抄録
Large sciaenid otoliths were presented from Narimasa Ikeda, the sixth feudal lord of the Okayama Han (clan) to Ienari Tokugawa, the eleventh Shogun of the Tokugawa Shogunate, the central government of then Japan, as one of crude medicines from 1794 to 1801, and now some of them are preserved as a historical heritage at Naito Museum of Pharmaceutical Science and Industry, Kakamigahara, Gifu Prefecture. In the preliminary survey in 2003, they were identifi ed as sagittae of Miichthys miiuy (Basilewsky) and Argyrosomus japonicus (Temminck et Schlegel) by the author, and their species names were publicly reported by Ebihara et al. 1) and Goto et al. 2) in 2004. In a follow-up survey, the author has confi rmed that the sagittae of Argyrosomus japonicus (Temminck et Schlegel) can mostly be divided into seven types (AtoG) from their polymorphic appearance. The Argyrosomus japonicus is a peculiar species: habitats of allopatric populations of this species are distributed in the East China Sea, Japan, South Africa, Pakistan, and Australia. On the other hand, the Miichthys miiuy is an endemic species which can only be seen in the East China Sea and the Yellow Sea.
Although no historical record has been found as to where these two species were captured, the author surmises that the otoliths were extracted from large individuals caught in the waters of the East China Sea near the Chushan Islands (Zhoushan Qundao) where the two species inhabit together. Besides, it is conjectured that the Okayama Han, which faced the Seto Inland Sea (Setonaikai), imported Chinese otoliths through a few ports such as Nagasaki where foreign trade only with Portugal was allowed under the national isolation of the Tokugawa Shogunate.
