Aquaculture Europe 2021

October 4 - 7, 2021

Funchal, Madeira

Add To Calendar 07/10/2021 09:20:0007/10/2021 09:40:00Europe/LisbonAquaculture Europe 2021THE APPLICATION OF NACL IN PIKE-PERCH AQUACULTURE TAKING INTO ACCOUNT ONTOGENYView Room-CasinoThe European Aquaculture Societywebmaster@aquaeas.orgfalseDD/MM/YYYYaaVZHLXMfzTRLzDrHmAi181982

THE APPLICATION OF NACL IN PIKE-PERCH AQUACULTURE TAKING INTO ACCOUNT ONTOGENY

 

Christopher Naas * ab, Werner Kloas b, Andreas Müller-Belecke a

 

a Institute of Inland Fisheries in Potsdam-Sacrow, Im Königswald 2, 14469 Potsdam

b Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin

E-Mail: christopher.naas@ifb-potsdam.de

 



The optimal salinity for rearing juvenile pike-perch (Sander lucioperca) in recirculating aquaculture systems (RAS) is 3g NaCl L-1. Hereby, an increased biomass gain and feed utilization can be expected. However, throughout pike-perch’s development from egg to yearling, fundamental morphological and physiological but also major nutritional changes take place. These alterations are likely to affect the optimal salinity of this species when reared in RAS.

In a set of different experiments, we investigated the performance of five different life stages of pike-perch exposed to different NaCl concentrations - and where possible - under RAS or RAS-like conditions, respectively. First, a standardized fish egg test was conducted in order to investigate the embryonic development of pike-perch considering NaCl (0 to 12g NaCl L-1). Free-swimming and feeding larvae (0.8mg body weight (bw)) and dry-feed adapted pike-perch (0.4 g bw) were exposed to NaCl (0 to 9g NaCl L-1) in static exposures. Furthermore, pike-perch fingerlings (30g bw) and yearlings (100g bw) were reared in RAS under different saline conditions (0 to 12g NaCl L-1). Based on aquaculture performance parameters (growth, feed efficiency), as well as further welfare indicators an optimal NaCl concentration for every life stage was determined.

Pike-perch’s embryonic development was not affected at concentrations up to 6g
NaCl L-1. Beneficially, the exposure to NaCl significantly reduced fungal infections during the incubation. Free-swimming and artemia-feeding larvae grew best under 6g NaCl L-1, but did not tolerate 9g NaCl L-1. Dry-feed adapted pike-perch showed best growth at 3g NaCl L-1 with a clear decrease in performance when NaCl concentrations increased. Also, pike-perch fingerlings showed best performance under 3g NaCl L-1, but displayed growth depression at 6 and 9g NaCl L-1 and did not tolerate 12g NaCl L-1 at all. Pike-perch yearlings can be reared up to 6g NaCl L-1 without negative effects on their growth performance.

Consequently, the optimal NaCl concentration varies with the ontogenetic development of pike-perch. Depending on the life stage, 3 to 6g NaCl L-1 is optimal for pike-perch in RAS and can thus safely be applied by fish farmers. In the context of available literature, an increase of tolerance towards salts with an increase in biomass can be derived.