[Jaine Perotti]

We use a simple hook to grap the tetra by the apex.

We decided against the use of a complicated, actuating mechanism because we would figure that it would take more time and precision, as well as having to lift more weight on the end of a cantilevered arm.

The drawback to this type of tetra grabber is that we have less control over the tetra, and it tends to swing around a little bit. We are planning on adding a horizontal beam to the hook that will keep it from sliding down the arm too easily, and to hopefully steady it a bit.

Non-actuating hooks work well, but only if you design them right.