Squid Vs. Cuttlefish

Many people ask me, what is the difference between squid and cuttlefish?

Squid a member of the cephalopod family, have a hard inner-body shell called a pen whereas Cuttlefish (also belonging to the cephalopod family) have an internal structure called a cuttlebone, which is porous and composed of aragonite, to provide the cuttlefish with buoyancy. The cuttlebone is unique to cuttlefish, and is one distinct feature that makes them different from their all their other cephalopod relatives. This bone aids the cuttlefish with buoyancy, by changing gas-to-liquid ratios in the chambered cuttlebone. Each species’ cuttlebone has a distinct shape, size, and pattern of ridges or texture. Cuttlefish are also among the most intelligent of the invertebrates. Both creatures, however, have amazing eyesight, swift flight-like movements and a tenacity for camouflage. Both are a delight to spend time with underwater and have the amazing ability to light up like a carnival ride.