The line along which the jaws of a fish close; the length of the gape is a straight-line measurement from the snout tip to the mouth angle; opening of the mouth, measured tranversely.

• 口裂沿著一条鱼关闭的颚的那条线；口裂的长度是一个从吻部顶端到嘴角的直线距离；嘴巴的开口，横向测量的。