Living reefs
Horse mussels, similar to but larger than the common blue mussel, bind to each other and to stones and shells with tough threads forming a platform for many other animals, small seaweeds and even kelps. The beautiful file shell or flame shell performs the same service by building a nest of shells, stones and gravel held together by a weft of threads. The flame shell directs a flow of water through its nest, trapping any nutritious material on the spectacular crown of orange tentacles which gives it its name. In Loch Creran another very unusual living reef is found comprising colonies of tube building worms – Serpula vermicularis.