Gauy Ana Carolina Dos Santos, Bolognesi Marcela Cesar, Martins Guilherme Delgado, Gonçalves-de-Freitas Eliane
Departamento de Ciências Biológicas, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista (UNESP), Rua Cristóvão Colombo, 2265, São José do Rio Preto 15054-000, SP, Brazil.
CAUNESP-Centro de Aquicultura da UNESP, Jaboticabal 14884-900, SP, Brazil.
Animals (Basel). 2021 Jul 8;11(7):2042. doi: 10.3390/ani11072042.
We tested whether territorial fish (Nile tilapia) perceive body tactile stimulation as a positive or negative resource. Individual male fish were placed for eight days in an aquarium containing a rectangular PVC frame, which was filled with vertical plastic sticks sided with silicone bristles in the middle of the tank. Fish passing this device received a tactile stimulus. The fish then underwent a preference test by choosing between areas half-with and half-without tactile bristles. Then, fish were submitted to a motivation test where they had to pass an aversive stimulus (bright light) to access the device. Fish were, then, paired to settle social rank, which occurs by way of fights (social stressor), and were assigned again to preference and motivation tests. A group without social stress was used as a control. Contrary to our expectations, fish preferred the area without tactile bristles, although subordinate fish reached tactile stimulation more than the dominant one. Social stress did not affect the preference and motivation, suggesting that fish do not perceive tactile stimulation as a stressor reliever. However, as fish did not avoid the stimulation, reached the device spontaneously, and faced an aversive stimulus to access it, we conclude that tactile stimulation is not a negative condition and, therefore, can be used in further studies regarding fish welfare.
我们测试了领地性鱼类(尼罗罗非鱼)是否将身体触觉刺激视为一种积极或消极的资源。将雄性个体鱼放置在一个装有矩形PVC框架的水族箱中八天,框架位于水箱中间,里面填满了带有硅胶刷毛的垂直塑料棒。经过这个装置的鱼会受到触觉刺激。然后,通过在有触觉刷毛和没有触觉刷毛的区域之间进行选择,对鱼进行偏好测试。接着,对鱼进行动机测试,在测试中它们必须通过一个厌恶刺激(强光)才能接触到该装置。然后,将鱼配对以确定社会等级,这是通过争斗(社会应激源)来实现的,之后再次对它们进行偏好和动机测试。使用一组没有社会应激的鱼作为对照。与我们的预期相反,鱼更喜欢没有触觉刷毛的区域,尽管从属鱼比占主导地位的鱼受到的触觉刺激更多。社会应激并没有影响偏好和动机,这表明鱼并不将触觉刺激视为一种应激缓解因素。然而,由于鱼没有避开这种刺激,而是自发地接触该装置,并面对厌恶刺激以接近它,我们得出结论,触觉刺激不是一种负面条件,因此可用于关于鱼类福利的进一步研究。