イボウミニナ死殻集団の殻サイズ分布形とその形成様式

概要

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The mode of formation of the primary size-frequency distribution and its post-mortem modification in Balillana zonalis (BRUGUiERE) have been studied with population ecologic tequnuque for the living and death populations in the bottom sediments in Irie Bay, Tsuyazaki, Kyushu. The size-frequency distribution of the primary death population, directly derived from the living population of the species, shows a bimodal pattern with a large variance, because of recruitment at long intervals of a few years, slow growth-rate and longevity. The size-frequency distribution patterns of dead shells within or near the habitat of the living population are, on one hand, similar to that of the primary death population. This fact implies that the degree of the post mortem modification of the size-frequency distribution might have been scare. On the other hand, those of dead shells far from the habitat of the living population have been strongly modified from that of the primary death population. The main factor controlling the postmortem modification of size-frequency distribution pattern of primary death population in this bay is attributed to the size selective use and transportation by intertidal hermit crabs, and the effect of tidal currents is considered to be much smaller and slower than the former.
地学団体研究会の論文
1980-01-25