Collar
Fleshy border separating head-foot from visceral mass
Eyes
Image-forming organs for detecting visual stimuli
Siphon
Hollow tube through which water is expelled from the mantle cavity at high velocity to propel the squid through the water
Mantle
Body tube encircling visceral mass forming a hollow chamber in which water is collected and used for propulsion
Arms
Shorter appendages (8) used to manipulate captured prey and act as a rudder for navigating while swimming
Tentacles
Long, extensible, prehensile appendages (2) for capturing prey
Fins
Triangular-shaped extensions of the dorsal end of the body tube that are used for leisurely swimming and for maneuvering during locomotion
Gills
Paired, feathery organs used for respiration
Esophagus
Thin tube connecting the mouth to the stomach
Pancreas
Small, granular digestive gland that secretes enzymes into the stomach to assist in the breakdown of food
Liver
Large, elongated gland that releases secretions into the stomach to facilitate enzymatic digestion of food
Cecum
Large, thin-walled digestive chamber prominent along the dorsal end of the body
Rectum
Portion of digestive tract leading to anus
Ink sac
Large sac that opens into the rectum and secretes a dark brown or black fluid when the animal is alarmed
Anus
Terminal portion of digestive tract located near siphon
Testis (male)
Produces sperm; located in dorsal end of body tube
Vas deferens (male)
Open-ended chamber that receives and stores sperm
Spermatophoric gland (male)
Coiled, convoluted tubules that package sperm cells into spermatophore packets
Penis (male)
Muscular organ that gathers spermatophores and releases them outside the body where they are transferred by the males hectocotylus to the female during mating
Ovary (female)
Site of egg production
Oviduct (female)
Open-ended chamber that receives eggs from the ovary
Nidamental glands (female)
Produce secretions that form an encasement around the strings of eggs to protect them
Retractor muscles
Long muscles that control the retraction of the siphon and the head
Kidneys
Paired excretory organs located near the systemic heart that filter nitrogenous wastes from the hemolymph and eliminate them from the body
Systemic heart
Large, muscular ventricle that receives oxygenated blood from the gills and pumps it throughout the body
Branchial hearts
Smaller, muscular chambers that receive deoxygenated blood from all parts of the body and pump blood to the gills