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Strombus luhuanus breeds in the summer from June to August at Snirahama. To copulate, the male follows the trail of the female or approaches the stationary female mounted on by another male. The female lays an egg mass either alone or being mounted by the male(s). Copulation and spawning occur mainly at the sand-pebble areas both in the shallow waters, where the conch appears only in the breeding season, and in the deep (<20m) waters. Factors affecting upon selection of spawning sites are discussed.

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Spatial distribution and growth of the gastropod Strombus luhuanus were investigated in the shallow waters of Shirahama, Japan. Newly settled juveniles smaller than 25 mm in shell length were found mainly on the rock flat shallower than ca. 5 m, where few adults were found. From O+ to 1 +year, they migrated downward to the fringe of rock and its adjacent areas, as they grew up to 40 mm in shell length, and then merged to the adult populations. At the age of 2+ years, they attained to 40-60 mm in shell length and some of them migrated offshore afterwards. Maturity and thickening of shell-lip usually occurred at the age of 2+ years or older. Adults showed seasonal changes in their distribution pattern. In winter they aggregated on the sand-pebble and near the fringe of rock, while from late spring to autumn they extended their distribution over sand and mud areas, offshore and inshore. Only in summer, many adults appeared on the sand-pebble area near the shoreline, being concurrent with coupling and spawning. S. luhuanus, thus, use the various substrata as their habitat, according to the life stages.

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