A Gift for the Emperor
(Click images for enlarged view)
n day in the year 1855 at the island of Dominica in the Caribbean Sea a hermit crab was found wearing a kind of sea shell which had previously been known only from fossils and thought to have been extinct for millions of years. For several decades the Dominican slit shell remained an intriguing enigma. Then, toward the end of the century, a Japanese fisherman brought up an unusual shell in a deep water fish trap. The Emperor at that time was a malacologist* and the shell was sent to him. He recognized it as a living pleutomarian or slit shell.
This was an event comparable to the discovery of a living coelacanth fish. Slit shells represent an early stage in the evolution of the gastropods or snail-like molluscs. They are characterized by a slit in the side of their shell running from the mouth of the shell half way around to the opposite side. It provides an opening for the anus which later in their evolution moved forward ending up next to their mouth thus eliminating the need for the slit in modern gastropods.
They are common as fossils from about 200,000,000 until some 60,000,000 years ago . Since the Emperor's discovery some 28 or 29 living species have been found in various parts of the world. All are from deep water at depths between 200 and 3000 feet. Most are known from only a few specimens. To collectors they are among the rarest and most valuable of shells.
In 1968 while making a deep dive in Edwin Link's Deep Diver submersible on The Wall off Fresh Creek, Andros Is. in the Bahamas I saw several large slit shells at depths between 300 and 600 feet. The sub had no manipulator arm and there was no place on the vertical wall to set it down and make a lock out dive. All I could do was look.
Two years later I came back having developed the first mixed gas electronic rebreather in the interim. In several dives to 300 feet I collected and photographed five Adansons slit shells, Entemnototrochus adansonianus. So far as I know they are still the only only ones ever collected by diving. As they were perfect specimens and of considerable scientific interest I gave them to the Smithsonian.
Some years later Emperor Hirohito made the only visit ever made by a Japanese Emperor to the U.S. It was a big event. As a special gift from the U.S. government he was given one of the Smithsonian specimens. I don't know which specific one it was but it was one of those pictured here.
*It is tradition for the Emperor to be a scholar. The current Emperor is an ichthyologist specializing in gobies.
shell at 300 feet.
Electrolung on "The Wall"
Slit shells (note slits)