Abstract: An electrically insulated water containable member has a first electrode and a pair of second electrodes bracketing the first electrode. A source of electric power is connected across the first electrode and each electrode of the pair of second electrodes to develop an electric field within the member between the first electrode and each electrode of the pair of second electrodes, which electric field causes narcosis or tetany in any fish present in water within the member and between the pair of second electrodes.

Abstract: A waterway, interconnecting two bodies of water, has a centrally mounted first electrode and a pair of grounded second electrodes bracketing the first electrode. A source of alternating current electric power is connected across the first electrode and the pair of grounded second electrodes to develop an electric field within the waterway, which electric field causes narcosis or tetany in any fish attempting to swim through the electric field.

Abstract: To minimize injury during electrofishing while inducing a high degree of electrotaxis, a packet of DC pulses having sharp leading edges and preferably an exponential or square decay are transmitted under water between an anode electrode and a cathode electrode several times each second to stimulate contraction of the red muscle tissues and bring about electrotaxis without inducing epileptic seizure of the white muscle tissues of fish and thereby avoiding injury to the fish. The power level of transmission is reduced between the packets.

Abstract: To minimize injury during electrofishing while inducing a high degree of electrotaxis, a packet of DC pulses having sharp leading edges and preferably an exponential or square decay are transmitted under water between an anode electrode and a cathode electrode several times each second to stimulate contraction of the red muscle tissues and bring about electrotaxis without inducing epileptic seizure of the white muscle tissues of fish and thereby avoiding injury to the fish.

Abstract: Anode and cathode electrodes are placed at the upstream downstream ends of an elongated tank containing fish to be electroanesthetized by applying an electric signal to the electrodes to create an electric field within the tank sufficient to induce petit mal in the fish. By maintaining a flow of water in the tank from the end containing the anode electrode to this end containing the cathode electrode, the fish will tend to head toward the anode electrode and be subject to the largest voltage gradient induced by the electric field. A barrier at each of the anode and cathode electrodes prevents contact by the fish to protect the fish against injurious electrical shock.

Abstract: To minimize injury during electrofishing while inducing a high degree of electrotaxis, a packet of DC pulses having sharp leading edges and preferably an exponential or square decay are transmitted under water between an anode electrode and a cathode electrode several times each second to stimulate contraction of the red muscle tissues and bring about electrotaxis without inducing epileptic seizure of the white muscle tissues of fish and thereby avoiding injury to the fish.

Abstract: Anode and cathode electrodes are placed at the upstream and downstream ends of an elongated tank containing fish to be electroanesthetized by applying an electric signal to the electrodes to create an electric field within the tank sufficient to induce petit mal in the fish. By maintaining a flow of water in the tank from the end containing the anode electrode to this end containing the cathode electrode, the fish will tend to head toward the anode electrode and be subject to the largest voltage gradient induced by the electric field. A barrier at each of the anode and cathode electrodes prevents contact by the fish to protect the fish against injurious electrical shock.

Abstract: To minimize injury during electrofishing while inducing a high degree of electrotaxis, a packet of DC pulses having sharp leading edges and preferably an exponential or square decay are transmitted under water between an anode electrode and a cathode electrode several times each second to stimulate contraction of the red muscle tissues and bring about electrotaxis without inducing epileptic seizure of the white muscle tissues of fish and thereby avoiding injury to the fish.

Abstract: A water permeable barrier is disposed about at least one electrode of the anode and cathode electrodes of electrofishing apparatus to shield the electrode against contact by the fish, the operator and other objects while maintaining the capability of establishing an electric field sufficient to induce petit mal in the fish.

Abstract: To minimize injury during electrofishing while inducing a high degree of electrotaxis, a packet of DC pulses having sharp leading edges and preferably an exponential or square decay are transmitted under water between an anode electrode and a cathode electrode several times each second to stimulate contraction of the red muscle tissues and bring about electrotaxis without inducing epileptic seizure of the white muscle tissues of fish and thereby avoiding injury to the fish.

Abstract: A fish barrier to prevent passage there past of fish is established by applying alternating asymmetrical pulses across water immersed anode and cathode electrodes, where the cathode electrode represents the barrier. A higher voltage negative pulse produces a direct current field in a first zone adjacent the cathode electrode which zone is sensed by the fish at a threshold value of field intensity. The first zone induces a neuromuscular twitch response to turn the fish away from the negative electrode. A lower voltage positive pulse produces an alternating current field in a second zone closer to the cathode electrode, which zone is sensed only by those fish in close proximity to the cathode electrode. The second zone induces muscular contraction followed by tetany and usually death. By placing the cathode electrode across a stream or canal to prevent upstream fish movement, most of the fish will be involuntarily prevented from swimming close to the barrier.

Abstract: An invasive anchor of a fish tag includes an anchor element for initial mechanical attachment and an element of inert material for adherence with the tissue of the fish through cellular growth.

Abstract: A ground cloth mounted barrier extending around an occupant in a sleeping bag shields the occupant from reptiles and crawling insects. The barrier, being of smooth surfaced material, such as vinyl plastic, precludes a sufficient gripping surface for the insects and the reptiles to permit them to traverse the barrier. The underlying ground cloth shields against intrusion beneath the barrier or from the ground from within the barrier. A peripheral smooth surfaced section of the ground cloth extending lateral to the barrier further discourages intrusion of reptiles by providing a large span over which they cannot obtain a grip.