Inactivation of Salmonella enterica serovar enteritidis in shell eggs by sequential application of heat and ozone

Aims:  To assess the contribution of ozone to lethality of Salmonella enterica serovar Enteritidis in experimentally inoculated whole shell eggs that are sequentially treated with heat and gaseous ozone in pilot-scale equipment.
Methods and Results:  Whole shell eggs were inoculated with small populations of Salmonella Enteritidis (8·5 × 10⁴–2·4 × 10⁵ CFU per egg) near the egg vitelline membrane. Eggs were subjected to immersion heating (57°C for 21 min), ozone treatment (vacuum at 67·5 kPa, followed by ozonation at a maximum concentration of approx. 140 g ozone m⁻³ and 184–198 kPa for 40 min) or a combination of both treatments. Survivors were detected after an enrichment process or enumerated using modified most probable number technique. Ozone, heat and combination treatments inactivated 0·11, 3·1 and 4·2 log Salmonella Enteritidis per egg, respectively.
Conclusions:  Sequential application of heat and gaseous ozone was significantly more effective than either heat or ozone alone. The demonstrated synergy between these treatment steps should produce safer shell eggs than the heat treatment alone.
Significance and Impact of the Study:  Shell eggs are the most common vehicle for human infection by Salmonella Enteritidis. Many cases of egg-related salmonellosis are reported annually despite efforts to reduce contamination, including thermal pasteurization of shell eggs and egg products. Treatment with ozone-based combination should produce shell eggs safer than those treated with heat alone.     

Influence of Temperature on Bacterial Infection of the Hen's Egg

Temperature of incubation had a marked effect on infection of eggs in which the air cells had been inoculated with a washed suspension of Serratia marcescens. There was no evidence of bacterial multiplication or spoilage in eggs held at 10 C for 42 days. Multiplication occurred in the shell membranes of eggs held at 30 or at 37 C when the yolk made contact with these membranes, and continued in the contents of the egg, at which time the first signs of spoilage appeared. In a few eggs, very large populations were present in the shell membranes and in the albumen. In eggs inoculated with Pseudomonas fluorescens and held at 10 C, bacterial multiplication occurred in the shell membranes in the first 7 days of incubation. These populations did not appear to change in size in the 7- to 14-day period of incubation. Renewed multiplication and concomitant spoilage of the contents was observed in many of the eggs thereafter.     

Influence of Temperature on Bacterial Infection of the Hen''s Egg

Temperature of incubation had a marked effect on infection of eggs in which the air cells had been inoculated with a washed suspension of Serratia marcescens. There was no evidence of bacterial multiplication or spoilage in eggs held at 10 C for 42 days. Multiplication occurred in the shell membranes of eggs held at 30 or at 37 C when the yolk made contact with these membranes, and continued in the contents of the egg, at which time the first signs of spoilage appeared. In a few eggs, very large populations were present in the shell membranes and in the albumen. In eggs inoculated with Pseudomonas fluorescens and held at 10 C, bacterial multiplication occurred in the shell membranes in the first 7 days of incubation. These populations did not appear to change in size in the 7- to 14-day period of incubation. Renewed multiplication and concomitant spoilage of the contents was observed in many of the eggs thereafter.     

Incidence and Spoilage Potential of Isolates from Vacuum-packaged Meat of High pH Value

Meat of high pH value (6·6) showing dark-cutting characteristics was vacuum-packaged and stored for up to 8 weeks at 0–2°C. 'Off'-odours were detected on opening the packages after 6 weeks of storage. Total counts at this stage were ca. 10⁷/cm² of which lactobacilli were the major component, with ca. 10⁶/cm² Gram negative organisms. Psychrotrophic Enterobacteriaceae represented a major proportion of the microflora only after the full 8 weeks of storage and were not detected previously. Aerobic storage of steaks cut from the vacuum packaged meat stored for 8 weeks resulted in a predominantly Gram negative spoilage flora.
Inoculation studies on meat of normal pH value (5·4) and appearance using representative isolates from the vacuum-packaged meat microflora indicated that most of the test organisms were capable of causing spoilage under aerobic conditions but few under vacuum-packaging when incubated at 4°C. On meat of higher pH value (6·15) many of the Gram negative isolates did not grow as well, whereas the Gram positive isolates grew better than on meat of normal pH value when held under aerobic conditions. Under vacuum-packaging all but one isolate grew as well or better on meat of high pH value than on normal meat at 4°C and objectionable odours were more marked.     

Storage diseases of carrots in East Anglia 1978 – 82, and the effects of some pre- and post-harvest factors

In a survey of nine carrot crops stored during four seasons 1978 – 82, the major causes of wastage were spreading soft rots caused by Botrytis cinerea and Rhizoctonia carotae; rots caused by Sclerotinia sclerotiorum, Mycocentrospora acerina and Stemphylium radicinum were only of secondary importance. Storage weight losses were lower and roots remained turgid for up to 40 wk in an ice-bank-cooled store at 0·5 °C, 97 – 98% r.h., whereas carrots in conventionally-cooled stores at 2 – 2.5 °C, 90 – 95% r.h. became flaccid after a few months. In some crops, losses due to fungal spoilage were also lower in the ice-bank store. In two seasons' losses, mostly due to B. cinerea, were similar in hand- and machine-harvested roots; pre-storage washing of carrots grown on mineral soils increased the incidence of Botrytis rots, and reduced rotting by R. carotae, but had no effect on spoilage of roots from peat soils. Post-harvest fungicide treatment with benomyl or iprodione (0·5 g/litre a.i.) effectively reduced rotting by B. cinerea and S. sclerotiorum, but not by R. carotae. The recoveries of sound carrots after 23 – 29 wk storage were consistently highest (mostly > 80%) from fungicide-dipped roots stored under ice-bank conditions, but recoveries from all treatments were lower and more erratic after 35 – 40 wk because of increased fungal spoilage. The practical applications of long-term ice-bank storage of UK-grown carrots are discussed.     

Effects of gaseous environment and temperature on the storage behaviour of Listeria monocytogenes on chicken breast meat

Portions of skinless chicken breast meat (pH 5·8) were inoculated with a strain of Listeria monocytogenes and stored at 1, 6 or 15°C in (1) aerobic conditions; (2) 30% CO₂+ air; (3) 30% CO₂+ N₂; and (4) 100% CO₂. When samples were held at 1°C the organism failed to grow under any of the test conditions, despite marked differences between treatments in spoilage rate and ultimate microflora. At 6°C counts of L. monocytogenes increased ca 10-fold in aerobic conditions before spoilage of the meat, but only when the inoculum culture was incubated at 1°C rather than 37°C. In CO₂ atmospheres growth of L. monocytogenes was inhibited on meat held at 6°C, especially under 100% CO₂. By contrast, storage at 15°C led to spoilage of the meat within 2 d, in all gaseous environments, and listeria levels increased up to 100-fold. Differences in the behaviour of L. monocytogenes on poultry and red meats are discussed.     

Fate of low temperature and acid-adapted Yersinia enterocolitica and Listeria monocytogenes that contaminate lactic acid decontaminated meat during chill storage

Pathogens found in the environment of abattoirs may become adapted to lactic acid used to decontaminate meat. Such organisms are more acid tolerant than non-adapted parents and can contaminate meat after lactic acid decontamination (LAD). The fate of acid-adapted Yersinia enterocolitica and Listeria monocytogenes, inoculated on skin surface of pork bellies 2 h after LAD, was examined during chilled storage. LAD included dipping in 1%, 2% or 5% lactic acid solutions at 55°C for 120 s. LAD brought about sharp reductions in meat surface pH, but these recovered with time after LAD at ≈1–1·5 pH units below that of water-treated controls. Growth permitting pH at 4·8–5·2 was reached after 1% LAD in less than 0·5 d (pH 4·8–5·0), 2% LAD within 1·5 d (pH 4·9–5·1) and after 5% LAD (pH 5·0–5·2) within 4 d. During the lag on 2% LAD meat Y. enterocolitica counts decreased by 0·9 log₁₀ cfu per cm² and on 5% LAD the reduction was more than 1·4 log₁₀ cfu per cm². The reductions in L. monocytogenes were about a third of those in Y. enterocolitica . On 1% LAD the counts of both pathogens did not decrease significantly. The generation times of Y. enterocolitica and L. monocytogenes on 2–5% LAD meats were by up to twofold longer than on water-treated controls and on 1% LAD-treated meat they were similar to those on water-treated controls. Low temperature and acid-adapted L. monocytogenes and Y. enterocolitica that contaminate skin surface after hot 2–5% LAD did not cause an increased health hazard, although the number of Gram-negative spoilage organisms were drastically reduced by hot 2–5% LAD and intrinsic (lactic acid content, pH) conditions were created that may benefit the survival and the growth of acid-adapted organisms.     

Immersion heat treatments for inactivation of Salmonella enteritidis with intact eggs

The effects of water-bath immersion heat treatments on the inactivation of Salmonellaenteritidis within intact shell eggs were evaluated. Six pooled strains of Salm. enteritidis ( ca 3×10⁸ cfu, inoculated near the centre of the yolk) were completelyinactivated within 50–57·5 min at a bath temperature of 58°C and within 65–75min at 57°C (an 8·4 to 8·5- D process per egg). Following the initial 24 to35-min come-up period, semilogarithmic survivor curves obtained at 58 and 57°C yieldedapparent decimal reduction times ( D -values) of 4·5 and 6·0 min, respectively.Haugh unit values increased during heating, while yolk index and albumen pH values wereunaffected. Albumen clarity and functionality were affected by the thermal treatments; therefore,extended whip times would be required for meringue preparation using immersion-heated eggwhites. Immersion-heated shell eggs could provide Salmonella -free ingredients for thepreparation of a variety of minimally-cooked foods of interest to consumers and foodserviceoperators.     

Autotriploid tench Tinca tinca (L.) larvae obtained by fertilization of eggs previously subjected to postovulatory ageing in vitro and in vivo

Eggs of diploid tench Tinca tinca were half-stripped out and stored for 0 (control batch), 1, 3 and 5 h at mean ± s . d . 17·0 ± 0·4 and 21·9 ± 0·5° C or for 0, 1, 2, 3, 4 and 5 h at 24·0 ± 0·0° C in vitro prior to fertilization. The eggs remaining in vivo in the fish kept at 17·0 ± 0·4 and 21·9 ± 0·5° C were collected and fertilized in the same time intervals. Fertilization rate and larval yield mostly decreased after 3–5 h storage of eggs both in vitro and in vivo and only the diploid larvae were found in all control batches. Triploid larval yields increased to a maximum 5·26% after 5 h in vitro storage at 24·0° C and 1·07 and 1·60% after 3 h in vitro storage at 21·9 and 17·0° C, respectively. Triploid larval yield during in vivo storage at 21·9° C reached a maximum 0·91% after 5 h. As the spontaneous autotriploid larvae arose solely from fertilized eggs previously subjected to postovulatory egg ageing by means of prolongated storage, the autotriploidy was probably caused by failure of extrusion of the second polar body.     

Monitoring of microbial metabolites and bacterial diversity in beef stored under different packaging conditions

Beef chops were stored at 4°C under different conditions: in air (A), modified-atmosphere packaging (MAP), vacuum packaging (V), or bacteriocin-activated antimicrobial packaging (AV). After 0 to 45 days of storage, analyses were performed to determine loads of spoilage microorganisms, microbial metabolites (by solid-phase microextraction [SPME]-gas chromatography [GC]-mass spectrometry [MS] and proton nuclear magnetic resonance [(1)H NMR]), and microbial diversity (by PCR-denaturing gradient gel electrophoresis [DGGE] and pyrosequencing). The microbiological shelf life of meat increased with increasing selectivity of storage conditions. Culture-independent analysis by pyrosequencing of DNA extracted directly from meat showed that Brochothrix thermosphacta dominated during the early stages of storage in A and MAP, while Pseudomonas spp. took over during further storage in A. Many different bacteria, several of which are usually associated with soil rather than meat, were identified in V and AV; however, lactic acid bacteria (LAB) dominated during the late phases of storage, and Carnobacterium divergens was the most frequent microorganism in AV. Among the volatile metabolites, butanoic acid was associated with the growth of LAB under V and AV storage conditions, while acetoin was related to the other spoilage microbial groups and storage conditions. (1)H NMR analysis showed that storage in air was associated with decreases in lactate, glycogen, IMP, and ADP levels and with selective increases in levels of 3-methylindole, betaine, creatine, and other amino acids. The meat microbiota is significantly affected by storage conditions, and its changes during storage determine complex shifts in the metabolites produced, with a potential impact on meat quality.     

Effect of formulation pH and storage temperatures on the preservative efficacy of some gases used as propellants in cosmetic aerosols

The effects of changes in formulation pH and storage temperature on the preservative activities of some aerosol propellants—butane, carbon dioxide, dimethylether and their combinations were investigated. A preservative challenge test method was used to determine the survival rates of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus niger at formulation pH levels 5·80, 7·28 and 8·10 and storage temperatures of 20°, 30° and 40°C.
A significant decrease in the pH of formulations was observed with no corresponding changes in the antimicrobial effectiveness when carbon dioxide was incorporated. Alterations in the antimicrobial profiles of these propellants due to changes in formulation pH were dependent on the propellant and the species of the micro-organism, especially when single propellants were used. Results also showed that the propellants exert antimicrobial activities against the various organisms at the three storage temperatures but there were significantly greater inhibitory activities at 40°C. With a combination of 10% butane/dimethylether (1:2) and 10 bar carbon dioxide there were no differences in the degree of microbial inhibition at the various formulation pH levels and storage temperatures. In most cases, the organisms were completely inactivated within 24 h. These findings showed that the combination of butane/dimethylether with carbon dioxide could be used to protect against microbial contamination and spoilage of formulations of different pH levels as well as those meant for storage at different temperatures.     

Lower Temperatures More Effective than Atmosphere Modification in Controlling Botrytis and Nectria Rots in Stored Apples

A series of small‐scale controlled inoculation experiments has been conducted during 2005–2009 to determine whether temperature and controlled atmosphere (CA) storage conditions affect significantly the incidence of Botrytis cinerea and Neonectria galligena rots of apples and to assess whether CA regimes can be ‘fine‐tuned’ to suppress fungal rotting. The incidence of B. cinerea and N. galligena rots on apple was reduced consistently by storage in lower temperatures (1.5–2°C). In no case was the disease incidence significantly higher than that under air storage conditions. However, the effect of CA conditions on rot development varied greatly from year to year so that overall there were no significant effects of CA conditions on the incidence of rot during storage till the following April. Thus, we can neither fine‐tune CA conditions to reduce rot development nor exploit the advantages of lower storage temperatures for Cox and Bramley for this purpose due to inevitable development of low temperature breakdown. Further research is needed to study the effects of ethylene control technologies and modulated storage temperatures on rot development.     

Changes in the spoilage-related microbiota of beef during refrigerated storage under different packaging conditions

The microbial spoilage of beef was monitored during storage at 5 degrees C under three different conditions of modified-atmosphere packaging (MAP): (i) air (MAP1), (ii) 60% O2 and 40% CO2 (MAP2), and (iii) 20% O2 and 40% CO2 (MAP3). Pseudomonas, Enterobacteriaceae, Brochothrix thermosphacta, and lactic acid bacteria were monitored by viable counts and PCR-denaturing gradient gel electrophoresis (DGGE) analysis during 14 days of storage. Moreover, headspace gas composition, weight loss, and beef color change were also determined at each sampling time. Overall, MAP2 was shown to have the best protective effect, keeping the microbial loads and color change to acceptable levels in the first 7 days of refrigerated storage. The microbial colonies from the plate counts of each microbial group were identified by PCR-DGGE of the variable V6-V8 region of the 16S rRNA gene. Thirteen different genera and at least 17 different species were identified after sequencing of DGGE fragments that showed a wide diversity of spoilage-related bacteria taking turns during beef storage in the function of the packaging conditions. The countable species for each spoilage-related microbial group were different according to packaging conditions and times of storage. In fact, the DGGE profiles displayed significant changes during time and depending on the initial atmosphere used. The spoilage occurred between 7 and 14 days of storage, and the microbial species found in the spoiled meat varied according to the packaging conditions. Rahnella aquatilis, Rahnella spp., Pseudomonas spp., and Carnobacterium divergens were identified as acting during beef storage in air (MAP1). Pseudomonas spp. and Lactobacillus sakei were found in beef stored under MAP conditions with high oxygen content (MAP2), while Rahnella spp. and L. sakei were the main species found during storage using MAP3. The identification of the spoilage-related microbiota by molecular methods can help in the effective establishment of storage conditions for fresh meat.     

Influence of diet on cold storage of the predator <Emphasis Type="Italic">Perillus bioculatus</Emphasis> (F.)

Cold storage of insects is a common practice used when transporting insects or to assist with efforts to increase the size of a colony. However, cold storage affects egg, nymphal and adult survival, fecundity, and egg viability. We evaluated the influence of nutrient source on the response of eggs, nymphs and adults of Perillus bioculatus when exposed to two temperatures most likely to be used for short and extended storage by comparing natural prey-fed insects to artificial diet-fed insects. The results of our study showed that the survival of eggs from either prey-fed or diet-fed insects declined at both 4 and 10°C as the length of storage exceeded one week. The survival of nymphs exposed to cold storage treatment was slightly higher than for eggs, with a similar response to time of storage. Unique to the nymphal stage was the superior performance of diet-fed insects over prey-fed insects. However, of the three developmental stages tested, the best survival was obtained with adults. Our results show that both prey-fed and diet-fed adults were able to withstand cold storage at 10°C for three weeks with very little loss of survival, fecundity or viability of eggs oviposited by those adults. Longer periods of storage resulted in a decline in survival, fecundity and egg viability and that decline was greatest at 4°C. Outcross mating of cold stored adults with adults held at 26°C indicated that adult females were more detrimentally affected by cold storage than males. There were differences in the response of P. bioculatus to cold storage compared to previously reported responses of P. maculiventris. However, the most notable difference is that P. maculiventris did better at almost all parameters than P. bioculatus. Collectively, these results demonstrate a nutrient influence on the response to cold storage at different developmental stages.     

Why fruit rots: theoretical support for Janzen's theory of microbe–macrobe competition

We present a formal model of Janzen''s influential theory that competition for resources between microbes and vertebrates causes microbes to be selected to make these resources unpalatable to vertebrates. That is, fruit rots, seeds mould and meat spoils, in part, because microbes gain a selective advantage if they can alter the properties of these resources to avoid losing the resources to vertebrate consumers. A previous model had failed to find circumstances in which such a costly spoilage trait could flourish; here, we present a simple analytic model of a general situation where costly microbial spoilage is selected and persists. We argue that the key difference between the two models lies in their treatments of microbial dispersal. If microbial dispersal is sufficiently spatially constrained that different resource items can have differing microbial communities, then spoilage will be selected; however, if microbial dispersal has a strong homogenizing effect on the microbial community then spoilage will not be selected. We suspect that both regimes will exist in the natural world, and suggest how future empirical studies could explore the influence of microbial dispersal on spoilage.     

Severity of spoilage storage rots of white yam (Dioscorea rotundata Poir.)

Severity of storage rots in different sections of white yam tubers (Dioscorea rotundata Poir.) was investigated. Yam samples with rots were collected from a yam barn and from selected markets in Accra, Ghana, to identify the most predominant pathogens associated with the rots. Nine fungal spoilage microorganisms, including Aspergillus flavus, Aspergillus niger, Botryodiplodia theobromae, Fusarium culmorum, Fusarium oxysporium, Fusarium sp., Penicillium brevi‐compactum, Penicillium sp. and Rhizopus stolonifer and a bacterium species Erwinia carotovora were identified. The mean incidence of occurrence of the organisms on rotten tissues ranged from 1.2% to 28.5%. Of the 10 microorganisms isolated, B. theobromae, F. oxysporium and R. stolonifer were the most frequently encountered spoilage microorganisms in the markets. E. carotovora, Fusarium solani and Penicillium sp. were relatively sparse (incidence not exceeding 3%) compared to the other yam spoilage microorganisms. The surface area and weight of necrotic tissue induced by the spoilage fungi in the various zones of the tubers over a 28‐day storage period were assessed. All the spoilage microorganisms produced rots in the yams, although to different degrees. The severity of the rots increased in weight and area over the period when the tubers were in store but were normally not significantly different in the zones of tubers. There was, however, a linear progression of rots in the various zones of the yam tubers. Although there was generally no significant (P ≥ 0.05) difference in the severity of rots induced by the different microorganisms in the tubers, R. stolonifer commonly induced more rot in the zones of the tubers compared to B. theobromae and F. oxysporium.     

The deposition and mortality of the eggs of the Baltic herring Clupea harengus membras L., on different substrates in the south-west archipelago of Finland

The environmental factors affecting the deposition and mortality of the eggs of the spring-spawning Baltic herring were studied in the inner Archipelago Sea of south-western Finland. On four spawning grounds, 27 study squares (area 1 m²) were surveyed by divers. In each square, one quantitative egg sample was taken and the following data were recorded: depth, temperature, bottom quality of the square and under the eggs, egg substrate, cover (%) of plants and/or the bivalve Mytilus edulis , and the heterogeneity of the environment, expressed as the total number of all bottom materials, plants and Mytilus found in the square.
Eggs were found in the depth zone of 1–4 m. Their density ranged from 6000 to 2·3 millions of eggs per square metre. Egg number had a significant negative correlation with both depth (r=-0·545, P <0·01, d.f. = 25) and temperature of the sea water ( r =-0.479,. P <0·01,d.f. = 25), and a positive correlation with the total cover (%) in the squares ( r = 0·375, P < 0·05, d.f. = 25).
The highest numbers of eggs were found on Cladophora glomerata, which the most preferred spawning substrate of those present. Mortality of the eggs varied according to the substrate. In eggs attached to Cladophora, Potamogeton and Mytilus, the proportion of dead eggs was 0.15·5%; in those attached to red algae it was significantly higher ( Furcellaria , 5·0–63·2%; Phyllophora , 0–95·2%).     

The influence of light on egg buoyancy and hatching rate of the walleye pollock, Theragra chalcogramma

Changes in buoyancy in fertilized bathypelagic eggs of the walleye pollock, Theragra chalcogramma , collected from Shelikof Strait in the Gulf of Alaska were measured under controlled laboratory conditions in density gradient columns from 90 h post–fertilization through hatching. Eggs were incubated at 6° C and exposed to either diel light or constant dark. Eggs held under diel light conditions became more dense than eggs under constant dark beginning <10 h after exposure to light and remained so until 12 h before hatching. Eggs held under constant dark then became more dense than those under diel light. Hatching of eggs under both conditions began at the same time but eggs under diel light showed a delayed hatching rate. Light–induced changes in egg density indicate the ability of walleye pollock eggs to respond to external stimuli and thereby alter their position in the water column in an ecologically meaningful way.     

Changes in the Spoilage-Related Microbiota of Beef during Refrigerated Storage under Different Packaging Conditions

The microbial spoilage of beef was monitored during storage at 5°C under three different conditions of modified-atmosphere packaging (MAP): (i) air (MAP1), (ii) 60% O₂ and 40% CO₂ (MAP2), and (iii) 20% O₂ and 40% CO₂ (MAP3). Pseudomonas, Enterobacteriaceae, Brochothrix thermosphacta, and lactic acid bacteria were monitored by viable counts and PCR-denaturing gradient gel electrophoresis (DGGE) analysis during 14 days of storage. Moreover, headspace gas composition, weight loss, and beef color change were also determined at each sampling time. Overall, MAP2 was shown to have the best protective effect, keeping the microbial loads and color change to acceptable levels in the first 7 days of refrigerated storage. The microbial colonies from the plate counts of each microbial group were identified by PCR-DGGE of the variable V6-V8 region of the 16S rRNA gene. Thirteen different genera and at least 17 different species were identified after sequencing of DGGE fragments that showed a wide diversity of spoilage-related bacteria taking turns during beef storage in the function of the packaging conditions. The countable species for each spoilage-related microbial group were different according to packaging conditions and times of storage. In fact, the DGGE profiles displayed significant changes during time and depending on the initial atmosphere used. The spoilage occurred between 7 and 14 days of storage, and the microbial species found in the spoiled meat varied according to the packaging conditions. Rahnella aquatilis, Rahnella spp., Pseudomonas spp., and Carnobacterium divergens were identified as acting during beef storage in air (MAP1). Pseudomonas spp. and Lactobacillus sakei were found in beef stored under MAP conditions with high oxygen content (MAP2), while Rahnella spp. and L. sakei were the main species found during storage using MAP3. The identification of the spoilage-related microbiota by molecular methods can help in the effective establishment of storage conditions for fresh meat.     

Investigating the relationship among abnormal patterns of cell cleavage, egg mortality and early larval condition in Limanda ferruginea

Normal (symmetrically cleaving) and abnormal (non‐symmetrically cleaving) eggs were selected from four batches of eggs from three yellowtail flounder Limanda ferruginea , and reared in Petri dishes as paired replicates under controlled conditions. Mortality rates were significantly higher in early (day 0–3) but not later (day 4–9) embryogenesis in abnormal eggs when compared to the normal eggs. Early larval morphology was not different between the two groups, but larvae from normal eggs were significantly longer than those from abnormal eggs ( P  < 0·05).