Why isn't mudskipper a amphibian but a fish and does it have lungs?
537108
Mudskipper is not an amphibian because it does not have lungs.It breathes by gills and hence it is a fish.\n\nWhen other fishes are taken out of water their gill filaments stick and are unable to absorb gaseous oxygen and hence they die.But the mudskipper uses a technique in which it can retain water in enlarged gill chambers. They rotate their eyes to swill the water in the gill chambers around and keep the gills fluffed up and oxygenated. \nMudskippers also have to regularly replenish the water in their gill chambers so they cannot stay far from water. \nPlz check the site it might be of help to you.
222438
This is a very interesting question!  Many famous evolutionary biologists have had cracks at answering similar questions.  The basic idea is that over the course of evolution - from ancient fish to ancient amphibians to ancient tetrapods - there were constraints in the development of the body plans to make a pelvis for holding the hindlimbs and a shoulder girdle for holding the forelimbs.  For physical reasons these two morphological features have not evolved in other locations along the body, because of this, tetrapods have only four legs.
399805
It seems to be a species of aquatic salamander.
257089
Depending on the fish there could be different obstacles. Certain sharks must continually swim to pass water over there gills to not suffocate. Also in certain shallow water mangroves oxygen depleted water can be another obtacle (except for the lemon shark which can survive better in low oxygen water). I also believe polluted water, such as oil spills and the like, can be perhaps the biggest obstacle of all the fish will face in the respiration process especially around coastal areas.
63404
u didnt really specific the frog, but at least there's two links (there's some more, u could just google it) and hope it helps =)
393775
All turtles have low metabolism, and thus their breathing rate is normally lower than in other vertebrates. Their anaerobic (=without oxygen) capabilities are higher than for us mammmals. And the large marine turtles can decrease their metabolism even more, making it possible for them to be submerged for long periods (usually up to 30 minutes but sometimes longer). \nIn addition, at least some freshwater turtles have supplementary cloacal breathing (their cloacal opening or vent can be dilated so that environmental water can enter and oxygen is absorbed through the cloacal epithelium).
1141662
Not sure but it ISN"T snakes and frogs. We have plenty here! Possibly a newt.
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.
1062365
no, because fish have gills (breathe on the outside) unlike us we have lungs in the inside.  In my aquarium tank I have a small mouth Bass & Yellow Perch, when i feed my bass minnows he would have three minnows in it's mouth (minnows literally sticking out it's mouth)/ my perch as well.  They will swim around with half a minnow sticking out it's mouth and act like it's no big deal.  You will see this with bluegill they will take the worm and swim around with it hanging out it's mouth.  I just feed my fish (thanks for reminding me) and I took pictures so if you want to see them just e-mail and I'll send it to you.  \n-About the dead smaller fish stuck in it's throat some fish I catch may puke up fish due to exhaustion.  When i go fishing for walleyes and northern pike I've had them cough up fish on me.  I've had bass do the same.  \n-Death? He could have died due to foul hooking (not meaning snagging) but if it hook in the middle or back of the throat can kill any fish especially if it's kept out of the water to long, just cut the line and release.  It doesn't work out all the time.
1071274
You have fish in inverted commas, does that mean you are unsure?  Did it have eyes, a mouth, gills?  Was it a vertebrate? The first thing I thought of was a sea slug or flatworm.  A sea slug seems more likely in a Carribean coral reef.
197081
am·phib·i·an\nn. \nA cold-blooded, smooth-skinned vertebrate of the class Amphibia, such as a frog or salamander, that characteristically hatches as an aquatic larva with gills. The larva then transforms into an adult having air-breathing lungs. \nAn animal capable of living both on land and in water. \nAn aircraft that can take off and land on either land or water. \nA tracked or wheeled vehicle that can operate both on land and in water.
228732
Interesting question, but I think you're putting the cart before the horse. \nI could say that they don't live out of the water because their many specializations make it impossible; you've seen what happens when a whale gets beached. \n\nAnd why not turn the question around? Why not ask\n"If dolphins live in the water, why do they have lungs instead of gills?"\nThe thing is, adaptation is a phenomenon that usually shows us amazing results, such as the entire lifestyle of cetaceans (and they have many specializations for aquatic life). But a specialized or well-adapted animal is not "perfectly" fitted, because of the way evolutionary processes work. \nEvolution and natural selection can only work on the "materials" that are already there; and the lungs of mammals are not something that can be "reverted" to gills; their origin goes way back to remote ancestors of the whales. This irreversibility of _complex_ evolutionary processes is known as Dollo's "law" (and creationists love to misinterpret it). Stephen J. Gould gave a good example with the giant panda's "thumb" (this additional finger arose from one of the bones of the carp (wrist), and the real thumb of pandas is as reduced as in the rest of the Carnivora). \nEven if cetaceans where to evolve back into terrestrial animals, the results would not look like their ancestors, or probably anything that we know.
967122
Well,\nReptiles have scales. Amphibians have smooth skin (although some are warty). \nReptiles are total land animals. Amphibians need the water. And yet this is not always true. There are many marine reptiles, but they must go ashore to lay their eggs, well the sea snake might be a possible exception there. There are also amphibians that are able to spend their whole lives out of the water. They are rare, but there. \nThe real big difference (other than scales) is that reptiles use hardshelled, amniotic eggs for their babies. All amphibians have soft jellylike eggs. \n\nThere are several anatomical (pertaining to body structure) and reproductive differences between reptiles and amphibians. Reptiles include alligators, crocodiles, turtles, and snakes. Amphibians include salamanders, toads, and frogs.\n\nOne difference between the two is the structure of their outer skin. Reptiles are covered with scales, shields, or plates, and their toes have claws. Amphibians, on the other hand, have moist, glandular skins, and their toes lack claws.\n\nThe eggs of reptiles have a thick, hard shell that protects the developing embryo from moisture loss, even on dry land. In contrast, the eggs of amphibians lack a hard outer covering and, thus, must be laid in water or in damp places.\n\nFinally, young reptiles are miniature replicas of their parents in general appearance, although not always in coloration and pattern....\n\nReptiles and amphibians, along with birds, fish, and mammals, belong to a group of animals known as vertebrates. Vertebrates have a bony backbone–a strong, flexible column to which other body structures are attached. Reptiles and amphibians vary enormously in size, from tiny frogs and lizards only half an inch (1cm) long to some crocodiles and snakes that can reach lengths of nearly 30 feet
335863
African and Australian lungfish, amphibians, reptiles/birds, mammals.
662518
Exactly what the first answerer said. The South American lungfish (Lepidosiren paradoxa) does the same as the African species, it buries itself in a more or less vertical burrow (30-50 cm deep) with an expanded chamber at the bottom, and stays there more or less rolled upon itself and protected from dessication by its own skin mucus. The  entrance to the burrow is stoppered with a "plug" made of clayish mud, with orifices for air to pass through (this species is an obligate air breather). \nThese fishes live in tropical/subtropical areas with distinct rainy and dry seasons, during which the physiognomy of their habitat undergoes striking changes. The estivation takes place in the same areas that were ponds and shallow waterbodies during the rainy season, but dry out during the dry period.\n\nThe Australian lungfish does not estivate in this way, it requires a minimum of aquatic environment to survive.
482324
One of the arguments would be the lack of fossils for intermediate species. As there are many fish and reptiles fossils discovered, shouldn't there be at least some half fish-half reptile fossils as well?
806285
Well, that depends on your definition of "tail".\n\nIf a tail is defined as an extension of the vertebrae (or notochord) behind the anus or cloaca, then most fish do have a tail.\n\nThere are some few exceptions, for example the ocean sunfish ( http://www.oceanlight.com/html/mola_mola.html). These fish don't have a caudal fin with normal tail vertebrae; it is replaced by modified caudal elements. This condition is known as "gephyrocercal" (http://www.briancoad.com/Dictionary/DicPics/gephyrocercal.htm).\n\nIf, however, you're thinking of a typical caudal fin, there are many fishes without them, such as eels and other anguilliform species. However, they usually do have caudal vertebrae (it is the membrane that they lack).