Faculty of Veterinary Medicine University of Zagreb
Abstract
Experiments were carried out on common carp (Cyprinus carpio L.) larvae in a recalculating aquatic system for a period of 21 days. Four feeding variants with different transition times from live (nauplii of Artemia salina) to artificial feed (Biomar larviva) were examined. The greatest average total length (25.72 ± 3.37 mm) and weight (213.81 ± 105.52 mg) was achieved by common carp larvae fed over the whole period with nauplii of the brine shrimp (group D). A significantly higher (P<0.05) final bodyweight was reported in group D in comparison with groups A and B. Survival in groups B, C and D was high (81.53, 84.14, 80.66% respectively) but not in group A (32.44 - 43.36%) with the earliest transition to artificial feed. A salinity stress test was carried out on the final day of rearing. Common carp fry survival in the salinity stress test was analyzed using the Kaplan - Meier test. High significant differences (P<0.001) have only been reported between feeding treatments at 14‰ salinity level.Istraživanja su provedena na ličinkama šarana (Cyprinus carpio L.) u uzgojnim uvjetima recirkulacijskog sustava u trajanju 21 dan. Promatrana su četiri hranidbena režima s različitim prijelazima sa žive hrane (naupliji artemije, Artemia salina) na umjetnu hranu (Biomar larviva). Najveću prosječnu dužinu tijela (25,72 ± 3,37 mm) i masu tijela (213,81 ± 105,52 mg) ostvarile su ličinke šarana hranjene čitavo vrijeme nauplijima artemije (A. salina) u skupini D. Značajno signifikantna (P<0,05) završna tjelesna masa utvrđena je u skupini D u odnosu na skupine A i B. Najveći postotak preživljavanja utvrđen je u skupinama B, C i D (81,53; 84,14; 80,66 %), dok je u skupini A s najranijim prijelazom na umjetnu hranu postotak preživljavanja znatno manji (32,44 - 43,36 %). Test na salinitetni stres proveden je zadnjeg dana uzgoja. Preživljavanje mladunaca šarana tijekom salinitetnog stresa analizirano je Kaplan-Meierovim testom. Statistički značajna razlika (P<0,001) utvrđena je između hranidbenih režima samo pri salinitetu od 14‰