The hydra is only dangerous to very little fish. It is a low type of life, a polyp, that devours fish up to about 3/16

Flat worms are generally between 1/8 to 3/16 -in. long, and coloured a pale grey, comparable to the body of a garden snail. They could

The water tiger is far more risky than the dragon-fly larva. It is the larval type of the big cruel water beetle (Dytiscus), and a

It is possible when collecting daphnia to include a couple of dragon-fly larvae in the net. Regrettably, any strainer that lets daphnia via will also