Salina Larvae Research Articles

Developmental toxicity of oxidized multi-walled carbon nanotubes on Artemia salina cysts and larvae: Uptake, accumulation, excretion and toxic responses

Using Artemia salina (A. salina) cysts (capsulated and decapsulated) and larvae [instar I (0–24 h), II (24–48 h) and III (48–72 h)] as experimental models, developmental toxicity of oxidized multi-walled carbon nanotubes (O-MWCNTs) was evaluated. Results revealed that hatchability of capsulated and decapsulated cysts was significantly decreased (p < 0.01) following exposure to 600 mg/L for 36 h. Mortality rates were 33.8, 55.7 and 40.7% for instar I, II and III larvae in 600 mg/L. The EC50 values for swimming inhibition of instar I, II and III were 535, 385 and 472 mg/L, respectively. Instar II showed the greatest sensitivity to O-MWCNTs, and followed by instar III, instar I, decapsulated cysts and capsulated cysts. Effects on hatchability, mortality and swimming were accounted for O-MWCNTs rather than metal catalyst impurities. Body length was decreased with the concentrations increased from 0 to 600 mg/L. O-MWCNTs attached onto the cysts, gill and body surface, resulting in irreversible damages. Reactive oxygen species, malondialdehyde content, total antioxidant capacity and antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) activities were increased following exposure, indicating that the effects were related to oxidative stress. O-MWCNTs were ingested and distributed in phagocyte, lipid vesicle and intestine. Most of the accumulated O-MWCNTs were excreted by A. salina at 72 h, but some still remained in the organism. Data of uptake kinetics showed that O-MWCNTs contents in A. salina were gradually increased from 1 to 48 h and followed by rapidly decreased from 48 to 72 h with a range from 5.5 to 28.1 mg/g. These results so far indicate that O-MWCNTs have the potential to affect aquatic organisms when released into the marine ecosystems.

Toxicity of α-Fe2O3 nanoparticles to Artemia salina cysts and three stages of larvae

Artemia salina cysts (capsulated and decapsulated) and larvae (instar I, II and III) were exposed to α-Fe2O3 nanoparticles (α-Fe2O3-NPs) to evaluate the effects on marine ecosystems. Hatchability, mortality and a number of ethological, morphological and biochemical parameters were selected as end-points to define the toxic responses. Results indicate that the hatchability of capsulated and decapsulated cysts was significantly decreased (p<0.01) following exposure to 600mg/L at 12, 18, 24 and 36h. Both increases of mortality and decreases of swimming speed were shown concentration-dependent manners. The LC50 values for instar II and III were 177.424 and 235.495mg/L, respectively (not calculable for instar I), the EC50 values for instar I, II and III were 259.956, 99.064 and 129.088mg/L, respectively. Instar II larvae show the greatest sensitive to α-Fe2O3-NPs, and followed by instar III, instar I, decapsulated cysts and capsulated cysts. Body lengths and individual dry weight of instar I, II and III larvae were decreased following exposure. α-Fe2O3-NPs attached onto the gills and body surface of larvae, resulting in irreversible damages. All of malondialdehyde content, total antioxidant capacity, reactive oxygen species and antioxidant enzymes activities were substantially increased in dose-dependent manners after exposure to α-Fe2O3-NPs suspensions, indicating that toxic effects were mediated by oxidative stress. Finally, the uptake result indicated that α-Fe2O3-NPs were ingested and distributed in the nephridial duct, primary body cavity and intestine of A. salina. Moreover, the uptake kinetics data show that the maximum α-Fe2O3-NPs content (8.818mg/g) was reached at 36h, and a steady state was reached after 60h. The combined results indicate that α-Fe2O3-NPs have the potential to affect aquatic life when released into the marine ecosystems.

Synthesis, characterization and cytotoxic evaluation of inclusion complexes between Riparin A and β-cyclodextrin

This study performed a physicochemical characterization of the inclusion complex generated between Riparin A and β-cyclodextrin (Rip A/β-CD) and compared the cytotoxic potential of the incorporated Rip A upon Artemia salina larvae. Samples were analyzed by phase solubility diagram, dissolution profile, differential scanning calorimetry, X-ray diffraction, infrared spectroscopy, proton nuclear magnetic resonance, scanning electron microscopy and artemicidal action. Riparin A/β-cyclodextrin complexes presented increased water solubility, AL type solubility diagram and Kst constant of 373 L/mol. Thermal analysis demonstrated reduction of the melt peak of complexed Rip A at 116.2 °C. Infrared spectroscopy confirmed generation of inclusion complexes, 1H NMR pointed out the interaction with H-3 of β-CD cavities, alterations in the crystalline natures of Rip A when incorporated within β-CD were observed and inclusion complexes presented higher cytotoxic on A. salina nauplii, with CL50 value of 117.2 (84.9–161.8) μg/mL. So, Rip A was incorporated into β-CDs with high efficiency and water solubility of Rip A was improved. Such solubility was corroborated by cytotoxic evaluation and these outcomes support the improvement of biological properties for complexes between Riparin A/β-cyclodextrin.

Toxicity evaluation of graphene oxide on cysts and three larval stages of Artemia salina

Using Artemia salina as an experimental model, the potential risks of graphene oxide (GO) to marine ecosystems were investigated. Hatchability of capsulated and decapsulated cysts, mortality of instar I, II and III larvae, and a number of morphological, ethological and physiological parameters were selected as end-points for toxicity assessment. Our results show that GO significantly decreased (p<0.01) the hatchability of capsulated and decapsulated cysts following exposure to 400 and 600mg/L for 36h. There was a concentration-dependent increase in mortality and decrease in swimming speed of larvae, and instar II larvae showed a greater sensitivity compared with instar I and instar III larvae. The LC50 values of instar II and III were 368.18 and 387.68mg/L, respectively (not calculable for instar I). The EC50 values for swimming speed alteration of instar I, II and III were 415.13, 273.50 and 289.05mg/L, respectively. Moreover, body lengths and individual dry weight of larvae (instar I, II and III) also decreased in dose-dependent manners. GO attached onto the surface of cysts and larvae, resulting in irreversible damage to the larval body surface. All of malondialdehyde content, total antioxidant capacity, reactive oxygen species and superoxide dismutase activity of A. salina larvae substantially increased in dose-dependent manners after exposure to GO suspensions, indicating that toxic effects were due to oxidative damages. However, for the activities of catalase, glutathione peroxidase and glutathione S-transferase, GO induced different effects on the larvae. Finally, the uptake result indicated that GO was ingested and concentrated in the gut, and was visible within the primary body cavity and yolk.

The Best Extraction Technique for Kaempferol and Quercetin Isolation from Guava Leaves (Psidium guajava)

Guava leaves contain various compounds that have biological activity such as kaempferol and quercetin as anticancer. Twelve extraction techniques were performed to obtain the best extraction technique to isolate kaempferol and quercetin from the guava leaves. Toxicity of extracts was tested against Artemia salina larvae. All extracts were toxic (LC50 value less than 1000 ppm) except extract of direct soxhletation on guava leaves, and extract of sonication and soxhletation using n-hexane. The extract with high content of total phenols and total flavonoids, low content of tannins, intense color of spot on thin layer chromatogram was selected for high performance liquid chromatography analysis. Direct sonication of guava leaves was chosen as the best extraction technique with kampferol and quercetin content of 0.02% and 2.15%, respectively. In addition to high content of kaempferol and quercetin, direct sonication was chosen due to the shortest extraction time, lesser impurities and high toxicity.

A Study of Acute Toxicity and Cytotoxic Activity of Prunus avium Extracts against Artemia salina Larva

A Study of Acute Toxicity and Cytotoxic Activity of Prunus avium Extracts against Artemia salina Larva

Chenopodolans E and F, two new furopyrans produced by Phoma chenopodiicola and absolute configuration determination of chenopodolan B

Two new furopyrans, named chenopodolans E and F (1 and 2), were isolated from the liquid culture of Phoma chenopodiicola, a fungal pathogen proposed for the biological control of Chenopodium album, a common worldwide weed of arable crops. They were characterized using spectroscopic methods as 3-(3-methoxy-2,6-dimethyl-7aH-furo[2,3b]pyran-4-yl)-but-2-enoic acid methyl ester and 1-(3-methoxy-2,6-dimethyl-7aH-furo[2,3b]pyran-4-yl)-ethanone, respectively. Furthermore, the absolute configuration of chenopodolan B (3) was established to be (7aR,9S) by a combined application of the advanced Mosher's method and of quantum mechanical calculations of chiroptical (ECD and ORD) properties. When 1 and 2 were assayed on punctured leaves at 2 μg/μL, only 2 was active on Sonchus arvensis while 1 caused around 75% larval mortality on Artemia salina larvae at 0.1 μg/μL.

Composición fitoquímica de extractos de Salvia hispánica L. Y su efecto de saciedad

A phytochemical study of the hexane, ethyl acetate and methanolic extracts of chia (Salvia hispanica L.) seeds was conducted. The effect of chia seeds aqueous extract on the weight gain of Wistar rats was also analyzed. The methanolic extract of the aerial part of the plant showed 268 fold more total flavonoids (268 ± 6 mEQ) compared to the chia seeds extract (1 pm 0.2 mEQ). However, the antioxidant capacity of the methanolic extract of the aerial part of the plant was low (2.0 ± 0.1 TEAC) compared to those reported for other plant extracts. Also, no toxicity was observed in A. Salina larvae for all the analyzed extracts. On the other hand, there were no significant differences (p > 0.05) of weight between rats that consumed the aqueous extract of chia seeds and the control group that consumed water. There were also no changes in the consumption of food and liquids indicating that chia seeds aqueous extract did not produce the satiety effect that has been attributed to the seeds in other studies.

Screening of Lichen Extracts Using Tyrosinase Inhibition and Toxicity Against Artemia salina

Nine lichen extracts were evaluated for tyrosinase inhibition and toxicity against Artemia salina larvae. Extract compositions were investigated by TLC and NMR analysis. The activity of constituents against tyrosinase was evaluated by bioautography, and the percent of inhibition was calculated based on the dopachrome produced during a set time interval. Cladia aggregata , Cladonia dimorphoclada , Stereocaulon ramulosum and Stereocaulon microcarpum extracts were active for tyrosinase inhibition. Barbatic, usnic, anziaic acids and an unidentified compound present in the extracts, are possibly responsible for tyrosinase inhibition. Cladia aggregata, Cladonia crispatula , Cladonia furcata , Lobaria erosa , Punctelia canaliculata and S. microcarpum proved to be less toxic to A. salina (LC 50 > 500 mg/mL) than Cladonia confusa and S. ramulosum (LC 50 45.0 and 100.3 mg/mL, respectively), while the extract of C. dimorphoclada was highly toxic (LC 50 < 10 mg/mL). DOI: http://dx.doi.org/10.17807/orbital.v8i3.842

Phytotoxicity, cytotoxicity and antioxidant activity of the invasive shrub Austroeupatorium inulifolium (Kunth) R.M. King &amp; H. Rob

Methanol and dichloromethane extracts of root, stem, leaves and flowers of invasive plant Austroeupatorium inulifolium were tested for cytotoxic, phytotoxic, antioxidant and antifungal activities. Significantly higher phytotoxicity was detected in methanol extracts of leaves and dichloromethane extracts of roots. This effect was most pronounced against amaranth seeds where the seed germination was reduced to 3.74 % with the addition of methanol extracts of leaves at 3000 mg/L. The dichloromethane extract of roots of A. inulifolium showed potent antifungal activity against Cladosporium cladosporioides. Cytotoxic activity was found in dichloromethane extract of roots (LD50 = 27.91 ± 8.55 mg/L), methanol extract of flowers (LD50 = 15.22±7.89 mg/L) and leaves (LD50 = 22.92±11.76 mg/L) against Artemia salina (brine shrimp) larvae. The results also revealed significant antioxidant activity in methanol extract of leaves (IC50 =33.66± 0.03 mg/L) against the reference α-tocopherol (IC50 =10.02 ± 0.01 mg/L).

Potensi Antelmintika Ekstrak Bakteri Simbion Spons Laut Terhadap Trichostrongylidae (Nematoda) Parasit Domba

Trichostrongylidae (nematodes) parasitic infection of sheep were recently resistance to anthelmintics. Bioactive utilization of bacteria derived sponges had potential as anthelmintics alternative naturally against trichostrongylidae parasitic infections. The Aims of this study was to determine the activity of bacteria derived sponge extracts which produced anthelmintics bioactive compounds against sheep trichostrongylidae parasite. Bacteria derived sponges isolates which labeled S1 and S2 were extracted by methanol. Phytochemical test were conducted to determined characterization of bioactive compounds which potentially to inhibit larvae migration. Concentration which used to Larva Migration Inhibition Assay (LMIA) were 25, 50, 100, 250, and 500 µg/ml. Positive control treatment was used albendazole while negative control by physiological of NaCl. Both of extracts were contained toxicity to againts Artemia salina larvae which <1000 µg/ml concentration. The higher concentration of S1 and S2 extracts were affected to increase larvae migration. Both of extracts were potential to inhibit larvae migration which LC50 value were 165.63 µg/ml (S1) and 374.9 µg/ml (S2). The ability of extracts which inhibit larvae migration caused by bioactive compounds which contained triterpenoids in both of extracts then flavonoid compounds only by S1. Albendazole was showed a highest inhibitory activity which contained 95.5% of the total test nematode larvae.

Antinociceptive effects of the aqueous and methanol extracts of the leaves of Pittosporum mannii Hook. F. (Pittosporaceae) in mice

Ethnopharmacological relevancePittosporum mannii (Pittosporaceae) is used in Africa traditional medicine to treat various ailments including pain and inflammation. Aim of the studyThe present work was undertaken to evaluate the antinociceptive effects of the aqueous (AEPM) and methanol (MEPM) extracts from the leaves of Pittosporum mannii. MethodsHigh performance liquid chromatography coupled with mass spectrometry (LCMS) was used for the phytochemical analysis of AEPM prepared as decoction and MEPM prepared as cold maceration. The in vitro cytotoxicity of AEPM and MEPM were evaluated on Artemia salina larvae. AEPM and MEPM antinociceptive effects were evaluated at the doses of 35, 75, 150 and 300mg/kg given orally, against pain induced by acetic acid, formalin, hot plate, capsaicin and glutamate. The rota rod test was also performed at the same doses. To determine the mechanism of action of these extracts, their antinociceptive effects were tested in animals pretreated with yohimbine (α2-adrenergic antagonist), atropine (muscarinic antagonist) or naloxone (an opioids antagonist). ResultThe LCMS analysis showed that both extracts contain pittovidoside and 1-O-rhamnopyranosyl-23-acetoxyimberbic acid 29-methyl ester, the aqueous extract being more concentrated. Oral administration of both extracts significantly reduced pain symptoms induced by acetic acid, formalin, capsaicin, glutamate and hot plate. The antinociceptive effect of AEPM was significantly inhibited by yohimbine, atropine and naloxone while these inhibitors tend to potentiate the activity of MEPM. Both extracts have no effect on Rota rod test. AEPM and MEPM showed respective LC50 of 2.44 and 0.70mg/ml on Artemia larvae and were therefore, considered non-toxic. ConclusionThese results indicate that AEPM and MEPM possesses analgesic effects with different mechanism of action. Although effects of both extracts may involve TRPV1 receptors and glutamatergic pathway, AEPM may in addition, interact with alpha-adrenergic, muscarinic and opioidergic pathways that are not involve in the effects of MEPM.

Composição química e toxicidade frente Aedes aegypti L. e Artemia salina Leach do óleo essencial das folhas de Myrcia sylvatica (G. Mey.) DC.

RESUMO A dengue está entre as doenças virais de propagação vetorial mais importante no mundo, causando sérios impactos de morbidade e mortalidade. Desta forma, o presente trabalho teve como objetivo analisar a composição química e a toxicidade do óleo essencial de Myrcia sylvatica (G. Mey) D.C. frente Aedes aegypti e Artemia salina. Folhas de M. sylvatica foram coletadas no Parque Nacional da Chapada das Mesas, no município de Carolina (MA) no mês de fevereiro de 2012. O óleo foi obtido por hidrodestilação e sua composição química foi determinada por cromatografia gasosa acoplada à espectrometria de massa (CG/EM). O bioensaio frente Artemia salina e às larvas de 3° estádio de Aedes aegypti foram realizados em diferentes concentrações. Os dados de mortalidade foram avaliados por regressão linear para determinar os valores de CL50. Obteve-se 0,5% de rendimento, sendo o (E)-cariofileno o constituinte majoritário. O óleo essencial apresentou uma CL50 = 79,44 µg/mL frente A. salina, sendo considerado altamente tóxico. No entanto, este óleo não demonstrou efeito sobre as larvas de A. aegypti. Considerando que o teste de Artemia salina tem correlação com atividades biológicas de grande interesse terapêutico como antitumoral, o óleo essencial das folhas de M. sylvatica demonstrou potencial para desenvolvimento de produtos farmacêuticos.

Artemia salina as a new index for assessment of acute cytotoxicity during co-composting of sewage sludge and lignocellulose waste

Considering the necessity to constantly monitor the safety of use of sewage sludge, we have focused on evaluating the toxicity of raw sludge and sludge treated by co-composting with date palm waste using an in vitro assessment of cytotoxicity based on Artemia salina larvae as a simple new sensitive and reliable routine test. The efficiency of co-composting in decreasing sludge toxicity was evaluated in terms of cytotoxicity abatement reaching 100% by the second month of composting for mixture A (1/3 sludge+2/3 date palm waste) and the third month for mixture B (1/2 sludge+1/2 date palm waste). Cytotoxicity abatement was confirmed by the increase of germination index, which reached over 100% with positive correlation for lettuce (R2=0.81 and 0.86) and for turnip (R2=0.87 and 0.74) for mixtures A and B respectively. A strong correlation between the proposed cytotoxicity test and the evolution of regulatory physical–chemical approaches was found, (R2=0.88 and 0.89) for NH4+/NO3− and (R2=0.80 and 0.88) for C/N respectively for mixture A and B. These findings allow the inexpensive bioassay reported to be used as a highly sensitive test to determine the cytotoxicity and maturity of composts.

Acute Toxicity (LD50) Studies Using Swiss Albino Mice and Brine Shrimp Lethality (LC50 and LC90) Determination of the Ethanol Extract of Stem Bark of Echinaceae angustifolia DC

The ethanol extract of Echinaceae angustifolia DC was tested for acute toxicity (LD50) using Swiss Albino Mice and was screened for Brine Shrimp lethality using Artemia salina larvae. The results showed that the plant was toxic to the mice at even a lower concentration (300 mg/Kg) and caused death at a concentration of 500 mg/Kg body weight of the live mice. The LD50 was found to be 3,807.89 mg/Kg. The result of the Brine Shrimp lethality showed that the extract was toxic to the naupli with an LC50 and LC90 values of 125.89 μg/mL and 794.33 μg/mL respectively.

Insecticidal Activity of Ethyl Acetate Extracts from Culture Filtrates of Mangrove Fungal Endophytes

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration (LC50) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.

Assessment of toxicity of Moringa oleifera flower extract to Biomphalaria glabrata, Schistosoma mansoni and Artemia salina

This study reports the effect of an aqueous extract from Moringa oleifera Lam. flowers on Biomphalaria glabrata embryos and adults and on Schistosoma mansoni adult worms. The extract contains tannins, saponins, flavones, flavonols, xanthones, and trypsin inhibitor activity. The toxicity of the extract on Artemia salina larvae was also investigated to determine the safety of its use for schistosomiasis control. After incubation for 24h, the flower extract significantly (p<0.05) delayed the development of B. glabrata embryos and promoted mortality of adult snails (LC50: 2.37±0.5mgmL−1). Furthermore, treatment with the extract disrupted the development of embryos generated by snails, with most of them remaining in the blastula stage while control embryos were already in the gastrula stage. Flower extract killed A. salina larvae with a LC50 value (0.2±0.015mgmL−1) lower than that determined for snails. A small reduction (17%) in molluscicidal activity was detected when flower extract (2.37mgmL−1) was exposed to tropical environmental conditions (UVI index ranging from 1 to 14, temperature from 25 to 30°C, and 65% relative humidity). Toxicity to A. salina was also reduced (LC50 value of 0.28±0.01mgmL−1). In conclusion, M. oleifera flower extract had deleterious effects on B. glabrata adults and embryos. However, unrestricted use to control schistosomiasis should be avoided due to the toxicity of this extract on A. salina.

High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae

We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated. These nanomaterials were ingested and concentrated in the gut, and attached onto the body surface of the A. salina larvae. This attachment was responsible for concentration–dependent inhibition of larval swimming, and partly for alterations in the enzyme activities, that differed according to the type of tested nanomaterials. No lethal effects were observed up to 0.5mg/mL carbon black and 0.1mg/mL multiwall carbon nanotubes, while graphene oxide showed a threshold whereby it had no effects at 0.6mg/mL, and more than 90% mortality at 0.7mg/mL. Risk quotients calculated on the basis of predicted environmental concentrations indicate that carbon black and multiwall carbon nanotubes currently do not pose a serious risk to the marine environment, however if uncontrolled release of nanomaterials continues, this scenario can rapidly change.

Phytochemical Analysis and Biological Activities of Cola nitida Bark.

Kola nut is chewed in many West African cultures and is used ceremonially. The aim of this study is to investigate some biological effects of Cola nitida's bark after phytochemical screening. The bark was collected, dried, and then powdered for the phytochemical screening and extractions. Ethanol and ethyl acetate extracts of C. nitida were used in this study. The antibacterial activity was tested on ten reference strains and 28 meat isolated Staphylococcus strains by disc diffusion method. The antifungal activity of three fungal strains was determined on the Potato-Dextrose Agar medium mixed with the appropriate extract. The antioxidant activity was determined by DPPH and ABTS methods. Our data revealed the presence of various potent phytochemicals. For the reference and meat isolated strains, the inhibitory diameter zone was from 17.5 ± 0.7 mm (C. albicans) to 9.5 ± 0.7 mm (P. vulgaris). The MIC ranged from 0.312 mg/mL to 5.000 mg/mL and the MBC from 0.625 mg/mL to >20 mg/mL. The highest antifungal activity was observed with F. verticillioides and the lowest one with P. citrinum. The two extracts have an excellent reducing free radical activity. The killing effect of A. salina larvae was perceptible at 1.04 mg/mL. The purified extracts of Cola nitida's bark can be used to hold meat products and also like phytomedicine.

Toxicity Effect of Copper oxide Nanoparticles onArtemia salina

We evaluated the stability of CuO NPs, and the toxic effects of their suspensions to Artemia salina (A. salina) larvae to elucidate the chemical and toxicological impact to marine micro-organisms. The results pointed to the fact that suspensions of CuO NPs were not acutely toxic to Artemia at environmentally feasible levels. However, prolonged exposure to the same suspensions induced significant toxicity. The results revealed that CuO NPs aggregate in seawater to micrometer particles. This process would ultimately reduce the toxic properties of the NPs. Nevertheless, CuO NPs showed differences in toxic effects depending on the concentration of nanoparticles. In future studies more attention should be given to the formulations of CuO NPs to better understand their toxicological properties since both surface properties and ion release kinetics change with underlying manufacturing processes. The exposure of these A. salina larvae to the selected MO-NPs did not induce significant mortality, although the NPs accumulated in the gut. However, behavioral and chemical analysis occurred after the exposure. The swimming speed alterations represent valid endpoints for CuO NP exposure.