The Imperial Shrimp (Periclimenes imperator) is a brightly coloured small commensal shrimp species that belongs to the family Pontoniinae. This species is generally found living on nudibranchs and sea cucumbers and occasionally on seastars and urchins and this relationship with the other animal is known as symbiosis or mutualism. Symbiosis is a Greek word simply meaning ‘living together’ and can be used to describe any association between organisms whilst mutualism means that both species apparently benefit from the relationship.
The Imperial Shrimp has a body colour that is orange to red and is the back is generally covered with tiny white dots – these dots can be absent and their presence is generally related to the colouration of the shrimp’s host. The legs and claws of this shrimp are purple and the eyes are orange. It is often found living on the Spanish Dancer nudibranch Hexabranchus sanguineus and its habitat is generally in relation to live where its host lives.
The Imperial Shrimp (Periclimenes imperator) grows to a maximum length of approximately 2cm