Asian branched murex

A gastropod shell of the family Muricidae in the class Gastropoda of the phylum Mollusca. It is named after the turban shell, which has many spines, but it is not related to the turban shell in terms of taxonomy, and is not only in a different family but also in a different order. It is also called Iwabora. The name Kiebora is a misreading of the kanji, and is not the correct name. It is found in various parts of the western Pacific Ocean south of the Boso Peninsula, and is often found on rocky reefs from the intertidal zone to a depth of about 20 meters, and is often caught in bottom gill nets for spiny lobsters. Its shell is 90 mm high and 50 mm in diameter, and the spiral layer has thick longitudinal ribs every 120 degrees, and above these are branch-like spines. The spines on the shoulders are particularly thick and long, and curve slightly backward, reaching up to 25 mm. The opening of the shell is egg-shaped, the inside of the shell is white, but the edges are pale pink. The operculum is egg-shaped and leathery. In summer, they lay yellowish-white, vase-shaped egg capsules about 15 mm high. They are carnivorous and feed on other shellfish by boring holes into them.

[Takashi Okutani]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

軟体動物門腹足綱アクキガイ科の巻き貝。殻に棘(とげ)の多い点がサザエに似ているとしてこの名があるが、分類上は縁遠く、科ばかりでなく目の段階でも異なる。別名をイワボラという。キエボラという名は漢字名の読み違えによるもので、正しい呼び名ではない。房総半島以南、西太平洋の各地に分布し、潮間帯から水深20メートルぐらいまでの岩礁に多く、イセエビをとる底刺網に多くかかる。殻高90ミリメートル、殻径50ミリメートルになり、螺層(らそう)には120度ごとに太い縦肋(じゅうろく)があり、この上に樹枝状に開いた棘が出る。とくに肩の棘は太くて長く、いくぶん後方に反り、25ミリメートルにもなる。殻口は卵形で殻内は白いが、縁は淡紅色。蓋(ふた)は卵形で革質。夏季に黄白色の高さ15ミリメートルぐらいの花瓶状の卵嚢(らんのう)を固めて産み付ける。ほかの貝を穿孔(せんこう)して食べる肉食性である。

［奥谷喬司］

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