how are fish hearts the same as a human herat?
99873
a fish heart has 3 chamber. a human heart has four. they are the same in the fact that they have a "double pump", that is, they blood fish goes to get oxygenated, then come back to the heart, and then goes to the body. unlike a human heart, however, is that a fishes heart does not have a diveded heart like humans do, so they oxygenated blood mixes with the deoxygenated blood, so it is a less efficient sytem.
343910
Probably externally, like lots of other fishes.  They male releases the sperm, and the female releases the egg.  The sperm drifts towards the egg, and then the egg is fertilized.
351401
Well-trained athletes CAN pump more blood from their hearts at maximal exercise, but the main reason they tend to have slower heart rates is because their muscles are much more efficient when it comes to extracting oxygen from their blood.  Therefore, for the same amount of work that their muscles are doing, not as much blood flow is needed to supply the necessary amount of oxygen.  Therefore, their hearts don't need to pump as fast or as hard to keep the muscles well-supplied with oxygen.\n\nThink of it as two people standing on a riverbank.  One guy (the non-athletic heart) is using a crappy fishnet and can only catch 10% of the fish that swim by.  If he needs 10 fish an hour to survive, he needs to have 100 fish swim by to in an hour.  If the guy next to him (the athletic heart) has a brand new fishnet that can catch 50% of the fish that swim by and HE needs 10 fish an hour to survive as well, he can do just fine with only 20 fish swimming by every hour.  Does that make sense?
145520
Both are hydrodynamic, that is, with the fusiform shape that is best to "pierce" the water when moving forward. In addition, such a shape maintains a laminar water flow around them (as opposed to turbulent). A laminar flow ensures support of the body (as opposed to sinking).\nMovement in water differs from terrestrial movement because the body may move in 3 dimensions; therefore, fish fins (comparable to the "flaps" of submarines... well I know nothing about submarine architecture so I guess that's not their name) counteract pitch (up/down tilt), yaw (left/right) and roll (rotation around the greater body axis).
50614
Yes.\n\nA Yahoo search on:\n\nanatomy of a shrimp heart\n\nbrought up this Web site with a diagram:\n\nhttp://www.shrimpcrabsandcrayfish.co.uk/Shrimp.htm?Anatomy.htm~mainFrame
933572
1 fish is always fish...  \nmultiple fish of the same variety are still fish..\na group of fish of different varieties are fishes.
69404
True lovers of fish will ponder your question & try to answer it for themselves as well. As humans, we tend to evaluated the mental ability of each animal by the size of their brain, an accepted "rule of thumb" by the scientific community. They have not invented a way to measure the dreams, the pains, or the sentiments (the feelings) of our earthly companions. If fish don't show more interest in their dead, their time frame is just quicker than ours & they must get on with surviving, whatever the method.Thanks!
20143
Hi,\n\nAccording to this site:\nhttp://www.tonmo.com/articles/articles.php\n\nOctopus has three hearts.\n\nQuote:\n"Does an octopus really have three hearts?\n...and how do they breathe? I've been asked these questions on a few occasions. \n\nThe fact is that octopuses do possess three hearts. Each has an important role in fueling the impressive respiration and circulatory system of the octopus."
294418
Sharks are fish and Dolphins are mammals. They have no scientific relationship, totally different species.
32854
Fishes, as all other vertebrates, have closed circulatory systems; they have a single blood circuit in which the heart pumps the blood toward the gills where it picks up oxygen, and is then distributed to the body. However, our (human) anatomy is very derived with respect to aquatic pisciform vertebrates. In fishes the circulatory system is very symmetrical and more metameric. The best place to look is the gill area, where the major vessels occur. The heart, which looks like an elongated bulb, is situated ventrally right behind the gill basket. The ventral aorta is the major vessel extending forward below the gills, and emits branches to each functional gill. Once they go through the gill filaments, these vessels reunite dorsally and form the dorsal aorta (paired, then joined). Other vessels are difficult to observe as they usually collapse in dead materials, but if you have fresh large specimens you could try injecting a colored rubber solution (VERY carefully) inside the largest vessel you can find and if the walls are not broken, you will get an internal cast of part of the system. \nAlso look for the dorsal longitudinal vessels that are really close to the vertebrae, passing through the haemal arches.
241627
usually, they eat each other. Have you ever heard that "the big fish eats the small one"? Also, they can eat plancton, or algae... there are plenty of food (organic material) floating around in the ocean.
159675
Octopus it actually has 3 hearts. Each gill has its own heart. Blood picks up oxygen in the gills, but after going through capillaries, it loses pressure. The third heart then pumps the oxygenated blood to the tissues all over the body.
517409
Fishes have well-developed nervous systems that organize around a central brain, that is divided into different parts. The most anterior, or front, end of the brain are the olfactory bulbs, which are involved in the fish's sense of smell. Unlike most vertebrates, the cerebrum of the fish is primarily processes the sense of smell rather than being responsible for all voluntary actions. The optic lobes process information from the eyes. The cerebellum coordinates body movements while the medulla oblongata controls the functions of internal organs. Most fishes possess highly developed sense organs. Nearly all daylight fish have well-developed eyes that have color vision that is at least good as a human's. Many fish also have specialized cells known as chemoreceptors that are responsible for extraordinary senses of taste and smell. Although they have ears in their heads, many fish may not hear sounds very well. However, most fishes have sensitive receptors that form the lateral line system. The lateral line system allows for many fish to detect gentle currents and vibrations, as well as to sense the motion of other nearby fish and prey. Some fishes, such as catfish and sharks, have organs that detect low levels electric current. Other fishes, like the electric eel, can produce their own electricity.
1184651
They only hold the eggs in a special sac, until they hatch.  (I think seahorses are egglayers.)  Once the young seahorses are ready to lead independent lives, he dumps them out of the sac.\n\nI think it is comparable to the way male emus incubate the eggs of their partners.  Male emus (an Australian bird, similar to the ostrich and rhea) also cares for the young; they follow him, for a while after hatching.\n\nSee?  The females lay eggs / give birth, really.  These males just participate in care of their offspring.  Their babies are thus more likely to grow up and have offspring; the trait has selective advantages.\n\nIn general, females put a lot more into young than males do.  In some species, the way "female" is distinguished from "male" is by comparing the size of their gametes.  Note how sperm are smaller than ova, for example.  In many cases, the female adds a huge load of nutrients to the young, too; the yolk + / or white of the egg, the placental nutrition of the foetus, the milk of mammals...  It all weakens the females, in cases where nutrients are limiting (which is the normal situation, "in the wild".\n\nIn cases where males take on the bulk of after - care, it just evens the load a bit, really.  It lets the females get back to replenishing their body nutrients, to get ready for the next brood.... probably sired by the same male.  (He wins again.)
23556
What the traditional "heart shape" actually depicts is a matter of some controversy. It only vaguely resembles the human heart. Some claim that it actually depicts the hearts of cattle, a more readily available sight to most people in past centuries than an actual human heart. However, while beef hearts are more similar to the iconic heart shape, the resemblance is still slight. The shape does resemble that of the three-chambered heart of the turtle, and that of the human male prostate gland, but it is very unlikely that the image was patterned after either of these organs.\n\nThere are many claims that the "heart" shape actually depict features of the human female, such as the female's pubic mound or vulva. A Sumerian cuneiform symbol for "woman" closely resembles the heart shape, and is believed to directly depict the pubic mound. Others maintain that the heart resembles the shape of the female breasts or the female buttocks, especially when bent over in readiness for copulation. Any of these origins would indicate that the heart was originally a symbol of fertility and sexuality, explaining its current association with love.
1035087
Oxygen is carried in the blood.  The oxygen transfers from the atmosphere to your blood through an exchange in your lungs...\n\nA fish's gills accomplish the same thing, but they get the oxygen from the water.
386723
Yes, a fish is classed as an animal. They are vertebrates, there are more than 30,000 different species of fish.