What is a neetlefish?

Are sharks the oldest animals ever? Why do sharks have nostrils if they breathe through gills? Why did my girl guppy just dropped from the top of the tank and it's tail change the? How do you now when a female guppy is pregnant? What does the eel do that indicates it is an ambush predator? Do sharks have a amniotic egg? Is a pond bigger than a stream? Can diamonds be found in creeks or streams? What class is the megalodon? Is a yellow tang fish a consumer producer or decomposer? Can goldfish choke on their food? Does a pond have an inlet and outlet? Are manta rays afraid of sharks? Are guppies surface swimmers? Can you use bluegill as live bait in Maryland? Can small freshwater crabs be kept with goldfish? Can you put an ocsar fish with communtiy? Do chelicerata molt to grow? Why do you pronounce the L in salmonella and not in salmon? Is 80 degrees an ok temperature for your betta fish?