Cichlids and stingrays can add and subtract ‘one’ in the number space from one to five

Abstract

The numerical understanding of cichlids and stingrays was examined regarding addition and subtraction abilities within the number space of one to five. Experiments were conducted as two-alternative forced-choice experiments, using a delayed matching to sample technique. On each trial, fish had to perform either an addition or subtraction, based on the presentation of two-dimensional objects in two distinct colors, with the color signaling a particular arithmetic process. Six cichlids and four stingrays successfully completed training and recognized specific colors as symbols for addition and subtraction. Cichlids needed more sessions than stingrays to reach the learning criterion. Transfer tests showed that learning was independent of straightforward symbol memorization. Individuals did not just learn to pick the highest or lowest number presented based on the respective color; instead, learning was specific to adding or subtracting ‘one’. Although group results were significant for both species in all tests, individual results varied. Addition was learned more easily than subtraction by both species. While cichlids learned faster than stingrays, and more cichlids than stingrays learned the task, individual performance of stingrays exceeded that of cichlids. Previous studies have provided ample evidence that fish have numerical abilities on par with those of other vertebrate and invertebrate species tested, a result that is further supported by the findings of the current study.

Different ways of evolving tool-using brains in teleosts and amniotes

“…Remarkably complex behaviors (tool use in the case of C. anchorago and T. hardwicke (Bernardi, 2012; Paśko, 2010), and social cognition in the case of L. dimidiatus (Kohda et al, 2022; McAuliffe et al, 2021; Wismer et al, 2016)) have been reported in the group of wrasses. Cichlids are phylogenetically close to wrasses and display relatively complex social and cognitive behaviors, although no instances of tool use have been observed (Barks and Godin, 2013; Hotta et al, 2019; Schluessel et al, 2022; Snekser and Itzkowitz, 2020). By contrast, no such behaviors have been reported in the “outgroup” species.…”

GoFish: A low-cost, open-source platform for closed-loop behavioural experiments on fish

“…Also, due to the fact that tasks become fully automated, it reduces the chance of human errors. Moreover, in combination with the automation, its low cost (Figure 1a, Table 1) We stress that the experimental configuration presented here (a Y-maze setup for two alternative forced choice reversal learning and colour discrimination tasks) is a proof-of-concept but that GoFish's basics could be used without configural changes in multiple other experimental paradigms e.g., quantity discrimination experiments (Potrich et al, 2022;Schluessel et al, 2022), behavioural timing (Talton et al, 1999, foraging (Aw et al, 2009;Newport et al, 2021), object recognition (Newport et al, 2016), and navigation (Burt de Perera & Holbrook, 2012;Newport et al, 2016).…”

“…We stress that the experimental configuration presented here (a Y-maze setup for two alternative forced choice reversal learning and colour discrimination tasks) is a proof-of-concept but that GoFish ’s basics could be used without configural changes in multiple other experimental paradigms e.g., quantity discrimination experiments (Potrich et al, 2022; Schluessel et al, 2022), behavioural timing (Talton et al, 1999), foraging (Aw et al, 2009; Newport et al, 2021), object recognition (Newport et al, 2016), and navigation (Burt de Perera & Holbrook, 2012; Newport et al, 2016). GoFish could also be used to implement experiments using a range of set-ups differing to that reported here (e.g., open field and maze configurations that could employ a greater number of screens and/or feeders than we have).…”

Smart sharks: a review of chondrichthyan cognition

“…The upper limit, up to which two amounts of presented objects differing by only one item could still be successfully differentiated, was four (Kreuter et al 2021 ), which is similar to most vertebrates (Agrillo 2015 ). A follow up study (Schluessel et al 2022 ) tested the stingray’s addition and subtraction abilities within the number space of one to five. Based on a protocol established for honeybees (Howard et al 2019 ), stingrays learned to perform either an addition or subtraction, depending on the presentation of two-dimensional objects in two distinct colours, with the colour signalling a particular arithmetic process.…”