中文翻译与英英解释

ink sac ＝ ink bag.

ink:    n. 1.墨水；(印刷用的)油墨。 2.(乌贼分泌的)墨 ...

sac:    n. 1.【生物学】囊，液囊。 2.上衣 (＝sack) ...

With the exception of nocturnal and very deep water cephalopods, all coeloids which dwell in light conditions have an ink sac, which can be used to expel a cloud of dark ink to confuse predators. This sac is a muscular bag which originated as an extension of the hind gut; it is a modified hypobranchial gland.