- A very large whalebone whale(Sibbaldus musculus) having a bluish-gray back, yellow underparts, and several ventral throat grooves. It is considered the largest living animal, sometimes reaching a length of 30.5 meters (100 feet). Also called sulphur-bottom 蓝鲸：一种巨大的须鲸（蓝鲸） ，背呈蓝灰色，下部呈黄色，有几个换气孔。它被认为是最大的存活动物，最大可长30.5米(100英尺） 也作 sulphur-bottom