The freshwater pearl mussel was once abundant enough to support commercial activities, and Scotland is the remaining European stronghold with about half the global number present.
22.
Pearls gathered in the wild from the Holarctic freshwater pearl mussel were much used, with Scotland a major source; this species is now endangered in most areas.
23.
In addition to her herbarium, she formed a remarkable collection of pearls obtained from large pearl mussels found in abundance in the river Ambl�ve and its tributaries.
24.
These freshwater pearl mussels occur not only in hotter climates, but also in colder more temperate areas such as Scotland ( where they are protected under law ).
25.
Salmon spawn right up through Eskdale, and a number of " freshwater pearl mussels, although these are threatened with extinction due to buildups of silt in the river.
26.
In the designation, the houting and the freshwater pearl mussel were identified as priority species; especial weight is to be given to fulfilment of provisions relating to their habitat.
27.
More than a decade ago the freshwater pearl industry of China shifted production from the cockscomb pearl mussel to the triangle shell mussel ( " Hyriopsis cumingii " ).
28.
Attached to the substrate, juvenile freshwater pearl mussels typically burrow themselves completely into the sand or gravel, while adults are generally found with a third of their shell exposed.
29.
The "'Alabama pearl shell "', scientific name " Margaritifera marrianae ", is a species of freshwater mussel, an aquatic bivalve mollusk in the family Margaritiferidae, the freshwater pearl mussels.
30.
Like all bivalve molluscs, the freshwater pearl mussel has a shell consisting of two parts that are hinged together, which can be closed to protect the animal's soft body within.
