抄録
The Titan Acorn barnacle Megabalanus coccopoma was described by Darwin (1854) from the Pacific coast of Panama. Since then, barnacle has became well-known as the introduced barnacle along the Atlantic coasts of Brazil, the USA, and Europe. As was reported in 2009, M. coccopoma was first detected in Japan on September 22, 2007, at the Port of Mizushima in Okayama Prefecture on the hull of an iron-ore carrier that had mainly being cruising between Japan and Australia, then also from the some points of Japanese coast and in various eastern Australian ports (Yamaguchi et al., 2009). In this paper, the current geographic distribution of M. coccopoma in Japan is reported. Also re-examination of my older collections has resulted in a few earlier confirmed records of this barnacles in Japan, in 1978 on oil tanker in the Port of Chiba and in 1981 and 1982 on fishing-net buoys in the Cape Muroto.
