Cuttlefish

Many people think cuttlefish is octopus or squid. In fact, cuttlefish is a separate species from both octopus and squid. However, cuttlefish belongs to the same class as octopus and squid - Cephalopoda. Just like squid, cuttlefish have an internal shell, arms, tentacles, and suckers. Besides that, just like all animals in Class Cephalopoda, it has an ink sac that stores ink as a defense mechanism. Some cuttlefish are venomous. For example, the muscles of a flamboyant cuttlefish are extremely poisonous. Taken by me, the picture on the bottom shows a flamboyant cuttlefish near the reef in Mabul Island, Malaysia, and the picture on top shows a common cuttlefish in the same reef.