Binary individual recognition in Lysmata debelius (Decapoda : Hippolytidae) under laboratory conditions

Lysmata debelius is a territorial species, characterised by forming long-te rm pair bonds between individuals. This species is popular in the aquarium trade, and although it has culture potential it is not yet raised on a comm ercial scale. These coral reef inhabitants are considered to be key species in the natural habitat, and their culture is of conservation interest. One of the main causes of death in captivity is due to a disturbance of the pa ir bond, which results in one individual killing the other. However, the fa ctors that induce this behaviour are not understood. A three-chambered appa ratus was constructed to test binary individual recognition. One individual from a pair and one outsider (a stranger), both in similar reproductive st ate and size, were placed in different chambers. The other individual of th e pair was placed in the remaining space. and its behaviour continuously re corded with a video camera during 3 h. The number of visits and the total t ime spent in the chamber of its mate over a 30-min interval, analysed with a two-way ANOVA, were significantly higher than for the time spent in the s tranger's chamber These results suggest that Lysmata debelius is able to di stinguish a partner from a stranger, and this ability appears to remain for at least 3 h after separation.