Three-dimensional spatial cognition: freely swimming fish accurately learn and remember metric information in a volume

Welfare assessment of rainbow trout reared in a Recirculating Aquaculture System: Comparison with a Flow-Through System

“…Like mammals, fish are able to associate neutral stimuli to food-rewards (Bratland et al, 2010;Nilsson et al, 2008Nilsson et al, , 2010Yue et al, 2008) or to punishment (Moreira et al, 2004;Yue et al, 2008). Fish are also capable of spatial learning (Braithwaite and de Perera, 2006;Holbrook and de Perera, 2013;Odling-Smee et al, 2008) and show for example increased swimming activity around feeders prior to feeding. This food-anticipatory activity is commonly considered as an indicator of good welfare (Folkedal et al, 2012;Kristiansen and Ferno, 2007;Spruijt et al, 2001) since foraging and feeding motivation may translate a better well-being than prostration.…”

Three-dimensional space: locomotory style explains memory differences in rats and hummingbirds

“…R. Soc. B 281: 20140301 horizontal component would, however, suggest otherwise [13] as do data showing isotropic three-dimensional orientation in fishes [16]. In addition, the firing patterns of bat place cells also appear rather different from those of rats: place fields of free-flying bats did not appear to be compressed or elongated in any direction [23][24][25].…”

“…However, while energy expenditure might explain why hummingbirds relocate a single rewarded location more accurately in the vertical dimension than in the horizontal [13], and why rats move less vertically than they do horizontally when free-foraging [12], energetic cost does not explain why the sighted morph of the fish Astyanax fasciatus, trained on a Y-maze, when forced to choose one or the other dimension, consistently chose the vertical over the horizontal [14,15]. Rather than minimizing movement in the vertical the fish appear to prefer to move in that dimension [16]. Furthermore, hummingbirds trained and tested on a onedimensional (linear) array learned a rewarded location only when the array was oriented horizontally rather than vertically.…”

“…For example, rats might remember the horizontal component of a three-dimensional location more precisely than its vertical component owing to the different firing patterns of grid cells, the neurons responsible for the metric encoding of space [19], while animals that move freely through three-dimensions such as fish and hummingbirds might not be impaired in the vertical dimension. Support for such neural variation correlated with locomotory style comes from the similar degree of encoding accuracy by fishes in both the horizontal and vertical dimensions of a Y-maze [16,20]. It may also be that such equivalence is enabled owing to their ability to estimate absolute depth through their swim bladder using hydrostatic pressure cues [21].…”

Spatial learning in the cuttlefish Sepia officinalis: preference for vertical over horizontal information

“…Indeed, 3D-moving species acquire spatial information in the vertical plane with a similar or higher accuracy than information in the horizontal plane, whereas surface-bound species are less accurate in the vertical space (Dacke and Srinivasan, 2007;Eckles et al, 2012;Flores-Abreu et al, 2014;Holbrook and Burt de Perera, 2013;Hurly et al, 2010). However, locomotory style does not predict the relative importance of horizontal and vertical information to an animal: vertical information is preferred in fish (both benthic and non-benthic organisms) but not in hummingbirds, two equally 3D-moving species.…”