Ezo bafun sea urchin - Ezo bafun sea urchin

A marine animal belonging to the Echinodermata phylum, Echinoidea class, and family Unidiidae. It is a short-spined sea urchin that is most commonly found along the coasts of Hokkaido and the northeastern Tohoku region. It reaches a shell diameter of 6 cm and a height of 3.5 cm. It is similar to the bafun sea urchin found in Honshu, but is nearly twice as large and has thicker and longer spines. It can also be distinguished by the fact that it has five pairs of tube foot pores on its shell plate compared to the four pairs of the bafun sea urchin. Its body color is not consistent, and it can be dark green, greenish brown, reddish brown, or even yellowish white or greenish purple. It is found in rocky and boulder-like areas from the low tide line to a depth of about 30 meters, and feeds mainly on brown algae such as kelp. Its spawning season varies greatly depending on the region, ranging from May to November. It is the most commonly caught of all the sea urchins found in Japan.

[Michio Shigei]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

棘皮(きょくひ)動物門ウニ綱オオバフンウニ科に属する海産動物。北海道と東北地方北東部沿岸でもっとも普通にみられる棘(とげ)の短いウニ。殻径6センチメートル、高さ3.5センチメートルに達する。本州産のバフンウニに似ているが、大きさは倍近くになり、棘もより太くて長い。また殻板の管足孔対数がバフンウニの4対に対して5対あることによって区別できる。体色は一定せず、暗緑色、緑褐色、赤褐色、あるいは黄白色や緑紫色を帯びたものもある。低潮線付近から水深30メートルぐらいまでの岩礁帯や転石帯に多く、コンブなどの褐藻類を中心に摂食する。産卵期は地方によって大幅にずれ、5～11月にわたる。日本産ウニ類のうちもっとも漁獲量が多い。

［重井陸夫］

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