  We establish sharp universal upper bounds on the length of the shortest
closed geodesic on a punctured sphere with three or four ends endowed with a
complete Riemannian metric of finite area. These sharp curvature-free upper
bounds are expressed in terms of the area of the punctured sphere. In both
cases, we describe the extremal metrics, which are modeled on the Calabi-Croke
sphere or the tetrahedral sphere. We also extend these optimal inequalities for
reversible and non-necessarily reversible Finsler metrics. In this setting, we
obtain optimal bounds for spheres with a larger number of punctures. Finally,
we present a roughly asymptotically optimal upper bound on the length of the
shortest closed geodesic for spheres/surfaces with a large number of punctures
in terms of the area.
