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Microplastic (MP) environmental contamination has been widely studied in Mexico. However, the evaluation of the associated risk to MPs in environmental compartments is scarce. Therefore, this study addresses this issue using diverse indicators such as the Pollution Load Index (PLI), the Polymer Risk Index (PRI), and the Potential Ecological Risk Index (PERI). The results of a meta-analysis revealed high MP contamination levels in most of the studied compartments, which included marine and estuarine waters, beach sand, freshwater, sediments, and biota. Regarding the risk assessment indicators, PLIs indicated low (56%), dangerous (22%), moderate (12%), and high (10%) levels across compartments. Meanwhile, PRIs displayed concerning values, with 36%, 35%, 20%, and 9% exhibiting dangerous, high, moderate, and low levels, respectively. Thus, high PRI values emphasized the significant rise in MP pollution, largely attributed to high-hazard polymer compositions. Otherwise, PERIs showed low (56%), very dangerous (29%), moderate (6%), high (5%), and dangerous (4%) levels. Thus, the ecological risk in Mexico is widespread and mainly linked to MP abundance, polymer type, environmental matrix, and characteristics of organisms. This study represents the first attempt at MP ecological risk assessment in Mexico, providing crucial insights for developing mitigation strategies to address concerns about MP contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Researchers in the Global South (GS, developing countries) make valuable contributions to the field of comparative physiology, but face economic and scientific disparities and several unique challenges compared with colleagues in the Global North (developed countries). This Perspective highlights some of the challenges, knowledge gaps and disparities in opportunity faced by GS researchers, especially those at early-career stages. We propose collaborative solutions to help address these issues, and advocate for promoting investment and cultural and societal change for a more inclusive research community. Additionally, we highlight the role of GS researchers in contributing expert knowledge on local biodiversity and the environment; this knowledge can help to shape the future of comparative physiology, allowing us to achieve a better understanding of the evolution of physiological mechanisms and to develop innovative solutions to environmental and biomedical challenges. With this Perspective, we hope to highlight the need to foster a more diverse, equitable and inclusive research landscape in comparative physiology; one that empowers GS scientists to address the global challenges associated with biodiversity loss, climate change and environmental pollution., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Imidacloprid is a neonicotinoid insecticide that has received particular attention due to its widespread use and potential adverse effects for aquatic and terrestrial ecosystems. Its toxicity to aquatic organisms has been evaluated in central and southern Europe as well as in (sub-)tropical regions of Africa and Asia, showing high toxic potential for some aquatic insects and zooplankton taxa. However, its toxicity to aquatic organisms representative of tropical regions of Latin America has never been evaluated. To fill this knowledge gap, we carried out a mesocosm experiment to assess the short- and long-term effects of imidacloprid on freshwater invertebrate communities representative of the Ecuadorian Amazon. A mesocosm experiment was conducted with five weekly applications of imidacloprid at four nominal concentrations (0.01 μg/L, 0.1 μg/L, 1 μg/L and 10 μg/L). Toxic effects were evaluated on zooplankton and macroinvertebrate populations and communities, as well as on water quality parameters for 70 days. Given the climatic conditions prevailing in the study area, characterized by a high solar radiation and abundant rainfall that resulted in mesocosm overflow, there was a rapid dissipation of the test compound from the water column (half-life: 4 days). The macroinvertebrate taxa Callibaetis pictus (Ephemeroptera), Chironomus sp. (Diptera), and the zooplankton taxon Macrocyclops sp., showed population declines caused by the imidacloprid treatment, with a 21-d Time Weighted Average No Observed Effect Concentrations (21-d TWA NOEC) of 0.46 μg/L, except for C. pictus which presented a 21-d TWA NOEC of 0.05 μg/L. In general terms, the sensitivity of these taxa to imidacloprid was greater than that reported for surrogate taxa in temperate zones and similar to that reported in other (sub-)tropical regions. These results confirm the high sensitivity of tropical aquatic invertebrates to this compound and suggest the need to establish regulations for the control of imidacloprid contamination in Amazonian freshwater ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We use the sentinel mangrove crab, Minuca rapax, as a model to investigate the effects of metallic settleable particulate matter (SePM) on wetland. Multiple levels of energetic responses, including (i) metabolic rate and energy budget, (ii) oxidative stress, and (iii) behavioral response by righting time, were assessed as well as the metal and metalloid content in crabs exposed to 0, 0.1 and 1 g.L -1 of SePM, under emerged and submerged conditions over five days, simulating the rigors of the intertidal habitat. Al, Fe, Mn, Cr, and Y exhibited a concentration-dependent increase. Metal concentrations were higher in submerged crabs due to the continuous ingestion of SePM and direct exposure through gills. Exposure concentration up to 1 g.L -1 decreased metabolic rate and enzymatic activities, reduced assimilation efficiency and energy for maintenance, and induces a slower response to righting time, probably by metal effects on nervous system and energy deficits. In conclusion, SePM exposure affects the redox status and physiology of M. rapax depending on he submersion regime and SePM concentration. The disruption to the energy budget and the lethargic behavior in M. rapax exposed to SePM implies potential ecological alterations in the mangrove ecosystem with unknown consequences for the local population., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Ecuador's wetlands and aquatic ecosystems are chronically exposed to ash contamination due to the frequent volcanoes' eruptions in the country. Still, the short and long-term effects of ash contamination on the aquatic biota are not well understood. We used ashes released by the Cotopaxi volcano in 2016 to investigate their acute and chronic effects in Daphna magna. We calculated the half maximal effective concentration (EC 50 ) after 2 and 21 days of exposure, the non-observed effect concentration (NOEC), and the lowest observed effect concentration (LOEC) on offspring production. We also analyzed the metal concentration present in the ashes. The EC 50 values at 2 and 21 days were found at 80% and 5% ash leachate concentrations, respectively. After 21 days of exposure, high mortality and low neonatal production were observed in all leachate concentrations (NOEC was at 15%, and LOEC was at 20% leachate concentration). Our results suggest that the ashes from the Cotopaxi volcano can cause acute and chronic toxicity to aquatic life and should be classified as hazardous waste, depending on the dose. There is an urgent need for further studies that assess toxicity caused by the intense volcanic activity in Ecuador., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

We investigated the distribution and effects of waterborne microplastic (MP) (polyethylene microspheres, 53-63 um) on the emergent model for ecotoxicology, the amphipod Parhyale hawaiensis, during 30 days of exposure. The following life-history traits were measured: (1) survival, (2) specific growth rate (SGR), (3) reproductive performance (precopulatory pairing behavior, fecundity, and time to release neonates), (4) molting frequency, (5) F1 newborn offspring survival and (6) MP bioaccumulation. No significant mortality or molt was seen in any of the treatments. MP caused a reduction in SGR, being more pronounced in females. The time for precopulatory pairing was 3-fold longer in amphipods exposed to MP. Fecundity decreased by 50 %, and the time to release juveniles was 6.7 days longer for amphipods exposed to MP. Finally, neonate survival decreased by 80 % after ten days of release. MP disrupts the reproductive mechanisms and triggers adverse effects on life history traits in P. hawaiensis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We exposed adult individuals of the sentinel mangrove crab Minuca rapax to waterborne microplastics (MP; 53-63 μm polyethylene spheres) in a long-term experiment (56 days). Weassessed 1) MP effects on growth, survival, and food intake. and 2) the MP tissue acumulation and its reduction of body burden through feces and molting. MP exposure did not affect growth and survival. The hepatopancreas accumulated more MP than the gills and muscle. Most of the ingested MP particles were released in the feces and molts, indicating a rapid passage through the digestive tract. MP impaired food intake of M. rapax, with unknown consequences to the local populations. These results provide insights on MP translocation mechanisms, its elimination and toxicity associated with MP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Environmental stressors in aquatic organisms can be assessed using a bioenergetic approach based on the evaluation of changes in their physiological parameters. We evaluated the chronic effects of cadmium (Cd 2+ ) on the energy balance as well as the survival, growth, metabolism, nitrogen excretion, hepatosomatic index, oxidized energy substrate, and osmoregulation of the shrimp Penaeus vannamei with the hypothesis that the high energy demand related to the homeostatic regulation of Cd 2+ could disrupt the energy balance and as a consequence, their physiological functions. The shrimp exposed to Cd 2+ had higher mortality (30%), directed more energy into growth (33% of energy intake), ingested 10% more energy, and defecated less than control animals. Cd 2+ exposure caused a tendency to decrease metabolism and ammonia excretion but did not alter the hepatosomatic index, type of energy substrate oxidized, and the hyperosmorregulatory pattern of the species. The Cd +2 exposure may have induced a trade-off response because there was a growth rate increase accompanied by increased mortality., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Ecotoxicological tools, namely biomarkers and bioassays, may provide insights on the ecological quality status of mangroves under restoration. We investigated how 1) physicochemical parameters and water bioassays using Artemia franciscana; and 2) quantification of sublethal (osmoregulatory capacity, biochemical, and oxidative stress) and individual biomarkers (density, length-weight relationship [LWR], parasitic prevalence) in the sentinel fiddler crab Minuca rapax, can improve restoration indicators in mangroves from the Yucatán Peninsula, Southern Gulf of Mexico. We showed that water quality was improved with restoration, but still presented toxicity. Regarding sublethal biomarkers, M rapax from restored areas lower osmotic regulatory capacity, higher oxidative stress, and showed lipid peroxidation. As to the individual biomarkers, the density, LWR, and the prevalence of parasites in M. rapax was higher in restored areas. The use of bioassays/biomarkers were useful as early warning indicators to better assess the health of mangroves under restoration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We assessed the tolerance, safety margins, and behavioral responses to extreme conditions of the mangrove fiddler crab Leptuca speciosa during a heatwave event (May of 2022), in the Yucatán Peninsula, Mexico. In the field, L. speciosa demonstrated aggregation behavior, congregating in areas that were above the water level to escape the extreme water conditions. In the laboratory, we determined that the upper critical thermal limits (UT 99 ) ranged from 40.2 °C and 42 °C. For salinity, the lethal concentration was LC 99  = 39 psu. Our study showed that L. speciosa, one of the most conspicuous and resilient inhabitants of mangroves, had no safety margin and low tolerance to the climatic conditions as measured in the heatwave, and displayed a protective behavior. Considering that the frequency and intensity of heatwaves have been predicted to increase in the next few years, the combined multiple stressors effect may increase the vulnerability of mangrove organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microplastics (MP) are vectors for other environmental contaminants, such as metals, being a considerable problem, especially in the aquatic ecosystem. To investigate the combined effects of MP (high density polyethylene) with lead (Pb), we exposed the mangrove fiddler crab Minuca vocator to Pb (50 mg L -1 ), and MP (25 mg L -1 ) alone and in mixture, for 5 days. We aimed to determine Pb and MP bioaccumulation, as well as physiological (oxygen consumption and hemolymph osmolality) and biochemical (superoxide dismutase, catalase, glutathione peroxidase, and lipid peroxidation) traits effects. Co-exposure of MP and Pb significantly increased the bioaccumulation of Pb, but reduced MP tissue accumulation. Regarding the physiological traits, increasing osmolality and oxygen consumption rates compared to the control were observed, particularly in the combined Pb and MP exposure. As to biochemical traits, the combination of Pb and MP induced the most significant responses in the enzymatic profile antioxidant enzyme activity. The catalase (CAT), glutathione peroxidase (GPx), and dismutase superoxide (SOD) decreased compared to individual exposure effects; the combination of MP and Pb had a synergistic effect on promoting lipid peroxidation (LPO). The co-exposure of MP and Pb acted synergistically when compared to the effects of the isolated compounds. Due to the increasing MP contamination in mangroves, more severe physiological and biochemical effects can be expected on mangrove crabs exposed to metal contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The escalating global concern on phthalate esters (PAEs) stems from their status as emerging contaminants, marked by their toxicity and their potential to harm both the environment and human health. Consequently, this study aimed to evaluate the occurrence, spatial distribution, and ecological and health risks associated with PAEs in the Atoyac River, an urban waterway in central Mexico that receives untreated and poorly treated urban and industrial wastewater. Of the 14 PAEs analyzed in surface water samples collected along the river mainstream, nine were detected and quantified by GC-MS. The concentration of each detected PAE ranged from non-detected values to 25.7 μg L -1 . Di (2-ethylhexyl) phthalate (DEHP) and di-n-hexyl phthalate (DnHP) were detected in all sampling sites, with concentrations ranging from 8.1 to 19.4 μg L -1 and from 6.3 to 15.6 μg L -1 , respectively. The cumulative Σ 9 PAEs concentrations reached up to 81.1 μg L -1 and 96.0 μg L -1 in sites downstream to high-tech industrial parks, pinpointing industrial wastewater as the primary source of PAEs. Given that the river water is stored in a reservoir and used for cropland irrigation, this study also assessed the ecological and human health risks posed by PAEs. The findings disclosed a high ecological risk to aquatic organisms exposed to di-n-octyl phthalate (DOP), dicyclohexyl phthalate (DCHP), benzyl butyl phthalate (BBP), DEHP, and DnHP. Additionally, a high carcinogenic (CR > 10 -4 ) and noncarcinogenic (HQ > 10) risk for the DEHP exposure through ingestion of crops irrigated with river water was identified for both children and adults. These data on PAEs provide valuable insights for the Mexican government's future strategies in regulating these pollutants in water bodies, thereby minimizing the environmental and human health risks that they pose., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

To assess "bottom-up" to "top-down" trophic transfer, we analyze As, Cd, Co, Cr, Cu, Hg, Ni, Se, Zn, Fe, and Mn from two sediment chemical fractions (exchangeable and organic-bound), red mangrove (Rhizophora mangle) leaves, and fiddler crab (M. rapax) soft tissues from Isla del Carmen, Yucatán Peninsula. Both mechanisms were observed indictive that R. mangle and M. rapax indeed bioaccumulated the toxic elements from the different matrices with the latter being a macro-concentrator only for Cu and Zn. Although the modified Geo-accumulation factor (combined exchangeable and organic matter fractions) suggested that the studied sites are practically "uncontaminated", Hg is the only toxic element to be having a "moderately to strongly" impact. Data shows how M. rapax had progressively bioaccumulated Hg, but no biomagnification could be corroborated given that the fiddler crab behaved as a de-concentrator., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Metal contamination associated with mining activities has been considered one of the main environmental pollution problems in the Amazon region. Understanding the levels of metal contamination from mining activities requires a good understanding of background metal concentrations, which may vary notably according to the geology/lithology characteristics of the region, soil type, and predominant biogeochemical processes. This review assessed 50 papers and reports published between 1989 and 2020 describing environmental concentrations of different metals and metalloids (As, Hg, Mn, Fe, Cd, Cu, Cr, Pb, Ni, and Zn) in water and sediments of mining and non-mining areas in five geographic regions of the Amazon basin. Metal enrichment caused by mining activities was calculated and exposure concentrations were compared with sediment and water quality standards set for the protection of aquatic life. Significant enrichments of Cd, Cu, Cr, Fe, Hg, Mn, Ni and Zn were observed in mining areas in both sediment and water. Regarding background levels in the different geographic regions, the highest prevalence of metal enrichment (i.e., concentrations 10 to 100-fold higher than mean background values) in sediment samples was found for Fe (100% of samples), Ni (90%), and Mn (69%). For water, high prevalence of metal enrichment occurred for Zn, Mn, and Fe (100% of samples), and for Hg (86%). Hg, Fe, Pb, Cu, Cd, Ni and Zn exceeded water and/or sediment quality standards in a significant number of samples in the proximity of mining areas. This study indicates that mining activities significantly contribute to water and sediment contamination across the Amazon basin, posing hazards for freshwater ecosystems and potentially having human health implications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The Ecuadorian Amazon has experienced a significant land use change due to the demographic increase and the expansion of the agricultural frontier. Such changes in land use have been associated to water pollution problems, including the emission of untreated urban wastewater and pesticides. Here we provide the first report on the influence of urbanization and intensive agriculture expansion on water quality parameters, pesticide contamination and the ecological status of Amazonian freshwater ecosystems of Ecuador. We monitored 19 water quality parameters, 27 pesticides, and the macroinvertebrate community in 40 sampling locations of the Napo River basin (northern Ecuador), including a nature conservation reserve and sites in areas influenced by African palm oil production, corn production and urbanization. The ecological risks of pesticides were assessed using a probabilistic approach based on species sensitivity distributions. The results of our study show that urban areas and areas dominated by African palm oil production have a significant influence on water quality parameters, affecting macroinvertebrate communities and biomonitoring indices. Pesticide residues were detected in all sampling sites, with carbendazim, azoxystrobin, diazinon, propiconazole and imidacloprid showing the largest prevalence (>80% of the samples). We found a significant effect of land use on water pesticide contamination, with residues of organophosphate insecticides correlating with African palm oil production and some fungicides with urban areas. The pesticide risk assessment indicated organophosphate insecticides (ethion, chlorpyrifos, azinphos-methyl, profenofos and prothiophos) and imidacloprid as the compounds posing the largest ecotoxicological hazard, with pesticide mixtures potentially affecting up to 26-29% of aquatic species. Ecological risks of organophosphate insecticides were more likely to occur in rivers surrounded by African palm oil plantations, while imidacloprid risks were identified in corn crop areas as well as in natural areas. Future investigations are needed to clarify the sources of imidacloprid contamination and to assess its effects for Amazonian freshwater ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Mining areas may suffer long-term metal contamination and represent harmful remnants of former mining activities. In the northern Amazon of Ecuador, former mining waste pits are used in Oreochromis niloticus (Nile tilapia) fish farming. Given the high consumption of this species by the local population, we aimed to estimate human consumption risks by determining Cd, Cu, Cr, Pb, and Zn tissue bioaccumulation (liver, gills, and muscle) and genotoxicity (micronucleus essay) in tilapia cultivated in one former mining waste pit (S3) and compare the findings to tilapias reared in two non-mining areas (S1 and S2); 15 fish total. Tissue metal content was not significantly higher in S3 than in non-mining areas. Cu and Cd were higher in the gills of tilapias from S1 compared to the other study sites. Higher Cd and Zn were detected in the liver of tilapias from S1 compared to the other sampling sites. Cu was higher in the liver of fish from S1 and S2, and Cr, in the gills of fish from S1. The highest frequency of nuclear abnormalities was observed in fish from S3, indicating chronic exposure to metals at this sampling site. The consumption of fish reared at the three sampling sites results in a 200-fold higher Pb and Cd ingestion than their maximum tolerable intake thresholds. Calculated estimated weekly intakes (EWI), hazard quotients (THQ), and Carcinogenic Slope Factors (CSF ing ) denote potential human health risks, indicating the need for continuous monitoring in this area to ensure food safety not only in areas affected by mining, but in general farms in the region., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

The effects of salinity on the accumulation and toxicity of microplastics (MPs) in mangrove invertebrates are still scarcely described. We assessed the accumulation and osmoregulatory toxicity of the estuarine fiddler crab Minuca rapax, exposed to 25 mg L -1 of high-density polyethylene MPs at three combinations of osmotic media (hypo- 6, iso- 25, or hyper-35 psu), in 1, 3 and 5 days of exposure. Gills accumulated more MPs than the digestive tract (DT) and muscle. MP accumulation in the gills and DT was enhanced at 6 psu and reduced at 21 and 35 psu after 1 day of exposure. Muscle MP accumulation was not affected by salinity or exposure time. Osmotic regulation was unaffected by MP exposure in any exposure time. Our findings demonstrate that M. rapax accumulates MPs in gills and DT depending on the salinity and that MPs are not osmoregulatory toxicant for this species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Gold mining (GM) is a major source of metals and metalloids in rivers, causing severe environmental pollution and increasing the exposure risks to the residents of surrounding areas. Mining in Ecuadorian Amazonia has dramatically increased in recent years, but its impacts on Indigenous local populations that make use of rivers are still unknown. The aim of this study was to assess the risks to adults and children caused by the exposure to metals and metalloids in freshwater ecosystems contaminated with tailings released by GM activities in 11 sites of the upper Napo River basin, Ecuador. We selected a carcinogenic and a noncarcinogenic risk assessment method to estimate the hazard index (HI) and total cancer risk (TCR). The concentration of Ag, Al, As, Cd, Cu, Fe, Mn, Pb, Zn, B, and V in water and sediment samples was considered to assess the risks to human health. The calculated HI was 23-352 times greater than the acceptable limits in all sites for both children and adults. Mn and Fe were the main contributors (75% in water and 99% in sediment) to the total calculated risk based on the HI. The calculated TCR for children and adults exceeded approximately one to three times the permissible threshold in all sites. As and Pb contributed up to 93% of the total calculated risk based on TCR for both children and adults. This study demonstrates that the emission and mobilization of metals and metalloids caused by mining activities increase the risk to human health, to which we recommend further monitoring of freshwater contamination in the area and the implementation of preventive health management measures. Integr Environ Assess Manag 2023;19:706-716. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)., (© 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).)

Despite the increasing plastic discharge into the environment, few articles have dealt with the macroecological implications of microplastics (MPs) bioaccumulation on organisms. We performed a meta-analysis of MPs accumulation in true crabs and pseudocrabs worldwide and made use of macroecotoxicological approaches to know if: I) functional traits influence the bioaccumulation of MPs in the tissues of crabs; II) there is a latitudinal pattern of MPs bioaccumulation; III) there are tissues that can accumulate more MPs; IV) crabs can sort particles according to size, color, shape and type. Our results showed that functional traits influence the accumulation of MPs. Smaller crabs in size and weight and with shorter lifespans tended to exhibit more plastic particles. According to the environment, estuarine crabs from the intertidal and muddy substrates held more MPs. Also, burrowers exhibited significantly more particles in the tissues than omnivorous crabs. Besides, we recorded that crabs from low latitudes tended to exhibit more plastic particles, probably because of the mangroves' location that acts as traps for MPs. Non-human-consumed crabs accumulated significantly more MPs than human-consumed ones. Considering the tissues, gills were prone to accumulate more debris than the digestive tract, but without significant differences. Finally, colorless fibers of 1-5 mm of PA, PP and PET were the predominant characteristics of MPs, suggesting that crabs accumulated denser types but did not sort plastic according to color. These results indicate that functional traits might influence the accumulation of MPs and that there are coastal regions and geographical areas where crabs tend to accumulate more MPs. Analyzing MPs accumulation patterns with macroecological tools can generate information to identify the most affected species and define priorities for monitoring and implementing actions toward reducing plastic use globally., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Organochlorine pesticides (OCPs) have been intensively used without proper regulation and control in Latin America due to the prevalence of diseases and pests, thus posing potential risks to nontarget organisms. Initiatives for ecosystem preservation, such as to designate protected areas, may not be enough to avoid contamination by OCPs, considering that protected areas tend to be permeable to diffuse sources. Here, we investigate multi-level responses of the oyster Crassostrea virginica to OCPs in Laguna de Términos, a RAMSAR coastal lagoon in the southern Gulf of Mexico. For this aim, OCPs occurrence and concentrations in the water, sediment, and in oysters from 3 settlement banks were assessed. Enzymatic and non-enzymatic biochemical biomarkers were quantified in the oysters' mantle and digestive gland, and the human health risk due to oyster consumption was also evaluated. OCPs in water were below detection limits. Fourteen OCPs were detected in sediments (∑OCPs mean of 49 ngg -1 ) and 7 in oyster tissues (∑OCPs mean of 121 ngg -1 ). The occurrence of OCPs was related to the land uses along the watersheds of the rivers that drain into the lagoon. Biochemical responses were correlated with OCPs (∑HCH, ∑DDT, heptachlor and endosulfan) in sediment, and oyster tissues. OCPs in oyster tissues showed a strong association with pro-oxidant forces and oxidative stress responses (Superoxide dismutase, Catalase, Glutathione Peroxidase, and lipid peroxidation), and neurotoxicity (Acetylcholinesterase), suggesting that the current OCPs contamination exerts significant stress. Our study also shows that the consumption of oysters from the lagoon increases the potential human health risk. Considering that Laguna de Términos is a protected Ramsar site, we suggest that environmental protection measures should be increased and that a monitoring program for OCPs exposure is necessary to assess the effects on this ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Emerging contaminants in water bodies is an issue of concern due to their impact on the ecosystem and human health. The COVID-19 pandemic has forced the implementation of protective measures such as social distancing, lockdowns, and remote work, which have affected the tourism influx. This study aimed to evaluate the occurrence of emerging pollutants in bodies of water in Esmeraldas, a coastal province of Ecuador, before and during the COVID-19 pandemic in a highly touristic region. For this purpose, surface waters from 14 beaches and ten river mouths were sampled at two-time points in November 2019 and November 2020. Compounds widely consumed in Ecuador: acetaminophen, caffeine, sodium diclofenac, trimethoprim, and sulfamethoxazole were extracted from water samples by solid phase extraction SPE and detected with a UPLC-QTOF-MS system. We found a decrease in the occurrence of caffeine from 100 % to 4.2 % of caffeine and 25 % to 0 % of diclofenac, likely related to the decline in tourist afflux due to the lockdown measures. Most of the compounds diminished in terms of frequency and/or concentration; however, as COVID-19 treatments make use of different pharmaceutical compounds such as antivirals, antibiotics, antiparasitics, or glucocorticoids, future studies should include these to assess their environmental impact., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The effects of emerging contaminants on environmental health are of high concern, especially those potentially induced by mixtures. We assessed single and composite mixtures of triclosan (T), 17β-estradiol (E2), sulfamethoxazole (SMX), and nicotine (N) at various concentrations, on neonates of Daphnia magna. When used in single exposure, T and N induced high toxicity (100% immobility, each one), compared to SMX and E2 (2.5% and 10% immobility, respectively). When T, E2, SMX and N were in mixture, T had the highest contribution to the overall toxicity in mixture exposures. The N toxicity lowered when in a fourfold exposure (85% immobility in fourfold exposure). Due to the high toxicity of T and N, both alone and in the mixtures, our results can serve as a warning about the use of these substances and their release in the aquatic ecosystem., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This review compiles the studies (2007-2021) regarding the occurrence of emerging organic contaminants (EOCs) and endocrine disruptors (EDs) in wastewater, surface water and groundwater in Mexico. A total of 174 compounds were detected, including pharmaceuticals, hormones, plasticizers, personal care products, sweeteners, drugs, and pesticides considered as EDs. The levels of EOCs and EDs varied from ng/L to 140 mg/L, depending on the compound, location, and compartment. Raw wastewater was the most studied matrix, showing a greater abundance and number of detected compounds. Nevertheless, surface waters showed high concentrations of bisphenol-A, butylbenzil-phthalate, triclosan, pentachlorophenol, and the hormones estrone, 17 α-ethinylestradiol, and 17 β-estradiol, which exceeded the thresholds set by international guidelines. Concentrations of 17 α-ethinylestradiol and triclosan exceeding the above-mentioned limits were reported in groundwater. Cropland irrigation with raw wastewater was the principal activity introducing EOCs and EDs into groundwater. The groundwater abundance of EOCs was considerably lesser than that of wastewater, highlighting the attenuation capacity of soils/aquifers during wastewater infiltration. However, carbamazepine and N,N-diethyl-meta-toluamide showed higher concentrations in groundwater than those in wastewater, suggesting their accumulation/concentration in soils/pore-waters. Although the contamination of water resources represents one of the most environmental concerns in Mexico, this review brings to light the lack of studies on the occurrence of EOCs in Mexican waters, which is important for public health policies and for developing legislations that incorporates EOCs as priority contaminants in national water quality guidelines. Consequently, the development of legislations will support regulatory compliance for wastewater and drinking water, reducing the human exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We assessed microplastics (MPs) contamination in water, sediments, and tissues (gills, digestive tract, and muscle) of two intertidal crab species with different ecological traits and commercial importance (Menippe mercenaria and Callinectes sapidus), from a coastal lagoon in the southeastern Gulf of Mexico. There were significant differences between MP abundances in the abiotic matrices and between crab species. The burrower, sedentary and carnivorous M. mercenaria bioaccumulates 50 % more MPs than the free-swimming, omnivorous C. sapidus. However, no differences were observed between species' tissues. Fragments were the predominant shape in the tissues of both species, with the exception in the digestive tract of M. mercenaria. We identified polyethylene, and polyethylene terephthalate in water samples and Silopren® in sediment. In both crab species, Silopren and polyethylene predominated. Differences in ecological traits resulted in different bioaccumulation patterns in intertidal crabs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that might influence the present study., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

We identified and characterized microplastics (MPs) in the gastrointestinal tract (GT), gills (GI), and exoskeleton (EX) of Litopenaeus vannamei in a coastal lagoon from the SE Gulf of California. The most common MPs were fibers and fragments with an average size of 403 ± 296 μm, in which the transparent and blue colors predominated. The abundance (items/g as wet weight (ww)) in the GT, GI, and EX was 114.7 ± 33.2, 13.7 ± 5.3 and 3.0 ± 0.5, respectively. The abundance of MPs per shrimp was 13.3 ± 1.1, while the abundance per individual (ww) was 0.9 ± 0.2 MPs/g. Considering the consumption of shrimp in Mexico, MP abundance, and shrimp consumption (discarding GI and EX), we estimated MP ingestion as 280 items/person/year. The results from this study can be used as background information for future MP biomonitoring in shrimp species of ecological and commercial importance., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Fiddler crabs are known as "eco-engineers" who maintain habitat health through sediment bioturbation. They regularly interact with microplastics (MPs) due to their contact with the sediment. In this study we compared MPs concentration between burrows and pellets resulting from bioturbation, and MPs bioaccumulation in the soft tissues of Minuca rapax (Smith, 1870), along a gradient of urbanization in Isla del Carmen, southern Gulf of Mexico. Overall, MPs shape and color in the pellets and in the tissues reflected those of the burrow's sediments. MPs were more abundant and diverse in burrows (9 ± 12 MPs.g -1 ) than in pellets (5 ± 5 MPs.g -1 ) or in the soft tissues (1.3 ± 1.2 MPs.g -1 ). Bioturbation can concentrate MPs in pellets and tissues, depending on the MPs contamination and urbanization level. M. rapax is an important structuring agent of sedimentary MPs, showing a strong top-down translocation of MPs in subtropical tidal flats., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

To comprehend mangrove crab responses to predicted global climate changes, we assessed submersion and desiccation survival durations and salinity tolerances and upper thermal limits in fiddler crabs from Isla del Carmen, Yucatán Peninsula. Based on their tolerances of extreme ambient conditions, we also calculated safety margins using abiotic monitoring data. The two most terrestrial species, Minuca rapax and Leptuca panacea, exhibited submersion tolerances of from 22 to 40 h, and desiccation tolerances of from 30 to 55 h; LC 50 's were ≈45‰S and UT 50 's were ≈40 °C. The two least terrestrial species, M. vocator and L. speciosa, were less tolerant of all experimental challenges, showing submersion and desiccation tolerances of <6 h, and LC 50 's of 36‰S and UT 50 's of 38 °C. While these fiddler crabs inhabit niches closer to their salinity and desiccation/submersion tolerances than to their temperature limits, all are clearly vulnerable to the multiple stressors that accompany anticipated global climate change., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Microplastic (MPs) contamination is ubiquitous in most terrestrial and aquatic ecosystems. Recently MPs have been reported at high altitudes which indicates that air masses can transport and deposit MPs in the surface snow of high mountain ecosystems, however, whether MPs typification and abundance can be influenced by direction and origin of air masses still remains an open question. Here we present the first report of MPs above 5000 m a.s.l from surface snow of a glacier in the tropical Andes. We collected surface snow along an elevational gradient, from 5000 to 5400 m a.s.l., in the Antisana Glacier, in the northern Andes cordillera of Ecuador to analyze MPs abundance and polymeric identification with the Fourier Transform Infrared (FTIR) and also to hypothesized the possible MPs sources in this remote area by comparing the oxygen and hydrogen stable isotopic ratio composition of the snow samples and by analyzing the wind direction. We observed an average of 131 ± 24 MPs L -1 in our samples. Fibers corresponded to 70% of all MP shapes; FTIR results showed that MPs composition mainly included polyurethane, polyethylene, polyamide, polyester, and high-density polyethylene in surface snow. There were no statistically significant differences of MPs abundance among sampled elevations, and the isotopic ratio composition did not differ among locations. Our results suggest that MP that accumulated in the glacier may be transported from the east, across the Amazonia, by the prevalent eastward air flow. The absence of industrial cities at least 2000 km further east from Antisana, indicates that the remote Andean glaciers could constitute important depositional zones for long-distance transported contaminants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study represents the first assessment of microplastic (MP) contamination in the coastal area of the Esmeraldas Province, Ecuador. MPs were quantified in 14 coastal waters in beaches with different urbanization level and in 10 rivers. The most abundant MP types were transparent fibres, brown fragments, grey fragments, transparent fragments, and black fragments, which together represented 84% of the total count. Coastal waters presented significantly higher quantities of MP than rivers. No difference in microplastic abundance was detected between beaches with higher and lower urban occupation, nor between beaches facing North or West. Our results indicate that MP contamination is widespread, and most likely transported from multiple sources. Our results can serve as a baseline for future MP monitoring in the area., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Several methoxybenzo[ h ]quinoline-3-carbonitrile analogs were designed and synthesized in a repositioning approach to developing compounds with anti-prostate cancer and anti-Chagas disease properties. The compounds were synthesized through a sequential multicomponent reaction of aromatic aldehydes, malononitrile, and 1-tetralone in the presence of ammonium acetate and acetic acid (catalytic). The effect of the one-pot method on the generation of the target product has been studied. The compounds were in vitro screened against bloodstream trypomastigotes of T. cruzi (NINOA and INC-5 strains) and were most effective at showing a better activity profile than nifurtimox and benznidazole (reference drugs). A study in silico on absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox) profiling to help describe the molecular properties related to the pharmacokinetic aspects in the human body of these compounds was reported. In addition, X-ray data for the compound 2-Amino-5,6-dihydro-4-(3-hydroxy-4-methoxy-phenyl)-8-methoxybenzo[ h ]quinoline-3-carbonitrile 6 was being reported. Spectral (IR, NMR, and elemental analyses) data on all final compounds were consistent with the proposed structures.

Degradation of freshwater ecosystems by uncontrolled human activities is a growing concern in the tropics. In this regard, we aimed at testing an integrative framework based on the IFEQ index to assess freshwater ecosystem health of river basins impacted by intense livestock and agricultural activities, using the Muchacho River Basin (MRB) as a case study. The IFEQ combine multiple lines of evidence such as riverine hydromorphological analysis (LOE 1), physicochemical characterization using ions and pesticides (LOE 2), aquatic macroinvertebrate monitoring (LOE 3), and phytotoxicological essays with L. sativa (LOE 4). Overall, results showed an important reduction in streamflow and an elevated increase in ion concentrations along the MRB caused by deforestation and erosion linked to agricultural and livestock activities. Impacts of the high ion concentrations were evidenced in macroinvertebrate communities as pollution-tolerant families, associated with high conductivity levels, represented 92 % of the total abundance. Pollution produced by organophosphate pesticides (OPPs) was critical in the whole MRB, showing levels that exceeded 270-fold maximum threshold for malathion and 30-fold for parathion, the latter banned in Ecuador. OPPs concentrations were related to low germination percentages of Lactuca sativa in sediment phytotoxicity tests. The IEFQ index ranged from 44.4 to 25.6, indicating that freshwater ecosystem conditions were "bad" at the headwaters of the MRB and "critical" along the lowest reaches. Our results show strong evidence that intense agricultural and livestock activities generated significant impacts on the aquatic ecosystem of the MRB. This integrative approach better explains the cumulative effects of human impacts, and should be replicated in other basins with similar conditions to help decision-makers and concerned inhabitants generate adequate policies and strategies to mitigate the degradation of freshwater ecosystems., (Copyright © 2021. Published by Elsevier Ltd.)

We assessed the quality of Andes-Amazonia streams in Ecuador impacted by gold mining (GM), discharges from inefficient sewage network in urban areas (UA), wastes from fish farming (FF) and from non-functional landfill (LF) and other few threats (FT). We selected three lines of evidence (LOE) that were used separately and integrated into a index: water quality (WQI) and macroinvertebrate community (AAMBI) indices and phytotoxicity tests. Streams affected by UA and LF had the lowest scores to WQI and phytotoxicity, and by GM had the lowest scores to AAMBI. Macroinvertebrate absence in GM should be considered as a warning signal of long-term mining impacts in the area. The integrated LOE index showed that sites with identified threats had 30%-53% stream quality decline compared to FT sites. The use of the selected LOE seems to be a useful tools for long-term monitoring and evaluation of this sensitive aquatic ecosystem., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

We quantify plastic litter (PL, > 2 cm) and microplastics (MP, < 5 mm) from the sediments of a beach formed at a riverine depositional area, at the upper Amazon River basin, Ecuador. In the collection area (4400 m 2 ), the PL density was 0.045 items m -2 , where low-density polyethylene bags were the prevalent PL. The beach was classified as "very clean" (Clean Coast Index (CCI) of 1.3 items m -2 ). Regarding MP, in 55 sampling stations, average MP concentrations ranged from 0 to 2200 items kg -1 of dry sediment (0.5-2 mm), and 0-4200 items kg -1 of dry sediment (2-5 mm). Blue fibers were the prevalent MP. Our results represent the first report to show the ubiquitous presence of PL and MP for the area. The monitoring and management of plastic disposal in freshwater beaches are necessary, as here we report a small part of an undocumented issue., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

This work is a study on the occurrence of emerging pollutants in the northeast Ecuadorian Amazon. Emerging contaminants (ECs)-caffeine, triclosan, estradiol, acetaminophen, nicotine, and ibuprofen-were quantified by gas chromatography-mass spectrometry in rivers and streams of the Amazon basin near the city of Tena, Ecuador. For that, a total of 16 natural water samples were taken in 8 locations. Sampling sites included areas impacted by discharges from inefficient sewage networks in urban areas, wastes from fish farming and non-functional landfill, a stream with few threats, tap water, and treated sewage. Caffeine was found in the 38% of the samples studied while trimethoprim and acetaminophen had an occurrence of 13%. Caffeine was detected at two sites receiving untreated sewage and one site receiving treated sewage with mean concentrations that ranged between 19 and 31.5 μg L -1 . Acetaminophen (50.4 μg L -1 ) and trimethoprim (2 μg L -1 ) were only detected in the river receiving treated sewage effluent. This is the first assessment of emerging contaminants in the upper Ecuadorian Amazon basin, and our observations highlight the need for better sewage treatment and water quality monitoring in Amazonian cities., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

We assessed the concentration of organophosphate pesticides (OPs) and microplastics (MPs) in water and sediments from the burrows, and tissues of the fiddler crabs Leptuca festae and Minuca ecuadoriensis, from Isla Santay, a Ramsar site in the estuary of the Guayas River, Ecuador. MPs concentrations in the burrows were 660 ± 174.36 items kg -1 (w.w.) and 26 ± 1 items L -1 in collected sediments and water, respectively. Regarding OPs, water and sediment concentrations were up to 26 times above the USEPA thresholds for chronic exposure, indicating environmental risk. MPs were found in tissues collected from both species. The highest abundance was in the gills followed by the digestive tract and hepatopancreas. OPs concentrations in tissues were below the detection limits. Because fiddler crabs are chronically exposed to environmental contamination, they are suitable bioindicators to monitor Isla Santay and to comprehend human impacts in coastal environments of Ecuador., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

We compared sediment quality in estuaries at three locations along the coast of São Paulo State, Brazil, using geochemical analyses and whole sediment toxicity tests, during the southern summer and winter of 2013. Each locality is afforded a distinct degree of legal protection, and exhibits a different level of metal pollution: overall, Rio Diana (RD, the most polluted, a Permanent Protection Area) > Rio Itapanhaú (RI, intermediate contamination, an Environmental Protection Area) > Rio Picinguaba (RP, pristine, a State Park). Chronic sediment toxicity tests evaluated reproductive rates of the copepod Nitokra sp. RI sediments showed the highest metal concentrations and toxicity in both seasons. Metal concentrations at RD were low but toxic in summer. RP sediments were not contaminated, suggesting effective legal protection from pollution at this locality. RI and RD, although provided some legal protection, showed clear signs of environmental degradation, emphasizing the need for more effective pollution control.

We examined copper accumulation in the hemolymph, gills and hepatopancreas, and hemolymph osmolality, Na + and Cl - concentrations, together with gill Na + /K + -ATPase and carbonic anhydrase activities, after dietary copper delivery (0, 100 or 500 Cu µg g -1 ) for 12 days in a fiddler crab, Minuca rapax. In contaminated crabs, copper concentration decreased in the hemolymph and hepatopancreas, but increased in the gills. Hemolymph osmolality and gill Na + /K + -ATPase activity increased while hemolymph [Na + ] and [Cl - ] and gill carbonic anhydrase activity decreased. Excretion likely accounts for the decreased hemolymph and hepatopancreas copper titers. Dietary copper clearly affected osmoregulatory ability and hemolymph Na + and Cl - regulation in M. rapax. Gill copper accumulation decreased carbonic anhydrase activity, suggesting that dietary copper affects acid-base balance. Elevated gill Na + /K + -ATPase activity appears to compensate for the ion-regulatory disturbance. These effects of dietary copper illustrate likely impacts on semi-terrestrial species that feed on metal-contaminated sediments.

Currently, several concerns have been raised over metal contamination in the upper Amazon basin. Rivers that flow from the high Andes to the lowland Amazon are threatened by anthropogenic activities, which may, in turn, lead to increased metal concentrations in both water and sediments. In the present study, the impacts of multiple metal contamination sources in these ecosystems were identified. The degree of metal contamination was assessed in water and sediment and seed phytotoxicity analyses were carried out in samples taken from 14 sites located in upper Napo River tributaries, combining geochemical and ecotoxicological techniques. These tributaries were chosen based on their degree of anthropogenic contamination and proximity to known sources of relevant pollution, such as small-scale gold mining (MI), urban pollution (UP), fish farming (FF) and non-functional municipal landfill areas (LF). Our results suggest that anthropogenic activities are introducing metals to the aquatic ecosystem, as some metals were up to 500 times above the maximum permissible limits for the preservation of aquatic life established by Ecuadorian and North American guidelines. Sites located close to small-scale gold mining and sanitary landfills presented 100 to 1000 times higher concentrations than sites classified as "few threats". In water, Cd, Pb, Cu, Zn and Hg were mostly above the maximum permissible limits in the samples, while Cd in sediment reached concentrations 5-fold above the probable effect level (PEL). Phytotoxicity was associated through the diffuse contamination present in urban and landfill areas. Overall, metal concentrations and phytotoxicity assessments suggest anthropogenic effects to environmental contamination, even though natural sources cannot be disregarded. Anthropogenic effects in the eastern Andean Rivers need to be constantly monitored in order to build a complete picture on how pollution sources may affect this strategic Amazon basin area., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest with any governmental agency or commercial entity., (Copyright © 2019. Published by Elsevier B.V.)

This study investigates the combined effects of waterborne copper exposure and acute temperature change on oxygen consumption and the oxidative stress biomarkers, glutathione S-transferase (GST) and glutathione peroxidase (GPx), in the gills and hepatopancreas of the fiddler crab Minuca rapax. Crabs held at 25 °C were acclimated to 0 (control), 50, 250 or 500 μg Cu L -1 for 21 days, and were then subjected to 15, 25 and 35 °C for 24 h. Aerial oxygen consumption rates of crabs in copper free media increased with increasing temperature from 15 to 35 °C, Q 10 values reaching ≈3. Crabs exposed to increasing copper concentrations exhibited variable responses, Q 10 values falling to ≈1.5. Copper had no effect on oxygen consumption at 25 °C. However, at 35 °C, rates decreased in a clear concentration-response manner in the copper exposed crabs, revealing impaired aerobic capability. At 15 °C, oxygen consumption rates increased with copper concentration, except for a decrease at 500 μg Cu L -1 . Gill GST activity was ≈2-fold that of the hepatopancreas, while hepatopancreas GPx activity was 3-fold that of the gills. Gill GST activities were reduced by copper exposure only at 25 °C while hepatopancreas GST activities were altered by copper at all temperatures. Hepatopancreas GST and GPx activities increased in crabs exposed to copper at 35 °C, revealing oxidative stress induction. Hepatopancreas GST and GPx activities were reduced in copper exposed crabs at 15 °C, suggesting a diminished capability to mitigate the effects of copper exposure at low temperature. These findings reveal that copper exposure increases oxygen consumption at low temperatures but decreases consumption at high temperature. Hepatopancreas GPx activities decreased at low temperature and increased at high temperature. These novel findings demonstrate that the interaction between copper exposure and temperature should be considered when evaluating biomarker activities in semi-terrestrial crabs., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The mudflat fiddler crab Minuca rapax, typical of mangroves and intertidal zones in the Western Atlantic Ocean, responds to fluctuations in environmental parameters by biochemical and physiological adjustments. Such biochemical effects are commonly employed in environmental studies as biomarkers of estuarine contamination. This study evaluates biochemical responses in the gills and hepatopancreas of M. rapax in situ from localities exhibiting different types and levels of contamination, against a backdrop of fluctuations in environmental parameters like salinity and temperature common to estuarine regions. The biochemical biomarkers metallothionein (MT)-like protein titers and glutathione S-transferase (GST), glutathione peroxidase (GPx) and acetylcholinesterase (AChE) activities were used to evaluate responses to environmental contamination and seasonal changes in environmental parameters. Crabs were collected during two seasons, the austral winter and summer, at three sites along the coast of the state of São Paulo, Brazil that present decreasing degrees of environmental contamination: Ilha Diana, Santos (ID) > Rio Itapanhaú, Bertioga (RI) > Picinguaba, Ubatuba (P), a pristine control site. Our findings show that MT were induced in crabs from the contaminated sites (ID and RI) mainly during winter, revealing the activation of detoxification mechanisms; however MT were also induced in P crabs during the summer rainy season. GPX, GST and AChE activities were altered in P crabs during summer and in ID and RI crabs in winter. While enzyme activities in summer crabs may reflect seasonal changes in precipitation and salinity, in winter these altered activities appear to reflect contamination, although an effect of environmental parameters cannot be excluded. These findings reveal a strong seasonal influence on biochemical biomarker responses in Minuca rapax, a relevant factor to consider when interpreting the impact of environmental contamination in estuaries., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The effects of exposure to copper (Cu) on tissue Cu accumulation, on hemolymph osmotic, Na + and Cl - regulation, and on gill Na + /K + -ATPase (NKA) and carbonic anhydrase (CA) activities were evaluated in the fiddler crab Minuca rapax. Waterborne copper was delivered to the crabs at one of three salinities (seawater at 25‰ salinity [S] = isosmotic control; distilled water [<0.1‰ S] = hypo-osmotic medium; or 60‰ S = hyper-osmotic seawater) either for 5 days in a 0.5-cm water film containing 0, 50, 150, 250 or 500µg Cu/L with free access to a dry surface, or in crabs fully submerged for 5h at 0, 250 or 500µg Cu/L. In the crabs with free access to a dry surface, the highest Cu concentrations were found in the hemolymph and hepatopancreas with some accumulation in the gills; accumulation in the hemolymph and gills was enhanced in low salinity but was salinity independent in the hepatopancreas. Osmotic regulation was unaffected by Cu exposure; however Na + and Cl - hypo- regulation was impaired by Cu in 25 and 60‰ S. Gill NKA activity was stimulated 2-fold at 50µg Cu/L and markedly inhibited at 150µg Cu/L and above in 0 and 25‰ S. Gill CA was inhibited in <0.1‰ S but stimulated in 25 and 60‰ S; an inverse concentration-CA activity response was seen above 150µg Cu/L for all salinities. In the submerged crabs, Cu accumulated in all tissues in 60‰ S; however, there was no clear-cut Cu concentration-accumulation relationship evident in any tissue for either exposure regime, likely owing to the crabs' ability to regulate Cu. Copper exposure diminished osmotic, [Na + ] and [Cl - ] hypo-regulatory ability, especially in higher salinities. Gill NKA activity was markedly inhibited by Cu overall, and particularly above 250µg Cu/L in <0.1‰ S. Gill CA activity was inhibited in 25‰ S but inconsistently affected in 0 and 60‰ S. These findings show that Minuca rapax is affected both physiologically and biochemically by Cu contamination, although to different degrees, depending on the delivery regime, salinity, copper concentration and target tissue., (Copyright © 2017. Published by Elsevier Inc.)

The contamination of estuaries by metals can impose additional stresses on estuarine species, which may exhibit a limited capability to adjust their regulatory processes and maintain physiological homeostasis. The mudflat fiddler crab Uca rapax is a typical estuarine crab, abundant in both pristine and contaminated areas along the Atlantic coast of Brazil. This study evaluates osmotic and ionic regulatory ability and gill Na(+)/K(+)-ATPase activity in different salinities (<0.5, 25 and 60‰ S) and oxygen consumption rates at different temperatures (15, 25 and 35°C) in U. rapax collected from localities along the coast of São Paulo State showing different histories of metal contamination (most contaminated Ilha Diana, Santos>Rio Itapanhaú, Bertioga>Picinguaba, Ubatuba [pristine reference site]). Our findings show that the contamination of U. rapax by metals in situ leads to bioaccumulation and induces biochemical and physiological changes compared to crabs from the pristine locality. U. rapax from the contaminated sites exhibit stronger hyper- and hypo-osmotic regulatory abilities and show greater gill Na(+)/K(+)-ATPase activities than crabs from the pristine site, revealing that the underlying biochemical machinery can maintain systemic physiological processes functioning well. However, oxygen consumption, particularly at elevated temperatures, decreases in crabs showing high bioaccumulation titers but increases in crabs with low/moderate bioaccumulation levels. These data show that U. rapax chronically contaminated in situ exhibits compensatory biochemical and physiological adjustments, and reveal the importance of studies on organisms exposed to metals in situ, particularly estuarine invertebrates subject to frequent changes in natural environmental parameters like salinity and temperature., (Copyright © 2016. Published by Elsevier Inc.)

A highly regiospecific synthesis of a series of indenoindoles is reported, together with X-ray studies and their activity against human prostate cancer cells PC-3 and LNCaP in vitro. The most effective compound 7,7-dimethyl-5-[(3,4-dichlorophenyl)]-(4bRS,9bRS)-dihydroxy-4b,5,6,7,8,9bhexahydro-indeno[1,2-b]indole-9,10-dione 7q reduced the viability in both cell lines in a time and dose-dependent manner. Inhibitory effects were also observed on the adhesion, migration, and invasion of the prostate cancer cells as well as on clonogenic possibly by inhibition of MMP-9 activity. Molecular docking of 7q and 6k into MMP-9 human active site was also performed to determine the probable binding mode., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Precocious maturity is an important life history trait and might be advantageous if the juvenile habitat is risky. Larvae of the mottled shore crab Pachygrapsus transversus settle to the benthic habitat at a very large size, undergo a brief juvenile development and mature within a few months at a size about a fourth of the asymptotic maximum size for this species. This strategy may rely on the capacity of this species to molt to a juvenile-like morphotype (mI) in which reproduction is suppressed. In the laboratory, winter temperature triggered the puberty molt for a large proportion of juveniles, and still allowed high growth rates if combined with long photoperiod. This would result in a large number of juvenile crabs to join the adult reproductive stock in spring, at the beginning of the breeding season. Adult morphs (mII) grow faster under winter conditions, and therefore might be able to direct resources to reproduction during summer. Yet, females held in captivity without any interaction with conspecifics failed to maintain their reproductive status and often reversed to mI stages. In contrast, when a potential mate was presented, all crabs held their mII status, regardless of whether interaction involved visual, visual + chemical, or visual + chemical + tactile cues. Males discriminate female morphs, and physical interactions, including the inspection of mate receptivity and copulation, took longer when they were interacting with mII females. More than a trade-off between growth and reproduction, sustaining a breeding condition in P. transversus females is apparently a bet for successful mating in the presence of a suitable male conspecific., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

The design and synthesis of novel sterol hydrazone analogues (9, 10, 11 and 12) are described, followed by their evaluation as inhibitors of fungal growth, using Paracoccidioides brasiliensis as the biological tester. Compounds 9, 10, 11 and 12 generated a dose-dependent effect in fungal growth, particularly 9, 11 and 12, which were active at nanomolar concentrations (100 nM). When P. brasiliensis in its pathogenic yeast-like phase was treated individually with each of the aforementioned compounds at concentrations that reduced growth rate around 50%, the analysis of sterol composition in the resulting surviving cells demonstrated a 50% reduction of the final sterols brasicasterol and ergosterol, and concomitant increase in the levels of lanosterol. These results indicate that these compounds inhibit the enzyme Δ(24)-sterol methyl transferase (SMT), in a manner dependent on the stereochemical location of the hydrazone group. Compound 12, instead, induced a good antiproliferative activity not associated with blockage of any step in the pathway to sterol biosynthesis, suggesting a different mode of action. The X-ray crystal structure of H1 was determined to obtain information regarding the rings and side chain conformation of the sterol hydrazones. Comparison of the inhibitory effects of sterol hydrazones (9-12) and azasterols (AZA1-AZA3) on SMT with the molecular electrostatic potential, negative isopotential energy surfaces (-10 kcal/mol) and local ionization potential calculated via DFT methods, showed that changes in the electronic moiety introduced by the N and O atoms were not as important as the additional flexibility of the side chain introduced by an extra methylene group., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The title compound, C(10)H(11)NTe, is the first organyl ethynyl telluride, R-Te-C C-H, to be structurally characterized. In the L-shaped mol-ecule, the aryl moiety, viz. Me(2)NC(6)H(4)Te, is almost perpendicular to the Te-C C-H fragment. The Te-Csp(2) bond [2.115 (3) Å] is significantly longer than the Te-Csp bond [2.041 (4) Å]. The Te-C C group is approximately linear [Te-C-C = 178.5 (4)° and C C = 1.161 (5) Å], while the coordination at the Te atom is angular [C-Te-C = 95.92 (14)°]. In the crystal structure, there are Csp-H⋯N hydrogen bonds which are perpendicular to the CNMe(2) group; the N atom displays some degree of pyramidalization. Centrosymmetrically related pairs of mol-ecules are linked by Te⋯π(ar-yl) inter-actions, with Te⋯Cg = 3.683 (4) Å and Csp-Te⋯Cg = 159.1 (2)° (Cg is the centroid of the benzene ring). These inter-actions lead to the formation of zigzag ribbons which run along c and are approximately parallel to (110).

A series of phenylsubstituted pyrazolo and pyrimido benzothiazine dioxide derivatives were synthesized and investigated for their abilities to inhibit beta-hematin formation, hemoglobin hydrolysis and in vivo for their antimalarial efficacy in rodent Plasmodium berghei. Compounds 3-amino-7-chloro-9-(2'-methylphenyl)-1,9-dihydro-pyrazolo-[4,3-b]benzothiazine 4,4-dioxide 2b and 2,4-diamino-8-chloro-10H-phenyl-pyrimido-[5,4-b]benzothiazine 5,5-dioxide 3a were the most promising as inhibitors of hemoglobin hydrolysis, however, their effect as inhibitors of beta-hematin formation was marginal, except for compound 3-amino-7-chloro-9-(3'-chlorophenyl)-1,9dihydro-pyrazolo-[4,3-b]benzothiazine 4,4-dioxide 2g. The most active compound to emerge from the in vitro and in vivo murine studies was 2b, suggesting an antimalarial activity via inhibition of hemoglobin hydrolysis, however, not as efficient as chloroquine.