System for transporting and storing a liquid and for transporting said liquid from the container to a destination outside of the container, the system comprising: • a container for transporting and storing a liquid, comprising a container body provided with a neck portion; • a cap assembly secured on the neck portion for fluidly-tight closing the container body; • a coupler assembly configured to be mechanically coupled to the cap assembly so as to achieve a coupled configuration for a liquid connection to and/ or from the container, comprising a male probe to be connected to a female part of the cap assembly; wherein the cap assembly comprises the female part and a plug, the female part having an essentially cylindrical body comprising two concentric interconnected cylindrical walls (12, 13) defining there between a cylindrical slit having an open end and a closed end where the outer cylindrical wall is connected to the inner cylindrical wall, the slit being adapted to receive the neck portion of the container body to provide a fluid-tight closure around the neck portion; the inner wall of the cylindrical body defining an axial bore extending from an insert opening for the male probe through the body to an opposed plug opening at opposed ends of the body; the inner wall of the cylindrical body comprising a seat adjacent the plug opening, extending around the bore, for the plug which serves to close off the bore fluid-tight; wherein the bore of the female part between the insert opening and the seat comprises a shoulder, facing towards the insert opening, and the plug is provided with a hooking system with multiple elastic hooking parts (21a, 21b, 21c, 21d, 21e) with corresponding hooking surfaces (21a", 21e"), at least one of the hooking parts resting in a first position with its hooking surface against the shoulder (fig. 1a), in which first position the plug closes off the bore and hence fluidly-tight closes the plug opening of the container body; wherein the coupler assembly has a male probe with a head and a recess located behind the head for receiving at least one of the hooking parts of the plug when the male probe is inserted into the bore, so that the plug connects with the male probe, wherein radially next to the at least one of the hooking parts in its first position there is a space between the hooking part (21a, 21b, 21c, 21d, 21e) and the female part, wherein the at least one hooking part is designed such that - when the male is inserted into the bore - the head of the male probe pushes the hooking part from its first position into this space to a second position which is located radially further outward compared with the first position, in which second position the plug still closes off the bore and hence fluidly-tight closes the plug opening of the container body; and such that at least one of the hooking parts, after axially passing the head of the male probe towards a bottom of the container body, springs elastically inward to a third position and falls into the recess of the male probe while contact between the hooking surface and the shoulder is maintained and while the contact between hooking surface and shoulder is maintained the plug still closes off the bore and hence fluidly-tight closes the plug opening of the container body; wherein the recess in the male probe is such that a radial space is present between the hooking part, located in its third position, and the male probe, in such a way that inserting the male probe further into the bore towards a bottom of the container body causes the hooking part to pass the shoulder in the bore, the hooking part moves under the influence of a force exerted by the shoulder of the bore on the hooking part to a fourth position (Fig. 1c) which is located further inward in the recess compared with the third position, such that the plug engaged with the male probe opens the bore and hence allows fluid to pass from and to the container body; characterized in that a seal cover is provided over the bore, essentially parallel to the plug, which serves to close off the bore airtight. • a container for transporting and storing a liquid, comprising a container body provided with a neck portion; • a cap assembly secured on the neck portion for fluidly-tight closing the container body; • a coupler assembly configured to be mechanically coupled to the cap assembly so as to achieve a coupled configuration for a liquid connection to and/ or from the container, comprising a male probe to be connected to a female part of the cap assembly;