91 Acta Biol. Univ. Daugavp. 16 (1) 2016 ISSN 1407 - 8953 BEHAVIORAL RESPONSES OF SALMONID FINGERLINGS TO NEW INVASIVE FISH PREDATOR PERCCOTTUS GLENII Arturs Skute, Mihails Pupins, Aija Pupina Skute A., Pupins M., Pupina A. 2016. Behavioral responses of salmonid ingerlings to new invasive ish predator Perccottus glenii. Acta Biol. Univ. Daugavp., 16 (1): 91 – 98. The research on behavioural responses of salmonid ingerlings to the new invasive in Latvia and Europe predator ish Rotan, Amur sleeper, Perccottus glenii was conducted as a part of the research on modernization of aquaculture technology. The main aim of the present study was to investigate the antipredator behavior of tiger trout as a model objects of salmonid, exposed to a potential new predator P.glenii. The antipredator behaviour of tiger trout ingerlings was investigated in ten small groups (10 specimen each) in a comparison before and after releasing of one big P.glenii in their basin. According to its size (250 mm in length from the end of the caudal in to the tip of the snout; weight 278 g), the model specimen of the Perccottus glenii was potential predator for investigated tiger trout ingerlings. In the result of the research we found that tiger trout ingerlings have innate antipredator behaviour used counter new invasive predator P.glenii. Key words: antipredator behaviour, aquaculture, tiger trout, predator, invasive species, Perccottus glenii, Chinese sleeper, Perciformes, Gobioidei. Arturs Skute, Mihails Pupins, Aija Pupina. Daugavpils University, Ecology department, 1A Parades Str, Daugavpils, LV-5401, e-mail: arturs.skute@du.lv, mihails.pupins@gmail.com, bombinalatvia@inbox.lv INTRODUCTION At the moment aquaculture is a stable developing and leading section of agriculture in the world and Europe; its main goal is the satisfaction of increasing needs of people. The aquaculture of many species is widely used both to get food stuf and other resources directly, and to recruit natural populations of hydrobionts for diferent purposes. One of the important and valuable group of ish species, which is bred and kept in the world aquaculture and released into the nature for food, nature protection, scientiic and research, aesthetic and recreational purposes, is Salmonidae. The most frequently they are released in wild at the stage of ingerlings, whitebait, and larvae. These released Salmonidae can become a prey of predator which reduces economic eiciency of this aquaculture. Thereby the researches devoted to studying of reactions of prey – predator for ingerlings, which are kept in the aquaculture, are actual and widespread (Ferrari et al. 2010, Gall & Mathis 2010).