Are narwhals extinct? If not can you describe their life cycle?
538229
The narwhal has the most northerly range of any mammal, among icefields and floes of Arctic waters. Fish, mollusks, crustaceans, and other prey are probably sucked into the mouth by the narwhal's powerful lips and tongue. Like belugas - indeed, often with them - narwhals can sometimes form large schools of thousands, which may be segregated by age and sex. They communicate with a wide variety of sounds including humlike tones which may be for individual recognition. \nThe narwhal's tusk grows with age, through the upper lips, spiraling clockwise, to reach 9 3/4 ft. long. It may be a swordlike weapon to "fence" rival males at breeding time. Any use in feeding seems unlikely, since most females lack tusks, but survive well. An occasional male has 2 tusks, or a female has one. \nThe narwhal stays year round in the Arctic Ocean and is locally common.
493992
DEFINITELY a dolphin, it is the smallest aquatic mammal. otters are not wholely aquatic. and sea monkeys sea lions etc are not mammals. whales are the largest mammals.
393749
I haven't heard of any shark species being endangered.  I know "Jaws" author Peter Benchley was an advocate of their conservation (which was reported at the time of his recent death), but I was and am still unaware that there was a need for conservation.  The only shark species I know to be extinct is the Megalodon (the much larger ancestor of the Great White).
414504
the last lionfish seen would be instantly before you ask the question r read this answer (loinfish are alive in the wild as well as in the aquarium trade)\n\nsomeone somewhere is probably seeing one right now
357665
i've lived in the outback for most of my childhood and never seen any such animals. i say there's no proof and there not here. it would be cool to see one though
52717
Good question. Many animals live longer in captivity because once they have adapted to their human-made conditions (and some are born there), they have no predators, no intraspecific competition and usually a team of vets taking care of them. \nIt's not easy to find reliable records of lifespan for wild dolphins, due to their life habits. A wild dolphin lived 20 years  and a bottle-nosed dolphin lived 35 years (see link for references); some people indicate that their average lifespan is 46-48 years but they don't cite sources or species.  Captive animals usually have shorter lifespans, and wild-captured individuals are sometimes  very stressed and die; again, not many reliable sources out there (which would be understandable if aquariums did not want comparisons to be made from the data). There's a 30-year record for a captive bottlenose dolphin; many webpages state shorter lifespans, but again, no statistics or reliable sources.\nI'd like to read the opinions of knowledgeable Answerers out there!
752420
Mostly, they don't unless their in zoos.  Once there habitat is gone, they're gone.  Squirrels are the exception.
534498
I do not know what the growth rate or percentage is but I do know they will first of all have to ascertain that they are capable of surviving in their natural habitats and have man-made habitats (protected) grown specially for them to survive. Once they have successfully have offsprings for 3 generations then are they considered to be taken off the endangered species list.
485065
Apparently upto 4 years, depending on species. See \n\nhttp://www.seahorses.de/seahorses.htm\n\nAnother site,\n\nhttp://seahorse.fisheries.ubc.ca/biology4.html\n\nhas this to say\n\nNatural lifespans for seahorses are virtually unknown. Most estimates come from laboratory or aquarium observations. Known lifespans for seahorse species range from about one year in the smaller species to an average of three to five years for the larger species.
516925
Dolphins are mammals, first of all, which means that they reproduce and female give births to offsprings (babies).\n\nThe babies stay often with their mothers until they are capable of hunting by themselves.\n\nBy then, they are more independent but stay in groups.\nLater on as adults, dolphins find mates and reproduce and give birth again to dolphins.\n\nLife cycle repeats...\n\n\nFor more info:\n\nhttp://library.thinkquest.org/J0110164/Life%20of%20the%20dolphin/life%20cycle.htm
277528
A mammal? Nah. An organism? Yep. All living things are organisms, it's just some are a tad more complex than others. If a shark was a mammal, then it would have to have shark boobies, right? Whoa - there's a scary picture... a shark with boobies. Kinda reminds me of my ex-wife....
743378
It looks like it:\nhttp://www.uwsp.edu/gEo/faculty/heywood/geog358/extinctm/LEKitFox.htm\n\nThat is a web site about mammal extinction & states that the last one was trapped in California in 1903.  Apparently it was exterminated because it was a pest.
60032
Blue whales live about 25-30 years!
283592
They are part of the food chain for many species, whether it be at the beginning or in the middle. If dolphins disappeared, certain species would become over populated, and others would die off.
1137807
Life expectancy of animals and plants\nThe vast majority of animals have shorter life expectancies than humans do, and typically the lifespan of the animal increases with size. Some examples include:\n\nCats have lifespans in the 14-20 year range. \nLarge herbivores (cattle, horses, camels, deer) in the 30-50 year range. \nBirds usually live 10-30 years, with parrots - particularly macaws - and several seabirds notable exceptions, with lifespans ranging from 40-80 years. \nElephants have lifespans of 50-80 years. \nBlue whales can live from 40 to 80 years. \nBowhead whales are thought to live up to 200 years, with a few individuals found to have century-old harpoons embedded in their blubber. \nDogs live 10-25 years. \nSome turtles live to 150 years or more. \nCertain trees have almost outlived recorded human history; the baobab tree can live for 1,000-4,000 years, although it is understandably difficult to measure this. Similarly long-lived are olive trees, domesticated in the Mediterranean. Several olive trees still alive today were nurtured by the ancient Greeks. \nMany corals can potentially live for over 100,000 years. However, there is no consensus among marine biologists how to determine age of a coral, and whether or not it is really a single organism.
438744
That is a narwhal.  It is an Arctic species of cetacean with a body similar to that of a beluga whale and Irrawaddy Dolphin. It is rarely found south of latitude 70°N. It is one of two species of whale in the Monodontidae family (the other is the beluga whale). It is possibly also related to the Irrawaddy Dolphin.
359638
1.)No one knows for sure how long killer whales live. \n\n2.) For unknown reasons, killer whales have a high calf mortality rate in some areas of the world.  In the Pacific Northwest, for example, 43% of all calves die in the first six months.  In other killer whale populations, calf mortality may be as high as 50% during the first year. \n\n3.)  Long-term studies will ultimately answer this question.  By counting growth layers in teeth, scientists find that killer whales in the North Atlantic may live at least 35 years.  Studies are still refining this method of aging. \n\n\nResearchers can estimate a killer whale's age by examining a sliced section of tooth and counting growth layer groups.\n\n\n4.)  Scientists in the Pacific Northwest estimate life expectancies by using information derived from field observations that began in the 1970s.  These scientists believe that if a killer whale survives the first six months, a female's life expectancy is 50 years and a male's is 30 years. \n\n5.)  With continued research, it is likely that differences in longevity will be found in killer whale populations around the world.