Benefits of familiarity persist after prolonged isolation in guppies

The persistence of familiarity in the Trinidadian guppy Poecilia reticulata , reunited after prolonged periods of separation, was studied and benefits of this association were tested. Choice experiments following 5 weeks of isolation confirmed that the fish continued to prefer familiar group mates. Furthermore, guppies emerged more rapidly from a shelter in the presence of a familiar individual from which they had been isolated, as opposed to a completely unfamiliar individual. This experiment indicated that the benefits associated with the exploration of new surroundings in the presence of familiar fish were not transitory, and could persist over time periods that allow for shoal mixing and re‐assembly, or movement out of the home range.