Toxicological effects of N,N,N′,N′-tetramethylethylenediamine on electric eel (Electrophorus electricus) acetylcholinesterase and human serum butyrylcholinesterase

This study examined the adverse effects of N,N,N′,N′-tetramethylethylenediamine (TEMED) on electric eel (Electrophorus electricus) acetylcholinesterase (AChE) and human serum butyrylcholinesterase (BChE). Data show that TEMED inhibited AChE in electric eel as well as human serum BChE. Kinetic studies indicated that the inhibition produced by TEMED in both sources was of mixed type, i.e. K_m increased and V _max decreased in a concentration-dependent manner. K_I (constant of ChE–substrate–TEMED complex into ChE–substrate complex and TEMED) was estimated to be 0.674 mM for electric eel and 0.024 mM for human serum BChE. The γK_m (dissociation constant of ChE–substrate–TEMED complex into ChE–TEMED complex and substrate) was 0.083 and 0.2 mM for electric eel AChE and human serum BChE, respectively. The IC₅₀ for electric eel and for human serum ChE was 1.57 and 0.043 mM, respectively. The present results suggest that TEMED produced adverse effects on electric eel and human serum via inhibition of ChE.     

Quantification of 17 endocrine disruptor compounds and their spatial and seasonal distribution in the Iberian Ave River and its coastline

The Ave River flows through the most urbanized and industrialized Porto district areas. Despite ovotestis was recently reported in male fish from the estuary, no data exist on the water levels of natural and pharmaceutical estrogens (17β-estradiol, estrone, and 17α-ethynylestradiol), xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol and their mono and diethoxylates, and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, and genistein), and sitosterol. Absence of analyses applies to the river, estuary, and nearby coastline. Those compounds mimic the action of endogenous estradiol, being well-recognized endocrine disrupters (EDCs). To conclude about suspected influxes of estrogenic EDCs into the river and coastline, water samples were taken at eight sites every two months, during one year (2010), at low tide. Data showed ubiquitous presence of potentially hazardous amounts of estrogens (particularly ethynylestradiol, up to 10 ng L^?1), nonylphenol (up to 250 ng L^?1), and sitosterol (up to 6 μg L^?1), which helps explaining the ovotestis emergence in local fish. Also, because physicochemical parameters used in water quality evaluation, such as pH, dissolved oxygen, nitrates, and nitrites levels, were within legal limits – suggesting good quality – our study supports that assessment of human and environmental risks by targeting surface waters requires integrating EDCs monitoring in routine analyses.     

Physiological and behavioral responses of temperate seahorses (Hippocampus guttulatus) to environmental warming

The aim of the present study was to evaluate, for the first time, the effect of environmental warming on the metabolic and behavioral ecology of a temperate seahorse, Hippocampus guttulatus. More specifically, we compared routine metabolic rates, thermal sensitivity, ventilation rates, food intake, and behavioral patterns at average spring temperature (18 °C), average summer temperature (26 °C), temperatures that they endure during summer heat wave events (28 °C), and in a near-future warming scenario (+2; 30 °C) in Sado estuary, Portugal. Both newborn juveniles and adults showed significant increases in metabolic rates with rising temperatures. However, newborns were more impacted by future warming via metabolic depression (i.e., heat-induced hipometabolism). In adult stages, ventilation rates also increased significantly with environmental warming, but food intake remained unchanged. Moreover, the frequency of swimming, foraging, swinging, and inactivity did not significantly change between the different thermal scenarios. Thus, we provide evidence that, while adult seahorses show great resilience to heat stress and are not expected to go through any physiological impairment and behavioral change with the projected near-future warming, the early stages display greater thermal sensitivity and may face greater metabolic challenges with potential cascading consequences for their growth and survival.     

Trophic and reproductive biochemistry of a deep-sea gelatinous octopus, Opisthoteuthis calypso

The present study provides a comprehensive analysis of the biochemical composition (proximate composition, amino acids and fatty acids in gonad, digestive gland and muscle) of the cirrate octopod, Opisthoteuthis calypso, collected off the coast of Portugal. Protein and energy contents of O. calypso were significantly lower (p < 0.05) than those observed for coastal octopods, suggesting that the gelatinous musculature of the cirrate octopus may not be a direct consequence of food limitation, but rather associated with reduced selective pressure for strong swimming ability in the deep sea. Moreover, principal component analyses of fatty acid (FA) data clearly separated coastal octopods from O. calypso. Saturated FA biomarkers (namely 16:0, 17:0, 18:0) and monounsaturated FA 22:1 suggest a higher phytodetrital influence on diet of O. calypso. A clear separation between groups was also observed with amino acid (AA) data. However, essential AA and non-essential AA designations (based on the flow of carbon through biochemical systems) do not necessarily provide an accurate picture of the origins of amino nitrogen in the deep-sea environment. Consequently, the interpretation of the present data is a challenging task but opens a new window of opportunity to unravel new trophic biomarkers in the deep sea.     

Predator guild does not influence orangutan alarm call rates and combinations

Monkey alarm calls have shown that in the primate clade, combinatorial rules in acoustic communication are not exclusive to humans. A recent hypothesis suggests that the number of different call combinations in monkeys increases with increased number of predator species. However, the existence of combinatorial rules in great ape alarm calls remains largely unstudied, despite its obvious relevance to ideas about the evolution of human speech. In this paper, we examine the potential use of combinatorial rules in the alarm calls of the only Asian great ape: the orangutan. Alarm calls in orangutans are composed of syllables (with either one or two distinct elements), which in turn are organized into sequences. Tigers and clouded leopards are predators for Sumatran orangutans, but in Borneo, tigers are extinct. Thus, orangutans make a suitable great ape model to assess alarm call composition in relation to the size of the predator guild. We exposed orangutans on both islands to a tiger and control model. Response compositionality was analyzed at two levels (i.e., syllable and syllable sequences) between models and populations. Results were corroborated using information theory algorithms. We made specific, directed predictions for the variation expected if orangutans used combinatorial rules. None of these predictions were met, indicating that monkey alarm call combinatorial rules do not have direct homologues in orangutans. If these results are replicated in other great apes, this indicates that predation did not drive selection towards ever more combinatorial rules in the human lineage.     

Monitoring of heavy metals and butyltin compounds in coastal waters of Ligurian Sea: Results of a mussel watch project

From December 1994 up to October 1995 a “Mussel Watch Project”; was carried out to assess the quality of water of the Ligurian Sea and to identify the possible sources of heavy metal pollution. Several metals and organotin compounds were measured in mussels (Mytilus galloprovincialis, Lam) transplanted in different months from a marine farm to eight sites of the Ligurian coast.

Spatial differences and temporal trends in tissue concentrations of Zn, Cu, Ni, Cr, Fe, Al, V, Cd and Mn were evaluated. Concentrations resulted in the same range as those obtained in a previous Mussel Watch Project carried out in the same area. In general, areas of known pollution display high concentrations of these metals, but also some areas not greatly influenced by human activities showed high concentrations of some metals.

Data from this study show little evidence of any overall seasonal pattern except for Cu, Zn and V, concentrations of which were a function not only of sampling site, but also of reproductive cycle.

Organotin compounds show differences in terms of both concentration and speciation between the investigated sites.     

Toxic effects of the ingestion of water-soluble elements found in soil under the atmospheric influence of an industrial complex

In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks.     

Fertilisation, embryogenesis and larval development in the tropical intertidal sand dollar Arachnoides placenta in response to reduced seawater pH

We examined the response of the tropical sand dollar Arachnoides placenta to reduced seawater pH in experiments spanning ca. 50 % of the planktonic larval duration. A. placenta inhabits intertidal sandy beaches where we observed a minimum in situ pH range 0.06 pH units (pH 8.10–8.16). The responses of gametes and larvae to seawater pH were tested in vitro in ambient (pH 8.14, pCO₂ = 525.7 μatm, total alkalinity = 2,651 μmol kg soln^?1) and three reduced pH seawater treatments (7.8–7.0). Percentage fertilisation decreased significantly with decreasing pH across a range of sperm/egg ratios (4:1 up to 4,000:1). A. placenta reached the advanced pluteus stage in 4 days, and during this time, we saw no difference in survival rate of larvae between the ambient (67 %) and pH 7.79 (72 %) treatments. Four-day survival was, however, reduced to 44 and 11 % in the pH 7.65 and 7.12 treatments, respectively. Larval development and morphometrics varied among pH treatments. Embryos reared in pH 7.12 exhibited arrested development. Larvae reared at pH 7.65 showed delayed development and greater mortality compared with those reared at pH 7.79 and 8.14. When larval morphometrics are compared among larvae of the same size, differences in larval width and total arm length between pH treatments disappear. These results suggest that variation in larval size among the three highest pH treatments at a given time are likely the result of slower development and apparent shrinkage of surviving larvae and not direct changes in larval shape. There were no differences in the percentage inorganic content (a proxy for calcification) in larvae reared in either an ambient or a pH 7.7 treatment. The responses of fertilisation and development to decreased pH/increased pCO₂ in A. placenta are within the range of those reported for other intertidal and subtidal echinoid species from colder latitudes.     

Environmental performance evaluation of agro-industrial innovations – part 1: Ambitec-Life Cycle,a methodological approach for considering life cycle thinking

As sustainability considerations increasingly dominate the technology development debate worldwide, practical approaches to assess environmental performance of innovations have been warranted. The present study (Part 1) introduces Ambitec-Life Cycle, a method derived from Ambitec-Agro for considering life cycle thinking in the environmental performance evaluation (EPE) of agro-industrial innovations. An agro-industrial innovation case study related to residue recycling is presented, revealing steps in the product life cycle where opportunities are best for technological improvements. In Part 2 (this issue) of this study, a methodological approach for considering the environmental vulnerability of watersheds and to integrate this analysis in EPE methods is presented. This approach is applied to Ambitec-Life Cycle and to the same residue case study, allowing the identification of performance indicators with greater potential to cause impacts at the studied watersheds.