A genderless connector adapted for forming a fluid flow pathway therethrough by connection with a genderless reciprocal connector, wherein both the connector and the reciprocal connector each comprise: a fluid flow passageway part defining a fluid flow opening; a socket part located upon the fluid flow passageway part adjacent to the fluid flow opening; a plug part located upon the fluid flow passageway part adjacent to the fluid flow opening and spaced from the socket part such that the plug part and the socket part are located upon the fluid flow passageway part adjacent to opposite respective sides of the fluid flow opening, being separated in a direction transverse to the axis of the fluid flow passageway part, wherein the socket part of the connector is configured to receive therein the plug part of said reciprocal connector to connect thereto such that the fluid flow opening of the connector is aligned in register with the fluid flow opening of the reciprocal connector; and, a closure part arranged to openably close the fluid flow opening of the connector and to receive an urging force from said received plug part of the reciprocal connector thereby to be displaced in a direction crossing the fluid flow opening transversely to the axis of the fluid flow passageway part to uncover the fluid flow opening such that the connector is thereby connectable to the reciprocal connector with respective fluid flow openings in fluid communication; a releasable catch mechanism operable to change from a first state in which the releasable catch mechanism is configured to retain the closure part in a position closing the fluid flow opening to a second state in which the releasable catch mechanism is configured to permit said displacement of the closure part; wherein the releasable catch mechanism comprises an abutment surface configured for abutment by the plug part of the reciprocal connector when the plug part of the reciprocal connector is received within the socket part of the connector, for actuation of the releasable catch mechanism by the plug part of the reciprocal connector from within the socket part of the connector whereby the state of the releasable catch mechanism is operable to change from said first state to said second state in response to said abutment between the releasable catch mechanism and the plug part of the reciprocal connector thereby to change from said first state to said second state by action of receiving the plug part of the reciprocal connector within the socket part of the connector. a fluid flow passageway part defining a fluid flow opening; a socket part located upon the fluid flow passageway part adjacent to the fluid flow opening; a plug part located upon the fluid flow passageway part adjacent to the fluid flow opening and spaced from the socket part such that the plug part and the socket part are located upon the fluid flow passageway part adjacent to opposite respective sides of the fluid flow opening, being separated in a direction transverse to the axis of the fluid flow passageway part, wherein the socket part of the connector is configured to receive therein the plug part of said reciprocal connector to connect thereto such that the fluid flow opening of the connector is aligned in register with the fluid flow opening of the reciprocal connector; and, a closure part arranged to openably close the fluid flow opening of the connector and to receive an urging force from said received plug part of the reciprocal connector thereby to be displaced in a direction crossing the fluid flow opening transversely to the axis of the fluid flow passageway part to uncover the fluid flow opening such that the connector is thereby connectable to the reciprocal connector with respective fluid flow openings in fluid communication; a releasable catch mechanism operable to change from a first state in which the releasable catch mechanism is configured to retain the closure part in a position closing the fluid flow opening to a second state in which the releasable catch mechanism is configured to permit said displacement of the closure part; wherein the releasable catch mechanism comprises an abutment surface configured for abutment by the plug part of the reciprocal connector when the plug part of the reciprocal connector is received within the socket part of the connector, for actuation of the releasable catch mechanism by the plug part of the reciprocal connector from within the socket part of the connector whereby the state of the releasable catch mechanism is operable to change from said first state to said second state in response to said abutment between the releasable catch mechanism and the plug part of the reciprocal connector thereby to change from said first state to said second state by action of receiving the plug part of the reciprocal connector within the socket part of the connector.