The shark described a circle around the shoal of fish.

这条鲨鱼围绕着鱼群游动。

《牛津词典》

Recent research had shown that fish recognised individual "shoal mates", social prestige and even tracked relationships.

最近的研究表明鱼可以识别各自的“鱼群伙伴”、社会威望，甚至相关的人际关系。

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Agrillo's team found that mosquitofish can discriminate between numbers up to 16, but only if the ratio between the fish in each shoal was greater than 2:1.

阿格利罗的团队发现，食蚊鱼最多可以分辨大到16的两个数字的大小，但前提是每个鱼群中鱼的比例大于2:1。

youdao

His job was to shout when he spotted a shoal of fish enter the cove, so the team below could trap and catch it.

BBC: Oman��s sleepy Musandam Peninsula