2005 年 60 巻 2 号 p. 39-44
Abstract: In many harpacticoid species, adult males engage in precopulatory mate guarding. We investigated male mate preference in Phyllopodopsyllus sp. by surveying mate guarding in populations from Otsuchi Bay, north-eastern Japan. Adult males were found clasping other individuals throughout the seasons. They generally clasped fifth-and fourth-stage copepodite females. Third-stage copepodites were also occasionally grasped, while coupling with an adult female or a copepodite male was very rare. Statistical analyses suggest that males do not clasp cope podites at all stages randomly, but rather guard juveniles at the third and later stages of development. However, they do not show a clear preference for any one of the three copepodite stages(third-, fourth-, and fifth-stage)that they select. Overall, we documented a very low frequency of pairing, which suggests that males of this species spend much more time feeding or searching for better mates than guarding juveniles until their final molt.