Hi K M HosterGlad to have you here! There are a lot of questions in there, which is good, I just apologize if I miss something in my response. I would first start out searching through the literature.
The Oxford English Dictionary lists "octopuses", "octopi", and "octopodes", in that order, reflecting frequency of use, calling "octopodes" rare and noting that "octopi" is based on a misunderstanding. The giant Pacific octopus Enteroctopus dofleini is often cited as the largest known octopus species.
The head includes the mouth and brain. The foot has evolved into a set of flexible, prehensile appendagesknown as "arms", that surround the mouth and are attached to each other near their base by a webbed structure. The skin consists of a thin outer epidermis with mucous cells and sensory cells, and a connective tissue dermis consisting largely of collagen fibres and various cells allowing colour change.
The octopus can squeeze through tiny gaps; even the larger species can pass through an opening close to 2. They can extend and contract, twist to left or right, bend at any place in any direction or be held rigid. The suckers allow the octopus to anchor itself or to manipulate objects.
Each sucker is usually circular and bowl-like and has two distinct parts: When a sucker attaches to a surface, the orifice between the two structures is sealed. The infundibulum provides adhesion while the acetabulum remains free, and muscle contractions allow for attachment and detachment.
The eyes of the octopus are large and are at the top of the head. They are similar in structure to those of a fish and are enclosed in a cartilaginous capsule fused to the cranium. The cornea is formed from a translucent epidermal layer and the slit-shaped pupil forms a hole in the iris and lies just behind.
The lens is suspended behind the pupil and photoreceptive retinal cells cover the back of the eye. The pupil can be adjusted in size and a retinal pigment screens incident light in bright conditions.
Members of the suborder Cirrina have stout gelatinous bodies with webbing that reaches near the tip of their arms, and two large fins above the eyes, supported by an internal shell. Fleshy papillae or cirri are found along the bottom of the arms, and the eyes are more developed. Octopuses have three hearts; a systemic heart that circulates blood round the body and two branchial hearts that pump it through each of the two gills.
The systemic heart is inactive when the animal is swimming and thus it tires quickly and prefers to crawl. This makes the blood very viscous and it requires considerable pressure to pump it round the body; octopuses' blood pressures can exceed 75 mmHg.
The haemocyanin is dissolved in the plasma instead of being carried within blood cells, and gives the blood a bluish colour. The blood vessels consist of arteries, capillaries and veins and are lined with a cellular endothelium which is quite unlike that of most other invertebrates.
The blood circulates through the aorta and capillary system, to the vena cavae, after which the blood is pumped through the gills by the auxiliary hearts and back to the main heart.
Much of the venous system is contractile, which helps circulate the blood. The siphon is used for respiration, waste disposal and discharging ink.Newsreel footage.
Voice Over (newsreel voice) In the modern Britain, united under a great leader, it's the housewives of Britain who are getting things moving.(Red Devils flying; picture of Edward Heath) Here a coachload of lovely ladies are on their way to speed up production in a car factory.(coach load of pepperpots, middle class, grey hair, Mary Whitehouse glasses; the coach says 'Tory.
Learning from the Soft Intelligence: Cephalopods as Indicators of Ocean Changes ENSP Internship Paper Cephalopods are exclusively marine invertebrates which . May 18, · The argonauts are a group of octopuses unlike any other.
The females secrete a thin, white, brittle shell called the paper nautilus. Nestled with their arms tucked inside this beautiful. Initially, their preferred research objects were fish, but it soon became evident that cephalopods have features which make them particularly suited to research.
After the first studies, which outlined the anatomical structure of cephalopods' eyes and optic nerves, the research rapidly shifted to the electrophysiology and biochemistry of vision.
The octopus is a soft-bodied, eight-limbed mollusc of the order ashio-midori.com species are recognised, and the order is grouped within the class Cephalopoda with squids, cuttlefish, and ashio-midori.com other cephalopods, the octopus is bilaterally symmetric with two eyes and a beak, with its mouth at the center point of the eight limbs (traditionally called "arms", sometimes mistakenly.
The Marine Biological Laboratory (MBL) is dedicated to scientific discovery – exploring fundamental biology, understanding biodiversity and the environment, and informing the human condition through research and education.
Founded in Woods Hole, Massachusetts in , the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.