Boatfish skeleton.

This is the decaying remains of a Boat fish. You can clearly see the skeletal remains of its undercarriage. These were massive creatures that were once a very familiar site in the waters along the canal, but are all but extinct now. A breed of fish called the Barge fish have been a key element in their demise - due to the barge fish's sheer size the boat fish often jumped out of the water and got beached like this one and so met their untimely end.