TY - JOUR
T1 - The importance of stable schooling
T2 - Do familiar sticklebacks stick together?
AU - Barber, Iain
AU - Ruxton, Graeme D.
PY - 2000/1/22
Y1 - 2000/1/22
N2 - Preferences for rejoining shoals composed of familiar individuals have recently been documented in a variety of small, shallow-water fish species. Such preferences are assumed to be adaptive, since familiar groups have improved anti-predator defences and more stable dominance hierarchies. However, the design of these studies may have created conditions that elevate preferences for familiar individuals. Furthermore, in natural habitats, where significant opportunities for inter-shoal transfer may exist, it is unclear whether shoals stay together long enough for such preferences to develop. Here we present the results of a laboratory study examining whether prior familiarity influences the subsequent shoal composition of sticklebacks (Gasterosteus aculeatus) allowed to re-assort freely in a large arena tank. We show that fish from different familiarity groups associate with familiar conspecifics significantly more than predicted by a model of random assortment, suggesting that even when there is ample opportunity for inter-group transfer, shoal composition can remain stable. We discuss the phenomena that may lead to the formation of familiar groups in natural habitats. In addition, we suggest that familiarity benefits may reduce the relative value of transferring to otherwise more attractive (e.g. larger or more phenotypically matched) groups, and thereby stabilize shoal structure.
AB - Preferences for rejoining shoals composed of familiar individuals have recently been documented in a variety of small, shallow-water fish species. Such preferences are assumed to be adaptive, since familiar groups have improved anti-predator defences and more stable dominance hierarchies. However, the design of these studies may have created conditions that elevate preferences for familiar individuals. Furthermore, in natural habitats, where significant opportunities for inter-shoal transfer may exist, it is unclear whether shoals stay together long enough for such preferences to develop. Here we present the results of a laboratory study examining whether prior familiarity influences the subsequent shoal composition of sticklebacks (Gasterosteus aculeatus) allowed to re-assort freely in a large arena tank. We show that fish from different familiarity groups associate with familiar conspecifics significantly more than predicted by a model of random assortment, suggesting that even when there is ample opportunity for inter-group transfer, shoal composition can remain stable. We discuss the phenomena that may lead to the formation of familiar groups in natural habitats. In addition, we suggest that familiarity benefits may reduce the relative value of transferring to otherwise more attractive (e.g. larger or more phenotypically matched) groups, and thereby stabilize shoal structure.
KW - Familiarity
KW - Fish
KW - Group dynamics
KW - Shoal composition
KW - Shoaling
KW - Three-spined stickleback
UR - http://www.scopus.com/inward/record.url?scp=0034700799&partnerID=8YFLogxK
U2 - 10.1098/rspb.2000.0980
DO - 10.1098/rspb.2000.0980
M3 - Article
C2 - 10687820
AN - SCOPUS:0034700799
SN - 0962-8452
VL - 267
SP - 151
EP - 155
JO - Proceedings of the Royal Society B: Biological Sciences
JF - Proceedings of the Royal Society B: Biological Sciences
IS - 1439
ER -