Fish Scraps Research Articles

The Fishy Off-Odor Removal and Umami Enhancing Effect of Enzymatic Hydrolysis of Fish By-Products by Proteases

ABSTRACT The aim was to study the changes in flavor compounds hydrolyzed by different proteases in fish soup boiled with fish scraps The odor compounds were extracted by solid-phase microextraction (SPME) and analyzed by two-dimensional comprehensive gas chromatography-olfactometry-mass spectrometry (GC×GC-O-MS). The state of the distribution of free amino acids, 5’-nucleotides, peptides and equivalent umami concentration (EUC) were investigated. It was found that enzymatic hydrolysis significantly reduced off-flavor compounds, and the umami taste increased significantly. The synergistic effect between FlavourzymeTM and ProtamexTM (F-P) made the flavor of enzymatic hydrolysis better than that of other enzymes.

Variation in foraging strategies of New Zealand albatross species within a dominance hierarchy

ABSTRACT Co-occurring species sharing a limited resource are thought to adopt alternative strategies to coexist. Here, we investigate four species of co-occurring albatrosses in southern New Zealand that share food resources but differ in dominance status to test for variation in strategies to acquire supplemental food provided by ecotourism boats. We found evidence for distinct foraging strategies consistent with each species’ dominance rank. Buller’s albatross (Thalassarche bulleri) was the most subordinate species and frequently pursued scraps of fish on the periphery of the feeding flocks and avoided interacting with other species. Salvin’s albatross (Thalassarche salvini) and White-capped albatross (Thalassarche cauta) were intermediate in dominance status; both had fast responses to fish and typically pursued the largest fish scraps, though T. cauta successfully stole fish while T. salvini did not. In contrast, Southern Royal albatross (Diomedea epomophora) was the dominant species and did not avoid interactions with other species and pursued the largest fish scraps but was slower to respond compared with some subordinates. Natural food sources approximate the scenarios seen behind ecotourism boats, suggesting that differences in foraging strategies are likely present without human intervention. Overall, our results suggest that foraging strategies associated with dominance hierarchies could help structure seabird communities.

Pemanfaatan Ikan Red Devil (Amphilophus sp.) Sebagai Pakan Alternatif dalam Budidaya Ikan Nila (Oreochromis niloticus)

This study aims to determine the growth, survival and feed conversion ratio of tilapia fed with red devil fish scrap feed. This research was conducted 56 days culture peroid. The research treatments consisted of treatment A (control); feeding 100% commercial pellets, treatment B; feeding 100% small chopped devil fish and treatment C; giving 50% pellet feed + 50% small chopped devil fish. The stocking density of fish in this study was 20 fish/50 liters of water with fish size of 4-6 cm obtained from nursery farmers in the Bangli area. The parameters observed in this study were the fish length, specific growth rate, survival rate, feed conversion ratio and water quality. The results of the research that have been carried out showed that treatment C has the highest value and significantly different (P<0,05) compared to other treatments on absolute length growth and fish survival. The measured water quality parameters including temperature was in the range of 23.80-24.18oC, pH has an average of 7.03 and DO in the range of 5.82-6.13 mg/L which still within optimum rabge for tilapia culture.
 Keywords: Tilapia; Red devil fish; Growth rate

Heterarchy Reveals Social Organization of a Smooth Stingray (Bathytoshia brevicaudata) Population in a Provisioned Food Context

The advent of new technologies and statistical analyses has provided valuable insights into chondrichthyan social behavior. It has become apparent that sharks and rays lead more complex social lives than previously believed. Heterarchy combines hierarchy and social network theory and although it is not a new concept, it is rarely applied to animal social interactions. Here, we applied heterarchy to a case study involving smooth stingrays foraging for fish scraps at boat ramp in Jervis Bay, NSW Australia. We took advantage of their attraction to this site to examine their social behavior during agonistic interactions over the provisioned resource. We observed a stable, relatively linear but shallow dominance hierarchy that was highly transitive dominated by a single individual. Social network analysis revealed a non-random social network centered on the dominant individual. Contrary to previous research, size did not predict dominance, but it was correlated with network centrality. The factors determining dominance of lower ranks were difficult to discern, which is characteristic of despotic societies. This study provides the first heterarchical assessment of stingray sociality, and suggests this species is capable of complex social behavior. Given higher dominance and centrality relate to greater access to the provisioned resource, the observed social structure likely has fitness implications.

Animal-borne video reveals atypical behaviour in provisioned green turtles: A global perspective of a widespread tourist activity

Feeding wildlife as a tourist activity is a growing industry around the world. However, providing alternative food sources can affect wildlife ecology and behaviour. In this study, we combined animal-borne cameras on five sub-adult green turtles (Chelonia mydas) from the Bahamas with a global review to directly assess impacts of provisioning on the behaviour of an endangered marine species for the first time. Descriptive evidence from video footage, with videos included in the manuscript, showed that the tagged turtles spent 86% of their time in shallow water (<1.5 m) at a provisioning site. All individuals observed, both tagged and untagged, actively approached people and boats, with up to 10 turtles recorded feeding on squid offered by tourists at one time. During these feeding events, multiple accounts of atypical aggressive behaviour such as biting and ramming conspecifics were recorded. Furthermore, a review of online sources revealed the widespread significance of turtle feeding as a tourist activity in at least 20 locations within the global range of green sea turtles, as well as five locations with regular provisioning of either loggerhead (Caretta Caretta) or hawksbill (Eretmochelys imbracata) turtles. At the majority of the locations, turtles were fed animal matter such as fish scraps and squid. Although sample size limited quantitative analyses, we found indications of relatively high growth rates of two tagged turtles and low seagrass intake rates of all five tagged turtles. Therefore, our results emphasize the need to further investigate the impacts of turtle provisioning on natural foraging behaviour, ecosystem functioning as well as turtle growth rates and health implications. Supplemental feeding may increase habituation and dependency of turtles on humans with risks for turtle conservation. The innovative use of animal-borne camera technology may provide novel insights to behavioural consequences of human-wildlife interactions that can aid in the management and conservation of rare or endangered species.

Lipid profile and growth of black soldier flies (Hermetia illucens, Stratiomyidae) reared on by-products from different food chains.

The total amount of bio-waste produced annually in the EU by the food and beverage chains is estimated at 37 billion kg. The use of insects for the valorization of by-products from these value chains may represent a sustainable solution. This study aimed to investigate the by-products obtained from different food chains and used for the rearing of black soldier fly (BSF) prepupae, and to evaluate the content and profile of the lipid extracted from the prepupae and outline its possible applications. The substrates used in this experiment were: (i) industrial by-products (brewery spent grains, cows' milk whey, grape stalks, and tomato peels and seeds) and (ii) by-products from retailers (bread dough, fish scraps, and spent coffee ground). Fat extracted from prepupae using an adjusted Folch method was used for total lipid content and fatty acid profile. The best larval performances were obtained from beer (0.22 gweight per prepupa), tomato (0.19 gweight per prepupa), and cheese (0.14 gweight per prepupa) food-chain by-products. The extremely different compositions of the substrates were reflected in the differentiated lipid profile of the BSF prepupae and in the range of ratios between unsaturated and saturated fatty acids, which varied from 0.37 for cows' milk whey to 1.34 for tomato peels and seeds. The lipids, proteins, and chitin extracted from prepupae are high-value bio-based products that could be used in the feed / food industry or for the development of innovative biomaterials, such as biodiesel. These results suggest that food-chain by-products are the best candidates for insect-bioconversion purposes. © 2020 Society of Chemical Industry.

Kleptoparasitism of the sea otter (Enhydra lutris) and Steller sea lion (Eumetopias jubatus) by the glaucous-winged gull (Larus glaucescens) at Seward, Alaska

Observations of seabirds stealing food (kleptoparasitism) from marine mammals are rarely reported. During 67 h of observation at Seward, Alaska, where fishers frequently discard scraps of fish, we documented 16 incidents of gulls attempting to kleptoparasitize sea otters (Enhydra lutris) and seven incidents of gulls attempting to kleptoparasitize Steller sea lions (Eumetopias jubatus). An average of 3.5 ± 3.5 SD (range 1–13) glaucous-winged gulls (Larus glaucescens) and < 0.1 ± 0.3 SD (range 0–1) black-legged kittiwakes (Rissa tridactyla) attacked sea otters with discarded fish scraps, with a success rate of 53% per incident and 16% per individual gull. The gulls ignored sea otters with invertebrate prey. An average of 3.6 ± 1.7 SD (range 1–7) glaucous-winged gulls and 0.1 ± 0.4 SD (range 0–1) black-legged kittiwakes attacked sea lions with discarded fish scraps, with a success rate of 29% per incident and 8% per individual gull. Only glaucous-winged gulls succeeded in stealing food, usually comprising fragments of the original item floating on the surface after the victim dived, but twice food was stolen directly from sea otters. To avoid kleptoparasitism, sea otters used five evasive maneuvers (swimming away, diving, rolling, lunging toward gull, and pulling food from gull), whereas sea lions used only two (swimming away and diving). Kleptoparasitism of sea otters and sea lions by gulls is a previously overlooked behavior that merits further study of its potential benefits and costs.

Effect of Bio and Organic Fertilizers on Flowering,Yield, and Fruit Quality of Kalamata Olive Trees under North Sinai Condition

Kalamata olive trees (Olea europea L.) about 10 -years- old of nearly moderate vigor and productivity grown in sandy loam soil were selected. The trees were planted at 6 × 7 m apart and under drip irrigation system during the two consecutive seasons of 2014-2015and 2015-2016 at the Experimental Station of the Faculty of Environmental Agricultural Sciences, Arish University, North Sinai Governorate to study the effect of bio and organic fertilizers on olive trees all of them received regularly the annual horticultural practices as usually adopted in the orchards. The four organic fertilizer sources i.e. fish scrap 2.5 Kg/tree/ Year, goat manure 16.8 Kg/tree/ Year, chicken manure 7.8 Kg/tree/Year and olive pomace 8.5 Kg/tree, were applied annually in tranches. Three biofertilizers and amino acid treatments alone or combined with them i.e. Nitrobein 150 g.tree/Year in trenches, Protamine at concentration 1.5 % and dissolving in one liter of water then added to the soil at three times, at 70% full-bloom, after fruit set, and a month later and combination of Nitrobein + Protamine®. These treatments were arranged in a randomized complete block design with three replicates for each treatment and each replicate was represented by two trees. the use of organic fertilization, especially fish scrap, through the addition of bio-fertilization using nitrobein with amino acid protamine at a concentration of 1.5% combined. This treatment improved the production of high yield with characteristics and high quality of fruits in addition to protecting the environment from the problems of pollution resulting from mineral fertilization as well as the use of environmental waste.

Meat waste as feedstock for home composting: Effects on the process and quality of compost

Home composting is a powerful tool, which is spreading in different parts of the world, to reduce the generation of municipal waste. However, there is debate concerning the appropriateness, in terms of domestic hygiene and safety, of keeping a composter bin in the household deputed to kitchen waste of animal origin, such as meat or fish scraps and pet droppings. The purpose of our work was to study how the addition of meat scraps to household waste influences the composting process and the quality of the final compost obtained. We compared four raw material mixtures, characterized by a different combination of vegetable and meat waste and different ratios of woody bulking agent. Changes in temperature, mass and volume, phenotypic microbial diversity (by Biolog™) and organic matter humification were determined during the process. At the end of the experiment, the four composts were weighed and characterized by physicochemical analysis. In addition, the presence of viable weed seeds was investigated and a germination bioassay was carried out to determine the level of phytotoxicity. Finally, the levels of pathogens (Escherichia coli and Salmonella spp.) were also determined in the final compost.Here we show that the presence of meat waste as raw feedstock for composting in bins can improve the activity of the process, the physicochemical characteristics and maturity of the compost obtained, without significantly affecting its salinity, pH and phytotoxicity. Pathogen levels were low, showing that they can be controlled by an intensive management and proper handling of the composter bins.

Investigating Cross‐Sectoral Synergies through Integrated Aquaculture, Fisheries, and Agriculture Phosphorus Assessments: A Case Study of Norway

SummaryFuture phosphorus (P) scarcity and eutrophication risks demonstrate the need for systems‐wide P assessments. Despite the projected drastic increase in world‐wide fish production, P studies have yet to include the aquaculture and fisheries sectors, thus eliminating the possibility of assessing their relative importance and identifying opportunities for recycling. Using Norway as a case, this study presents the results of a current‐status integrated fisheries, aquaculture, and agriculture P flow analysis and identifies current sectoral linkages as well as potential cross‐sectoral synergies where P use can be optimized. A scenario was developed to shed light on how the projected 2050 fivefold Norwegian aquaculture growth will likely affect P demand and secondary P resources. The results indicate that, contrary to most other countries where agriculture dominates, in Norway, aquaculture and agriculture drive P consumption and losses at similar levels and secondary P recycling, both intra‐ and cross‐sectorally, is far from optimized. The scenario results suggest that the projected aquaculture growth will make the Norwegian aquaculture sector approximately 4 times as P intensive as compared to agriculture, in terms of both imported P and losses. This will create not only future environmental challenges, but also opportunities for cross‐sectoral P recycling that could help alleviate the mineral P demands of agriculture. Near‐term policy measures should focus on utilizing domestic fish scrap for animal husbandry and/or fish feed production. Long‐term efforts should focus on improving technology and environmental systems analysis methods to enable P recovery from aquaculture production and manure distribution in animal husbandry.

Functional diversity of the macro‑invertebrate community in the port area of Kerkennah Islands (Tunisia)

The harbour area of Sidi Youssef in Kerkennah islands is characterized by specific anthropogenic pressures linked to fishing activities. To study the functional diversity of benthic macro invertebrates, 10 stations located around the port and along the ship canal were sampled by SCUBA diving. Collected invertebrates were identified, counted and preserved. For the functional organization of the community, the most common biodiversity indices and functional groups were assessed at each station, and main physical and chemical parameters were measured. Results showed that the main apparent anthropogenic stress, that could lead to negative impacts on the studied area, was related to dredging/harbour activities. Suspension feeders, consisting essentially of polychaetes, which may be disturbed by water turbidity, dominated the stations farthest from the port, where the intensity of harbour activities is obviously reduced. On the contrary, carnivores dominated inside the port, possibly benefiting from fish scraps discarded at the area, while stations close to the port appeared to be more balanced trophically. The applied biotic indices showed that the area is in good ecological status, except of the navigation channel and the port entrance, which were slightly degraded.

Living on predictability: modelling the density distribution of efficient foraging seabirds

In areas with regular fishing coastal fleets seabirds may benefit from the predictability of discards from fishing vessels, but it is not clear to what extent birds rely on this predictable resource and whether foraging is synchronized with the diel availability of discards. In this paper we investigate if a typical scavenger species, the yellow‐legged gull Larus michahellis, takes advantage of the temporal and spatial predictability of fish discards in the western Mediterranean Sea. The activity and distribution of the trawling fleet in this area is regulated and very predictable in time and space. We gathered aerial survey data across a relatively large area close to the coast to study the spatial distribution and density of L. michahellis, and modelled the density distribution of the species in relation to several oceanographic, ecological and temporal variables, using two different modelling approaches: MARS (multivariate adaptative regression splines) and GLM (generalized linear models). Our models suggest that the spatial density of trawlers at sea and the time of the day are the best explanatory variables of gull distribution, and that gulls concentrate in areas with vessels mainly during fish discarding time, supporting the hypothesis that gulls optimize time foraging to take advantage of fishery waste predictability. Additional surveys from the main gull roosting sites inshore support this hypothesis, as gulls start leaving to the sea just before fishing is completed and vessels begin discarding fish scraps when back to the harbour. This study represents one of the few examples of applying MARS to density distribution modelling, although its application to marine ecosystems should be conducted with caution because of large areas with real absence data. GLMs have shown to be more adaptable to such kind of data. Our data confirm the importance of fishery waste for L. michahellis, not only as a food resource but also as a major driver of their activity and distribution patterns. The ability of seabirds to predict accurately when a food resource will be available implies that modelling their distribution at sea needs to include such variables, both in spatial and temporal dimensions.

Peptone preparation from fishing by‐products

AbstractPanulirus argus and P laevicauda lobster carapace meat, lobster tail parings, whole shrimp tails from Cinnamon shrimp, (Macrobachium amazonicum) and scraps left over from filleting Piaui croaker (Plagioscion squamosissimus) were separated, hydrolysed and then lyophilised and used as individual sources of peptone in media for the cultivation of Escherichia coli. The composition of the test media was: 0.3% meat extract, 0.5% peptone and 0.1% lactose. These new sources of peptone were compared with commercially obtained peptone (OXOID), commonly used in laboratory media, and which served as the control. E coli growth curves for each source of peptone were evaluated using the turbidimetry method and biomass quantification was determined by the dry curve method in order to obtain the respective growth rates for these media. E coli grew faster and for longer using alternative sources of peptone than with the control. The peptone yield from lobster carapace meat was 17.6%, from lobster tail parings 10.2%, from Piaui croaker fish scraps 23% and from whole Ciannamon shrimp tails 12.9%. Growth curves and the biomass figures indicate the feasibility of using these fishery by‐products as raw materials for peptone production for microbial media. Copyright © 2005 Society of Chemical Industry

Concentration Dependent Effect of Enzymatic Fish Protein Hydrolysate on the State of Water and Denaturation of Lizard Fish (Saurida wanieso) Myofibrils during Dehydration

To utilize fishery waste products as functional food material, the fish protein hydrolysate (FPH) was prepared from fish scraps of three marine species by protease treatment. The added-concentration dependent effects of FPH (2.5-12.5%, dry weight/wet weight) on the state of water and denaturation of lizard fish myofibrils were evaluated by desorption isotherm curves, myofibrillar Ca-ATPase activity, and unfrozen water which was determined by differential scanning calorimetry during dehydration. The water activity (Aw) in myofibrils was distinctly decreased with the increasing concentration of FPH from 2.5% up to 10.0%, although the Aw added with 12.5% of FPH was almost equal to that with 10.0% of FPH. The amount of unfrozen water in myofibrils during dehydration was increased by the addition of FPH, and the greatest increase was found at 5.0-10.0%. The FPH suppressed the inactivation of myofibrillar Ca-ATPase activity during dehydration, and a larger effect of suppression was observed at 7.5% addition of FPH. These findings suggest that peptides produced in FPH functioned to stabilize the hydrate water surrounding the myofibrils and suppressed their dehydration-induced denaturation.

Effect of enzymatic fish-scrap protein hydrolysate on gel-forming ability and denaturation of lizard fish Saurida wanieso surimi during frozen storage

: Fish protein hydrolysate (FPH) was prepared from fish scrap of five marine species by enzymatic treatment for the effective utilization of fish wastes. The major components of the FPH were peptide (82.3–85.8%) with other nitrogenous compounds (11.5–16.3%). Lizard fish Saurida wanieso surimi containing FPH (5.0%, dried weight/wet weight) was stored at −25°C and the suppressive effects of FPH on the decrease in the gel-forming ability, unfrozen water content and Ca-ATPase activity were determined during the frozen storage. FPH maintained a high gel-forming ability and Ca-ATPase activity were determined during the frozen storage. FPH also suppressed the decrease of unfrozen water content of surimi. These results suggest that FPH can be used as a cryoprotectant to suppress the denaturation of muscle protein of lizard fish surimi during frozen storage.

Effect of Enzymatic Fish Protein Hydrolysate from Fish Scrap on the State of Water and Denaturation of Lizard Fish (Saurida wanieso) Myofibrils during Dehydration

Fish protein hydrolysate (FPH) was prepared from scraps of 5 marine species, in order to utilize by-products effectively by protease treatment. Protein was the major component of the FPH ranging 82–86%. The effects of 5% FPH (dried weight/wet weight) on the state of water and the denaturation of lizard fish Saurida wanieso myofibrils were evaluated by desorption isotherm curves, Ca-ATPase activity, and differential scanning calorimetry (DSC) during dehydration. The myofibrils with FPH showed a decreased water activity (Aw), while they exhibited significantly higher Ca-ATPase activity compared to myofibrils without FPH (control). The myofibrils with FPH had higher amount of unfrozen water than the control. These results suggest that the FPH suppressed dehydration-induced denaturation, which seems to be attributable to the stabilization of the hydrated water surrounding the myofibrils.

An alternative to dolphin oil as a fish attractant in the Ganges River system: conservation of the Ganges River dolphin

Oil extracted from blubber of the Ganges River dolphin, Platanista gangetica, is used as a fish attractant in India and Bangladesh. This oil fishery is associated with the mortality of hundreds of dolphins every year. Oil from fish scraps was field tested for 121 days during 1997–1999 in the Ganges at Patna and was a very effective alternative to dolphin oil as a fish attractant. Fishing with fish oil resulted in higher catches and greater income per person per hour (Rs. 17.8±12.5) than fishing with dolphin oil (Rs. 11.6±9.3). However, there is no statistically significant difference between the results from fishing with dolphin and fish oil. Oil from fish scraps is inexpensive and can be made readily available to all the fishermen. Its widespread use would help in conserving the endangered Ganges River dolphin.

Cultivation of the Mediterranean amberjack, Seriola dumerili (Risso, 1810), in submerged cages in the Western Mediterranean Sea

The growth rate, survival and food conversion ratio (FCR) of the Mediterranean amberjack ( Seriola dumerili, Risso, 1810) was ascertained in cultivation using submerged net cages in the Gulf of Castellammare (NW Sicily), from September to December 1994. Two net cages (volume=75 m 3) were placed at a depth of 10 m in a sheltered area 1000 m off the coast. Juveniles (mean total length=141.4±34.2 mm; mean total wet weight=48±28.1 g) were caught in the gulf under floating wreckage with a purse seine and transplanted to the cages ( n=800 per cage) in August. Fish in one cage, group A, were fed with fish scraps whilst fish in group B were fed with pellets. The total length and body wet weight were recorded each month and compared with the wild population of the gulf. Negligible mortality occurred due to capture and transportation to the cages and no diseases were found during the rearing period. Group A reached a final size of 438.1±25.3 mm and 1149±172.2 g, while group B reached 347±25.6 mm and 576±139 g. At this time the wild population was 404.13±17 mm and 777±89.4 g. Food conversion ratios of 1.22 for group A and 3.51 for group B were in the low range compared with other research on S. dumerili in the Mediterranean. S. dumerili seemed to find fish scraps more appetising than pellets. The low level of investment required, limited breeding period and compatibility with small-scale fishing make submerged net cages a promising system of cultivation for the conversion of coastal fishing.

Experiences of integrated mariculture in a southern Tyrrhenian area (Mediterranean Sea)

To ascertain the potential for exploiting marine areas for mariculture, data on the cultivation of molluscs and fish in the open sea of the southern Tyrrhenian were collected from May 1994 to June 1995. The aims of this integrated study were to test simple breeding methods for molluscs and fish, to apply these to the practices employed by local fishermen and to experiment with the use of a cage system requiring a low level of investment. Crassostrea gigas (Thunberg) and Mytilus galloprovincialis (Lamarck) were cultivated on submerged long lines around cages used for cultivating Seriola dumerili (Risso) and Diplodus puntazzo (Cetti). S. dumerili specimens were placed in two cages and fed with either fish scraps or pellets, while in a third cage, D. puntazzo were fed with pellets only. After a period of 12 months, the following results were obtained: the oysters measured 47.50 ± 12.30 mm and weighed 0.13 ± 0.09 g; the mussels placed in culture as juveniles reached a length of ≈ 40 mm, while the mussels placed in culture as subadults reached the commercial size of about 60 mm. The mean length and weight measurements of the two fish species were as follows: Diplodus 228 ± 14.4 mm and 228 ± 40.48 g; Seriola (lot A) 438.1 ± 25.28 mm and 1149 ± 172.2 g; Seriola (lot B) 347 ± 25.6 mm and 576 ± 139 g.

Screening for yeasts incorporating the exogenous eicosapentaenoic and docosahexaenoic acids from crude fish oil

The screening for yeasts incorporating exogenous eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into their cellular lipids was conducted. Two percent of oil from fish scraps was added to a yeast isolation medium as a sole carbon source. From 143 soil samples, we isolated 23 yeast strains, nine of them were found to be capable of quickly assimilating the scrap fish oil. These nine strains, in addition to four previously isolated triglyceride-assimilating and lipase-producing strains, Yarrowia lipolytica and three Geotrichum species (FO274A, FO347-2 and FO401B), were cultured in a growth medium at 30°C. Strains FO726A, FO765A and FO347-2 were selected on the basis of dry cell weight production and ability to store EPA and DHA in their cells, and their performance was further compared by varying cultivation temperature and time. From 1 g of the scrap fish oil, FO726A yielded 620 mg of dry cells, containing 47.1% lipid, 38.1% triglyceride, 3.3% EPA, and 4.9% DHA, when cultured at 25°C for 36 h. Strain FO726A apparently has the highest ability to incorporate EPA and DHA into its cellular lipids. Results from further experiments showed that the incorporated EPA and DHA mainly existed in the form of triglyceride in the FO726A cell. These results suggest that FO726A is suitable for the production of cell mass rich in EPA and DHA for feed.