An order of ray-finned fish, also called the Microcyprini, and comprising mostly small, fresh-water fish. They are closely related to the Atheriniformes[?] and are occasionally included with them. Many popular aquarium fish, such as killifish and live-bearers, belong here.
... 65 years of age or older. The median age is 37 years. For every 100 females there are 95.2 males. For every 100 females age 18 and over, there are 90.1 males.
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