Sowerby's nerita

A gastropod snail of the family Neritidae in the class Gastropoda of the phylum Mollusca. It attaches to pebbles in places where freshwater and seawater mix, such as estuaries along the tropical coast of the western Pacific Ocean south of the Kii Peninsula. Its shell is thick and hemispherical, reaching a height of 15 mm and a diameter of 17 mm, and is covered with a thick, yellowish-brown skin that varies in color, with triangular spots, bands, and stripes in black, brown, red, and yellow. The opening of the shell has a calcareous, crescent-shaped lid.

[Takashi Okutani]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

軟体動物門腹足綱アマオブネガイ科の巻き貝。紀伊半島以南の西太平洋の熱帯域沿岸の河口など淡水と海水の混じるところの小石の上に付着する。殻高15ミリメートル、殻径17ミリメートルに達し、殻は半球状で厚く、黄褐色の厚い殻皮に覆われていてその殻色は変化が多く、黒、褐、赤、黄などの三角形の斑(はん)や帯や筋(すじ)がある。殻口には石灰質で半月形の蓋(ふた)がある。

［奥谷喬司］

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