First record of Holophryxus fusiformis Shiino, 1937 (Crustacea, Isopoda, Dajidae) from the sakura shrimp, Lucensosergia lucens, in Taiwan

Abstract

Holophryxus fusiformis Shiino, 1937, a species of dajid isopod that at- taches to the carapace of sakura shrimp, Lucensosergia lucens (Hansen, 1922), is re- ported from the sea of Taiwan for the first time. This species was first described as in- festing Prehensilosergia prehensilis (Bate, 1881) from Kanbara, Shizuoka Prefecture, Japan. The current finding represents the second occurrence of H. fusiformis and iden- tifies a new host. Approximately 1% of the sakura shrimps in Yilan, Taiwan are infect- ed by H. fusiformis. Holophryxus fusiformis has been found offshore from both Yilan, Taiwan and Nagasaki and in Suruga Bay, Japan; thus, the distribution of the parasite possibly follows the Kuroshio Current. When large quantities of parasites occur in the sea of Taiwan, the parasites are likely to flow into the Japanese waters along with the Kuroshio Current, subsequently influencing the production of the Japanese sakura shrimps. The establishment of a monitoring program for infection of the dajid in saku- ra shrimps between Taiwan and Japan is recommended. This study provides additional information on this species, including a new host, distribution, redescription, infection rate, and morphological variation. Key