Trials on New Methods for Seed Culture in Japanese Abalones.

Abalones are one of the most important coastal animal resources in Japan, and the study of their seed culture has a long history of more than 40 years. Most of the produced seeds have been released to the seabeds. The total number released nowadays is almost 3 million (small individuals) per year. However, the annual production of natural abalones has decreased remarkably in the last 10 years. Still, the culturing of market-size abalones has been started in several regions in Japan, such as Haliotis discus in the south and H. discus hannai in the north. The production of cultured abalones is slowly increasing. This tendency has the benefits of preventing over catching of natural stocks and reducing the importation of cultured abalone from foreign countries. Under these conditions, we tried to improve this trend with some experiments on seed culture methods. 1. Using artificial food (a microparticle diet) to replace natural diatoms for feeding post-larval abalones to improve the survival and growth rates 2. Trials for the improvement of artificial production of inter-specific hybrids among three large size species The result will lead to recommendations for newly developed adult cultures in closed spaces. The possibility of producing regional specialities is suggested. [ABSTRACT FROM AUTHOR]