ea Star Shrimp (Zenopontonia soror) are also known as Starfish Shrimp

Sea Star Shrimp-Facts and Photographs

December 1, 2023 0 3 min read3

Sea Star Shrimp (Zenopontonia soror) are also known as Starfish Shrimp. They live exclusively on Sea Stars or Starfish. During the day they are usually found on the underside of the Sea stars and they seem more confident venturing out at night. They have an amazing ability to match their hosts coloration and in a study conducted in the gulf of California it was empirically found that they could change colors to match a new host in 36 hours. Sea Star shrimps are found on several genera of Sea Stars , Linkia where they can be end to be blue, Acanthaster where they tend to be red and white as in the above image and on Culcita they can be blue , maroon, white , transparent or green or brown. Due to their color changing abilities they were once described as many different species but these have now been unified. The relationship between the shrimp and the Sea Stars is generally described as commensal.

APPEARANCE

Sea Star Shrimp have a maximum body length of some 15 millimeters and the colors vary greatly depending on the hosts coloration. The shrimp have chromatophores in the outer layers and by altering the shape and density of them the shrimp is able to change color to match its host. Often one only sees them after a dive when going through ones images. They can be very difficult to spot unless they move.

SEA STAR SHRIMP IN THE WILD

Generally we only see the sea star shrimp at night . If one checks all the sea stars that one swims past on a night dive one will find one or two , but they are usually quick to head under the host sea star. Researchers have tried removing them from heir host and if this occurs they will go for the same species of host again if they are in the locality. Probably this saves them from changing color and from the danger that could be experienced while changing color. Sometimes one sees a shrimp that does not match the host at all ( image below) and presumably they have just relocated. It is much easier to spot them when they do not match.

HABITAT

Sea Star Shrimp have a wide distribution and are found across the Indian and Pacific oceans ,from the east coast of Africa to French Polynesia and New Caledonia. In Tanzania we have seen them from 6 meters to 22 meters in depth.

DIET

The Sea Star Shrimp feed on secretions and probably waste from the host sea star.

REPRODUCTION

There seems to be little information on their breeding habits. There are often more than one specimen on a single host.

AQUARIUMS

Sea Star Shrimp are not generally kept in aquariums due to the difficulty in feeding sea stars and without the host it would be difficult to keep the shrimp.