Premium
Behavioural Responses to Crowding Modification and Home Intrusion in Acanthopleura gemmata (Mollusca, Polyplacophora)
Author(s) -
Chelazzi Guido,
Parpagnoli Daniele
Publication year - 1987
Publication title -
ethology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.739
H-Index - 74
eISSN - 1439-0310
pISSN - 0179-1613
DOI - 10.1111/j.1439-0310.1987.tb00646.x
Subject(s) - polyplacophora , foraging , crowding , overcrowding , intrusion , intertidal zone , nocturnal , biology , population , ecology , geography , mollusca , law , demography , geochemistry , neuroscience , sociology , political science , geology
The intertidal chiton Acanthopleura gemmata (Blainville) is a central place forager which rests in a dug scar and moves at nocturnal low tide. The fraction of chitons abandoning the home during each potential foraging phase is reduced after experimental overcrowding. On the contrary, reduced crowding in the natural population increases number of active chitons. Feeding excursions after increasing or reducing crowding are shorter than in control chitons. Also the orientation of migration is scattered after manipulation. Animals sharing their home with a conspecific suppress migrations, but local overcrowding when body‐contact is lacking also reduces activity. Rest zonation in overcrowded areas shifts upward, and most imported chitons fail to home. Induced home co‐ownership is followed by overt aggressive patterns and by a “waiting war”. Conflicts are resolved according to size ratio between contestants.