A wellbore apparatus to control the flow of fluids into the wellbore, comprising: a housing; a passage disposed within the housing; a flow communicator for allowing communication into the passage; a flow control member; and frangible members releasably retaining the flow control member to the housing in a retained position, and configured, while the apparatus is disposed in an operative orientation, for becoming fractured in response to application of a force in a downhole direction to release the flow control member from the housing such that the flow control member becomes displaceable relative to the flow communicator; wherein: the flow communicator and the flow control member are configured such that, while the apparatus is disposed in the operative orientation within the wellbore, the flow control member is disposed uphole relative to the retained position while the flow communicator is disposed in the open condition.