Comparative composition and shelf-life of fillets of wild and cultured turbot (Scophthalmus maximus) and Atlantic halibut (Hippoglossus hippoglossus)

Turbot and Atlantic halibut are highly valued fish species. However,very little is known about fillet shelf-life characteristics associated withboth species. Thus, fillet -tocopherol content and proximate compositionof wild turbot (1.5 kg) and Atlantic halibut (1.1 kg)caught off the south coast of Ireland and the north-west coast of Iceland,respectively, were investigated. In addition, the susceptibility of fillets, storedunder retail conditions, to lipid oxidation and colour change was studied.Proximate composition analysis showed that turbot had significantly highermoisture (P < 0.001) and lower protein (P < 0.001) contents compared toAtlantic halibut. Atlantic halibut incorporated significantly higher (P <0.001) levels of -tocopherol into fillets than turbot. Over 14 days ofstorage on ice, fillets from Atlantic halibut exhibited significantly lower (P =0.020) levels of lipid oxidation than those of turbot. However, malondialdehyde(MDA) concentrations were generally very low, never exceeding 0.6 gg^–1 fillet. Turbot maintained a significantly higher (P< 0.001) pH over the storage period. The lightness (L^* values) offillets from both species increased over 14 days of storage, but wassignificantly higher (P < 0.001) in Atlantic halibut than in turbot. Turbotdeveloped a relatively intense yellow colour during storage (decrease in hueangle and increase in b^* values), whereas this was not the case forAtlantic halibut. The results of this study demonstrate that fillets of wildAtlantic halibut stored on ice, were less prone to lipid oxidation anddiscolouration than those of wild turbot. However, quality changes in turbotwere very small showing that both fish have tremendous shelf-life capacities interms of lipid oxidation. These findings are considered in the context of knownmaterial for farmed fish.     

Feed intake, growth and feed conversion efficiency of Atlantic halibut, Hippoglossus hippoglossus (L.)

The individual food intake of each fish in each of four groups of Atlantic halibut, Hippoglossus hippoglossus (L.) (mean weight: 422 g) was monitored by direct observation over a period of 21 days. Gross feed conversion efficiency (= growth·feed intake^?1), net feed conversion efficiency and maintenance ration were estimated by regression analysis. Specific growth rates were found to be linearly related to weight-specific consumption at a temperature of 8–9°C: growth = 1.922· feed intake ? 0.242. Maintenance ration was 0.126% of body weight day^?1. The gross feed conversion efficiency increased asymptotically with increasing feed intakes and growth rates, and was found to approach 1.9 at high growth rates (0.5 on a dry weight basis). One feeding per day seemed to be sufficient for maximum food intake and growth rate.     

A formulated diet for Atlantic halibut (Hippoglossus hippoglossus, L.) larvae

A diet for Atlantic halibut-larvae was formulated taking into account the fact that marine-fish larvae have a limited ability to assimilate protein and lipid. Dietary protein consisted of a free amino-acid premix (7.2% of crude protein), predigested-squid mantle (7.2%), squid mantle (8.6%) and cod-muscle mince (77.0%). Lipid sources were soyabean lecithin (33% of crude lipids), crude phospholipids extracted from cod roe (10%) and sardine oil (57%). Larvae were weaned onto the experimental diet at wet-body weights of 0.07, 0.10 or 0.16 g, respectively. The experimental diet was fed for 31, 25 or 17 days, respectively, and the experiment was terminated on the same calendar day for all groups. A control group was fed with Artemia nauplii enriched with DHA Selco™ from 0.07 g. Survivals ranged from 78% in larvae transferred at 0.10 g to 96% in those transferred at 0.16 g and in the control group. Daily specific-growth rates (SGR) were 3.1 ± 0.07, 3.3 ± 0.11 and 2.2 ± 0.01% day⁻¹ in larvae transferred at 0.07, 0.10 and 0.16 g, respectively, while growth in the control group was 5.1% day⁻¹. It was concluded that weaning of Atlantic-halibut larvae is feasible from 0.7 g (approximately 20 days post first-feeding) when the formulated diet contains predigested protein and ample amounts of phospholipids.     

Effect of predigested protein on growth and survival of Atlantic halibut larvae (Hippoglossus hippoglossus L.)

In this study Atlantic halibut (Hippoglossus hippoglossus L.) larvae (0.12 ± 0.04 g) were, from day 40 post first feeding, offered six diets in which 10% or 30% of the dietary protein was hydrolysed with (a) pepsin (P), (b) pepsin + trypsin (PT) or (c) pepsin + trypsin + chymotrypsin (PTC). In addition, a diet without hydrolysed protein was offered, and enriched Artemia was fed as control. The amount of soluble protein increased progressively with the enzyme treatments P, PT and PTC and with higher inclusion levels of hydrolysed protein. Survival was highest among the larvae offered Artemia (83 ± 0%) or the diet 10P (10% pepsin hydrolysed protein; 67 ± 4%). The diet 10P supported survival significantly better than the more hydrolysed diets 10PTC, 30P, 30PT and 30PTC, but not significantly better than the non‐hydrolysed diet and 10PT. Specific growth rate (SGR) was 1.76 ± 0.20 in average for all groups of larvae and was not significantly affected by the diets. Still, the larvae offered pepsin hydrolysed diets tended to have better growth (2.10 ± 0.05 SGR; P < 0.06) than the larvae offered the other hydrolysed diets. The larvae offered the formulated diets did not differ in chemical composition.     

Feed intake, growth and nutrient utilization in Atlantic halibut (Hippoglossus hippoglossus) fed diets containing a bacterial protein meal

Triplicate groups of Atlantic halibut were fed diets containing 0%, 9% or 18% of a bacterial protein meal (BPM) produced from natural gas in a 9‐week trial. Growth rates, relative feed intake, feed efficiency ratio and retention of all indispensable amino acids were significantly lower in fish fed the 18% BPM diets than in those fed the 0% and 9% BPM diets. There were no significant treatment effects on urea levels in plasma, liver or muscle, or in uric acid levels in plasma. The hepatosomatic index was lowest in fish fed the 18% BPM diet. Although the concentration of copper, an element abundant in BPM, increased in the liver as dietary BPM level increased, the total copper content in liver decreased. Fish fed the 0% and 9% BPM diets had a higher degree of supranuclear vacuolization of pyloric caeca and mid‐intestine epithelia compared with fish fed the 18% BPM diet. In conclusion, the halibut fed the 9% BPM diet performed equally well as the control group regarding growth, feed intake and feed efficiency ratio, whereas performance was reduced in the fish fed the 18% BPM diet.     

Growth, feed conversion efficiency and growth heterogeneity in Atlantic halibut (Hippoglossus hippoglossus) reared at three different photoperiods

Juvenile Atlantic halibut, Hippoglossus hippoglossus (initial weight (SD) 191.3 (±44.7)) g, were reared for 99 days at a constant temperature of 11°C and subjected to three different light regimes from 13 September to 21 December: continuous light (LD24:0), simulated natural photoperiod of Bergen (60°25′N, LDN) and constant 20 h light:4 h dark (LD20:4). The fish reared on the different photoperiod regimes differed in their growth patterns as juveniles exposed to long days, i.e. LD20:4 and LD24:0, exhibited faster growth than those experiencing a natural photoperiod. The LD20:4 group showed the highest average specific growth rate (0.72% body weight day^?1), whereas fish on LDN displayed the lowest average specific growth rate (0.60% body weight day^?1). The final mean weights of the LD20:4 and the LD24:0 groups were 15% and 12% higher than those of the LDN group. Dividing the duration of the experiment into three time periods shows that the LD20:4 and LD24:0 had a higher feed conversion efficiency (FCE) as compared with the LDN group during the first and the last period, while a reversed situation was observed in the second period. Our data indicate a larger variation in growth rates among individuals in the best‐performing groups (here LD20:4 and LD24:0). This may indicate that formation of size hierarchies is more pronounced in groups with more homogenous growth (here LDN). Overall, our findings indicate that extended light regimes result in faster growth and better feed conversion in juvenile Atlantic halibut. In line with findings on other flatfish species, this supports the concept that constant long day:short night or continuous light regimes should be used by the farmer in order to maximize growth and improve feed conversion in Atlantic halibut.     

Suitable methods for cryopreservation of semen from Atlantic halibut, Hippoglossus hippoglossus L.

Decrease in the quality and quantity of Atlantic halibut, Hippoglossus hippoglossus L., semen towards the end of the reproductive season hampers production of good-quality embryos. Therefore, cryopreservation of spermatozoa is a method showing potential to facilitate controlled reproduction in Atlantic halibut. The present study aimed at establishing the appropriate cryopreservation procedure. We tested 20 extenders composed of four various diluents and five cryoprotectants (DMSO, DMA, methanol, propylene glycol, and glycerol) to determine the best extender. Then, we examined cryopreservation quality using various methods of loading and various volumes of cryopreserved samples. In most of the tested variants, sperm diluted with an extender showed high motility after 24-h incubation despite the high osmotic pressure of the extender. Modified turbot extender (MTE) was the best of the tested diluents, securing the highest post-thaw motility (P < 0.05), and DMSO, DMA, and methanol were the best cryoprotectants (P < 0.05). There was no significant effect of 15-min equilibration of semen in MTE-based extenders prior to freezing on post-thaw motility (P > 0.05). MTE-based extender was chosen as the most suitable. Semen cryopreserved in straws, Eppendorfs or Ziploc bags in volumes ranging from 0.25 to 20 ml showed similar high fertilization ability. Survival of larvae produced with the cryopreserved sperm did not differ from controls produced with freshly collected sperm. Motility 3 h after thawing was high but depended on the type of cryoprotectant and the volume of cryopreserved sperm (P < 0.05). The developed cryopreservation procedure has been applied at our Atlantic halibut breeding station for seed production.     

Folate in eggs and developing larvae of Atlantic halibut, Hippoglossus hippoglossus L.

Folate mobilization from the yolk compartment during larval development was studied by analysing the folate concentration in whole body, embryo and yolk in a single batch of Atlantic halibut, Hippoglossus hippoglossus L., eggs and larvae that showed successful fertilization and development. There was a net loss of approx. 50% of folate from yolk during endogenous feeding. Further, only 23% of the decrease in yolk folate was retained in the larval body. The data suggest a need for folate for metabolic and growth purposes during embryogenesis of approximately 2 μg g^?1 weight gain. Relative to these data and published folate requirement for cold‐water species, batches of egg from 16 Atlantic halibut brood fish contained variable and, for some batches, critically low levels of folate. This may constitute a potential problem for larval development until start feeding.     

Best among unequals? Effect of size grading and different social environments on the growth performance of juvenile Atlantic halibut

In order to study the effect of rearing juvenile halibut in different social environments, individually tagged juvenile halibut were size-graded into two size classes (Large, L, and Small, S) with ungraded fish as control. After ca 6 weeks, the two size-graded groups were again graded into two size classes creating four experimental groups: Large of the Large (LL), Small of the Large (SL), Large of the Small (LS), and Small of the Small (SS). Grading (overall mean of the four grading groups) improved growth rate by 10% compared with ungraded controls, but the effect was also significantly affected by social environments, because in the latter half of the experiment overall growth was improved by 11 and 12% in the two groups with larger size variation (i.e. SL and LS, respectively) compared with the two other groups (i.e. LL and SS). Significant size rank correlations were maintained during the experiment, these were higher in the ungraded (Control) group and the SS and LL groups than in the SL and LS groups. Further, the degree of mean rank position changes varied between the experimental groups and was higher in the SL (20.7) and LS (25.6) groups than in the Control (10.5), LL (15.1), and SS (15.4) groups. This could possibly indicate a stronger social hierarchy in the last three groups. Growth rate differences may be the product of different degrees of interactions among individuals, and based on the higher overall growth rates in the groups with larger size variation (i.e. SL, LS) it is concluded that juvenile halibut should not be too intensively size graded. Imsland and Jenssen have contributed equally.     

Distribution of α-tocopherol in fillets of turbot (Scophthalmus maximus) and Atlantic halibut (Hippoglossus hippoglossus), following dietary α-tocopheryl acetate supplementation

The present study investigated the distribution of α‐tocopherol (vitamin E) in fillets of turbot (Scophthalmus maximus) and Atlantic halibut (Hippoglossus hippoglossus). Turbot and Atlantic halibut were fed commercial diets, supplemented with different levels of α‐tocopheryl acetate at the dietary target levels of 100, 500 and 1000 mg α‐tocopheryl acetate kg^?1 diet. The actual levels were 72, 547 and 969 for turbot, while halibut received 189, 613 and 875 mg α‐tocopheryl acetate kg^?1 diet. Turbot were fed the diets for 24 weeks, while Atlantic halibut were fed for 20 weeks prior to slaughter. At the end of the feeding periods fish had reached a final weight of around 1 kg. Fish were slaughtered and filleted. From the four fillets obtained per fish, 22 samples were taken from designated areas and analysed for their α‐tocopherol content. The average concentrations of α‐tocopherol incorporated in turbot and Atlantic halibut increased with increasing levels of α‐tocopheryl acetate in the diet. Atlantic halibut had significantly (P < 0.05) more α‐tocopherol in positions 2/II and 1/I than in position 9/IX. Turbot had significantly (P < 0.05) more α‐tocopherol in position 2/II than in positions 1/I, 4/IV and 11/XI. By mapping α‐tocopherol concentrations in fish fillets, a high degree of quality prediction may be established. Moreover, this study may help scientists in their choice of sampling position, when investigating if α‐tocopheryl acetate supplementation resulted in successful α‐tocopherol incorporation.     

Experimental susceptibility of Atlantic cod, Gadus morhua (L.), and Atlantic halibut, Hippoglossus hippoglossus (L.), to different genotypes of viral haemorrhagic septicaemia virus

Viral haemorrhagic septicaemia (VHS) is a well-characterized disease of rainbow trout, Oncorhynchus mykiss, which has also caused economic losses in marine turbot farms in the British Isles. We have previously demonstrated that turbot, Scophthalmus maximus, are susceptible to isolates of viral haemorrhagic septicaemia virus (VHSV) that are endemic in the marine environment, highlighting a potential risk to marine aquaculture. Given the increasing interest in the intensive rearing of additional aquaculture species such as Atlantic cod, Gadus morhua, and Atlantic halibut, Hippoglossus hippoglossus, this study aimed at investigating the susceptibility of these species to VHSV. Both species were found to be largely resistant to VHS following immersion challenge with a selection of 18 isolates, representing the known marine VHSV genotypes. Only one and two VHSV-associated mortalities occurred out of a total of 1710 and 1254 halibut and cod, respectively. These findings suggest that there is a low direct risk to the development of commercial cod and halibut aquaculture from the existing endemic reservoir of VHSV. This study, coupled to field observations has, however, highlighted the fact that both species can become infected with VHSV. The known adaptability of RNA viruses, together with the selection pressures associated with intensive aquaculture would thus advocate a cautious approach to VHSV surveillance within these emerging industries.     

Change in flesh quality associated with early maturation of Atlantic halibut (Hippoglossus hippoglossus)

To determine the effect of maturation on flesh quality, 20 Atlantic halibut (Hippoglossus hippoglossus) consisting of mature and immature fish of both sexes were killed on site, exsanguinated and stored on ice. After 6 days of storage, the fish was gutted and filleted before colour, texture hardness and shear force were evaluated to determine the effect of maturation. Results show that mature males excreted black mucus from the skin during ice storage, while a greyish mucus was observed from immature fish. Mature fish had approximately 2% lower slaughter yield and 6% lower fillet yield compared with immature fish. The fillets from mature males were significantly harder compared with fillets from immature fish and the muscle structure proved to be stronger as an increased fracturability was observed in mature fish. In colour, fillets from mature fish proved to have a whiter appearance (L^*) than immature fish, while no difference was seen in a^* and b^* values. We conclude that the physiological changes associated with maturation affects the end quality, and may be related to slower growth.     

Effects of protein hydrolysate in weaning diets for Atlantic cod (Gadus morhua L.) and Atlantic halibut (Hippoglossus hippoglossus L.)

The study aims to test whether predigested dietary protein enhances the utilization of formulated diets at weaning, and also whether it stimulates intestinal maturation. In this study, Atlantic cod [ Gadus morhua L.; 41 days posthatch (dph)] and Atlantic halibut [ Hippoglossus hippoglossus L.; 63 days postfirst feeding (dpff)] were weaned onto diets with graded levels of protein hydrolysate. By increasing the inclusion of dietary protein as hydrolysate from 0 to 400 g kg⁻¹, cod increased the rate of survival from 7 ± 1% to 18 ± 2% (82 dph; regression, P =  4*10⁻⁷). In halibut, the survival rate decreased from 57 ± 9% to 22 ± 7% as the inclusion of protein in the form of hydrolysate increased from 0 to 450 g kg⁻¹ (119 dpff; regression, P =  8*10⁻⁵). Growth was not affected in any of the species. Results in specific activities of the intestinal enzymes leucine aminopeptidase (LAP) and alkaline phospatase (AP) supported the results in survival in halibut and partly also in cod, by showing increased activities in groups with increased survival ( anova , P <  0.05). The lower optimal level of hydrolysed protein in halibut than in cod is suggested mainly because of a slower feeding practice in halibut, which allows more extensive nutrient leaching before ingestion.     

Evaluation of Calanus finmarchicus copepod meal in practical diets for juvenile Atlantic halibut (Hippoglossus hippoglossus)

The copepod, Calanus finmarchicus, has potential as a new ingredient in practical feeds for marine fish. Two experiments were conducted to evaluate the nutritional value of C. finmarchicus meals when fed to juvenile Atlantic halibut. The first study determined protein, lipid and energy digestibility coefficients of four C. finmarchicus meals prepared under different processing conditions. The second study evaluated growth and nutrient utilization efficiency of juveniles fed diets containing varying proportions of fish meal, plant meals and C. finmarchicus meal. Moisture, ash, protein, lipid and gross energy contents of the C. finmarchicus meals were 28–93, 74–138, 505–648, 123–269 g kg⁻¹, and 21–26 MJ kg⁻¹, respectively. Protein, lipid and energy digestibilities of C. finmarchicus meals were 91–99%, 90–95% and 90–99%. The digestibilities significantly decreased for the Calanus meals processed at higher temperatures. During the growth study, halibut fed a diet containing 240 g kg⁻¹ C. finmarchicus meal had significantly higher weight gain and growth rate than all other groups. Nitrogen and energy retention efficiencies ranged between 35–45% and 33–43%, and were significantly higher for fish fed 160–240 g kg⁻¹ C. finmarchicus meal than for fish fed plant protein and control diets. The results indicate that growth and nutrient utilization efficiency are improved in Atlantic halibut fed diets supplemented with C. finmarchicus meal.     

Protection against atypical furunculosis in Atlantic halibut,Hippoglossus hippoglossus (L.); comparison of a commercial furunculosis vaccine and an autogenous vaccine

Atlantic halibut, Hippoglossus hippoglossus (L.), was shown to be sensitive to infection by three different isolates of Aeromonas salmonicida ssp. achromogenes in pre-challenge tests using intraperitoneal (i.p.) and intramuscular (i.m.) injections as well as bath challenges. A commercial furunculosis vaccine, Alphaject 1200, and an autogenous vaccine, AAS, based on the challenge strain, induced immune protection as shown in challenge tests 8 weeks post-immunization. The survival rate of vaccinated fish after i.p. challenge was 100%, whereas mortality of control fish was 61%. Employing i.m. challenge, relative percentage survival induced by the furunculosis vaccine and the AAS vaccine was 47 and 44, respectively. Mortality of i.m. injected controls was 68%. Vaccinated fish behaved normally following vaccination but the weight gain was significantly reduced in vaccinated fish 8 weeks post-vaccination compared with control fish receiving phosphate-buffered saline. At the same time, intra-abdominal adhesions were observed in fish injected with either of the two vaccines or adjuvant alone. Antibody response against A. salmonicida ssp. achromogenes was detected in sera from fish receiving either vaccine.     

The relation between age at first maturity and growth in Atlantic halibut (Hippoglossus hippoglossus) reared at four different light regimes

The effect of extended photoperiods on growth and age at first maturity was investigated in 166 (79 females and 87 males) individually tagged Atlantic halibut. The halibut were reared at 11°C on four different light regimes from 10 February to 6 July 1996: simulated natural photoperiod, (LDN), continuous light (LD24:0), constant 8 h light and 16 h darkness (LD8:16) and LD8:16 switched to continuous light on 4 May 1996 (LD8:16–24:0). From 6 July 1996 to 9 February 1998 the LD24:0 and LD8:16–24:0 were reared together under continuous light and the LDN and LD8:16 together under natural photoperiod. Juveniles subjected to continuous light exhibited faster growth than those experiencing a natural photoperiod or a constant short day. Moreover, the results suggest an overall growth enhancing effect of continuous light in females, but not in males. No females matured during the trial, but the proportion of mature males differed between the photoperiod groups, with significantly fewer males maturing in groups reared at continuous light. Independent of photoperiod regime and maturation status, females were significantly bigger than males from 14 April 1997 onwards. Immature males were bigger than maturing males from 23 March 1996 onwards. As continuous light reduced maturation at age 2+ in males, this could be used to reduce precocious maturation in males.     

Nutrient composition and metamorphosis success of Atlantic halibut (Hippoglossus hippoglossus, L.) larvae fed natural zooplankton or Artemia

Atlantic halibut larvae were fed docosohexanoic acid- (DHA) selco enriched Artemia (RH-cysts) or wild zooplankton in duplicate tanks from first-feeding and 60 days onward. The zooplankton were collected from a fertilized sea water pond and consisted mainly of different stages of Eurytemora affinis and Centropages hamatus . There were no differences in survival, or in growth during the first 45 days of feeding, between larvae fed the two prey items, but the larvae fed Artemia showed much higher incidence of malpigmentation and impaired eye migration than larvae fed zooplankton. The prey organisms contained similar amounts of dry matter and protein, but Artemia was higher in lipid and glycogen than the zooplankton. Larvae fed Artemia were higher in both glycogen and lipid than the zooplankton-fed larvae towards the end of the feeding period. There were large differences between the prey organisms in the concentrations of essential fatty acids (% of total fatty acids) which was reflected in the fatty acid composition of the larval body. It is concluded that the macronutrient composition of Artemia in the present study was probably within the optimal range for promotion of growth and survival in young Atlantic halibut. The concentration of n-3 HUFA, and especially DHA, is however, very much lower in enriched Artemia than in copepods, and may be one of the factors triggering developmental errors in Atlantic halibut.     

Pigmentation and eye migration in Atlantic halibut (Hippoglossus hippoglossus L.) larvae: new findings and hypotheses

Atlantic halibut juveniles, which have been fed Artemia during larval development, frequently demonstrate malpigmentation and impaired eye migration. This is in contrast to the high percentage of normally developed larvae fed copepods, reared under similar conditions. Nutrition is therefore an important component influencing larval development. Analyses of the nutrient composition of Artemia and copepods show that Atlantic halibut larvae fed Artemia probably receive sufficient amounts of vitamin A by converting canthaxanthin, while iodine may be deficient, possibly leading to interrupted thyroid hormone synthesis. An unbalanced fatty acid composition, such as high levels of arachidonic acid and low levels of docosahexaenoic acid, can be another limiting factor in Artemia. Vitamin A, fatty acids and thyroid hormones have all been shown to affect pigmentation in flatfish. They are ligands to nuclear receptors, thyroid hormone receptors, retinoic acid receptors, retinoic X receptors and peroxisomal proliferator‐activated receptors, which are members of the superfamily of steroid hormone receptors. The receptors interact with each other to promote gene expression that modulates proliferation and differentiation of cells. Our hypothesis is that these interactions are important for development during flatfish metamorphosis. Very little data exist on the topic of impaired eye migration. However, energy limitation, iodine deficiency and an unbalanced fatty acid composition have been proposed as possible explanations. Here, we review the literature on development of pigment cells and the possible mechanisms behind the effects of vitamin A, fatty acids and thyroid hormone on pigmentation and eye migration during development of Atlantic halibut larvae.     

Egg yolk nutritional constituents as indicators of egg quality in Atlantic halibut (Hippoglossus hippoglossus L.)

Variation in oocyte quality affects sustainability of finfish aquaculture products including Atlantic halibut (Hippoglossus hippoglossus L.). To have an insight into role of major egg yolk constituents in the oocyte quality, egg fatty acid (FA), amino acid (AA) and folate contents were related to normal blastomere symmetry, and fertilization and hatching success. Significant correlations were found between dihomo‐γ‐linolenic acid (DGLA, 20:3n6), palmitic acid (PA, 16:00) and docosapentaenoic acid (DPA, 22:5n3), and normal blastomere symmetry and survival success. Egg concentrations of myristic acid (MA, 14:0), oleic acid (OA, 18:1n9), stearidonic acid (SA, 18:4n3) and eicosadienoic acid (EDA, 20:2n6) explained 56 % variation in fertilization success. OA and EDA explained 70 % of variation in blastomere symmetry. Palmitoleic acid (POA, 16:1n7) and linolenic acid (LNA, 18:3n3) concentrations explained 57% of variation in hatching success. Egg valine concentrations correlated with fertilization rates, and aspartic acid and leucine correlated with normal blastomere symmetry. Alanine and valine concentrations explained together 45% of variation in fertilization. Glutamic acid and tyrosine concentrations explained 68% of variation in normal blastomere symmetry while serine, arginine and valine explained 36% of variation in hatching. These FAs and AAa may be potential indicators of oocyte quality in Atlantic halibut.