Effect of thermal management on vitellogenesis and maturation in indoor-reared pikeperch (Sander lucioperca)

The present study aimed to assess the effects of thermal manipulation on the vitellogenesis and final oocyte maturation (FOM) in pikeperch. Two groups of fish were stocked in two separate tanks of the climate chamber. One group was stocked at 10-month age (THERMAL), while the other was continually kept under stable photothermal conditions until 19-month-age (CONTROL) and then transferred to a climate chamber. The progress of vitellogenesis was assessed via evaluation of the oocyte diameter at the mid- and late-autumn phases, and the gonadosomatic index (GSI) at the late-autumn phase. Finally, females from the CONTROL group were hormonally stimulated before (WARMING) and after (STABLE) increase of the temperature from wintering to spawning, and the FOM progress, ovulation and plasma levels of 17 α, 20β dihydroxy progesterone (DHP) were assessed. Significantly larger oocytes at the mid-autumn phase (878.8 ± 40.1 μm vs 836.5 ± 46.5 μm) as well as the GSI at the end of the autumn phase (10.5 ± 1.7% vs 7.6 ± 1.1%) were noticed in THERMAL fish. Significantly faster FOM was seen in fish under the WARMING post-stimulation regime, and these fish had higher DHP levels at the moment of hormonal stimulation (5.4 ± 1.4 ng/ml vs 3.8 ± 1.2 ng/ml). According to the obtained results, it appears that photothermal induction of fish at a younger stage might have a positive impact on the first spawning, while the WARMING thermal regime seems to be more efficient in stimulating the FOM in fish upon first wintering

Reproduction of Hatchery-Reared Pike-Perch (Sander lucioperca) Fed Diet with Low-Marine-Ingredients: Role of Dietary Fatty Acids

This research aimed to evaluate the reproductive potential of hatchery-reared (F1) pike-perch (Sander lucioperca) broodstock fed a commercial diet with low levels of long-chain polyunsaturated fatty acids (Lc-PUFA) and wild (F0) pike-perch broodstock fed forage fish. Reproductive parameters, including pseudogonadosomatic index (PGSI), egg size, latency time, hatching rate, embryo survival, and eggs’ fatty acid (FA) composition, as well as plasma sex hormone, glucose and immunoglobulin levels after hormone injection, were analyzed. The results showed low PGSI (10% in F1 vs. 14% in F0) and embryo survival (24% in F1 vs. 61% in F0) in F1 broodstock, but a satisfactory hatching rate (63% in F1 vs. 78% in F0) and larval size (4.6 mm in F1 vs. 4.7 mm in F0). A low arachidonic acid (ARA) percentage in F1 fish eggs (1.32%), along with increased immunoglobulin levels (17.31 g/L), suggests that immune system activation might have depleted the reserves of ARA in F1 fish, which is the key fatty acid for successful oocyte maturation. We assumed that the administration of more sustainable diets, based on terrestrial plant ingredients, is not inferior to higher-quality diets based on marine ingredients

Impact of Handling and Pre-Mortal Stress on the Flesh Quality of Common Carp (Cyprinus carpio L.)

The aim of this study was to investigate stress in common carp Cyprinus carpio L. caused by harvesting, transport, and the stunning method, and the effect of the latter on flesh quality Serum cortisol concentration increased during harvesting and transport. The percussive stunning (blow on head) method caused the least stress and resulted in a significant increase in blood cortisol concentration (P<0.01). This method had no significant effect on conventional flesh quality. CO2 asphyxiation which was more stressful delayed stiffening in rigor mortis development. The greatest stress was caused by live chilling. There was a decline of pH levels in the CO2 asphyxiated and live chilled groups compared to the percussive stunned group. According to our results percussive stunning led to the best fillet quality and is the least objectionable method according to animal welfare standards

Case study on the aptness of in-pond raceways for pikeperch, Sander lucioperca, grow-out

Pikeperch Sander lucioperca is a species of increasing presence in recirculation aquaculture system and the vast majority of thus far research was dedicated to its indoor farming. Concerning the present pond infrastructure in Central and East Europe, it is of interest to evaluate the intensive pond-connected system for pikeperch rearing. Therefore, the present study evaluated the grow-out performance in recirculation aquaculture system (RAS) and in-pond-raceway (IPR) in triplicated tanks. A 16-week trial with 1-year-old pikeperch (mean weight 215.7 ± 8.1 g RAS and 217.7 ± 2.6 g IPR) was conducted from June to October evaluating both culture and welfare parameters. Significantly higher final mean weight (443.1 ± 17.5 vs 400.6 ± 13.2) and lower feed conversion (2.1 ± 0.1 vs 3.0 ± 0.1) was obtained in fish reared in IPR. Cortisol levels were overall higher in the RAS group throughout the trial being significantly higher at the first and last sampling. Elevated lysozyme levels were found in IPR in the first half of the trial, while further on they were higher in RAS being significantly higher compared to IPR in middle sampling. Thus, both in terms of culture performance and fish welfare, IPR proves aptness for pikeperch rearing. This study presents the first insight into the suitability of pond-connected intensive rearing of pikeperch describing IPR as a promising system for final grow-out during the growing season. More comprehensive studies in terms of stocking densities and growing period are required to explore the full potential of pikeperch outdoor farming

Raw data for the article: Péter, G., Lukić, J., Brlás-Molnár, Z., Ardó, L., Horváth, Z., Rónyai, A., Bársony, P.,& Ljubobratović, U.. (2023). Effect of single-generation domestication of pikeperch on the performance of the offspring in conventional and pond recirculation aquaculture system. in aquaculture reports, 32, 101702. https://doi.org/10.1016/j.aqrep.2023.101702

Raw data for: [https://doi.org/10.1016/j.aqrep.2023.101702]Related to published version:[https://imagine.imgge.bg.ac.rs/handle/123456789/2069

Differences in the antibody response and survival of genetically different varieties of common carp (Cyprinus carpio L.) vaccinated with a commercial Aeromonas salmonicida/A. hydrophila vaccine and challenged with A. hydrophila

Males of two strains of carp, wild Duna (D), and inbred Szarvas 22 (22), were selected for high and low stress response. Two purebreds of D and 22, from randomly chosen parents and four crosses, 22 &times; 22-L (low stress response), 22 &times; 22-H (high stress response), 22 &times; D-L (low stress response) and 22 &times; D-H (high stress response) from selected stress response parents were produced and vaccinated with a commercial Aeromonas salmonicida/Aeromonas hydrophila vaccine and their circulating antibody response evaluated 1, 3, 5, and 7 weeks post-vaccination by ELISA. Significantly higher titres of circulatory antibodies against A. hydrophila were found in the families 22 and cross 22 &times; 22-L compared to other groups. The development of circulatory antibodies against A. hydrophila in all crosses having at least one D parent was low and remained low throughout the experiment. The level of circulatory antibodies against atypical A. salmonicida in the inbred strain increased following a booster vaccination with the highest values measured in inbred strain 22 and cross 22 &times; 22 L. The different varieties of carp had different levels of survival against experimental challenge with A. hydrophila. The greatest survival was obtained in strain 22 and cross 22 &times; 22-L, while ~90% of D wild carp and cross 22 &times; D (independent of their stress response) died. Survival results correlated well with the antibody response of the different groups: 22 and 22 &times; 22-L had the highest antibody titres against A. hydrophila and the greatest level of survival