Dietary LC-PUFA deficiency early in ontogeny induces behavioural changes in pike perch (Sander lucioperca) larvae and fry Ivar Lund a, ⁎, Erik Höglund a , Lars O.E. Ebbesson b , Peter V. Skov a a Technical University of Denmark, DTU Aqua, Section for Aquaculture, The North Sea Research Centre. P.O. Box 101, DK-9850, Hirtshals, Denmark b Uni Research AS, Thormøhlensgt. 49B, N-5006 Bergen, Norway abstract article info Article history: Received 11 November 2013 Received in revised form 5 May 2014 Accepted 26 May 2014 Available online xxxx Keywords: Pike perch Larvae LC-PUFA DHA Stress Behaviour Learning ability This study examined whether dietary supply of DHA and phospholipids during early ontogeny affected the out- come of behavioural challenges in pike perch larvae and fry, and whether the history of lipid nutrition carried over in long-term effects on learning ability. Pike perch larvae were fed Artemia enriched with either refined olive oil high in oleic acid (A); refined olive oil supplemented with a low (B) or a high (C) level of DHA; or refined olive oil acid supplemented with fish oil with a high content of phospholipids (PL) and DHA (D). The enriched live diets were provided until 28 days post hatch (dph), at which time larval behavioural responses to visual and mechano-sensory stimuli were assessed. All dietary groups were subsequently fed an identical enriched live feed (diet D) and gradually weaned to an extruded dry feed, on which they were maintained for 112 days. At the end of this period, assessment of fry avoidance behaviour was repeated and individuals were tested for spatial learning ability in a maze. At the larval stage, individuals maintained on Artemia rich in DHA showed a 5–8 fold increase in swimming speed when subjected to a visually simulated predator test, a response that was not ob- served for larvae on diets low in DHA content. Independent of the predator simulation, larvae deficient or low in DHA exhibited significantly more time swimming along the edge of a test arena and had overall higher loco- motor activities compared to larvae fed a diet with a high DHA content. Larvae on DHA rich diets showed an abil- ity to achieve significantly higher peak acceleration rates during the escape response, which was maintained at 112 dph. Time spent locating the exit of a maze decreased with repetitious training sessions, although fish fed diets low in DHA spent longer time in the maze, caused by extended periods of inactivity or “freezing” behaviour (time lag) prior to the onset of active searching behaviour. The consistency of behavioural responses to mechano-sensory stimuli in larvae and fry suggests long-term effects on the neuromuscular path-way involved in escape responses. A longer period of freezing in the learning test may reflect a more anxious and fragile behaviour profile in fish fed low levels of DHA. Further studies should aim at verifying whether this affects performance related traits, such as immune competence and robustness. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Pike perch (Sander lucioperca) is considered a species with a high po- tential for inland freshwater aquaculture in Europe (Wang et al., 2008) and a strong candidate for the potential diversification of intensive freshwater recirculation aquaculture systems (RAS) farming in Europe (Dalsgaard et al., 2013). A major bottleneck for further expansion of pikeperch culture today is its high sensitivity to stressors (pers. comm. Martin Vestergaard, AquaPri Innovation, DK, 2013). In modern intensive aquaculture, the robustness and stress resilience are of crucial impor- tance in terms of welfare, health, growth, quality of the end product and thus overall production costs. Studies on percid larvae suggest that dietary supplementation with phospholipids and/or specific vita- mins increase the health status of farmed pike perch, by decreasing the incidence of scoliosis and lordosis and increase larval resistance to osmotic stress (Hamza et al., 2008; Henrotte et al., 2010; Kestemont et al., 1996; Lund et al., 2012). The major essential nutrient require- ments for pikeperch are still unknown, and information is lacking about the link between nutritional composition early in ontogeny and the robustness of produced fish. Pike perch eggs have a high DHA content, which could be related to its strictly carnivorous nature and/or may be an evolutionary remnant from life adapted to a marine environment. We have recently shown, that diets deficient in LC-PUFAs, particularly DHA, during first feeding (i.e. within 25 days post hatch) is accompanied by a suite of negative consequences. These effects include increased mortality and sensitivity to salinity stress in both larvae and juveniles and brain developmental disorders (Lund and Steenfeldt, 2011; Lund et al., 2012), suggesting Aquaculture xxx (2014) xxx–xxx ⁎ Corresponding author. Tel.: +45 35883205. E-mail address: il@aqua.dtu.dk (I. Lund). AQUA-631199; No of Pages 9 http://dx.doi.org/10.1016/j.aquaculture.2014.05.039 0044-8486/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Aquaculture journal homepage: www.elsevier.com/locate/aqua-online Please cite this article as: Lund, I., et al., Dietary LC-PUFA deficiency early in ontogeny induces behavioural changes in pike perch (Sander lucioperca) larvae and fry, Aquaculture (2014), http://dx.doi.org/10.1016/j.aquaculture.2014.05.039