What is Argonauta?
{{other uses|3=Argonaut (disambiguation)}} {{italic title}} {{Taxobox | name = Argonauts | fossil_range = [[Miocene]] – Recent | image = Argonauta species.PNG | image_caption = Eggcases of various ''Argonauta'' species | regnum = [[Animal]]ia | phylum = [[Mollusca]] | classis = [[Cephalopod]]a | ordo = [[Octopoda]] | superfamilia = [[Argonautoida]] | familia = '''Argonautidae''' | genus = '''''Argonauta''''' | genus_authority = [[Carolus Linnaeus|Linnaeus]], 1758 | subdivision_ranks = | subdivision = }} '''''Argonauta''''', the argonauts, is the only [[extant taxon|living]] [[genus]] in the '''Argonautidae''' family. They are a group of [[pelagic]] [[octopod]]s. They are also called '''paper nautiluses''', because of the paper-thin eggcase that females make. This structure does not have the gas-filled chambers of [[nautilus]] shells, and is not a true [[cephalopod]] [[shell]]. It is an [[evolution]]ary [[innovation]] unique to the [[genus]] ''Argonauta''.<ref>{{in lang|de}} {{cite journal | author = Naef A. | year = 1923 | title = Die Cephalopoden, Systematik | journal = Fauna Flora Golf. Napoli (35) | volume = 1 | pages = 1–863}}</ref> Argonauts are found in [[Tropics|tropical]] and [[subtropical]] waters worldwide: they live in open ocean. Like most octopods, they have a rounded body, eight [[arm]]s and no [[fin]]s. However, unlike [[octopuses]], argonauts live close to the sea surface rather than on the [[seabed]]. ''Argonauta'' species have very large eyes and small distal webs. They have a mantle-funnel locking apparatus, which is a way to identify the genus. It consists of knob-like cartilages in the [[Mantle (mollusc)|mantle]] and corresponding depressions in the funnel. Unlike the closely related genera ''[[Ocythoe]]'' and ''[[Tremoctopus]]'', ''Argonauta'' species lack water pores. ==Physical description== ===Sexual dimorphism and reproduction=== In Argonauts, males and females are quite different in size and lifespan. Females grow up to 10&nbsp;cm and make shells up to 30&nbsp;cm, while males rar