Gastrotrich red algae. Polarised light micrograph of a Gastrotrich (centre) swimming over Batrachospermum sp. red algae. Commonly known as a hairyback, this is tiny worm-like animal has two glands used to anchor and detach itself to a surface. One secretes an adhesive glue, the other secretes a dissolving substance to sever the connection. Magnification: x200 when printed 10 centimetres wide.