Krystyna Demska-Zakęś

Rates of oxygen consumption and ammonia excretion of juvenile Eurasian perch Perca fluviatilis L

The impact of feeding, fish size (body weight from 18.5 to 56.5 g) and water temperature (20 and 23 °C) on oxygen consumption (OC, mg O2 kg−1 h−1) and ammonia excretion (AE, mg TAN kg−1 h−1) was studied in Eurasian perch held in recirculation systems. OC for both fed and feed-deprived (3 days) fish was higher at 23 °C (278.5 and 150.1 mg O2 kg−1 h−1) than at 20 °C (249.3 and 135.0 mg O2 kg−1 h−1; P < 0.01). AEs for both fed and feed-deprived fish were also significantly higher at 23 °C than at 20 °C (P < 0.001). Water temperature and fish size had a significant impact on the oxygen:feed ratio (OFR, kg O2 kg−1 feed fed day−1) and ammonia:feed ratio (AFR, kg TAN kg−1 feed fed day−1; P < 0.001). Their average values at temperatures of 20 and 23 °C were 0.17 and 0.19 kg O2 kg−1 feed fed day−1 and 0.009 and 0.011 kg TAN kg−1 feed fed day−1, respectively.

Impact of butyl benzyl phthalate on development of the reproductive system of European pikeperch, Sander lucioperca (L.).

The effect of butyl benzyl phthalate (BBP) on the sex differentiation process of fish is practically unknown. The experimental material of this study was juvenile European pikeperch [Sander lucioperca (L.)], which is gonochoristic, undergoes immediate sex differentiation, and has a fixed gonad differentiation period. The fish were fed a diet supplemented with BBP (during the sex differentiation phase: age 61-96 days post hatch) in the following quantities: 1.0; 2.0; 4.0; 8.0; 16.0 g BBP kg-1 feed. The control feed was a xenobiotic-free base feed. In the present experiment lasting 10 weeks, the survival and growth of fish, the histopathological changes of the fish gonads and the sex ratio were evaluated. After administration of the two highest doses of BBP, growth inhibition of the fish was observed. BBP also seriously disturbed the gonadal differentiation process of pikeperch. All analysed concentrations of BBP delayed testicular development and, at concentrations of 4.0, 8.0 and 16.0 g BBP kg-1, induction of the feminisation process was observed. The sex ratio was distinctly disrupted in groups receiving 8.0 and 16.0 g BBP kg-1.

Impact of dibutyl phthalate and benzyl butyl phthalate on motility parameters of sperm from the European pikeperch Sander lucioperca (L.).

Impact of dibutyl phthalate and benzyl butyl phthalate on motility parameters of sperm from the European pikeperch Sander lucioperca (L.) The present study was the first attempt to evaluate the impact of dibutyl phthalate (DBP) and benzyl butyl phthalate (BBP) at concentrations of 100, 1000, and 10000 μg DBP dm-3 and 20, 200, and 2000 μg BBP dm-3 on the motility parameters of the sperm of European pikeperch, Sander lucioperca (L.), using computer assisted sperm analysis (CASA). The in vitro studies were conducted in the seminal plasma, which is the natural environment of the sperm, using two methods. The first was with the immediate activation of sperm movement in the presence of phthalates (0 h), while the second utilized phthalate incubation for 4, 24, and 48 h. It was confirmed that none of the compounds analyzed had a significant impact on the percentage of motile sperm (MOT), average path velocity (VAP), curvilinear velocity (VCL), straight line velocity (VSL), or amplitude of lateral sperm head displacement (ALH) (P > 0.05). It is plausible that in natural aquatic ecosystems, neither dibutyl phthalate nor benzyl butyl phthalate will affect motility of fish sperm at external fertilization event. It is necessary to track in vivo the impact these compounds have in concentrations similar to existing in the natural environment on the fish sperm quality. Wpływ ftalanu dibutylowego i benzylowobutylowego na parametry ruchu plemników sandacza europejskiego Sander lucioperca (L.) W badaniach analizowano dodatek do nasienia in vitro ftalanów dibutylowego (DBP) i benzylowobutylowego (BBP) w stężeniach występujących w środowisku oraz w koncentracjach blisko granicy ich rozpuszczalności w wodzie na wybrane parametry ruchliwości plemników sandacza europejskiego, Sander lucioperca (za pomocą systemu CASA - Computer-aided-sperm analysis). Analizę przeprowadzono dwiema metodami. Zastosowano natychmiastową aktywację ruchu plemników w obecności ftalanów (0 h), przez co uzyskano efekt bezpośredniego wpływu ksenobiotyków na plemniki oraz inkubowano nasienie z ftalanami przez 4, 24 i 48 h w celu wywołania subletalnego efektu działania zanieczyszczeń na układ rozrodczy (efektu bioakumulacji toksykanta). Nie wykazano istotnego wpływu badanych stężeń DBP i BBP na parametry ruchu plemników sandacza. Odsetek ruchliwych plemników, poszczególne prędkości ruchu: krzywoliniowa (VCL), prostoliniowa (VSL) i całkowita (VAP) oraz amplituda odchyleń bocznych główki plemnika nie różniły się istotnie statystycznie od grupy kontrolnej, zarówno po zastosowaniu natychmiastowej aktywacji ruchu, jak i po 4 oraz 24 h inkubacji (P > 0,05). Na podstawie uzyskanych wyników można przypuszczać, że oba ftalany w naturalnych ekosystemach wodnych nie wpłyną na jakość nasienia oddawanego podczas aktu tarła, pośrednio na zdolność plemników do zapłodnienia komórki jajowej. Istnieje potrzeba prześledzenia wpływu ftalanów in vivo na jakość nasienia ryb w stężeniach występujących w środowisku wodnym.

Slaughter yield and growth performance indexes of pikeperch (Sander lucioperca (L.)) selects reared in recirculating aquaculture systems at suboptimal temperatures

Abstract The aim of the study was to determine the impact diet has on the basic growth performance indexes and slaughter yield of pikeperch selects (body weight > 1.35 kg). Tagging the individual fish with PIT tags also permitted determining the impact of sex on the studied growth performance indexes. The fish were fed two diets with protein/fat/carbohydrate ratios of 50.5/11.8/29.4 in group I and 47.1/14.1/29.0 in group II. Neither the diets nor the sex of the fish has a significant impact on the final body weight or condition of the pikeperch (P > 0.05). Significant differences were noted between the relative indicators of pikeperch growth performance (SGR and DGR) (impact of diet and sex; P < 0.05). Among the growth performance indexes analyzed, e.g., viscerosomatic (VSI), hepatosomatic (HSI), and gonadosomatic (GSI), statistically significant differences were noted with regard to HSI (impact of diet and sex) and GSI (impact of sex) (P < 0.05). The analysis of the relative values of the pikeperch body parts studied (expressed in % body weight) indicated that the studied parameters had significant impacts on the slaughter yield of the viscera (impact of sex) and skin (impact of diet), as well as on gutted whole fish, gutted and headed whole fish, fillets with skin, and skinned fillets (impact of sex) (P < 0.05). The slaughter yields of the skinned fillets of males from both dietary treatments were approximately 5% higher than those of the females.

Impact of diets supplemented with rapeseed, soy, and sunflower oils on growth rates and the histological picture of the livers of juvenile pikeperch, Sander lucioperca (L.)

Impact of diets supplemented with rapeseed, soy, and sunflower oils on growth rates and the histological picture of the livers of juvenile pikeperch, Sander lucioperca (L.) Juvenile pikeperch (120 g initial body weight) were fed a commercial diet (group CD) or experimental diets supplemented with rapeseed (group RO), soy (group SO), or sunflower (group SFO) oils for 55 days. The experimental diets were made by adding the given vegetable oil (VO) in quantities of 160 g kg-1 feed (84% of the total raw lipid in the diet) to a base of an extruded, commercial diet (containing 30 g kg-1 raw lipid). The dietary treatments had no significant influence on fish growth rates, apparent net protein retention (ANPR), or apparent net energy retention (ANER) (P > 0.05). The apparent lipid retention (ALR) in group SO was significantly higher than in the other groups (P < 0.05). The dietary treatments tested had a significant impact on the size of the hepatocytes and their nuclei, as well as on the nucleocytoplasmic index values (P < 0.05). No significant differences were noted in the overall image of the hepatocytes (degree of vacuolization or hepatocyte degeneration (P > 0.05)). Wpływ żywienia paszami suplementowanymi olejem rzepakowym, sojowym i słonecznikowym na tempo wzrostu i obraz histologiczny wątroby juwenalnego sandacza Sander lucioperca (L.) Juwenalnego sandacza o początkowej masie ciała 102 g podchowywano w obiegu recyrkulacyjnym i żywiono przez 55 dni paszą komercyjną (grupa CD) lub paszami eksperymentalnymi suplementowanymi olejem rzepakowym (grupa RO), sojowym (grupa SO) lub słonecznikowym (grupa SFO). Pasze doświadczalne uzyskiwano dodając do ekstrudowanej, komercyjnej paszy bazowej (zawierającej 30 g kg-1 tłuszczu surowego) dany olej roślinny (VO) w ilości 160 g kg-1 paszy (84% całkowitego tłuszczu surowego w paszach). W efekcie otrzymano pasze o porównywalnym składzie chemicznym: białko surowe 449,0-452,1 g kg-1 paszy (sucha masa (d.m.)), tłuszcz surowy 189,1-191,1 g kg-1 paszy (d.m.), popiół surowy 73,9-74,5 g kg-1 paszy (d.m.). Kontrolną grupę ryb żywiono komercyjną paszą pstrągową o składzie chemicznym zbliżonym do pasz eksperymentalnych (pasza CD; tabela 1). Analizowano wpływ stosowania ww. pasz na wskaźniki wzrostu ryb, retencji nutrientów i energii oraz budowę histologiczną wątroby (tabela 2). Nie stwierdzono istotnego wpływu żywienia na tempo wzrostu ryb, w tym również na współczynniki retencji białka (ANPR) i energii (ANER) (P > 0,05; tabela 3). Współczynnik retencji tłuszczu (ALR) w grupie SO przyjął istotnie wyższą wartość niż w pozostałych grupach (P < 0,05). Wartość indeksu hepatosomatycznego (HSI) była zbliżona. Stwierdzono natomiast istotny wpływ testowanych pasz na wielkość hepatocytów i ich jąder, a także wartość indeksu nukleocytoplazmatycznego (P < 0,05). Nie odnotowano natomiast istotnych różnic w ogólnym obrazie hepatocytów (stopniu wakuolizacji i degeneracji komórek wątrobowych) (P > 0,05; tabela 4).

Propiscin — A safe anaesthetic for pikeperch (Sander Lucioperca L.)

The aim of this work was to determine the impact of etomidate (Propiscin) dose (1 and 2 ml l-1) and exposure time (2 and 10 min) on the biochemical and haematological parameters of juvenile pikeperch (Sander lucioperca) [mean body length (Lc) 25.9 cm; body weight (W) 189.9 g] that were reared in a recirculating aquaculture system (RAS). Significant changes in the mean values of total protein, globulin, calcium, magnesium, and ammonia were noted in all groups immediately following exposure. The greatest changes in the haematological indicators were observed in groups subjected to 10-min exposure at both doses of the anaesthetic. The specimens from these groups had higher values for white blood cells (WBC), red blood cells (RBC), haemoglobin (HGB), haematocrit (HCT), and mean corpuscular volume (MCV). Statistically significant differences in these same parameters were also noted in the groups of fish exposed to the anaesthetic for 2 min at a dose of 2 ml l-1, but they were not as pronounced. Twenty-four h following exposure to etomidate, all blood parameters in the experimental groups were comparable to those of the control group. Etomidate can be recommended as a safe, effective anaesthetic for pikeperch.

Impact of feeding juvenile tench (Tinca tinca (L.)) feeds supplemented with vegetable oils on hematological indexes and liver histology

Impact of feeding juvenile tench (Tinca tinca (L.)) feeds supplemented with vegetable oils on hematological indexes and liver histology The aim of the study was to identify the impact of feeding juvenile tench commercial feed supplemented with fish oil, linseed oil, arachide oil, and rapeseed oil on the hematology, cytology, and histology indexes of the liver. The fish were reared in a recirculating system and fed feed containing 470 g protein kg-1 feed and 120 g fat kg-1 feed (1000 g of base feed containing 70 g fat kg-1 feed was supplemented with 50 g of additional fat, i.e., fish oil (FO) or vegetable oils - linseed oil (LO), arachide oil (AO), or rapeseed oil (RO)). Statistically significant inter-group differences were noted for hematocrit (Ht), hemoglobin (Hb), red blood cell (RBC) counts, and other red blood cell indexes, including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) (P < 0.05). The lowest Ht and Hb values were noted in fish fed feed supplemented with fish oil (group FO), while the highest was noted in the tench from group AO. These differences were mainly caused by the occurrence of smaller erythrocytes in the peripheral blood of the fish from the FO group. No pathological changes were observed in the blood cells, which was in contrast to the parenchymal cells of the liver. Congestion, lipid vacuolization in hepatocytes, regressive changes in cytoplasm density, nuclear chromatin, and nucleus disintegration were observed in all fish. These changes were more pronounced in groups LO and AO. The fish from these groups were characterized by smaller hepatocytes and significantly higher nucleocytoplasmic ratios (P < 0.05).

Impact of two telemetry transmitter implantation incision suturing methods on the physiological state and condition of perch (Perca fluviatilis)

Abstract The aim of this work was to determine the impact on European perch, Perca fluviatilis L. (mean body weight – 78.33 g) of the intraperitoneal implantation of telemetry transmitters using different suturing methods. In the first experiment silk sutures were used (experiment I – group ST), while in the second tissue adhesive was used (experiment II – group GT). Following the procedure, the fish were kept for 42 days in a recirculating system. Differences in growth and condition parameters were only noted in the first week of the experiment. Specimens from group GT had lower values for DGR (daily growth rate) and SGR (specific growth rate), but a higher value for FCR (feed conversion ratio) values. For the hematological parameters, lower values of MCV (mean corpuscular volume) and PLT (blood platelets) were noted in group GT, while for the biochemical parameters, lowered ALP (alkaline phosphatase) activity and Mg (magnesium) concentrations were noted in group ST. In group ST, 33.3% of the specimens loss their tags, while in group GT 77.8% did so. Differences in incision healing were only noted in the second week, when specimens in group ST were observed to have fully closed incisions, while in group GT 50% of the incisions were open. Despite the high percentage of implantation incision healing in both groups, because of the high values of tag loss rate, neither method can be recommended for perch. It might be more effective to use tag with external antennae in this species. The method use for closing implantation incisions also must be improved to eliminate tag shedding.

Impact of sex and diet on hematological and blood plasma biochemical profiles and liver histology of pikeperch (Sander lucioperca (L.))

Abstract The aim of the study was to determine the impact of diet and sex on the hematological and blood plasma biochemical profiles and the liver histology of pikeperch, Sander lucioperca (L.) reared in recirculating aquaculture systems (RAS) (initial mean body weight (BW) 1.35 kg). The proximate composition of the two commercial feeds used were (protein/lipid/nitrogen-free extracts) (P/L/NFE)) P505/L118/NFE294 g kg−1 (group I) and P471/L141/NFE290 g kg−1 (group II). Neither diet nor sex had a significant impact on final fish body weight (≈ 2.0 kg). Sex was noted to significantly impact glucose content (Glu – higher in males) and cholesterol (Chol – higher in females) in the blood plasma. Diet was confirmed to have a significant impact on levels of hematocrit (Ht), hemoglobin (Hb), and mean corpuscular hemoglobin (MCH), and the values of these indicators were higher in group I. Sex had a significant impact on Ht, Hb, MCH, and mean corpuscular hemoglobin concentration (MCHC), with higher values in male pikeperch. Diet and sex had significant impacts on the values of the pikeperch hepatosomatic index (HSI), hepatocyte size and that of their nuclei, and the values of the nucleocytoplasmic index (NCI).

Impact of feeding juvenile pikeperch (Sander lucioperca (L.)) diets supplemented with vegetable oils on proximate body composition and fatty acid profile

Impact of feeding juvenile pikeperch (Sander lucioperca (L.)) diets supplemented with vegetable oils on proximate body composition and fatty acid profile Juvenile pikeperch, Sander lucioperca (L.) were reared in recirculating aquaculture systems for 55 days and fed a commercial trout diet (group CD) or diets supplemented with the following vegetable oils (VO): rapeseed (group RO), soy (group SO), sunflower (group SFO). The level of feed supplementation with VO was 84% of the total crude fat (CF), which was achieved by adding 160 g VO kg-1 feed to the commercial feed base that contained 30 g CF kg-1 feed. The diets tested did not have a significant impact on the proximate composition of the whole fish, fillets, or viscera (P > 0.05). Significant differences were noted in the protein and fat contents of the pikeperch livers; these were significantly higher in the groups fed diets supplemented with VO (P < 0.05). The fatty acid (FA) profiles of the pikeperch body parts (whole fish, fillets, viscera, liver) analyzed reflected the proximate composition of the diets applied. The FA profiles of pikeperch muscles were the most stable. The diets tested did not have a significant impact in the fillets of fish from the VO groups on the value of summed products of polyunsaturated FA from the n-3 family (n-3 PUFA) to the PUFA from the n-6 family (n-6 PUFA) (n-3/n-6 ratio) (P > 0.05). They were, however, significantly lower than the values noted in group CD (P < 0.05) (1.03-2.07 vs. 3.50). Wpływ żywienia juwenalnego sandacza (Sander lucioperca (L.)) paszami suplementowanymi olejami roślinnymi na podstawowy skład chemiczny ciała i profile kwasów tłuszczowych Młdocianego sandacza (początkowa masa ciała ok. 100 g) podchowywano w obiegach recyrkulacyjnych przez 55 dni i żywiono komercyjną paszą pstrągową (grupa CD) lub paszami suplementowanymi następującymi olejami roślinnymi (VO): rzepakowym (grupa RO), sojowym (grupa SO) lub słonecznikowym (grupa SFO). Poziom suplementacji pasz VO wynosił 84% całkowitego tłuszczu surowego (CF) - do komercyjnej mieszanki bazowej zawierającej 30 g CF kg-1 paszy dodawano 160 g VO kg-1 paszy. Podstawowy skład chemiczny pasz był podobny, a profile kwasów tłuszczowych (FA) w nich zawartych odzwierciedlały skład chemiczny olejów, którymi były suplementowane (tabela 1). Żywienie testowanymi paszami nie wpłynęło istotnie na wartości wskaźników wzrostu ryb i podstawowy skład chemiczny całej ryby, filetów i trzewi (P > 0,05; tabela 2). Odnotowano natomiast istotne różnice w zawartości białka i tłuszczu w wątrobie sandacza. Stwierdzono, że zawartość białka w grupach RO i SO była istotnie niższa niż u ryb z grup CD i SFO (P < 0,05). Poziom tłuszczu w wątrobie ryb z grup VO był wyższy od stwierdzonego w grupie CD, a w przypadku grup RO i SO różnice te były istotne statystycznie (P < 0,05; tabela 2). Profile FA analizowanych części ciała sandacza (cała ryba, filet, trzewia i wątroba) odzwierciedlały skład chemiczny stosowanych pasz (tabela 1, 3, 4, 5, 6). Udział wszystkich analizowanych grup FA, tj. nasyconych (SFA), nienasyconych (USFA), monoenowych (MUFA), polienowych (PUFA), polienowych z rodziny n-3 (n-3 PUFA) i polienowych z rodziny n-6 (n-6 PUFA) w całym ciele, trzewiach i wątrobie był istotnie determinowany stosowaną dietą (P < 0,05; tabela 3, 5, 6). Najbardziej stabilny był skład FA mięśni sandacza (tabela 4). W filetach ryb z grup VO nie stwierdzono istotnego wpływu żywienia testowanymi paszami na wartości ilorazów n-3 PUFA do n-6 PUFA (stosunek n-3/n-6) (P > 0,05). Były one jednak istotnie niższe niż w grupie CD (P < 0,05) (1,03-2,07 vs 3,50).