Friday, 30 October 2009
Thursday, 29 October 2009
Monday, 6 July 2009
Octopuses are characterized by their eight arms, usually bearing suction cups. The arms of octopuses are often distinguished from the pair of feeding tentacles found in squid and cuttlefish.[6] Both types of limbs are muscular hydrostats. Unlike most other cephalopods, the majority of octopuses – those in the suborder most commonly known, Incirrina – have almost entirely soft bodies with no internal skeleton. They have neither a protective outer shell like the nautilus, nor any vestige of an internal shell or bones, like cuttlefish or squid. A beak, similar in shape to a parrot's beak, is the only hard part of their body. This enables them to squeeze through very narrow slits between underwater rocks, which is very helpful when they are fleeing from morays or other predatory fish. The octopuses in the less familiar Cirrina suborder have two fins and an internal shell, generally reducing their ability to squeeze into small spaces.
An octopus moving between tide pools during low tideOctopuses have a relatively short life expectancy, and some species live for as little as six months. Larger species, such as the North Pacific Giant Octopus, may live for up to five years under suitable circumstances. However, reproduction is a cause of death: males can only live for a few months after mating, and females die shortly after their eggs hatch. They neglect to eat during the (roughly) one month period spent taking care of their unhatched eggs, but they don't die of starvation. Endocrine secretions from the two optic glands are the cause of genetically-programmed death (and if these glands are surgically removed, the octopus may live many months beyond reproduction, until she finally starves).
Stauroteuthis syrtensis, a finned octopus of the suborder CirrinaOctopuses 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. Although less efficient under normal conditions than the iron-rich hemoglobin of vertebrates, in cold conditions with low oxygen pressure, hemocyanin oxygen transportation is more efficient than hemoglobin oxygen transportation. The hemocyanin is dissolved in the plasma instead of being carried within 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.
An octopus moving between tide pools during low tideOctopuses have a relatively short life expectancy, and some species live for as little as six months. Larger species, such as the North Pacific Giant Octopus, may live for up to five years under suitable circumstances. However, reproduction is a cause of death: males can only live for a few months after mating, and females die shortly after their eggs hatch. They neglect to eat during the (roughly) one month period spent taking care of their unhatched eggs, but they don't die of starvation. Endocrine secretions from the two optic glands are the cause of genetically-programmed death (and if these glands are surgically removed, the octopus may live many months beyond reproduction, until she finally starves).
Stauroteuthis syrtensis, a finned octopus of the suborder CirrinaOctopuses 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. Although less efficient under normal conditions than the iron-rich hemoglobin of vertebrates, in cold conditions with low oxygen pressure, hemocyanin oxygen transportation is more efficient than hemoglobin oxygen transportation. The hemocyanin is dissolved in the plasma instead of being carried within 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.
Reproduction
When octopuses reproduce, males use a specialized arm called a hectocotylus to insert spermatophores (packets of sperm) into the female's mantle cavity. The hectocotylus in benthic octopuses is usually the third right arm. Males die within a few months of mating. In some species, the female octopus can keep the sperm alive inside her for weeks until her eggs are mature. After they have been fertilized, the female lays about 200,000 eggs (this figure dramatically varies between families, genera, species and also individuals). The female hangs these eggs in strings from the ceiling of her lair, or individually attaches them to the substrate depending on the species. The female cares for the eggs, guarding them against predators, and gently blowing currents of water over them so that they get enough oxygen. The female does not eat during the roughly one-month period spent taking care of the unhatched eggs. At around the time the eggs hatch, the mother dies and the young larval octopuses spend a period of time drifting in clouds of plankton, where they feed on copepods, larval crabs and larval starfish until they are ready to sink down to the bottom of the ocean, where the cycle repeats itself. In some deeper dwelling species, the young do not go through this period. This is a dangerous time for the larval octopuses; as they become part of the plankton cloud they are vulnerable to many plankton eaters.
When octopuses reproduce, males use a specialized arm called a hectocotylus to insert spermatophores (packets of sperm) into the female's mantle cavity. The hectocotylus in benthic octopuses is usually the third right arm. Males die within a few months of mating. In some species, the female octopus can keep the sperm alive inside her for weeks until her eggs are mature. After they have been fertilized, the female lays about 200,000 eggs (this figure dramatically varies between families, genera, species and also individuals). The female hangs these eggs in strings from the ceiling of her lair, or individually attaches them to the substrate depending on the species. The female cares for the eggs, guarding them against predators, and gently blowing currents of water over them so that they get enough oxygen. The female does not eat during the roughly one-month period spent taking care of the unhatched eggs. At around the time the eggs hatch, the mother dies and the young larval octopuses spend a period of time drifting in clouds of plankton, where they feed on copepods, larval crabs and larval starfish until they are ready to sink down to the bottom of the ocean, where the cycle repeats itself. In some deeper dwelling species, the young do not go through this period. This is a dangerous time for the larval octopuses; as they become part of the plankton cloud they are vulnerable to many plankton eaters.
Wednesday, 1 July 2009
Octopuses have keen eyesight. Although their slit-shaped pupils might be expected to afflict them with astigmatism, it appears that this is not a problem in the light levels in which an octopus typically hunts.[citation needed] Octopuses, like other cephalopods, can distinguish the polarization of light. Color vision appears to vary from species to species, being present in Octopus aegina but absent in Octopus vulgaris[19]. Attached to the brain are two special organs, called statocysts, that allow the octopus to sense the orientation of its body relative to horizontal. An autonomic response keeps the octopus' eyes oriented so that the pupil slit is always horizontal.
Octopuses also have an excellent sense of touch. An octopus' suction cups are equipped with chemoreceptors so that the octopus can taste what it is touching. The arms contain tension sensors so that the octopus knows whether its arms are stretched out. However, the octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.[20]
The neurological autonomy of the arms means that the octopus has great difficulty learning about the detailed effects of its motions. The brain may issue a high-level command to the arms, but the nerve cords in the arms execute the details. There is no neurological path for the brain to receive feedback about just how its command was executed by the arms; the only way it knows just what motions were made is by observing the arms visually.[20]
Octopuses swim headfirst, with arms trailing behind
[edit]
Octopuses also have an excellent sense of touch. An octopus' suction cups are equipped with chemoreceptors so that the octopus can taste what it is touching. The arms contain tension sensors so that the octopus knows whether its arms are stretched out. However, the octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.[20]
The neurological autonomy of the arms means that the octopus has great difficulty learning about the detailed effects of its motions. The brain may issue a high-level command to the arms, but the nerve cords in the arms execute the details. There is no neurological path for the brain to receive feedback about just how its command was executed by the arms; the only way it knows just what motions were made is by observing the arms visually.[20]
Octopuses swim headfirst, with arms trailing behind
[edit]
Octopuses have keen eyesight. Although their slit-shaped pupils might be expected to afflict them with astigmatism, it appears that this is not a problem in the light levels in which an octopus typically hunts.[citation needed] Octopuses, like other cephalopods, can distinguish the polarization of light. Color vision appears to vary from species to species, being present in Octopus aegina but absent in Octopus vulgaris[19]. Attached to the brain are two special organs, called statocysts, that allow the octopus to sense the orientation of its body relative to horizontal. An autonomic response keeps the octopus' eyes oriented so that the pupil slit is always horizontal.
Octopuses also have an excellent sense of touch. An octopus' suction cups are equipped with chemoreceptors so that the octopus can taste what it is touching. The arms contain tension sensors so that the octopus knows whether its arms are stretched out. However, the octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.[20]
The neurological autonomy of the arms means that the octopus has great difficulty learning about the detailed effects of its motions. The brain may issue a high-level command to the arms, but the nerve cords in the arms execute the details. There is no neurological path for the brain to receive feedback about just how its command was executed by the arms; the only way it knows just what motions were made is by observing the arms visually.[20]
Octopuses swim headfirst, with arms trailing behind
[edit]
Octopuses also have an excellent sense of touch. An octopus' suction cups are equipped with chemoreceptors so that the octopus can taste what it is touching. The arms contain tension sensors so that the octopus knows whether its arms are stretched out. However, the octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.[20]
The neurological autonomy of the arms means that the octopus has great difficulty learning about the detailed effects of its motions. The brain may issue a high-level command to the arms, but the nerve cords in the arms execute the details. There is no neurological path for the brain to receive feedback about just how its command was executed by the arms; the only way it knows just what motions were made is by observing the arms visually.[20]
Octopuses swim headfirst, with arms trailing behind
[edit]
Tuesday, 9 June 2009
Friday, 24 April 2009
Monday, 6 April 2009
As pets
Though octopuses can be difficult to keep in captivity, some people keep them as pets. Octopuses often escape even from supposedly secure tanks, due to their problem solving skills, mobility and lack of rigid structure.
The variation in size and life span among octopus species makes it difficult to know how long a new specimen can naturally be expected to live. That is, a small octopus may be just born or may be an adult, depending on the species. By selecting a well-known species, such as the California Two-spot Octopus, one can choose a small octopus (around the size of a tennis ball) and be confident that it is young with a full life ahead of it.
Octopuses are also quite strong for their size. Octopuses kept as pets have been known to open the covers of their aquariums and survive for a time in the air in order to get to a nearby feeder tank and gorge themselves on the fish there. They have also been known to catch and kill some species of sharks.
The variation in size and life span among octopus species makes it difficult to know how long a new specimen can naturally be expected to live. That is, a small octopus may be just born or may be an adult, depending on the species. By selecting a well-known species, such as the California Two-spot Octopus, one can choose a small octopus (around the size of a tennis ball) and be confident that it is young with a full life ahead of it.
Octopuses are also quite strong for their size. Octopuses kept as pets have been known to open the covers of their aquariums and survive for a time in the air in order to get to a nearby feeder tank and gorge themselves on the fish there. They have also been known to catch and kill some species of sharks.
Saturday, 4 April 2009
Octopuses have keen eyesight. Although their slit-shaped pupils might be expected to afflict them with astigmatism, it appears that this is not a problem in the light levels in which an octopus typically hunts.[citation needed] They do not appear to have color vision, although they can distinguish the polarization of light. Attached to the brain are two special organs, called statocysts, that allow the octopus to sense the orientation of its body relative to horizontal. An autonomic response keeps the octopus' eyes oriented so that the pupil slit is always horizontal.
Octopuses also have an excellent sense of touch. An octopus' suction cups are equipped with chemoreceptors so that the octopus can taste what it is touching. The arms contain tension sensors so that the octopus knows whether its arms are stretched out. However, the octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.[16]
The neurological autonomy of the arms means that the octopus has great difficulty learning about the detailed effects of its motions. The brain may issue a high-level command to the arms, but the nerve cords in the arms execute the details. There is no neurological path for the brain to receive feedback about just how its command was executed by the arms; the only way it knows just what motions were made is by observing the arms visually.[16]
Octopuses also have an excellent sense of touch. An octopus' suction cups are equipped with chemoreceptors so that the octopus can taste what it is touching. The arms contain tension sensors so that the octopus knows whether its arms are stretched out. However, the octopus has a very poor proprioceptive sense. The tension receptors are not sufficient for the octopus brain to determine the position of the octopus' body or arms. (It is not clear that the octopus brain would be capable of processing the large amount of information that this would require; the flexibility of an octopus' arms is much greater than that of the limbs of vertebrates, which devote large areas of cerebral cortex to the processing of proprioceptive inputs.) As a result, the octopus does not possess stereognosis; that is, it does not form a mental image of the overall shape of the object it is handling. It can detect local texture variations, but cannot integrate the information into a larger picture.[16]
The neurological autonomy of the arms means that the octopus has great difficulty learning about the detailed effects of its motions. The brain may issue a high-level command to the arms, but the nerve cords in the arms execute the details. There is no neurological path for the brain to receive feedback about just how its command was executed by the arms; the only way it knows just what motions were made is by observing the arms visually.[16]
Octopuses are highly intelligent, likely more so than any other order of invertebrates. The exact extent of their intelligence and learning capability is much debated among biologists,[4][5][6][7] but maze and problem-solving experiments have shown that they do have both short- and long-term memory. Their short lifespans limit the amount they can ultimately learn. There has been much speculation to the effect that almost all octopus behaviors are independently learned rather than instinct-based, although this remains largely unproven. They learn almost no behaviors from their parents, with whom young octopuses have very little contact.
An octopus opening a container with a screw capAn octopus has a highly complex nervous system, only part of which is localized in its brain. Two-thirds of an octopus' neurons are found in the nerve cords of its arms, which have a remarkable amount of autonomy. Octopus arms show a wide variety of complex reflex actions arising on at least three different levels of the nervous system. Some octopuses, such as the Mimic Octopus, will move their arms in ways that emulate the movements of other sea creatures.
In laboratory experiments, octopuses can be readily trained to distinguish between different shapes and patterns. They have been reported to practice observational learning,[8] although the validity of these findings is widely contested on a number of grounds.[4][5] Octopuses have also been observed in what some have described as play: repeatedly releasing bottles or toys into a circular current in their aquariums and then catching them.[9] Octopuses often break out of their aquariums and sometimes into others in search of food. They have even boarded fishing boats and opened holds to eat crabs.[6]
In some countries, octopuses are on the list of experimental animals on which surgery may not be performed without anesthesia. In the UK, cephalopods such as octopuses are regarded as honorary vertebrates under the Animals (Scientific Procedures) Act 1986 and other cruelty to animals legislation, extending to them protections not normally afforded to invertebrates.[10]
An octopus opening a container with a screw capAn octopus has a highly complex nervous system, only part of which is localized in its brain. Two-thirds of an octopus' neurons are found in the nerve cords of its arms, which have a remarkable amount of autonomy. Octopus arms show a wide variety of complex reflex actions arising on at least three different levels of the nervous system. Some octopuses, such as the Mimic Octopus, will move their arms in ways that emulate the movements of other sea creatures.
In laboratory experiments, octopuses can be readily trained to distinguish between different shapes and patterns. They have been reported to practice observational learning,[8] although the validity of these findings is widely contested on a number of grounds.[4][5] Octopuses have also been observed in what some have described as play: repeatedly releasing bottles or toys into a circular current in their aquariums and then catching them.[9] Octopuses often break out of their aquariums and sometimes into others in search of food. They have even boarded fishing boats and opened holds to eat crabs.[6]
In some countries, octopuses are on the list of experimental animals on which surgery may not be performed without anesthesia. In the UK, cephalopods such as octopuses are regarded as honorary vertebrates under the Animals (Scientific Procedures) Act 1986 and other cruelty to animals legislation, extending to them protections not normally afforded to invertebrates.[10]
Tuesday, 31 March 2009
octopus story and half shark story
one bright morning in a beautiful ocean there lived an octopus the octopus was near an shark and the octopus was changed couler so the shark couldn't see the octopus then the shark left. Then really slowly and really quiet and the octopus swam up and gabbed the shark then all that was left was the octopus because the shark was eaten by the octopus SUDDENLY THERE WAS A NET!!!!!!!!!!!!!!!!!!!!!!!!!!!THEN THE NET GRABBED THE OCTOPUS AND SWAM UP WITH THE OCTOPUS. Then there was no octopus left in the ocean because that was the last octopus in the ocean and there was 1 shark in the ocean then next morning the octopus was swimming around and looking for fish and he found some fishes and when the fishes were not looking the shark eat them as fast as it could . Next the fishes thought that whenever they see the shark they will hide in a good spot that were the shark would not find them and the next day 10 of the fishes saw the shark and they did what they thought and they found a very good hiding spot and then the shark couldn't see them and left.Then there was ANOTHER NET!!!and all the fishes hoped that the shark would get catched and there dream came true the shark did get caught!. Then the ocean was nothing but fishes and all other stuff that aren't bad and now they can do anything and olso the best part was they wont get eaten. the end
The octopus (pronounced /ˈɒktəpəs/, from Greek ὀκτάπους (oktapous), "eight-footed",[1][2] with plural forms: octopuses [ˈɒktəpʊsɪz], octopi [ˈɒktəpaɪ], or octopodes [ˌɒkˈtəʊpədiːz], see below) is a cephalopod of the order Octopoda that inhabits many diverse regions of the ocean, especially coral reefs. The term may also refer to only those creatures in the genus Octopus. In the larger sense, there are around 300 recognized octopus species, which is over one-third of the total number of known cephalopod species.
An octopus has eight flexible arms, which trail behind it as it swims. Most octopuses have no internal or external skeleton, allowing them to squeeze through tight places. An octopus has a hard beak, with its mouth at the center point of the arms. Octopuses are highly intelligent, probably the most intelligent invertebrates. They are known to build "forts" and "traps" in the wild, and for rearranging tanks and burying other animals alive in domestication[citation needed]. For this reason, they are quite notorious among aquarium operators.[3] For defense against predators, they hide, flee quickly, expel ink, or use color-changing camouflage. Octopuses are bilaterally symmetrical, like other cephalopods, with two eyes and four pairs of arms.
An octopus has eight flexible arms, which trail behind it as it swims. Most octopuses have no internal or external skeleton, allowing them to squeeze through tight places. An octopus has a hard beak, with its mouth at the center point of the arms. Octopuses are highly intelligent, probably the most intelligent invertebrates. They are known to build "forts" and "traps" in the wild, and for rearranging tanks and burying other animals alive in domestication[citation needed]. For this reason, they are quite notorious among aquarium operators.[3] For defense against predators, they hide, flee quickly, expel ink, or use color-changing camouflage. Octopuses are bilaterally symmetrical, like other cephalopods, with two eyes and four pairs of arms.
Tuesday, 17 March 2009
Monday, 9 February 2009
Saturday, 7 February 2009
Friday, 6 February 2009
Saturday, 31 January 2009
Thursday, 29 January 2009
Sunday, 25 January 2009
Thursday, 8 January 2009
Before I started this project I asked some people if they knew why Octopuses sqiurt black ink. This is my report.
33 children said yes Octopuses do squrt black ink becuse there scared.
5 children said no octopuses do not squrt black ink becuse there scared.
Most cildren said yes so the people who said yes is my answear.
33 children said yes Octopuses do squrt black ink becuse there scared.
5 children said no octopuses do not squrt black ink becuse there scared.
Most cildren said yes so the people who said yes is my answear.
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