Although navigation is common in many animals,only a few perform true navigation, meaning thatthey have the ability to return to a given place by relying onindirect cues obtained at the release site (i.e., by relying oninformation from a ‘‘map and compass’’ mechanism). Thecommon intertidal fish, Lipophrys pholis, is thought to havehoming abilities through a mechanism that primarily makesuse of familiar landmarks (i.e., piloting). Anecdotal reportsthat individuals return to their home pools after release atunfamiliar sites suggest that L. pholis might use cues collectedat the release site to find their way back (i.e., theymight use map and compass information). Using a completelyartificial setup, we tested the homing abilities of L.pholis as a function of age, sex, and familiarity with therelease site. The findings showed that motivation forhoming is present only in the adult phase and is independentof sex and/or familiarity with the release site. Moreover,adults released at a completely unfamiliar placeoriented themselves in a direction roughly similar to that oftheir home pools. The fact that L. pholis were tested in acomplete artificial environment means that hydrodynamiccues can be excluded as playing a role in this process andrestricts the candidate options (e.g., magnetic cues). Theability to perform navigation based on a ‘‘map and compass’’mechanism raises many interesting questions aboutthe learning process, once these individuals have restrictedhome ranges during their lives. In vertebrate navigation,the cues used during the navigation process are a questionof debate, and L. pholis offers an outstanding model to testhypotheses and ultimately provide answers.
展开▼
