Echinoderms (starfish and sea urchins)
Echinoderms are a group of invertebrates that includes starfish, sea urchins, feather stars, sand dollars and other related creatures. They only live in marine environments. The name ‘echinoderm’ means ‘spiny skin’ when translated from ancient Greek. These spines are particularly noticeable on live sea urchins. Once dead, they often lose their spines.
RAMM’s collection of Echinoderms
Most of RAMM’s starfish and sea urchins are from Percy Sladen‘s collection.
RAMM stores most of its echinoderm specimens in alcohol in cylindrical ‘ground glass’ jars. Some starfish are in rectangular ‘battery jars’. One side of the jar is very smooth and flat allowing a clear view of the attractive specimens inside. RAMM’s collection also includes dry specimens in cardboard trays. Some specimens are small enough to fit inside a microscope slide.
In life, starfish and sea urchins have bright colours and also beautiful markings. Museum specimens often look dull in comparison because they lose their colour when preserved in alcohol or dried..
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. Accordingly, Thompson asked Sladen to identify and describe the enormous wealth of Echinoderm material brought back from the voyage.
Museums all over the world have specimens from HMS Challenger. A RAMM project has reunited them on a single website. Please explore HMS Challenger Collections.