Not only do marine sticklebacks show increased association with the model school relative to freshwater benthic sticklebacks, they also display a greater degree of parallel swimming with the models.
Marine sticklebacks showed a more parallel position with the models than did benthic sticklebacks (Fig. 4C; marine = 83±2°; benthic = 54±4°, with 90° representing a parallel position with the models; F1,36 = 37.8, p<0.03).
Furthermore, some benthic sticklebacks do follow the school, albeit for significantly less time, suggesting that the difference in association is not due to an inability to detect and join the school, or a "fear" of the school.
The consequences of resource competition between coexisting stickleback do not seem to end with divergence in habitat and resource use.
Sexual preferences for red colouration may have been shaped by red food preferences in three- and nine-spined sticklebacks, and do not reflect a learned colour preference [37].
This was motivated by our observation that the benthic sticklebacks that do follow the school typically do not take parallel positions with the models and instead often appear as though they are "hiding" underneath the models (Fig. 4), whereas the marines exhibit obvious features of schooling behavior with the model school (Video S1, Fig. 4).
These differences persisted in mixed population groups: individual marine sticklebacks still schooled strongly in the presence of nonschoolers, and individual benthic sticklebacks did not school strongly even in the presence of strong schoolers.
In Coolen et al.'s study (experiment 2) the authors report that, following observation of demonstrator conspecifics feeding at two food patches that differ in their profitabilities, 9-spined sticklebacks acquired a preference for the richer quality patch, whilst 3-spined sticklebacks did not.
A preliminary study of a shoal of ten flesh-and-blood sticklebacks shows that they do indeed mingle with the robot and that they follow its leadership cues as predicted.
The sequence evolution analysis of the multiple PDE1Cb genes in stickleback did not provide strong evidence for neofunctionalization [ 1, 2] in their coding proteins.
