An optimal foraging strategy often requires identifying and choosing the larger amount of food in the presence of multiple options, in order to maximize food intake. Food quantity estimation frequently depends on the perceptual ability to segregate food from the surrounding background. In human and nonhuman animals, it has recently been shown that the perception of food size is affected by the size of the background on which food is presented, with a tendency to overestimate food items encircled by a small background. This perceptual bias resembles an illusory effect known as the Delboeuf illusion. We investigated whether this bias occurs in five fish species: zebrafish, Danio rerio, redtail splitfin, Xenotoca eiseni, angelfish, Pterophyllum scalare, Siamese fighting fish, Betta splendens, and three-spot gourami, Trichopodus trichopterus. In control trials, we observed their spontaneous preference for choosing the larger of two amounts of food. In test trials, two same-sized food amounts were presented on a small and a large plate, a pattern that causes the Delboeuf illusion in humans. Similarities in subjects’ choices between the five species were greater than differences, with a significant bias towards selecting the food amount on the large plate. This suggests the existence of a perceptual bias, although one operating in the opposite direction from that of humans, which might interfere with the accurate food size estimation necessary for an optimal foraging strategy.

中文翻译：

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Delboeuf 错觉对硬骨鱼类食物选择的偏见：种间研究

最佳觅食策略通常需要在存在多种选择的情况下识别和选择更大量的食物，以最大限度地提高食物摄入量。食物数量估计通常取决于将食物与周围背景分离的感知能力。在人类和非人类动物中，最近已经表明，对食物大小的感知受到呈现食物的背景大小的影响，并且倾向于高估被小背景包围的食物。这种知觉偏差类似于一种被称为德尔博夫错觉的错觉效果。我们调查了这种偏差是否发生在五种鱼类中：斑马鱼、Danio rerio、redtail splitfin、Xenotoca eiseni、神仙鱼、Pterophyllum scalare、暹罗斗鱼、Betta splendens 和三斑口吻鲈、Trichopodus trichopterus。在对照试验中，我们观察到他们自发地偏好选择两种食物量中较大的一种。在测试试验中，两个相同大小的食物分别放在一个小盘子和一个大盘子上，这种模式会导致人类产生 Delboeuf 错觉。五个物种之间受试者选择的相似性大于差异，对选择大盘子上的食物量有显着的偏见。这表明存在感知偏差，尽管它与人类的操作方向相反，这可能会干扰最佳觅食策略所需的准确食物大小估计。一种导致人类德尔博夫错觉的模式。五个物种之间受试者选择的相似性大于差异，对选择大盘子上的食物量有显着的偏见。这表明存在感知偏差，尽管它与人类的操作方向相反，这可能会干扰最佳觅食策略所需的准确食物大小估计。一种导致人类德尔博夫错觉的模式。五个物种之间受试者选择的相似性大于差异，对选择大盘子上的食物量有显着的偏见。这表明存在感知偏差，尽管它与人类的操作方向相反，这可能会干扰最佳觅食策略所需的准确食物大小估计。