Abstract
Commercial landing of Japanese spiny lobster has consisted of II to IV-age groups. Age composition and its seasonal change in the southern Izu Peninsula indicated that the distribution pattern of an age group was stable and specific to the age and geographical characteristics. Statistics of I-age Japanese spiny lobster as bycatch should be useful as an index of abundance of recruitment Linear regression relationship was observed in the catch quantity of I-age lobster to the catch of II-age group in the next year, and the catch of II-age group to the catch of III-age group in the next year. Therefore, the catch of Japanese spiny lobster depends on recruitment as I-age group lobster. The quantity of bycatch of I-age lobster was related to the location of the stream axis of the Kuroshio Current. This suggests a relationship between the number of pueruli recruited and the location of the stream axis of the Kuroshio Current. Although it is possible to estimate the abundance of recruitment using records of collections of pueruli, year round collection data of pueruli should improve the development of fisheries management procedure.
