Fatsini Elvira, Rey Sonia, Ibarra-Zatarain Zohar, Mackenzie Simon, Duncan Neil J
IRTA, Sant Carles de la Ràpita, Tarragona, Spain.
Institute of Aquaculture, Pathfoot Building, University of Stirling, Stirling, Scotland, United Kingdom.
PLoS One. 2017 Sep 6;12(9):e0184283. doi: 10.1371/journal.pone.0184283. eCollection 2017.
Dominance is defined as the preferential access to limited resources. The present study aimed to characterise dominance in a non-aggressive flatfish species, the Senegalese sole (Solea senegalensis) by 1) identifying dominance categories and associated behaviours and 2) linking dominance categories (dominant and subordinate) with the abundance of selected mRNA transcripts in the brain. Early juveniles (n = 74, 37 pairs) were subjected to a dyadic dominance test, related to feeding, and once behavioural phenotypes had been described the abundance of ten selected mRNAs related to dominance and aggressiveness was measured in the brain. Late juveniles were subjected to two dyadic dominance tests (n = 34, 17 pairs), related to feeding and territoriality and one group test (n = 24, 4 groups of 6 fish). Sole feeding first were categorized as dominant and sole feeding second or not feeding as subordinate. Three social behaviours (i. "Resting the head" on another fish, ii. "Approaching" another fish, iii. "Swimming above another" fish) were associated with dominance of feeding. Two other variables (i. Total time occupying the preferred area during the last 2 hours of the 24 h test, ii. Organisms occupying the preferred area when the test ended) were representative of dominance in the place preference test. In all tests, dominant fish compared to subordinate fish displayed a significantly higher number of the behaviours "Rest the head" and "Approaches". Moreover, dominant sole dominated the sand at the end of the test, and in the group test dominated the area close to the feed delivery point before feed was delivered. The mRNA abundance of the selected mRNAs related to neurogenesis (nrd2) and neuroplasticity (c-fos) in dominant sole compared to subordinate were significantly different. This is the first study to characterise dominance categories with associated behaviours and mRNA abundance in Senegalese sole and provides tools to study dominance related problems in feeding and reproduction in aquaculture.
优势地位被定义为对有限资源的优先获取。本研究旨在通过以下方式对一种非攻击性比目鱼——塞内加尔鳎（Solea senegalensis）的优势地位进行特征描述：1）确定优势类别及相关行为；2）将优势类别（优势和从属）与大脑中选定mRNA转录本的丰度联系起来。早期幼鱼（n = 74，37对）接受了与摄食相关的二元优势测试，在描述行为表型后，测量了大脑中与优势和攻击性相关的十种选定mRNA的丰度。晚期幼鱼接受了两项二元优势测试（n = 34，17对），分别与摄食和领地性相关，以及一项群体测试（n = 24，4组，每组6条鱼）。首先摄食的鳎被归类为优势个体，其次摄食或不摄食的鳎被归类为从属个体。三种社会行为（i. 将头靠在另一条鱼上，ii. 接近另一条鱼，iii. 在另一条鱼上方游动）与摄食优势相关。另外两个变量（i. 在24小时测试的最后2小时内占据偏好区域的总时间，ii. 测试结束时占据偏好区域的个体）代表了位置偏好测试中的优势地位。在所有测试中，与从属鱼相比，优势鱼表现出显著更多的“将头靠在另一条鱼上”和“接近”行为。此外，在测试结束时，优势鳎占据了沙地，在群体测试中，在投喂饲料之前，优势鳎占据了靠近饲料投放点的区域。与从属鳎相比，优势鳎中与神经发生（nrd2）和神经可塑性（c-fos）相关的选定mRNA的丰度存在显著差异。这是第一项在塞内加尔鳎中描述优势类别及其相关行为和mRNA丰度的研究，并为研究水产养殖中摄食和繁殖方面与优势相关的问题提供了工具。
