit
y of nuptial coloration, which changed according to the social rank. The fe
male sometimes tried to take a spawning posture but rejected spawning when
male positioning was not good for her, for example, far different from para
ding order. The female spawned with 2-5 males on each side. The nearest mat
ing positions to the female were usually occupied by two males that had bee
n staying at an anterior position in the parade for a long time. During the
spawning parade over a long distance and time, females of R. ercodes can c
hoose multiple suitable males in a variable environment like a temperate se
aweed bed.