However, as the lower-pitched instruments would be unacceptably long if straight, for ergonomic reasons, the larger instruments usually incorporate a U-bend at, or slightly above, the third-lowest tone hole.
Small trout caught on a barb-less hook can be released simply by: grasping the eyelet of the fly, and rotating the eyelet toward the bend (the U-bend).
The mouth was under the head, behind the proboscis, and pointed "backwards", so that the digestive tract formed a U-bend on its way towards the rear of the animal.
