• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.305-310
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• 2003

A rapid, inexpensive enzymatic method is proposed for indirect water quality testing in terms of heavy metal toxicity. The activity of glucose-6-phosphate dehydrogenase was applied for heavy metal toxicity test as an effective criterion in water quality. The toxicity of Pb (lead) and Cd (cadmium) for water flea, Moina macrocopa, were evaluated for 2-8 days with variables of mobilization ability. And the reproduction impairment of Moina macrocopa were investigated as the parameter of chronic toxicity test for Pb and Cd. As a result, the EC$_{50}$ for immobilization of Moina macrocopa were Pb and Cd were 1.6749 and 0.4683, respectively. The values of reproductive impairment to Moina macrocopa for Pb and Cd were 9.5938 and 8.3264 in EC$_{50}$ A significant alteration of G6PDH (Glucose-6-phosphate dehydrogenase) activity of Moina macrocopa was observed when Cd and Pb were treated in media. The results obtained indicate that G6PDH activity of Moina macrocopa can be used as an indicative parameter in aquatic toxicity tests for heavy metals.als.

• Korean Journal of Ecology and Environment
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• v.43 no.4
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• pp.513-517
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• 2010

The diel swarming of Moina macrocopa and the relationship between environmental factors were evaluated in a shallow reservoir. The littoral density of Moina macrocopa maintained low from night to noon, reached maximum density at the afternoon with compact swarms at the waters' edge, and dispersed after sunset. The recruitment of Moina macrocopa and changes of water temperature (r=0.709, p<0.001) and juvenile fish density (r=0.511, p=0.002) in the littoral zone showed a significant positive relationships. After the induction of diel horizontal migration toward littoral zone, therefore, direct juvenile fish predation pressure should be induced Moina macrocopa swarming.

• Environmental Analysis Health and Toxicology
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• v.23 no.1
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• pp.17-22
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• 2008

A rapid, inexpensive enzymatic method is proposed for indirect water quality testing in terms of heavy metal toxicity. The activity of glucose-6-phosphate dehydrogenase was applied for heavy metal toxicity test as an effective criterion in water quality. The toxicity of Pb (lead) and Cd (cadmium) for water flea, Moina macrocopa, were evaluated for $2{\sim}8\;days$ with variables of mobilization ability. And the reproduction impairment of Moina macrocopa were investigated as the parameter of chronic toxicity twst for Pb and Cd. As a result, the $EC_{50}$ for immobilization of Moina macrocopa were Pb and Cd were 1.6749 and 0.4683, respectively. The values of reproducive impairment to Moina macrocopa for Pb and Cd were 9.5938 and 8.3264 in $EC_{50}$. A significant alteration of G6PDH (Glucose-6-phosphate dehydrogenase) activity of Moina macrocopa was observed when Cd and Pb were treated in media. The results obtained indicate that G6PDH activity of Moina macrocopa can be used as an indicative parameter in aquatic toxicity tests for heavy metals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.154-160
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• 2016

Several our studies have focused recently on the mass production of the freshwater Cladoceran Moina macrocopa which can substitute Artemia nauplii for the culture of larval marin fish. A 6 weeks experiment was conducted to investigate the effects of enrichment on the fatty acid composition of Moina macrocopa through feeding Schizochytrium sp. containing highly unsaturated fatty acids and to study the impacts of n-3-HUFA enriched Moina on improving survival rate and fatty acid compostion of larval rockfish Sebastes schlegeli. After feeding for 6 weeks, the Moina-fed fry resulted in a higher survival rate of 99.2% compared to the Artemia-fed fry 12.8%. In addition, the Moina-fed fry had the fast growth rate 45.6mm compare to the Artemia-fed fry 25.7 mm at the end of the experiment. The Moina-fed fry showed significantly higher level of 16.47% DHA than their Artemia-fed fry counterparts of the level of 3.97% with respect to DHA. PL, the cell membrane components in living food organisms, constituted 63.8% of the Moina, which was significantly higher than in the 40.1% of the Artemia. The present study indicate that Moina macrocopa can be used as Artemia substitute and improving the survival rate rockfish larvae through enchriment Schizochytrium sp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.4
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• pp.183-186
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• 2007

The effect of live food and commercial diet on sweetfish Plecoglossus altivelis culture was assessed by determining the daily growth rate and feed conversion ratio. After feeding for 8 weeks, the Moina macrocopa diet resulted in a higher growth rate of 5.101 compared to commercial (3.441) and Artemia (2.729) diets. In addition fish fed the M. macrocopa diet had the weight gain, averaging 41.29 g at the end of the experiment. The content of n-3 highly unsaturated fatty acids (HUFA) was highest in the commercial diet, while free fatty acids were not detected in the M. macrocopa diet. Triglycerides, the energy source in fishes, constituted 40.0% of the M. macrocopa diet, which was significantly higher than in the commercial and Artemia diets at 20.0 and 12.0%, respectively These results indicate that freshwater M. macrocopa can be used as feed for sweetfish larvae, even without docosahexaenoic acid (DHA) enrichment from Artemia.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.285-291
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• 2001

Grazer-induced colony formation was examined using a green alga Scenedesmus dimorphus (T$\ddot{u}$rpin) K$\ddot{u}$tzing. Algae were cultured in a medium with or without filtered water taken from cultures of Daphnia magna Straus (300 ind./L) or Moina macrocopa Straus (500 ind./L). The exposure to zooplankton filtered water (ZFW)promoted colony formation in S. dimorphus, with the magnitude of this response being directly proportional to the relative volume of ZFW that was added to the culture medium. The number of cells/colony and mean particle biovolume of S. dimorphus increased between 24 and 72 hours after exposure to ZFW, most likely due to the influence of chemicals released from D. magna or M. macrocopa, and possily as a defense mechanism against zooplankton grazing.

• Korean Journal of Microbiology
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• v.42 no.2
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• pp.111-115
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• 2006

A feeding trial was conducted to test the use of marine yeasts isolated from seawaters and sediments as a dietary source in cultivating a Cladocera, Moina macrocopa which is available as an alternative live food for fish larvae. The marine yeast-fed M. macrocopa had similar essential amino acid profiles to the documented values for Rotifers and Artemia enriched in microalgae and commercial diets. Erythrobacter sp. $S{\pi}-1$ lacked ${\omega}-3$ high unsaturated fatty acids (HUFAs), $20:5{\omega}-3$ (EPA) and $22:6{\omega}-3$ (DHA), which were also poor but detected in both the marine yeasts. An increase in the $20:5{\omega}-3$ and $22:6{\omega}-3$ levels, compared with the levels in marine yeast strains themselves, was more pronounced in the $22:6{\omega}-3$ level of Moina fed the Candida sp. Y-16, resulting in a high DHA:EPA ratio. When the Moina diets were switched, their ${\delta}^{13}C$ values shifted gradually toward the values of the switched diets. Diet switch from Erythrobacter sp. $S{\pi}-1$to Candide sp. Y.16 resulted in a more rapid turnover of Moina tissue carbon than that in the inverse case. When fed a mixed diet, the ${\delta}^{13}C$ values of Moina tissue approached the value of marine yeasts immediately. These temporal changes in the ${\delta}^{13}C$ values of Moina tissue indicate the preferential ingestion of marine yeasts and a selective assimilation of the carbon originated from marine yeasts. These findings suggest that marine yeasts, particularly Candida sp. Y-16, are highly available to mass cultures of M. macrocopa, providing better nutritional and dietaty values than the commercial diet (Erythrobacter sp. $S{\pi}-1$).

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.271-277
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• 2007

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are fully flurorinated organic compounds which are highly persistent in environment and accumulated in organism. These chemicals are released to the environment at their manufacture, during their use in industrial and consumer applications and from disposal after their use. The purpose of this study was to determine the effects of PFOA and PFOS on the freshwater flea (Moina macrocopa). Acute toxicity test and chronic toxicity test were performed for 2 days and 10 days, respectively. Acute toxicity was assessed on the basis of mortality, while chronic toxicity was assessed by fecundity as well as mortality. The acute toxicity studies on PFOA and PFOS showed that the values of $LC_{50}$ were $73.9\;mg/L\;and\;27.7\;mg/L$ respectively. In the chronic toxicity test, fecundity was reduced significantly at 24.1 mg/L of PFOA and 9.3 mg/L of PFOS, respectively. Conclusively, the results of this work suggest that Moina macrocopa could be a suitable model organism for screening and assessing of environmental pollutants in water.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.1000-1007
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• 2010

In this study, toxicity monitoring of sediments collected from 25 stations in the Geum river basin was conducted using Daphnia magna and Moina macrocopa. According to the results of acute toxicity tests (immobilization and mortality) of organic extracts of semdiments, Miho stream showed much less toxicity than Gap and Nonsan streams. In particular, significant toxicity was observed in both species for St.15 and St.16 sediment samples that passed through Deajeon city as a branch of Gap stream. For Nonsan stream, St.23 sediment showed high toxicity toward M. macrocopa. This site seemed to be affected by upper agricultural industrial complex. Additionally, M. macrocopa showed a higher sensitivity than D. magna for organic extracts of sediments. In the case of toxicity tests using sediment pore water and aqueous extracts, only pore water of St.27 sediment was toxic against D. magna. Toxicity identification evaluation showed that hydrogen sulfide was likely a major toxicant in the pore water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.393-398
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• 2013

The purpose of this study was to determine how an ornamental fish, such as the fighting fish, Betta splendens would respond to the use of freshwater live-prey, such as rotifers Brachionus calyciflorus and water fleas Moina macrocopa. Ingested quantity, digestive velocity and somatic growth were compared between larvae fed a freshwater rotifer and those fed boiled yolk. Food efficiency and somatic growth were compared between larvae that were fed freshwater water fleas and those fed a micro-diet developed for flounder ($250{\mu}m$, I-hwa Ltd.). The number of rotifers ingested by larvae reached a maximum of 191 per day. However, based on the number ingested per hour and the digestive velocity of consumed rotifers, the maximum ingestible and digestible number of rotifers was calculated to be 272 per day. A maximum of 67 individuals (mean, 49.8 individuals) could be completely digested within the 1-h period from 90 to 180 min after feeding. Somatic growth was enhanced in larvae that were fed rotifers compared to those fed boiled yolk. Larvae exhibited greater growth at rotifer densities of 30 and 40 per mL than at lower densities. Among the water-flea (M. macrocopa and Bosmina sp.) and micro-particle diets, feeding with M. macrocopa resulted in the greatest somatic growth of larvae during the water-flea feeding stage.