Echinoderms are a group of invertebrates that includes starfish, sea urchins, feather stars, sand dollars and other related creatures. They are only found in marine environments. The name ‘Echinoderm’ literally means ‘spiny skin’ when translated from ancient Greek. These spines are particularly noticeable on live sea urchins, but they are often lost when the specimen is dried or preserved in alcohol.
RAMM’s Echinoderm collections
The majority of RAMM’s Echinoderms are from Percy Sladen‘s collection and are preserved as wet specimens. The fluid they are in is usually alcohol which supports the soft tissue and prevents it from decaying.
Many are stored in ground glass jars, whilst others have been placed in display jars and carefully mounted on a glass sheet in attractive patterns. Some starfish and sea urchins in our collections have been dried and are carefully stored in boxes and others are small enough to be preserved in fluid in a microscope slide.
Thanks to Sladen our collection of Echinoderms has attracted researchers from around the world. It is believed to be the largest and most comprehensive Echinoderm collection outside the Natural History Museum, London.
Sladen and HMS Challenger
Percy Sladen had a particular interest in Echinoderms. His knowledge of these attractive creatures brought him to the attention of Sir Charles Wyville Thompson; a Scottish scientist who was in charge of the Challenger expedition. This oceanographic survey and collecting expedition took place on HMS Challenger between 1872 and 1876. Thompson asked Sladen to identify and describe the enormous wealth of Echinoderm material that was collected.
Specimens from HMS Challenger can be found in Museums all over the world. A RAMM project has reunited them on a single website. Please explore HMS Challenger Collections.