University of Lorraine, INRA, UR AFPA, Nancy, France.
IRTA - SCR, Sant Carles de la Rapita, Sant Carles de la Ràpita, Spain.
J Fish Biol. 2020 Jun;96(6):1463-1474. doi: 10.1111/jfb.14322. Epub 2020 Mar 27.
The onset of piscivory in fish, resulting in a shift from zooplankton or invertebrate to fish prey, was studied on pikeperch (Sander lucioperca) larvae displaying and not displaying piscivorous behaviour at different ages (23, 30, 37, 44 and 52 days post-hatching) using behavioural (attack, capture and swimming activity), morphological (allometry) and digestive enzymatic (trypsin, α-amylase and pepsin) analyses. The shift from zooplanktonic food items (Artemia nauplii) to a piscivorous diet did not occur at the same time for all individuals within the same cohort. Predation tests, conducted under controlled conditions (20°C; ad libitum feeding), showed that some larvae attacked fish prey as early as the age of 3 weeks [11.0 ± 1.3 mm total length (TL)], whereas others did not start until the age of 6 weeks (16.6 ± 1.9 mm TL). Piscivorous individuals were bigger, with larger heads, longer tails, higher acid protease and lower alkaline protease activities, than non-piscivorous conspecifics. In conclusion, high interindividual variability in morphological and digestive system developments linked to the development of predatory abilities could induce cannibalism in fish.
摄食习性转变的研究在鱼类中很常见，即从浮游动物或无脊椎动物转变为鱼类为食。本研究以不同日龄（孵化后 23、30、37、44 和 52 天）显示和不显示捕食行为的欧鲈（Sander lucioperca）幼鱼为研究对象，通过行为（攻击、捕获和游泳活动）、形态（异速生长）和消化酶（胰蛋白酶、α-淀粉酶和胃蛋白酶）分析，研究摄食习性的转变。在同一群体中，并非所有个体都在同一时间从浮游动物食物（卤虫无节幼体）转变为肉食性饮食。在受控条件下（20°C；自由进食）进行的捕食测试表明，一些幼鱼早在 3 周龄（11.0±1.3 毫米总长度（TL））就开始攻击鱼类猎物，而另一些幼鱼直到 6 周龄（16.6±1.9 毫米 TL）才开始捕食。与非捕食同类相比，肉食性个体体型更大，头更大，尾巴更长，酸性蛋白酶活性更高，碱性蛋白酶活性更低。总之，与捕食能力发展相关的形态和消化系统发育的个体间高度变异性可能导致鱼类的同类相食。
