Biometrie Analysis of Nautilus pompilius from the Philippines and the Fiji Islands

Abstract

Since Moseley (1838) first analyzed the geometry of the Nautilus shell, its morphological features and allometric growth have been studied by many authors (Thompson, 1917; Huxley, 1932; Hirano, 1977; Hirano and Obata, 1979; Hirano et al., 1980). Most previous work was based on small collections of individual specimens, the sexes and detailed locality record of which were unknown. In 1981 and 1983, a research project on the ecology of N. pompilius was carried out in the Philippines and the Fiji Islands as a joint venture of Japanese, Philippine, and Fijian scientists (under the leadership of Prof. S. Hayasaka of Kagoshima University). During this project, we examined the biometrie properties of soft and hard tissues in captured animals (Hayasaka et al., 1982; Tanabe et al., 1983, 1985; Tsukahara, 1985). This chapter summarizes our work on N. pompilius, with special reference to sexual dimorphism expressed in allometric relationships and the variation in the shell and soft parts in the two populations from widely separated areas.