Ascension : Endemic Shrimps of Ascension
Submitted by The Islander (Gary Robinson) 27.07.2006 (Article Archived on 10.08.2006)

There are 74 species of crustaceans known around Ascension, of which 14 are endemic.

Conservation Weekly

 There are 74 species of crustaceans known around Ascension, of which 14 are endemic. A North American biologist has also identified 27 species of marine amphipods around Ascension Island some are fish invertebrates in rock pools.

Inland from Shelly Beach of east Mars Bay, there are groups of different pools. These represent an ‘anchialine’ habitat.  The pools are water filled crevices that have no surface connection with the sea, but are salt or brackish and are influenced by tides. The pools are about 50-100m inland and are evidently connected to the sea underground. These tiny pools are the only known habitat for two particularly interesting species of shrimp, which are found nowhere else in the world, they also contain a number of other endemic animals, as well as clusters of the striking of globular green alga Valonis ventricosa and interesting coral in the genus Favia. The shrimp probably survive because no predatory fish have managed to get into this habitat. The presence of shrimps in the pools was recorded by John Packer in the 1968 edition of his Ascension handbook, but the first collections were apparently made in 1970 by Douglas S Rogers, an employee of Pan American World Airways and at the time Curator of the Fort Hayes Museum of Ascension Historical Society. The first shrimp to be found was named Typhlatya rogersi in honour of Mr. Rogers, this species is pale pinkish and semi-transparent, and is abundant in the pools. The other remarkable fact about this species is that its relatives live mainly in freshwater subterranean habitats, especially on islands of the Carribean.

The second species was collected by Mr. Rogers later the same year and named Procaris ascensionis. It was the first known member of the new family of shrimps, but related species have been found in similar situations in Bermuda and Hawaii. It is a bright orange in colour and is larger but less common in the pools than Typhlatya of which it is a predator

               This is the Endemic Typhlatya rogersi

      This the Procaris ascensionis