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Species of the genus Moina Baird (Cladocera: Moinidae) often dominate freshwater crustacean communities in temporary water bodies. Several species of Moina are used as food for fish larvae in aquaculture, as bioindicators in toxicological studies, and as common subjects for physiological studies. The aim of this paper is to estimate biodiversity of Moina in northern Eurasia using the standard DNA barcoding approach based on the cytochrome c oxidase subunit I (COI) gene. We analysed 160 newly obtained and 157 existing COI sequences, and found evidence for 21 phylogroups of Moina, some of which were detected here for the first time. Our study confirmed the opinion that the actual species diversity of cladocerans is several times higher than is presently accepted. Our results also indicated that Moina has the second richest species diversity among the cladoceran genera (with only Daphnia O. F. Mueller having a greater diversity of species). Our study strongly supports division of Moina into two faunistic groups: European-Western Siberian and Eastern Siberian-Far Eastern, with a transitional zone at the Yenisey River basin (Eastern Siberia). Here, we refrain from taxonomic descriptions of new species, as this requires a thorough morphological and taxonomic study for each putative taxon.

An experimental ecology method was used to study the acute toxicity of nonylphenol (NP) and the effects of NP on growth, reproduction, and population growth in Moina mongolica . The effects were studied in a parent generation exposed to NP and three generations of offspring (F1, F2, and F3) not exposed to NP. The acute 24- and 48-h median lethal concentrations (LC 50 ) of M. mongolica were 0.066 and 0.046 mg L −1 , respectively, indicating that NP is very toxic to M. mongolica . In chronic exposure experiments using parent M. mongolica , NP clearly inhibited the lifespan, reproductive volume, total molting time, end-body length, and population growth parameters. In the recovery generations in a clean environment, three generations still suffered from toxic effects, with toxic amplification in generation F1. Generations F2 and F3 clearly followed a recovery trend in the groups in which the parents were exposed to 0.001–0.007 mg L −1 NP but recovered slowly in the groups in which the parents were exposed to 0.009 and 0.011 mg L −1 NP. The results indicated that NP has overt reproductive toxic and transgenerational effects on M. mongolica . Further studies of the damage caused to the aquatic environment by hormone-like chemicals such as NP should therefore be performed.

A new species of Moina Baird, 1850 (Cladocera, Moinidae), is described from a brackish lake in the northeast of China based on morphology and molecular phylogenetics. The morphological description of Moina heilongjiangensis sp. nov. includes details of the thoracic limb structure, and we compare the new species with other members of the genus Moina based on key morphological characteristics. Moina heilongjiangensis sp. nov. is one of the few members of the genus with two eggs in the ephippium and lacking superficial hairs on the body. We also applied two genetic markers (COI and ITS-1) to assess its position in the genus Moina . Our molecular phylogenetic tree indicates that M. heilongjiangensis sp. nov. is close to Moina affinis Birge, 1893, based on mitochondrial sequences.

Parabens are derivatives of alkyl esters of p-hydroxybenzoic acid and come in different classes. These compounds are primarily used as antimicrobial preservative agents in many commercial products, including cosmetics and pharmaceuticals. Accordingly, Benzyl paraben (BeP) is known to be a potential endocrine disruptor. The aim of this study was to determine the toxicity of benzyl paraben (BeP) on aquatic and terrestrial organisms, specifically Scenedesmus sp., Moina macrocopa, and Eisenia fetida. All the organisms were treated with different concentrations of BeP (0.025 mg/L and 1000 mg/L), and LC25, LC50, and LC90 values were used to measure the toxicity levels. Results showed the LC values of BeP for M. macrocopa (3.3 mg/L, 4.7 mg/L, 7.3 mg/L) and E. fetida (173.2 mg/L, 479.8 mg/L, 1062 mg/L), respectively. Toxicity tests on green algae (Scenedesmus sp.) were conducted, the green algae were subjected to various BeP concentration. At 50 mg/L of BeP, cell viability was reduced to 56.2% and the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay indicated 35.4% viable cells. The chlorophyll value and the biochemical parameters of the algal cells were corroborative with the cell viability test. Lethal indices (LC50) for M. macrocopa and E. fetida were evaluated for their toxicity on biochemical properties and were found to be catalase (0.111 mg/L, 0.5 mg/L), lipid peroxidation (0.072 mg/L, 0.056 mg/L), and total protein (0.309 mg/L, 0.314 mg/L), respectively. Overall, this study demonstrated the toxic impact of BeP on non-target aquatic as well as terrestrial species.

Moina is a group of tiny shrimp belonging to the class Crustacea and the sub-order Cladocera, which can reproduce and grow quickly in various food sources and can be cultivated under low oxygen and high ammonium content. Utilization of Moina as natural food is not maximized because it is still constrained by quality and management of food availability in cultivation media which affects its productivity. One of the efforts to make Moina available sustainably is by producing ephippia. Ephippia is a product of Moina ’s sexual reproduction which can be mass-produced to meet Moina ’s availability and continuity. This study aimed to examine the effect of aeration on the productivity of male individuals and ephippia Moina micrura . This study used an experimental method, a completely randomized design (CRD) consisting of 2 treatments with 6 replications. The treatments applied were Moina culture using aeration and Moina culture without aeration. The test animal used was Moina micrura , reared in a jar with a density of 50 ind/L for 14 days. The results of this study indicated that, Moina culture using aeration had a significantly decreased on individual male and ephippia Moina micrura productivity. The best productivity of male and ephippia individuals with culture treatment without aeration was 66 ± 2.79 ind/L and 10 ± 0.9 grains/20 ml of sample.

Moina siamensis is one of the most successful Cladocerans used for mass culture as live feed for the larvae of crustaceans and different fish. Moina is fed Chlorella; however, there is a risk of predation by larger zooplanktons, which appear in the tanks where the Chlorella are grown. As a solution, specialized commercial feeds have been produced. The main objective of this study was to explore an alternative to Chlorella for Moina culture. The present trial was conducted to compare the performance of Chlorella, yeast, and a commercial diet on the biography, population growth, and density. Seven adult Moina as replicates per treatment were placed in each plastic cup individually and monitored. They were fed three types of feed at a concentration of 6x106 mL-1. The experiment continued until all the adult Moina died. The result showed that the average day of maturation, the number of newborns per day, the number of newborns per crop, and the number of crops from different diets were similar. The Moina fed Chlorella sp. showed the longest life span (9.00+0.8 days), and the shortest with the commercial feed (5.6+0.3 days). However, commercial feed and the Chlorella did not differ in terms of the final population of Moina, but they produced more than when fed the yeast. Therefore, the results demonstrated that the commercial feed was similar to that of Chlorella and can serve as an alternative diet.

At the present time, no artificial larval diet is capable of entirely fulfilling the dietary requirements of several larval fish and crustacean species. Zooplankton live food is the basic foundation of fish larviculture, and successful rearing of fish larvae still heavily depends on an adequate supply of nutritious live food. Despite being important, the production protocols of copepods and cladocerans (Moina) are still underdeveloped in hatcheries. Rotifers and Artemia are the most commonly used live foods. However, these live foods are evidently lacking in crucial nutrient constituents. Hence, through nutrient enrichment, live food with the nutritional profile that meets the requirements of fish larvae can be produced. With the aim to maximize the effectiveness of production to optimize profitability, it is important to evaluate and improve culture techniques for the delivery of micro- and macro-nutrients as feed supplements to larvae in aquaculture systems. Bioencapsulation and enrichment are the evolving techniques in aquaculture that are commonly employed to enhance the nutritional quality of live food by integrating nutrients into them, which subsequently improves the growth, survival, and disease resistance of the consuming hosts. This review aims to highlight some of the approaches and methods used to improve the nutritional quality of live food by modifying their nutrient composition, which could have immense promise in the enhancement of aquatic animal health.

Salinity is a known factor in shaping population dynamics and community structure through direct and indirect effects on aquatic ecosystems. Salinity changes further influence food webs through competition and predation. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) was evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate high salinity stress. Specifically, the fatty acid composition, growth, survival, and reproduction of this cladocerans species was examined. Sodium chloride (NaCl) as used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15 salinity. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). The results indicated that optimal conditions produced the highest fatty acid content, especially the polyunsaturated fatty acid content, such as EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid), and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival was best at salinity 0, with a percentage of 98%, whereas the opposite occurred at salinity 15, with approximately 20% of viable animals surviving. Besides, M. macrocopa also showed the highest reproduction rate at salinity 0 (e.g., average initial age of reproduction, 4.33 ± 0.58 days) compared with other salinities level. Interestingly, the difference in growth at different salinities was not evident, an unusual finding when considering adverse effects such as osmoregulation pressure on the organism. Based on the results, we conclude that M. macrocopa can only tolerate salinity below salinity 8 and cannot withstand stressful environmental conditions associated with salinities above 8.

Inland waters potentially contain vast quantities of microplastics (MPs), being tropical ecosystems in developing countries possibly subjected to continuous and uncontrolled plastic waste disposal. This study reports on the intake of polyethylene terephthalate (PET) MPs by a small-sized tropical freshwater microcrustacean. We began by analyzing if the cladoceran Moina cf. micrura would ingest PET MPs with different shapes and sizes similar to the algae it feeds on (< 25 μm) but with lower concentration (9.4 × 102 particles/mL). We tracked the possible uptake of heterogeneous particles of PET MPs without dyes and nor fluorescently labeled by each individual during all the experiments via PET fluorescence under an epifluorescence microscope. Adults of M. cf. micrura and neonates born during the experiment ingested MPs, which accumulated (i) in the alimentary channels, (ii) on external parts of the cladocerans, (iii) on molting exudes, and (iv) in the gut and on appendages of dead individuals. We recorded efforts of MPs egestion by some individuals without success – which possibly contributed to the decrease in survival along the experiment. As Moina spp. are common tropical zooplankters and a widely recognized food source within aquaculture, the potential ecological consequences of such PET MPs ingestion on tropical aquatic food webs are highlighted.

It is increasingly being recognized that biotic ligand models (BLMs) can successfully predict the toxicity of divalent metals toward aquatic biota applied to temperate freshwater ecosystems. However, studies on the eutrophic lakes in tropical regions toward native tropical organisms, including Moina , are relatively limited. In this study, Moina dubia , the native organism of the Hanoi eutrophic urban lakes, were used in toxicological studies of lead (Pb); 24-h EC 50 value of Pb was 523.19 µg/L under optimal living conditions for M. dubia in the laboratory. The constant binding of Pb 2+ on M. dubia surface sites (log K PbBL  = 2.38) was significantly low. Other stability constants were obtained under experiments as logK CaBL  = 2.48, logK MgBL  = 2.80, logK NaBL  = 2.35, logK KBL  = 2.49, and logK HBL  = 3.026. A BLM was developed to calculate the acute toxicity (EC 50 -24 h) of lead on M. dubia based on the condition of the urban lakes of Hanoi. Validation with toxicity data in synthetic medium showed a coefficient determination of 79.16% and a mean absolute percentage error (MAPE) of 10.2%, while the validation with the toxicity data with natural water medium from 11 Hanoi lakes showed a coefficient determination of 73.7% and a MAPE of 13.66%. The BLM worked well with water at a pH of 7.0 to 8.0, but failed with water at a pH above 8.0. Eutrophic conditions proved to have a significant effect on the toxicity of lead on local zooplankton.