Humboldt squid squid uses its barbed tentacle suckers to grab its prey and slices and tears the victim's flesh with its beak and radula. They often approach prey quickly with all 10 appendages extended forward in a cone-like shape. Upon reaching striking distance, they open their eight swimming and grasping arms, and extend two long tentacles covered in sharp 'teeth', grabbing their prey and pulling it back towards a parrot-like beak, which can easily cause serious lacerations to human flesh. These two longer tentacles can reach full length, grab prey, and retract so fast that almost the entire event happens in one
Squid is given to reproduction; the female "Onychoteuthis banksii" for example, sheds its feeding tentacles on reaching maturity, and becomes flaccid and weak after spawning. The squid mantle cavity is a seawater-filled sac containing three hearts and other organs supporting circulation, respiration, and excretion. Squid have a main systemic heart that pumps blood to the general circulatory system, and two branchial hearts that pump specifically to the gills. The systemic heart consists of three chambers, a lower ventricle and two upper atria, which are all contractile. The blood contains the copper-rich protein, hemocyanin, which is used for oxygen transport at low