Octopus And Squid Views
An octopus has a round head and a mantle along with eight arms. The arms are endowed with one or two rows of suckers but these never have hooks or sucker rings. Squids are also cephalopods with a triangular shaped head, a mantle and eight arms. Along with that they have two fins on their head and two tentacles. The arms of a Squid are endowed with hooks and/or suckers or sucker rings. The tentacles are arranged in pairs.
Both octopuses and squids have three hearts. Two pump blood through each of the two gills, while the third pumps blood through the body. Octopus blood contains the copper-rich protein hemocyanin for transporting oxygen. The hemocyanin is dissolved in the plasma instead of being bound in red blood cells and gives the blood a blue color. Octopuses draw water into their mantle cavity where it passes through its gills. As mollusks, octopuses have gills that are finely divided and vascularized outgrowths of either the outer or the inner body surface. The hearts of a squid are surrounded by the renal sacs - the main excretory system of the squid. The kidneys are faint and difficult to identify and stretch from the hearts (located at the posterior side of the ink sac) to the liver.
Octopuses and squids move by jet propulsion , sucking water into a muscular sac in the mantle cavity surrounding their bodies and quickly expelling it out a narrow siphon. Octopuses and squids can swim in any direction and can alter their course quickly. Squids use fins located on their heads to propel themselves when swimming at low speeds. These fins steer and stabilize the squids when moving slowly, and wrap around the body when they move quickly, by way of jet propulsion. Most octopuses do not have fins as adults. Some deepwater octopuses are exceptions. The eyes of a Squid, found on either side of the head, each contain a hard lens. The lens is focused by moving, much like the lens of a camera or telescope, rather than changing shape like a human eye.
Octopuses use their eight sucker-lined arms to capture their prey and move about on the ocean floor. Squids have eight arms lined with suckers and two specialized tentacles that they use to reach out and capture prey. Octopuses pierce the shells of their prey, injecting venom that causes paralysis. They then release salivary enzymes, loosening the meat from the inner shell. Squids use their two specialized tentacles to quickly reach out and capture fishes. They tear off bits of flesh and scrape the meat into their mouths with their beaks.
Octopus And Squid Images
