Omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) are essential components of the diet of all vertebrates. The major dietary source of n-3 LC-PUFA for humans has been fish and seafood but, paradoxically, farmed fish are also reliant on marine fisheries for fish meal and fish oil (FO), traditionally major ingredients of aquafeeds. Currently, the only sustainable alternatives to FO are vegetable oils, which are rich in C 18 PUFA, but devoid of the eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) abundant in FO. Two new n-3 LC-PUFA sources obtained from genetically modified (GM) Camelina sativa containing either EPA alone (ECO) or EPA and DHA (DCO) were compared to FO and wild-type camelina oil (WCO) in juvenile sea bream. Neither ECO nor DCO had any detrimental effects on fish performance, although final weight of ECO-fed fish (117 g) was slightly lower than that of FO- and DCO-fed fish (130 and 127 g, respectively). Inclusion of the GM-derived oils enhanced the n-3 LC-PUFA content in fish tissues compared to WCO, although limited biosynthesis was observed indicating accumulation of dietary fatty acids. The expression of genes involved in several lipid metabolic processes, as well as fish health and immune response, in both liver and anterior intestine were altered in fish fed the GM-derived oils. This showed a similar pattern to that observed in WCO-fed fish reflecting the hybrid fatty acid profile of the new oils. Overall the data indicated that the GM-derived oils could be suitable alternatives to dietary FO in sea bream.

Increased substitution of marine ingredients by terrestrial plant products in aquafeeds has been proven to be suitable for Atlantic salmon farming. However, a reduction in n-3 long-chain PUFA is a consequence of this substitution. In contrast, relatively little attention has been paid to the effects of fishmeal and oil substitution on levels of micronutrients such as Se, considering fish are major sources of this mineral for human consumers. To evaluate the effects of dietary marine ingredient substitution on tissue Se distribution and the expression of Se metabolism and antioxidant enzyme genes, Atlantic salmons were fed three feeds based on commercial formulations with increasing levels of plant proteins (PP) and vegetable oil. Lipid content in flesh did not vary at any sampling point, but it was higher in the liver of 1 kg of fish fed higher PP. Fatty acid content reflected dietary input and was related to oxidation levels (thiobarbituric acid-reactive substances). Liver had the highest Se levels, followed by head kidney, whereas the lowest contents were found in brain and gill. The Se concentration of flesh decreased considerably with high levels of substitution, reducing the added value of fish consumption. Only the brain showed significant differences in glutathione peroxidase, transfer RNA selenocysteine 1-associated protein 1b and superoxide dismutase expression, whereas no significant regulation of Se-related genes was found in liver. Although Se levels in the diets satisfied the essential requirements of salmon, high PP levels led to a reduction in the supply of this essential micronutrient.

Vegetable oils (VO) are possible substitutes for fish oil in aquafeeds but their use is limited by their lack of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA). However, oilseed crops can be modified to produce n-3 LC-PUFA such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, representing a potential option to fill the gap between supply and demand of these important nutrients. Camelina sativa was metabolically engineered to produce a seed oil with around 15% total n-3 LC-PUFA to potentially substitute for fish oil in salmon feeds. Post-smolt Atlantic salmon (Salmo salar) were fed for 11-weeks with one of three experimental diets containing either fish oil (FO), wild-type Camelina oil (WCO) or transgenic Camelina oil (DCO) as added lipid source to evaluate fish performance, nutrient digestibility, tissue n-3 LC-PUFA, and metabolic impact determined by liver transcriptome analysis. The DCO diet did not affect any of the performance or health parameters studied and enhanced apparent digestibility of EPA and DHA compared to the WCO diet. The level of total n-3 LC-PUFA was higher in all the tissues of DCO-fed fish than in WCO-fed fish with levels in liver similar to those in fish fed FO. Endogenous LC-PUFA biosynthetic activity was observed in fish fed both the Camelina oil diets as indicated by the liver transcriptome and levels of intermediate metabolites such as docosapentaenoic acid, with data suggesting that the dietary combination of EPA and DHA inhibited desaturation and elongation activities. Expression of genes involved in phospholipid and triacylglycerol metabolism followed a similar pattern in fish fed DCO and WCO despite the difference in n-3 LC-PUFA contents.

The replacement of fish oil (FO) with a DHA-rich Schizochytrium sp. algal meal (AM) at two inclusion levels (11% and 5.5% of diet) was tested in Atlantic salmon post-smolts compared to fish fed a FO diet of northern (NFO) or southern hemisphere (SFO) origin. Fish were preconditioned prior to the 19-week experimental feeding period to reduce long-chain polyunsaturated fatty acid (LC-PUFA) and persistent organic pollutant levels (POPs). Dietary POP levels differed significantly between treatments in the order of NFO>SFO>11 AM/5.5 AM and were subsequently reflected in the flesh. Fish fed the 11 AM diet contained similar DHA levels (g 100 g(-1) flesh) to FO-fed fish, despite percentage differences. However, the low levels of EPA in the diets and flesh of algal-fed fish compromised the overall nutritional value to the final consumer. Nevertheless, further developments in microalgae culture offer a promising alternative lipid source of LC-PUFA to FO in salmon feeds that warrants further investigation.

For humans a daily intake of up to 500 mg omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) is recommended, amounting to an annual requirement of 1.25 million metric tonnes (mt) for a population of 7 billion people. The annual global supply of n-3 LC-PUFA cannot meet this level of requirement and so there is a large gap between supply and demand. The dietary source of n-3 LC-PUFA, fish and seafood, is increasingly provided by aquaculture but using fish oil in feeds to supply n-3 LC-PUFA is unsustainable. Therefore, new sources of n-3 LC-PUFA are required to supply the demand from aquaculture and direct human consumption. One approach is metabolically engineering oilseed crops to synthesize n-3 LC-PUFA in seeds. Transgenic Camelina sativa expressing algal genes was used to produce an oil containing n-3 LC-PUFA to replace fish oil in salmon feeds. The oil had no detrimental effects on fish performance, metabolic responses or the nutritional quality of the fillets of the farmed fish.

The study investigated cataract preventive effects of dietary histidine (His) supplementation in triploid Atlantic salmon during seawater grow-out. Groups of individually PIT tagged diploid (2N) and triploid (3N) postsmolts were fed one of two supplemented dietary histidine levels; low (L, 12.6 g kg−1 diet) or high (H, 17.4 g kg−1 diet) from March to September following their first sea winter. Low severity cataracts were detected in both ploidy prior to supplemented His diet application. Thereafter, 3N-L showed progression of cataract development in the second spring-summer period, while development was inhibited in 3N-H. Severity of cataract showed a strong family effect. A positive correlation between initial triploid seawater growth (weight and TGC) under increasing water temperature and cataract severity was identified as a major risk factor. The relationship was reversed at harvest, where triploids were on average 7.5% smaller than their diploid siblings. Lens N-acetyl-histidine content reflected dietary His inclusion level and cataract severity, although no significant differences in lens His content were evident between ploidy or dietary groups. Results indicate that triploid Atlantic salmon appear to have a higher dietary histidine requirement than diploids and that preventative measures can be taken to mitigate further cataract development.

Currently, one alternative for dietary fish oil (FO) in aquafeeds is vegetable oils (VO) that are devoid of omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFAs). Entirely new sources of n-3 LC-PUFA such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids through de novo production are a potential solution to fill the gap between supply and demand of these important nutrients. Camelina sativa was metabolically engineered to produce a seed oil (ECO) with > 20% EPA and its potential to substitute for FO in Atlantic salmon feeds was tested. Fish were fed with one of the three experimental diets containing FO, wild-type camelina oil (WCO) or ECO as the sole lipid sources for 7 weeks. Inclusion of ECO did not affect any of the performance parameters studied and enhanced apparent digestibility of individual n-6 and n-3 PUFA compared to dietary WCO. High levels of EPA were maintained in brain, liver and intestine (pyloric caeca), and levels of DPA and DHA were increased in liver and intestine of fish fed ECO compared to fish fed WCO likely due to increased LC-PUFA biosynthesis based on up-regulation of the genes. Fish fed ECO showed slight lipid accumulation within hepatocytes similar to that with WCO, although not significantly different to fish fed FO. The regulation of a small number of genes could be attributed to the specific effect of ECO (311 features) with metabolism being the most affected category. The EPA oil from transgenic Camelina (ECO) could be used as a substitute for FO, however it is a hybrid oil containing both FO (EPA) and VO (18:2n-6) fatty acid signatures that resulted in similarly mixed metabolic and physiological responses.

The effects of varying dietary digestible protein (DP) and digestible energy (DE) content on performance, nutrient retention efficiency and the de novo lipogenesis of DP origin were examined in triplicate groups of gilthead sea bream (Sparus aurata), fed nine extruded experimental diets. In order to trace the metabolic fate of dietary protein, 1·8% fishmeal was replaced with isotope-labelled whole protein (.98% 13C). The experiment was divided into a growth period lasting 89 d, growing fish from approximately 140 to 350 g, followed by a 3 d period feeding isotope-enriched diets. Isotope ratio MS was applied to quantify the 13C enrichment of whole-body lipid from dietary DP. Between 18·6 and 22·4% of the carbon derived from protein was recovered in the lipid fraction of the fish, and between 21·6 and 30·3% of the total lipid deposited could be attributed to dietary protein. DP retention was significantly improved by reductions in dietary DP:DE ratio, while the opposite was true for apparent digestible lipid retention. Both overall DE retention and whole-body proximate composition of whole fish were largely unaffected by dietary treatments, while feed conversion ratios were significantly improved with increasing dietary energy density. The present study suggests that gilthead sea bream efficiently utilises dietary nutrients over a wide range of DP:DE ratios and energy densities. In addition, they appear to endeavour a certain body energy status rather than maximising growth, which in the present trial was apparent from inherently high de novo lipogenesis originating from DP.

The effects of replacing a digestible energy source from fat (fish oil) with carbohydrate (wheat starch) on performance, glycogenesis andde novolipogenesis was examined in triplicate groups of juvenile gilthead sea bream (Sparus aurata), fed four extruded experimental diets. In order to trace the metabolic fate of dietary starch, 0·7 % wheat starch was replaced with isotope-labelled starch (>98 %13C). Fish were fed the experimental diets for three consecutive 10 d periods, and isotope ratio MS was applied to quantify13C enrichment of liver and whole-body glycogen and lipid pools over the three feeding periods. Glycogenesis originating from dietary starch accounted for up to 68·8 and 38·8 % of the liver and whole-body glycogen pools, respectively, while up to 16·7 % of the liver lipid could be attributed to dietary starch. Between 5 and 8 % of dietary starch carbon was recovered in whole-body lipid, and estimated deposition rates ofde novosynthesised lipid originating from starch ranged from 18·7 to 123·7 mg/kg biomass per d. Dietary treatments did not significantly affect growth, feed performance or body composition of the fish, while the hepatosomatic index and glycogen content of whole fish and livers correlated directly with dietary starch inclusion level. The study suggests that gilthead sea bream efficiently synthesises glycogen from both dietary starch and endogenous sources. In contrast, lipogenesis from carbon derived from starch seems to play a minor role in overall lipid synthesis and deposition under the specified experimental conditions.

The Murphy Roths Large (MRL) mouse, a strain capable of regenerating right ventricular myocardium, has a high postmyocardial infarction (post-MI) survival rate compared with C57BL/6J (C57) mice. The biological processes responsible for this survival advantage are unknown. To assess the effect of genetic background, the LG/J strain, which harbours 75% of the MRL composite genome, was included in the study. The MRL survival advantage versus C57 mice (92 versus 68%, P < 0.05) occurred primarily in the first 5 days; LG/J survival was intermediate (P = n.s.). Microarray data analysis revealed an attenuation of apoptotic (P < 0.05) and stress response transcripts in MRL hearts compared with C57 hearts post-MI. Supporting the microarray results, there were fewer TUNEL-positive cells 1 day post-MI in MRL infarcts compared with C57 infarcts (P = 0.001) and fewer CD45-positive cells in the MRL infarct border zone 2 days post-MI (P < 0.01); the LG/J results were intermediate (P = n.s.). The MRL hearts had smaller infarct scars and attenuated ventricular dilatation 30 days post-MI compared with C57 hearts (P < 0.05). We conclude that the early post-MI survival advantage of MRL mice over the C57 strain is mediated at least in part by reductions in apoptosis and inflammatory infiltration, and that these reductions may influence chronic remodelling. The intermediate survival, apoptosis and inflammation profile of LG/J mice suggests that this high tolerance for MI in the MRL mouse could be derived from its shared genetic background with the LG/J mouse.

Recently, we reported that growth of Atlantic salmon was reduced as dietary fishmeal (FM) was lowered from 25% to 5% in dual-substituted feeds compared to a control diet, formulated to represent the current upper levels of substitution of FM and fish oil. In the present study, the effects of different alternative protein blends and binders on growth of salmon fed dual-substituted feeds containing only 11% FM, and with 60% of dietary fish oil replaced by rapeseed oil were investigated. Salmon of initial weight 1.3 kg were grown to market size (>3 kg) over a period of 19 weeks. Salmon fed the diets with reduced FM showed lower final weight, SGR and TGC, associated with reduced feed intake. There was a tendency for increased FCR in fish fed the diets containing reduced FM although this was not significant, and there was no effect on PER. There were no significant effects on digestibility of protein or fat but the two parameters varied reciprocally and there were clear trends of increased protein and lower fat digestibilities in fish fed diets with reduced FM. Although lipid and fatty acid compositions did not vary greatly between diets there were significant effects on fish tissue compositions. Thus, liver lipid was generally reduced in fish fed diets with lower FM. significantly so in two of the four treatments. The proportions of monoenes were significantly lower and those of polyunsaturated fatty acids (PUFA) significantly higher in flesh and liver of fish fed diets with reduced levels of FM. The increased proportions of PUFA were due to increased percentages of 20:4n-6, 20:5n-3, 22:5n-3 and, although not consistently significant, 22:6n-3. The mechanisms for these unexpected effects of diet on tissue lipids and fatty acids are discussed. (C) 2011 Elsevier B.V. All rights reserved.

The current study investigated the effects of pea protein concentrate, soy protein concentrate and corn gluten, either singly at high inclusion, or in combination, each at lower inclusion, in diets for Atlantic salmon (Salmo salar L.). Growth performance, nutrient digestibility, intestinal brush border enzyme activity, and intestinal histology were studied in an 8-week feeding trial. Triplicate groups of Atlantic salmon (2.36kg initial weight) were kept in sea water at winter temperature. Five diets were tested, including a control diet based on fish meal (FM diet; 250gkg−1 fishmeal) and four low fishmeal (100gkg−1) diets: a diet containing 350gkg−1 pea protein concentrate (PPC diet), a diet containing 300gkg−1 soy protein concentrate (SPC diet), a diet containing 300gkg−1 corn gluten (CG diet) and a combination diet containing 130gkg−1 pea protein concentrate, 105gkg−1 soy protein concentrate and 105gkg−1 corn gluten (CMB diet). Fish fed CG and PPC diets showed lower SGR than fish fed the FM diet and there was a trend (P<0.09) towards a higher feed conversion (FCR) in the fish receiving the CG and PPC diets. Apparent fat digestibility was lower in fish fed SPC, PPC and CMB diets compared to FM. No difference in apparent crude protein digestibility was observed. Feeding the PPC diet resulted in reduced relative weight and inflammation in the distal intestine similar to those described for soy enteritis. Additionally, fish fed the PPC diet had reduced brush border enzyme activities in the distal intestine and increased trypsin activity in the digesta from the distal intestine region. In conclusion, pea protein concentrate at high inclusion was shown to induce an enteropathy in the distal intestine of Atlantic salmon and caution should be used when including it in formulated feeds for Atlantic salmon.

The Murphy Roth Large (MRL) mouse, a strain capable of regenerating right ventricular myocardium, has a high post‐ myocardial infarction (MI) survival rate compared with C57BL/6J (C57) mice. The biological processes responsible for this advantage are unknown. To assess the effect of genetic background, the LG/J strain, which provides 75% of the MRL composite genome, was included in the study. The MRL survival advantage versus C57 mice (P = 0.01) occurred largely in the first 5 days; LG/J survival was intermediate (P = NS). Analysis and annotation of microarray data revealed significantly attenuated acute apoptotis (P < 0.05) and delayed expression of stress response transcripts in MRL hearts compared to C57 hearts. Supporting the microarray results, there were fewer TUNEL‐positive cells 1 day post‐MI (P < 0.05) and fewer CD45‐positive inflammatory cells in MRL hearts 2 days post‐MI (P < 0.01) compared to the C57. Chronically, MRL hearts had smaller infarct scars and attenuated ventricular dilation 30 days post‐MI than C57 hearts (P < 0.05). We conclude that the early post‐MI survival advantage of MRL mice over the C57 strain is mediated at least in part by reductions in apoptosis and inflammatory infiltration, and that this may influence chronic remodeling. The intermediate survival rate of LG/J mice suggests the high tolerance for MI in the MRL could be derived from its shared genetic background with the LG/J. Support: NIH

Nutrient digestibility and gastrointestinal evacuation time for diets containing two levels of legumes were determined in European seabass (initial wt. 150 g). Seven isonitrogenous (44 g crude protein 100 g−1) and isoenergetic (20 kJ g−1) extruded diets were tested. Experimental diets contained 15 g or 30 g 100 g−1 of each legume including faba bean meal, (FB15, FB30), chickpea meal (CP15, CP30), field pea meal (FP15, FP30) and a control, wheat meal containing, diet. Inclusion of faba beans in diets significantly enhanced apparent digestibility coefficients (ADCs) of dietary protein and energy at both inclusion levels. Starch digestibility was significantly lower for the control and FP30 diet and significantly higher for the FB15 diet. Fat digestibility coefficients were elevated significantly for FB15, FB30, CP15, FP15 and FP30 diets, compared to the CP30 and the control diet. The incorporation of faba bean and chickpea greatly affected gastrointestinal evacuation time compared to fish fed the control diet. Longer passage times were observed when these legumes were included in the diet. Glucose serum peak value was delayed for FB30 and a slower decreasing rate was observed for the legume diets. The addition of legumes had a positive effect on physical properties of the pellets by increasing the hardness while water activity remained within the safety limits. The findings of this study suggest that the legumes tested are potential candidates for carbohydrate replacement (wheat) and, to a lesser extent, for protein substitution in diets for European seabass.

It has been known for almost 25 years now that inclusion of intact phospholipids in the diet could improve culture performance of various freshwater and marine fish species. The primary beneficial effect was improved growth in both larvae and early juveniles, but also increased survival rates and decreased incidence of malformation in larvae, and perhaps increased stress resistance. Determination of absolute dietary requirements has been hampered by the use, in different dietary trials, of a wide range of phospholipid preparations that can vary greatly both in phospholipid content and class composition. Larval studies have been compromised further by the need on many occasions to supply phospholipid through enrichment of live feeds with subsequent re-modelling of the phospholipid and fatty acid compositions. Generally, the levels of phospholipid requirement are around 2-4% of diet for juvenile fish and probably higher in larval fish. The effects were restricted to young fish, as a requirement for dietary phospholipids has not been established for adult fish, although this has been virtually unstudied. As the majority of studies have used crude mixed phospholipid preparations, particularly soybean lecithin, but also other plant phospholipids and egg yolk lecithin, that are enriched in several phospholipids, it has been difficult to elucidate which specific phospholipid classes impart beneficial effects. Based on the few studies where single pure phospholipid species have been used, the rank order for efficacy appears to be phosphatidylcholine > phosphatidylinositol > phosphatidylethanolamine > phosphatidylserine. The efficacy of other phospholipid classes or sphingolipids is not known. The mechanism underpinning the role of the phospholipids in larval and early juvenile fish must also explain their lack of effect in adult fish. The role of phospholipids appears to be independent of fatty acid requirements although the presence of an unsaturated fatty acid at the sn-2 position may be important. Similarly, the phospholipid requirement is not related to the delivery of other essential dietary components such as the bases choline and inositol. Studies also suggested that the phospholipid effect was not due to generally enhanced emulsification and digestion of lipids. Rather the evidence led to the hypothesis that early developing stages of fish had impaired ability to transport dietary lipids away from the intestine possibly through limitations in lipoprotein synthesis. The current hypothesis is that the enzymic location of the limitation is actually in phospholipid biosynthesis, perhaps the production of the glycerophosphobase backbone and that dietary supplementation with intact phospholipids in larvae and juvenile fish compensated for this. Thus, dietary phospholipids increase the efficiency of transport of dietary fatty acids and lipids from the gut to the rest of the body possibly through enhanced lipoprotein synthesis. (C) 2008 Elsevier B.V. All rights reserved.

Introduction: MRL/MpJ (MRL) mice heal better following myocardial infarction (MI) than C57BL/6J (C57) controls, may regenerate cardiac muscle, and have improved long‐term survival, though the mechanisms are unclear. We compared acute post‐MI survival and healing differences between the two strains as well as the LG/J strain, the major genetic background of the MRL. Methods: MI was induced in adult male MRL, LG/J, and C57 mice by permanent ligation of the left coronary artery. Infarct size was measured after 1, 5, or 30 days. Microarray analysis was performed on RNA collected before and 1 or 5 days post‐MI. Survival was tracked through 70 days. Results: Survival was significantly greater in MRL than C57 mice, due to decreased LV rupture in MRLs during days 2–5 post‐infarct. LG/J mice also appear more susceptible to rupture. Infarct size on day 1 was not different between the MRL and C57 strains, but was significantly larger in C57 mice after 30 days. Preliminary results suggest infarcts of all 3 strains expand to a similar degree after 5 days. Microarray analysis indicates the expression of transcripts associated with induction of apoptosis, the immune response, and inhibition of cellular proliferation may be reduced in the MRL day 1 infarct compared to the C57. The relative attenuation of these processes may contribute to the MRL's survival advantage and promote improved healing. Support: NIH

Biglycan, a small leucine-rich proteoglycan, has been shown to interact with extracellular matrix (ECM) collagen and may influence fibrillogenesis. We hypothesized that biglycan contributes to post-myocardial infarction (MI) scar development and that the absence of biglycan would result in altered scar structure and mechanics. Anterior MI was induced in biglycan hemizygous null and wild-type mice by permanent ligation of the left coronary artery. The initial extent of ischemic injury was similar in the two groups, as was the infarct size after 30 days, although there was some tendency toward reduced expansion in the biglycan-null. Electron microscopy revealed that collagen fibrils had a smaller average diameter and a narrower range in the biglycan-null scar, as well as appearing more densely packed. In vivo strain analysis showed that biglycan-null scars were stiffer than the wild-type. Remote LV collagen concentration tended to be reduced in biglycan-null hearts, but the difference was not statistically significant. Null-expression of biglycan may alter collagen fibril ultrastructure, and thereby influence scar mechanics and remodeling.

We tested the hypothesis that fast growth prior to harvest increased the incidence of soft flesh and gaping in Atlantic salmon (Salmo solar L.) fillets. Growth trials were conducted at Salar, South Uist Westem Isles, Scotland and at the Gildeskal Research Station-Gifas, Northern Norway in duplicate 5 m x 5 m x 5 m net pen sea cages, and feeding commercial diets. Individual growth rate was measured as the thermal growth coefficient (TGC) and a range of flesh quality attributes were measured including fillet firmness using an instrumental t.-xture analyser. The Uist trial comprised the offspring of seven families from the Stofhfiskur breeding programme (Stofnfiskur A/S, Iceland). Salmon from the Uist trial harvested in October 2003 had an average TGC of 2.1 (range 1.4 to 3.6) and showed a very minor but significant positive relationship between the work done (WD) (mJ) to shear a standardised fillet slab and TGC (R 2 =0.041; degrees of freedom 160; P=0.01). In the Gifas trial 1200 PIT-tagged 03 input Sl smolt of the NLA strain were tightly graded and stocked into 4 net pens in June 2004 at a mean weight of 1447 g (16% coefficient of variation). In order to gain salmon with a wide spectrum of growth rates of comparable harvest weight the fish were fed in duplicate cages either to satiation or restricted ration to target a lower growth rate whilst maintaining the same feed conversion rate. In September 2004 104 fish were harvested, selected for high growth rates (TGC = 3.7 +/- 0.06, mean SE; range 2.6 to 5.0) and 106 lower growth rate fish' (TGC=2.7 +/- 0.04, mean:LSE; range 1.7 to 3.6) were harvested in November 2004. For the September harvest there was no relationship between TGC and WD whereas for the November harvest there was a very minor but significant negative correlation between TGC and WD (R-2 = 0.046; degrees of freedom 102; P = 0.04). There was no relationship between TGC and the incidence of gaping 3d post-rigor as measured by the length (cm) gapes m(-2) fillet cross-sectional area (Uist trial) or gaping score (0=no gaping to 4=:severe gaping) (Gifas trial). In practical terms it was concluded that there was no evidence that fast growing fish had a materially higher incidence of soft flesh and gaping than slow growing fish for the stocks and sites studied. (c) 2007 Elsevier B.V All rights reserved.