Egg Carotenoid Research Articles

Effects of Fortified Laying Hen Diet with Moringa oleifera Leaves and Goji Berries on Cholesterol and Carotenoid Egg Content.

The biofortification of basal laying hen feed with natural matrices can improve the beneficial potential of eggs produced without relying on artificial fortification. The present study aimed to evaluate the effects of hen diet supplementation with dried Moringa leaves (DML) and goji berries (DGB) on egg functional properties in terms of cholesterol and carotenoid content. Forty Lohman Brown Classic laying hens were randomly divided into four groups. The control group (G1) received the basal poultry diet, group G2 received a diet with 5% DML + 10% DGB, group G3 received a diet with 3% DML + 7% DGB, and group G4 received a diet with 15% DML. HPLC-DAD analysis showed that feed supplementation positively influenced the egg carotenoid content, with a valuable increase in xanthophylls concentration, especially lutein (+333.24% in G4, +258.15% in G2, +189.24% in G3, compared to G1). The same trend was also followed by the β-carotene concentration (+181.38% in G3 and +116.01% in G4, compared to G1). Furthermore, the eggs obtained from G3 showed the lowest cholesterol content (−47.08%). Additionally, the performed antioxidant assays showed maximum activity in G2 (+39.11 compared to G1 for the DPPH test) and in G4 (+31.11 compared to G1 for the ABTS test). In conclusion, the G2 experimental diet could be potentially used in poultry industries to produce “functional eggs”.

Inherent immunological parameters in kutum, Rutilus frisii, larvae obtained from the adult females with orange and green eggs.

Kutum (Rutilus frisii) displays different egg colours during the spawning season, mostly due to the presence of carotenoid pigments. In this study, the authors investigated the relationship between the egg colour and muscle lipid of adult female kutum and the correlation between egg carotenoid content and the immune parameters of larvae. The results from this study highlighted the positive influence of egg carotenoid on post-fertilization stages, such as elevating the innate immune parameters in larvae.

Effect of commercial diets on female reproductive performance and offspring quality in the red cherry shrimpNeocaridina davidi(Caridea, Atyidae)

The red cherry shrimp Neocaridina davidi is a popular freshwater ornamental species traded worldwide for aquarium keeping. Its aquaculture generally relies on commercially available feeds. This study evaluated the effect of three commercial diets (A, B and C) on its female reproductive performance and offspring quality. Relative realized fecundity and egg size did not differ among treatments. However, egg carotenoid content was 40% and 52% lower in eggs from brooders fed B and C, respectively, than in those from brooders fed A, which had the highest carotenoid content. This suggests that dietary carotenoids directly affected egg carotenoid content. They also appeared to influence embryo survival, as relative actual fecundity was 59% and 47% lower for B and C compared to A, although this difference was not statistically significant. Although juvenile I weight was similar for all diets, the amount of lipid droplets in the perigastric organ region in juveniles I from brooders fed B, was about 20% lower than in the others. Offspring survival to the food restriction test was similar for all diets. However, the weight of 32-day-old juveniles was lower when brooders were fed C which had the lowest n-3 PUFAs content, but the highest content of linoleic acid.

Microsphere packages of carotenoids: intact sea urchin eggs tracked by Raman spectroscopy tools.

Although natural exposure to ambient UV radiation in oligotrophic seawater at small depths can reach the levels responsible for cellular damage, the sea urchin Paracentrotus lividus is frequently in such sites, particularly on the southern Adriatic Sea shore. Spawning their eggs and spending their early life stage in rocky shores at depths of 0.5-2 m are the results of their successful adaptation strategies, although adults may dwell at greater depths. Surprisingly, there is a paucity of reports regarding the carotenoid content in sea urchin eggs. Beyond their important role in photoprotection against high UV exposure, cell division and early development, the content and distribution of carotenoids contribute to the successful survival of sea urchins and also determine the color of their gonads (roe), which is of commercial importance as a delicacy. Herein, for the first time, we have described the carotenoid content and distribution in intact, freshly released eggs of P. lividus species, non-destructively employing resonance Raman spectroscopy and imaging; near-infrared Raman spectroscopy revealed additional molecular carotenoid content. Echinenone and β-carotene resonance Raman signals were the most intense, and they were identified as the principal carotenoids that are preferentially accumulated in eggs rather than in gonads. Raman imaging in confocal mode revealed the uniform distribution of the carotenoid signal over the whole eggs, while the distribution of proteins appeared spotted. Egg carotenoids generally maintained their identity after 2 months of dry storage, with slight signs of C[double bond, length as m-dash]C bond oxidation. The potential utilization of P. lividus sea urchin eggs as valuable microsphere packages of native carotenoids is discussed.

Egg production in relation to paternal weight in a freshwater caridean shrimp (Decapoda)

AbstractIn diverse invertebrate species, sperm quantity and quality are positively correlated with male size, egg fertilization rates being consequently affected by paternal weight. This factor may also have an indirect effect on egg quality, because females could adjust the quantity of yolk stored in oocytes before spawning according to their partner attractiveness. The objective of this study was to determine whether paternal weight influences egg production in a freshwater crustacean with external egg fertilization, the caridean shrimp Neocaridina davidi. Virgin females weighing 60–100 mg were paired with virgin males weighing 20–50 mg. The number (total and fertilized), size (volume, wet and dry weight) and carotenoid content of eggs were recorded for each pair. Paternal weight was not associated to any of the evaluated egg variables, while maternal weight showed a positive correlation with egg number and a negative correlation with egg carotenoid content. The percentage of fertilized eggs was similar and near 100% for all paternal sizes, which indicates that small mature males provided enough good‐quality sperm to fertilize almost all the oocytes laid by females, similarly to larger males. The relatively low fecundity of N. davidi females may explain, at least in part, the absence of sperm limitation even under a hypothetical decrease in sperm supply by smaller males. In addition, paternal weight had no effect on egg volume, weight and carotenoid content, which suggests that females do not modulate the total amount of biochemical reserves allocated to the maturing ovary as a function of their partner size. Present results are the starting point for a future evaluation of sperm production, in terms of quantity and quality, in males of different size and physiological condition.

Flaxseed and dried tomato waste used together in laying hens diet

ABSTRACTThe aim of this study was to investigate the effects of simultaneous supplementation of laying hens with dietary sources of n-3 polyunsaturated fatty acids (PUFA) and carotenoids on egg quality, fatty acids and carotenoid profile of the egg yolk and on feed and yolk lipid peroxidation. A 6-week experiment was carried out with 53-week old laying hens (96 Tetra SL) assigned to a control and three treatment groups supplemented with 5% flaxseeds and different levels of dried tomato waste (DTW, 2.5%, 5.0% and 10.0%). Hens from the groups supplemented with 5% and 7.5% DTW had a significantly lower average daily feed intake and laying percentage as compared to the control. Increased doses of dietary DTW enhanced yolk Roche colour score in direct correlation with the enrichment of egg yolk in carotenoids but decreased their transfer efficiency from feed to egg. After 4 weeks, egg yolk from hens fed with 5% flaxseeds and 7.5% DTW had increased lutein and zeaxanthin levels (by 29% and 24%, respectively) and the colour score was 3.5 fold higher compared to the control group. As a result of the dietary supplementation with flaxseed, the n-3 fatty acid content was 3.1–3.7-fold higher in egg yolk compared with the control and the n-6/n-3 ratio decreased from 18.3 (control) to 4.1–5.4 in supplemented diets. Dietary supplementation with 5% DTW effectively prevented lipid oxidation of eggs enriched with n-3 PUFA, but the increase in DTW content depressed the absorption and deposition of n-3 PUFA in egg yolk.

Significant differences in maternal carotenoid provisioning and effects on offspring fitness in Chinook salmon colour morphs.

In oviparous species, maternal carotenoid provisioning can deliver diverse fitness benefits to offspring via increased survival, growth and immune function. Despite demonstrated advantages of carotenoids, large intra- and interspecific variation in carotenoid utilization exists, suggesting trade-offs associated with carotenoids. In Chinook salmon (Oncorhynchus tshawytscha), extreme variation in carotenoid utilization delineates two colour morphs (red and white) that differ genetically in their ability to deposit carotenoids into tissues. Here, we take advantage of this natural variation to examine how large differences in maternal carotenoid provisioning influence offspring fitness. Using a full factorial breeding design crossing morphs and common-garden rearing, we measured differences in a suite of fitness-related traits, including survival, growth, viral susceptibility and host response, in offspring of red (carotenoid-rich eggs) and white (carotenoid-poor eggs) females. Eggs of red females had significantly higher carotenoid content than those of white females (6× more); however, this did not translate into measurable differences in offspring fitness. Given that white Chinook salmon may have evolved to counteract their maternal carotenoid deficiency, we also examined the relationship between egg carotenoid content and offspring fitness within each morph separately. Egg carotenoids only had a positive effect within the red morph on survival to eyed-egg (earliest measured trait), but not within the white morph. Although previous work shows that white females benefit from reduced egg predation, our study also supports a hypothesis that white Chinook salmon have evolved additional mechanisms to improve egg survival despite low carotenoids, providing novel insight into evolutionary mechanisms that maintain this stable polymorphism.

Consumption of carotenoids not increased by bacterial infection in brown trout embryos (Salmo trutta).

Carotenoids are organic pigment molecules that play important roles in signalling, control of oxidative stress, and immunity. Fish allocate carotenoids to their eggs, which gives them the typical yellow to red colouration and supports their resistance against microbial infections. However, it is still unclear whether carotenoids act mainly as a shield against infection or are used up during the embryos’ immune defence. We investigated this question with experimental families produced from wild-caught brown trout (Salmo trutta). Singly raised embryos were either exposed to the bacterial pathogen Pseudomonas fluorescens or sham-treated at one of two stages during their development. A previous study on these experimental families reported positive effects of egg carotenoids on embryo growth and resistance against the infection. Here, we quantified carotenoid consumption, i.e. the active metabolization of carotenoids into compounds that are not other carotenoid types, in these infected and sham-infected maternal sib groups. We found that carotenoid contents mostly decreased during embryogenesis. However, these decreases were neither linked to the virulence induced by the pathogen nor dependent on the time point of infection. We conclude that egg carotenoids are not significantly used up by the embryos’ immune defence.

Maternal allocation of carotenoids increases tolerance to bacterial infection in brown trout.

Life-history theory predicts that iteroparous females allocate their resources differently among different breeding seasons depending on their residual reproductive value. In iteroparous salmonids there is typically much variation in egg size, egg number, and in the compounds that females allocate to their clutch. These compounds include various carotenoids whose functions are not sufficiently understood yet. We sampled 37 female and 35 male brown trout from natural streams, collected their gametes for in vitro fertilizations, experimentally produced 185 families in 7 full-factorial breeding blocks, raised the developing embryos singly (n=2960), and either sham-treated or infected them with Pseudomonas fluorescens. We used female redness (as a measure of carotenoids stored in the skin) and their allocation of carotenoids to clutches to infer maternal strategies. Astaxanthin contents largely determined egg colour. Neither egg weight nor female size was correlated with the content of this carotenoid. However, astaxanthin content was positively correlated with larval growth and with tolerance against P. fluorescens. There was a negative correlation between female skin redness and the carotenoid content of their eggs. Although higher astaxanthin contents in the eggs were associated with an improvement of early fitness-related traits, some females appeared not to maximally support their current offspring as revealed by the negative correlation between female red skin colouration and egg carotenoid content. This correlation was not explained by female size and supports the prediction of a maternal trade-off between current and future reproduction.

Environmental stress linked to consumption of maternally derived carotenoids in brown trout embryos (Salmo trutta).

The yellow, orange, or red colors of salmonid eggs are due to maternally derived carotenoids whose functions are not sufficiently understood yet. Here, we studied the significance of naturally acquired carotenoids as maternal environmental effects during embryo development in brown trout (Salmo trutta). We collected eggs from wild females, quantified their egg carotenoid content, fertilized them in vitro in full‐factorial breeding blocks to separate maternal from paternal effects, and raised 3,278 embryos singly at various stress conditions until hatching. We found significant sire effects that revealed additive genetic variance for embryo survival and hatching time. Dam effects were 5.4 times larger than these sire effects, indicating that maternal environmental effects play an important role in determining embryo stress tolerance. Of the eight pigment molecules that we targeted, only astaxanthin, zeaxanthin (that both affected egg redness), and lutein were detected above our confidence thresholds. No strong link could be observed between carotenoid content in unfertilized eggs and embryo mortality or hatching timing. However, the consumption of carotenoids during our stress treatment was negatively correlated to embryo survival among sib groups and explained about 14% of the maternal environmental variance. We conclude that maternally derived carotenoids play a role in the ability of embryos to cope with environmental stress, but that the initial susceptibility to the organic pollution was mainly determined by other factors.

Bioaccessibility and digestive stability of carotenoids in cooked eggs studied using a dynamic in vitro gastrointestinal model.

Among dietary carotenoids, lutein and zeaxanthin are known to protect against age-related macular degeneration, a leading cause of irreversible vision loss in the elderly. Egg yolk is rich in lutein and zeaxanthin, however, the effect of cooking and gastrointestinal digestion on yolk carotenoids is poorly understood. An in vitro dynamic gastrointestinal model (TIM-1) was used to investigate the digestive stability and bioaccessibility of carotenoids from boiled, fried, and scrambled eggs. Bioaccessibility but not digestive stability was significantly affected by the method of cooking. The main egg carotenoids, all-E-lutein and all-E-zeaxanthin, were stable during the digestion with average recoveries of 90 and 88%, respectively. No trans-cis isomerization of carotenoids was observed during digestion. Both all-E-lutein and all-E-zeaxanthin from scrambled eggs showed significantly lower bioaccessibility compared to boiled eggs. The results indicate that the bioaccessibility of egg carotenoids can be affected by different food preparation methods.

Microbiome affects egg carotenoid investment, nestling development and adult oxidative costs of reproduction in Great tits

Summary Parasites influence allocation trade‐offs between reproduction and self‐maintenance and consequently shape host life‐history traits. The host microbiome includes pathogenic and commensal micro‐organisms that are remarkable in their diversity and ubiquity. However, experimental studies investigating whether the microbiome shapes host reproduction are still lacking. In this study, we tested whether the microbiome affects three important components of bird reproduction, namely (i) the maternal transfer of anti‐microbial compounds to the eggs, (ii) the development of nestlings and (iii) the trade‐off between reproduction and self‐maintenance, here measured by the oxidative costs of reproduction. We experimentally modified the microbiome of wild breeding Great tits (Parus major) by spraying nests with liquid solution that either favoured or inhibited bacterial growth compared to a control. These treatments modified the bacterial communities in the nests and on adult feathers. We found that females from the treatment that decreased bacterial densities in the nests laid eggs with less carotenoids than females from the control, while we found no significant effect of increasing bacterial densities and modifying community composition compared to the control. Nestlings exposed to decreased bacterial densities grew faster and had longer tarsus length at fledging. Moreover, our analyses revealed that the relationship between investment in reproduction and oxidative damage was affected by the treatments. Adults raising larger clutches suffered higher oxidative damage in control nests, whereas this oxidative cost of reproduction was not detected when we modified bird microbiome. Our study provides experimental evidence for an effect of the microbiome on egg carotenoid investment, nestling development and oxidative cost of reproduction and thus highlights the major effect that the microbiome may have on the evolution of host life‐history strategies.

Yolk carotenoids increase fledging success in great tit nestlings.

Avian mothers can influence offspring phenotype through the deposition of different compounds into eggs, such as antibodies, hormones and antioxidants. The concentration of carotenoids in yolk is larger than in maternal plasma, suggesting an important role of these compounds for offspring development. Since carotenoids have to be acquired from the diet, they may be available in limiting amounts to the mothers. Here, we investigated the role of egg carotenoids for offspring growth by experimentally increasing the concentration of yolk lutein, the main carotenoid in great tit (Parus major) yolk. We subsequently measured body condition, oxidative stress, immune response, plumage colouration and fledging success. Lutein increased body mass soon after hatching and fledging success, but did not affect tarsus length, oxidative stress, immune response and plumage colouration. The higher content of yolk lutein could have increased body mass by reducing oxidative stress caused by high metabolic rates of rapidly growing embryos or by promoting cell differentiation and proliferation. The positive effect of lutein on fledging success seems to be mediated by its influence on body mass 3 days post-hatch, since these two traits were correlated. The finding that our treatment did not affect traits measured later in the nestling period, except for fledging success, suggests that yolk lutein has short-term effects that are essential to increase survival until fledging. Our study shows the positive effect of yolk lutein on offspring survival in the great tit, and therefore suggests an important role of carotenoid-mediated maternal effects.

Maternal effects and warning signal honesty in eggs and offspring of an aposematic ladybird beetle

Summary The eggs of oviparous species are often subject to intense predation pressure. One parental strategy to deter predators is to produce eggs that are laced with noxious chemicals and are conspicuously coloured (i.e. aposematism). Ladybird eggs are conspicuously coloured and contain alkaloids; these traits are believed to function in concert as visual signal and chemical defence, respectively, to deter predators. However, it remains unclear whether such aposematic signals reveal the strength (rather than simply the existence) of chemical defences. Furthermore, additional functions of egg pigments and toxins could apply; in particular, mothers might deposit such resources into eggs to aid the development of offspring or to provide resources that could contribute to aposematic traits in offspring. We bred wild‐caught seven‐spot ladybird beetles (Coccinella septempunctata) in the laboratory and then measured relationships between egg coloration and toxin concentrations (i.e. the alkaloids precoccinelline and coccinelline). We also measured relationships between egg carotenoids and egg coloration, and between egg coloration and toxin levels, and the elytra coloration and toxin concentrations of offspring at eclosion for a subset of eggs that were allowed to develop. Egg carotenoids predicted egg colour saturation. In turn, egg colour saturation and hue positively predicted egg concentrations of precoccinelline. However, there were no significant relationships between egg coccinelline concentration and any measure of egg coloration. In recently eclosed adults of both sexes, elytra saturation was significantly explained by variation in egg saturation and hue. Finally, body concentrations of coccinelline were significantly explained by variation in elytra hue. These results suggest that the coloration of C. septempunctata eggs is a reliable signal of the strength of chemical defences contained therein, but in addition, maternal investment of pigments and toxins into eggs may serve to influence the reliability of aposematic signalling in resultant offspring.

Associations Between Female Reproductive Traits and Polychlorinated Biphenyl Sediment Concentrations in Wild Populations of Brown Bullhead (Ameiurus nebulosus)

Aquatic contaminants, specifically polychlorinated biphenyls (PCBs), a class of persistent organic contaminants, have been associated with sublethal effects on reproduction in fishes. Female brown bullhead (Ameiurus nebulosus) were used to assess variation in reproductive traits across eight populations differing in sediment sum PCB concentrations in the Lower Great Lakes region. Differences in maternal carotenoid allocation patterns among these populations were also examined. No significant associations were found between sediment sum PCB concentrations corrected for organic content (OC) and reproductive traits. However, egg diameter was negatively correlated with sediment PCB concentrations not corrected for OC, suggesting that observed relationships between sediment sum PCB concentrations and reproductive traits are driven by classes of environmental contaminants whose bioavailability are not predicted by OC, such as metals. An unexpected positive relationship was also found between egg carotenoid concentrations and sediment PCB concentrations. This positive relationship was explained by the maternal allocation of carotenoids based on a negative correlation between female muscle and egg carotenoid concentrations, where females from less contaminated locations had lower egg and greater muscle carotenoid concentrations than those from more contaminated locations. The results of this study identify sublethal effects of environmental contaminants on reproductive life-history traits in female brown bullhead, and investigations of adaptive mechanisms underlying this variation are warranted.

Female blue tits with brighter yellow chests transfer more carotenoids to their eggs after an immune challenge

Female ornaments are present in many species, and it is more and more accepted that sexual or social selection may lead to their evolution. By contrast, the information conveyed by female ornaments is less well understood. Here, we investigated the links between female ornaments and maternal effects. In birds, an important maternal effect is the transmission of resources, such as carotenoids, into egg yolk. Carotenoids are pigments with antioxidant and immunomodulatory properties that are crucial for females and developing offspring. In blue tits, we evaluated whether ultraviolet (UV)/blue and yellow feather colouration signals a female's capacity to allocate carotenoids to egg yolk. Because mounting an immune response is costly and trade-offs are more detectable under harsh conditions, we challenged the immune system of females before laying and examined the carotenoid level of their eggs afterward. A positive association between feather carotenoid chroma and egg carotenoid level would be expected if yellow colouration signals basal immunity. Alternatively, if female colouration more generally reflects maternal capacity to invest in reproduction under challenging conditions, then other components of colouration (i.e. yellow brightness and UV/blue colouration) could be linked to maternal capacity to invest in eggs. No association between egg carotenoid levels and UV/blue crown colouration or female yellow chest chroma was found; the latter result suggests that yellow colouration does not signal immune capacity at laying in this species. By contrast, we found that, among females that mounted a detectable response to the vaccine, those with brighter yellow chests transmitted more carotenoids into their eggs. This result suggests yellow brightness signals maternal capacity to invest in reproduction under challenging conditions, and that male blue tits may benefit directly from choosing brighter yellow females.

Yolk carotenoids have sex-dependent effects on redox status and influence the resolution of growth trade-offs in yellow-legged gull chicks

Avian eggs are rich in carotenoids, which derive from maternal diet where they may be available in limiting amounts. Egg carotenoids may accomplish major roles in antioxidant protection or modulate physiological functions and growth, interfering with offspring redox status, potentially in a sex-dependent way. In this study of maternal effects in relation to sex and laying order of yellow-legged gull (Larus michahellis) chicks, we analyzed the consequences of increased yolk lutein concentration on plasma antioxidant capacity (AOC) and an index of early oxidative damage (reactive oxygen metabolites, ROM), till 9 days after hatching. To this end, for the first time we directly manipulated yolk lutein, thus avoiding any effect on other components of egg quality due to maternal supplementation before laying. Lutein did not increase AOC but increased ROM in males and in first-laid chicks. Hence, lutein did not act as an antioxidant and determined increased early oxidative damage, possibly because of upregulation of immune or other physiological functions, but these effects were sex-related and apparent in first-laid chicks with larger yolk lutein supply. ROM positively covaried with AOC, suggesting a trade-off between AOC and oxidative damage. Moreover, lutein injection altered the covariation between body size or immunity and AOC or ROM. Carotenoids may thus not be major antioxidants in birds and rather affect redox status by increasing oxidative damage in a sex-dependent way and interfere with the resolution of growth trade-offs. In the absence of sex-related allocation, maternal decisions on egg carotenoid concentration may depend on the balance between divergent effects on either sex. Key words: antioxidants, carotenoids, egg, laying order, maternal effects, oxidative stress, sex. [Behav Ecol]

Reproductive performance of gilthead seabream (Sparus aurata L., 1758) fed two combined levels of carotenoids from paprika oleoresin and essential fatty acids

Despite carotenoids and essential fatty acids seem to play important roles in fish reproduction, no studies have yet been conducted to determine the effect of dietary carotenoids on gilthead seabream broodstock performance and their relation as antioxidants with dietary n-3 highly unsaturated fatty acid (HUFA) levels. In addition, the high cost of synthetic sources of carotenoids is leading to the search for new natural carotenoid sources such as paprika oleoresin. Four experimental diets containing two combined levels of carotenoids from paprika oleoresin (40 and 60 mg kg−1) and n-3 HUFA (25 and 40 g kg−1) were respectively fed to triplicate groups of gilthead seabream (Sparus aurata) broodfish. Elevation of n-3 HUFA dietary levels from 25 to 40 g kg−1 significantly improved gilthead seabream broodstock performance in terms of egg viability, hatching rates and fecundity. Besides, it markedly increased egg contents in HUFAs which play important energetic and structural roles and improve embryo development. Both arachidonic acid and eicosapentaenoic acid (20:5n-3) egg contents were more readily affected by dietary n-3 HUFA than docosahexaenoic acid. HUFA levels did not caused any negative effect suggesting an optimized content of antioxidants in broodstock diets. Increase in dietary carotenoids from 40 to 60 mg kg−1 increased carotenoid contents in eggs and significantly improved egg fertilization rates suggesting an important sperm cell’s protective role by reducing the risk of lipid peroxidation which is detrimental for sperm motility. The increased inclusion of dietary paprika oleoresin enhanced egg carotenoid deposition and improved fish reproductive performance, denoting the high nutritional value of this product as a source of carotenoids for broodstock of this species.

Dietary carotenoid levels affect carotenoid and retinoid allocation in female Chinook salmon Oncorhynchus tshawytscha

This study examined the effect of dietary carotenoid availability on carotenoid and retinoid concentrations in the flesh, plasma, skin and eggs of female Chinook salmon Oncorhynchus tshawytscha. Carotenoid concentrations in all tissues were closely related to dietary availability. Early in the breeding season, carotenoids were stored primarily in the muscle, with a flesh carotenoid concentration of 9.9 microg g(-1) in fish fed a high carotenoid diet compared with 1.9 microg g(-1) in fish fed a low carotenoid diet. During the breeding season, carotenoid reserves were mobilized predominantly to the eggs and also to the skin. By the end of the breeding season, carotenoid concentrations in the eggs were 17.9 microg g(-1) in fish fed a high carotenoid diet and 3.9 microg g(-1) in fish fed a low carotenoid diet. Conversely, egg retinoid concentrations were only c. 20% lower in fish fed a low v. high carotenoid diet, which suggests that retinoid concentrations were not limited by the availability of carotenoid precursors. Egg carotenoid concentrations were not correlated with either skin carotenoid concentration or colouration, which suggests that female carotenoid displays are not a reliable signal that males can use to evaluate egg carotenoid resources.

Growth performance, mortality and carotenoid pigmentation of fry offspring as affected by dietary supplementation of astaxanthin to female rainbow trout (Oncorhynchus mykiss) broodstock

Summary Growth performance, mortality and carotenoid pigmentation were studied in triplicate groups each with 1000 swim-up larvae of rainbow trout (Oncorhynchus mykiss), derived from five groups of female broodstock fed diets with 0.07, 12.5, 33.3, 65.1 or 92.9 mg astaxanthin kg−1, respectively. The first feeding fry (initial weight range from 113 to 148 mg) were fed a diet not supplemented with carotenoids in an experiment lasting 45 days. Fry were initially sampled for astaxanthin content and initial weight, and in subsequent 15-day intervals to determine weights, condition factors (CF), specific growth rates (SGR) and thermal growth coefficients (TGC). Total carotenoid concentration of the larvae was highly linearly correlated to that of the eggs (r2 = 0.97, P = 0.002). About 59–67% of fry carotenoids consisted of esterified astaxanthin, and on average 39.7% of the egg carotenoids were recovered in the fry. Overall (0–45 days) SGRs and TGCs were significantly higher (P 0.05), but higher than in the group derived from females fed the diet not supplemented with astaxanthin (P 12.5 mg kg−1) to maternal broodstock diets improves offspring SGR and TGC with up to 33 and 38%, respectively.