Preserved Slime Moulds in the Museum Collections

A strange & unusual group is stored in the museum collections. Not animals, not plants, they are difficult to define. They are often grouped with fungi in museum collections and studied by mycologists because of their superficial resemblance to some fungi, but they not part of the Kingdom Fungi. Taxonomists have classified as them Protists, distantly related to microscopic single-celled Amoebas.

Some slime moulds are able to do something amazing, they can group together to form colonies. In a similar way to jellyfish, this type of slime mould is formed of hundreds of tiny individual cells, working together to survive. Each cell can move independently but also communicates with the others via chemical signals to find food or to reproduce. Some colonies of slime moulds creep along, changing shape as they go, and to feed they engulf microscopic bacteria, fungi and other organic matter.

Slime moulds often live in damp, dark places for example within soil and decaying wood, only becoming obvious to us when they form spore-producing structures (often as a result in a drop in nutrients available to the colony). The beautifully named Dog Sick Slime Mould (Mucilago crustacea) and Dog Vomit Slime Mould (Fuligo septica) appear on lawns, while the round pink spore structures of Wolf’s Milk (Lycogala terrestre) appear on decaying wood. The Many-headed Slime Mould (Physarum polycephalum) has even been shown to solve a maze for food.

Like other botanical specimens, most Slime Moulds preserve well by drying. Their fragile spore structures are kept safe in conservation-grade boxes within the collections. As you might expect for such an unusual group, their classification fluctuates. Studies using new techniques such as DNA sequencing help scientists to understand how each species is related to another, or even whether one species should be split into two. This leads to changes in scientific names, and may require their order within the Museum collections to be changed.

There is an online list of the 157 slime mould species that are held at the Museum. Most specimens have been collected from Britain, with some from other parts of Europe and from North America.