Meeting Abstract
41.2 Monday, Jan. 5 Occurrence of the rhizocephalan and isopod parasites on three intertidal hermit crabs in Japan ASAKURA, A.*; IMAZU, M.; Nat. Hist. Mus. Inst. Chiba, Japan; Toho Univ., Funabashi, Japan asakura@chiba-muse.or.jp
To examine the prevalence of rhizocephalan and isopod parasitism, we sampled three hermit crab species, Pagurus filholi (n=5738), P. maculosus (n=720), and Clibanarius virescens (n=2436) for 13 months from the intertidal rocky shore at Chiba in Pacific coast of the middle Japan. Species of the Peltogastridae (Rhizocephala: ?Peltogaster paguri) and species of the Athelginae (Isopoda: Bopyridae: ?Athelges takanoshimensis) were found on the abdomens of the crabs and, species of the Pseudioninae (Isopoda: Bopyridae: ?Pseudione) occurred in the branchial chambers of the crabs. In total, 10.06% of the collected individuals of P. filholi, 4.12% of P. maculosus, and 0.93 % of C. viresens were infected with these parasitic crustaceans. No conspicuous seasonal difference was detected in the infection rate of these parasites in the all crab species. In P. filholi, 12.21% of the males and 8.32% of the females were infected with the rhizocephalan, and 0.05% of the males and 0.06% of the females were infected with the athelgins; the infection rate of the rhizocephalan and the athelgins tended to increase with crab size. The rhizocephalan more frequently parasitized upon males than females, but the infection rate of the athelgins was not significantly different between the sexes. In P. maculosus, 1.40% of the males and 0.58% of the females were infected with the rhizocephalan, 2.80% of the males and 2.90% of females were infected with the athelgins, and the 0.35% of the males and no females were infected with the pseudionins; the infection rate was not significantly different between the sexes in all these parasites. In C. virescens, 0.27% of the males and 0.43% of the females were infected with the athelgins, and 0.36% of males and 0.78% of females were infected with the pseudionins; the infection rate was not significantly different between the sexes in these parasites.
