Optimizing intensive culture protocols for Atlantic cod (Gadus morhua) larvae

Abstract Larval cod require live prey as food, and concentration (PC) feeding frequency (FF) often affect their growth survival. Apart from this, water exchange rates/water flow (WER/WF) current (WC) also the resident time in tank larval/early juvenile behaviour, respectively. High is known to induce stress finfish larvae, this response believed be dependent on larval developmental stage. Thus, we conducted a study evaluate three rearing protocols varying concentration, frequency, current/exchange rate. Three were used: low (PC), (FF), (protocol 1); medium PC, FF, WF 2); high 3) (see Table 1). Larvae sampled periodically for cortisol measurements. Cortisol extraction radioimmunoassay (RIA) using methods previously validated larvae. reared 2 3 significantly bigger heavier than larvae protocol 1. Rearing had significant effect level cod. showed stage-dependent response. Protocol higher survival 1 3. Our results indicate that an intermediate 2) suitable during rearing.