An 8-week feeding experiment was conducted to investigate the effects of curcumin nanomicelle, curcumin, and turmeric (
Curcuma longa
) on growth performances, body composition, fatty acid profile, ...and biochemical parameters of common carp (
Cyprinus carpio
), and their ameliorative effects against toxicity of silver nanoparticles (AgNPs). A total of 120 healthy carps were randomly distributed into four equal treatments. Curcumin nanomicelle, curcumin, and turmeric were each added separately to the basal diet. After the feeding trials, all treatments were exposed to a non-lethal concentration of AgNPs (0.5 mg L
−1
) for 96 h. Fish fed dietary turmeric showed a significantly higher weight gain. The body protein content was significantly increased in all feeding groups, while the lipid content showed a significant decrease in the turmeric-treated group. Dietary turmeric improved the concentration of saturated fatty acids (SFA) and monounsaturated fatty acid (MUFA). AgNP exposure led to increases in liver catalase (CAT) activity of carps fed with turmeric and curcumin. The lowest amount of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was obtained in fish fed with nanomicelle curcumin and curcumin diets. The lowest amount of silver accumulation in the liver of carps was found in fish fed with dietary curcumin nanomicelle. This experiment suggests that supplementation of turmeric (50 g kg
−1
) or curcumin (1000 mg kg
−1
) may play an important role in enhancing growth performances and fatty acid composition of the common carp. Moreover, administration of curcumin nanomicelle in the diet may have a potential ameliorative effect against toxicity of AgNPs.
The aim of this study was to assess the effects of different doses of selenium nanoparticles (nano-Se) on growth performance, feed conversion, tissue composition, Se accumulation in muscle and liver, ...antioxidant response and biochemical blood parameters of common carp, Cyprinus carpio. Nano-Se was added to the experimental basal diets at the rates of 0 (control), 0.5, 1 and 2mg/kg dry feed weight. Four groups of fish with an average weight of about 10g were fed one of the experimental diets for 8weeks. Fish that were fed diet supplemented with 1mg Se/kg displayed improved (P<0.05) growth performance, including final weight and weight gain (WG). No significant differences (P>0.05) in feed conversion ratio (FCR) and survival were observed in fish fed different diets for 8weeks. Dietary nano-Se had no effects on proximate composition of carps. Fish fed with nanoselenium-supplemented diets showed a higher (P<0.05) Se content in the muscle and liver tissues compared to that of the control. Liver malondialdehyde (MDA) level was significantly (P<0.05) lowered in fish fed on diet supplemented with 2mg nano-Se/kg, whereas the activity of glutathione peroxidase (GPx) and catalase (CAT) in livers of carp fed on diet supplemented with 2mg nano-Se was significantly (P<0.05) higher as compared to other experimental diets. The highest superoxide dismutase (SOD) activity was observed in fish fed on 2mg nano-Se, but it was not significantly (P>0.05) different from the enzyme activity in the 1mg nano-Se group. Fish fed on diet supplemented with 2mg nano-Se showed significantly (P<0.05) higher total protein and globulin contents but lower albumin level. The serum cholesterol level was significantly (P<0.05) decreased in fish fed diets containing 2mg nano-Se/kg. No significant difference (P>0.05) in serum triglycerides was observed in fish fed different diets. A significant (P<0.05) decrease in low-density lipoprotein (LDL) was observed in groups receiving 1 and 2mg nano-Se/kg, whereas serum high-density lipoprotein (HDL) was higher in carp fed on diet with 2mg nano-Se/kg. Fish fed on 1 and 2mg nano-Se/kg diets exhibited the highest values of aspartate transaminase (AST) activity as compared to other treatments. The activity of alanine transaminase (ALT) was significantly (P<0.05) higher in fish fed on 2mg nano-Se/kg as compared to other test groups. No significant differences (P>0.05) were found in serum alkaline phosphatase (ALP) activity among the experimental groups. Therefore, the data of the present study recommend adding 1mg nano-Se per kg diet to improve fish growth and antioxidant defense system.
The data of the present study recommend adding 1mg nano-Se per kg diet to improve carp growth and antioxidant defense system.
•Effects of dietary nanoselenium (nano-Se) on common carp were investigated.•Fish that were fed with 1mg nano-Se/kg displayed improved growth performance•Fish that were fed with nano-Se diets, showed higher Se accumulation.•One milligram nano-Se per kg diet can improve fish growth and antioxidant defense system.
Abstract Some cichlid fishes release urine‐containing chemical cues that lower aggression in their opponents. Bioassays to identify the aggression‐modulating pheromone include assessing the effect of ...urine fractions on the behavior towards a mirror image or in interactions with another male. However, many of these methods can be time‐consuming and require many fish. The objective of the present study was to assess the behavior of male Mozambique tilapia ( Oreochromis mossambicus ) towards male urine using two methods with the intent of simplifying the bioassays: aggression towards a mirror image (mirror assay) and real opponents in which the urogenital papilla was tied using surgical silk to prevent urination. The results confirm the aggression‐reducing effect of dominant male urine in both experimental approaches. Ten minutes of biting or 15 min of tail‐beating behaviors in the mirror assay, or 5 min of opercular expansion or 15 min of lateral display in interactions with real opponents were necessary to detect a statistically significant reduction in aggressive behavior towards dominant male urine. We also found that males with subordinate status had lower latency to initiate aggressive behaviors towards the mirror than dominants in the same condition, even though fish had been isolated for 1 week. However, no such differences in latency were found in the real opponent assay. We conclude that 5 min of opercular expansion behavior in real opponent fights or 10 min of biting behavior in the mirror assay are the shortest times necessary to test aggressive behavior in urine fractions in bioassay‐guided identification of pheromones.
The present study aimed to examine individual nutritional and ameliorative effects of silica nanoparticles (SiO
2
NPs) and natural zeolite nanoparticles (ZeNPs) and their potential role as carriers ...to alter the bioavailability of curcumin. Common carps (
Cyprinus carpio
) were fed during 60 days with a control diet, and curcumin, turmeric, SiO
2
NPs, curcumin-loaded SiO
2
NPs, ZeNPs, and curcumin-loaded ZeNPs each at 1, 50, 6.15, 7.15, 39, and 40 g/kg diet, respectively. The highest weight gain (WG) and specific growth rate (SGR) were observed in fish fed with turmeric (
P
< 0.05). Moreover, dietary curcumin and ZeNPs increased the content of monounsaturated fatty acids (
P
< 0.05). After exposure to silver nanoparticles (AgNPs), the lowest amount of aspartate aminotransferase (AST) was obtained in fish fed with curcumin (
P
< 0.05). In addition, alanine aminotransferase (ALT) decreased significantly in the negative control, curcumin, and curcumin-loaded SiO
2
NPs treatments in comparison to the positive control group (
P
< 0.05). The lowest silver accumulation was observed in the negative control and SiO
2
NPs groups (
P
< 0.05). This experiment demonstrated that while the nanoencapsulation of curcumin on SiO
2
NPs and ZeNPs did not enhanced the impact of curcumin on the growth and biochemical factors of carps, it can still be considered a potential dietary supplement for enhancing growth and antioxidant indices when added individually to the diet.
Graphical abstract
Chemical cues provide potential mates with information about reproductive status and resource-holding potential. In the Mozambique tilapia (Oreochromis mossambicus), males can distinguish female ...reproductive status through chemical cues, and accessibility of males to females depends on their position in the hierarchy, determined in part by chemical cues. Here, we hypothesized that tilapia faecal cues are attractive to conspecifics once released into the water. C18 solid-phase extracts of faeces from dominant males and pre-ovulatory females evoked stronger olfactory epithelium electrical responses (EOG) than, respectively, subordinate males and post-spawning females. Mass spectrometry of the reverse-phase C18 high-performance liquid chromatography fractions of these extracts with highest EOG, identified by amino acids and bile acids. Faeces from pre-ovulatory females contain significantly higher concentrations of cholic acid (CA) and taurocholic acid (TCH) than both post-spawning females and males. A pool of amino acids had no effect on aggression or attraction in males. However, males were attracted to the scent of pre-ovulatory female faeces, as well as CA and TCH, when applied separately. This attraction was accompanied by increased digging behaviour compared to the odour of post-spawning females. CA and TCH exert their action through separate receptor mechanisms. These findings are consistent with a role for faeces - and bile acids therein - in chemical communication in this species, acting as an attractant for males to reproductive females.
