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.
... are 65 years of age or older. The median age is 35 years. For every 100 females there are 95.1 males. For every 100 females age 18 and over, there are 89.3 males.
Th ...