Almeida Maria Mafalda, Cabrita Elsa, Fatsini Elvira
Centre of Marine Sciences (CCMAR), Faculty of Science and Technology, University of Algarve (Campus Gambelas), 8005-139 Faro, Portugal.
Animals (Basel). 2023 Mar 8;13(6):978. doi: 10.3390/ani13060978.
Physical complexity adds physical enrichment to rearing conditions. This enrichment promotes fish welfare and reduces detrimental characteristics that fish develop in captivity. Senegalese sole () is an important species for European aquaculture, where it is reared in intensive conditions using fibreglass tanks. However, reproductive dysfunctions present in this species do not allow it to complete its life cycle in captivity. Recently, dominance behaviour has been studied to try to solve this problem. The present study aimed to assess the effect of sand as environmental enrichment in the dominance behaviour and brain mRNA abundance of Senegalese sole juveniles. Four tanks of sole ( = 48 fish in total) were established in two different environments (with and without sand). Juveniles were subjected to dominance tests of feeding and territoriality. Behaviours analysed by video recordings related to the distance from the food delivered and harassment behaviour towards other individuals (e.g., resting of the head on another individual). In both environments, dominant sole were the first to feed, displayed more head-resting behaviour and dominated the area close to the feeding point, where the events were reduced in fish maintained in the sand. mRNA expression related to differentiation of dopamine neurons () and regulation of maturation () were significantly upregulated in dominant fish in the sand environment compared to dominants maintained without sand. The use of an enriched environment may affect Senegalese sole dominance, enhance welfare and possibly advance future maturation.
物理复杂性为养殖条件增添了物理丰富性。这种丰富性促进了鱼类福利，并减少了鱼类在圈养环境中形成的有害特征。塞内加尔鳎（）是欧洲水产养殖的重要品种，在集约化养殖条件下，使用玻璃纤维水箱进行养殖。然而，该品种存在的生殖功能障碍使其无法在圈养环境中完成生命周期。最近，人们对优势行为进行了研究，试图解决这个问题。本研究旨在评估沙子作为环境丰富物对塞内加尔鳎幼鱼优势行为和脑mRNA丰度的影响。在两种不同环境（有沙和无沙）中设置了四个鳎鱼水箱（总共48条鱼）。对幼鱼进行了摄食和领地优势测试。通过视频记录分析与投放食物的距离以及对其他个体的骚扰行为（例如，将头靠在另一个个体上）相关的行为。在两种环境中，优势鳎鱼都是最先进食，表现出更多的头靠行为，并占据靠近喂食点的区域，在有沙环境中饲养的鱼的此类行为减少。与多巴胺神经元分化（）和成熟调节（）相关的mRNA表达在有沙环境中的优势鱼中比无沙环境中的优势鱼显著上调。使用丰富的环境可能会影响塞内加尔鳎的优势地位，提高福利，并可能促进未来的成熟。
