Martin Ansaldo - Academia.edu (original) (raw)

Papers by Martin Ansaldo

Ecotoxicology, Sep 24, 2022

Deschampsia antarctica Desv. (Poaceae) is the only native grass described so far for Antarctica, ... more Deschampsia antarctica Desv. (Poaceae) is the only native grass described so far for Antarctica, with a distribution mainly centered on the Antarctic Peninsula. The plants were collected at Argentinian Scienti c Station Carlini, 25 de Mayo (King George) Island, to determine and evaluate in their leaves: the stomatic index (SI), density (SD), and area (SA) as pollution biomarkers. Samples were taken within the Station's in uence area: (A) Supply Area (loading and unloading of fuel and supplies), (B) the area adjacent to the Electric Power Station, and (C) area of Fuel Tanks. Besides, other samples were taken from a pristine area called Peñon 7 (D). The results of SD showed signi cant differences only on the leaf abaxial face from the plants of the 4 studied sites: Peñón 7 (57.36 ± 2.03), Supply Area (61.30 ± 2.32), Electric Power Station adjacent area (69.56 ± 2.23) and Fuel Tanks area (80.11 ± 2.42). The SI as well as the SA did not have signi cant differences (p > 0.05) for all the analyzed sites. However, correlation analyses between SD and SI showed a positive and signi cant association only for the leaf adaxial face from all sites. From the obtained results, we could suggest that the correlation (SD-SI) on the adaxial side of the leaves was a good biomarker to estimate the degree of anthropogenic impact in each studied area.

Science of The Total Environment, Mar 1, 2009

Biomphalaria glabrata is a widespread freshwater gastropod mollusc. The easy aquaculture of these... more Biomphalaria glabrata is a widespread freshwater gastropod mollusc. The easy aquaculture of these organisms allow its use as an accessible tool for contamination bioassays. B. glabrata showed marked metabolic responses when exposed to cadmium, lead and arsenic. Those responses could also affect the reproduction of the snails. Taking into account this hypothesis, B. glabrata were exposed for 96 h (acute laboratory bioassays) to different concentrations of cadmium (0.1, 0.05 and 0 mg/L), lead (0.5, 0.1, 0.05 and 0 mg/L) and arsenic (0.5, 0.1, 0.05 and 0 mg/L). Snails were removed from the aquaria while eggs were left in the same contaminant concentrations. The effect of the assayed toxicants on snail reproduction was registered as the alterations of the total number of laid eggs (TNLE), hatching time and embryonic survival. At 0.10 mg/L cadmium significantly decreased the TNLE (p<0.05) and no embryos survived. The lowest assayed level (0.05 mg/L) of cadmium, delayed the hatching time twice when it was compared with the control group (p<0.01). Lead decreased the TNLE at 0.5 mg/L level (p<0.01). The other assayed doses (0.05 and 0.10 mg/L) also decreased embryonic survival significantly (p<0.05 and p<0.01 respectively) and extended twice the time to hatching (p<0.01). The 0.50 mg/L level killed all embryos. Arsenic at all studied concentrations decreased the TNLE (p<0.05) while the hatching time was increased by 50%. Embryo survival only decreased at the highest level (0.5 mg/L) of arsenic assayed. In summary, the acute exposure (96 h) to cadmium lead and arsenic, altered the reproduction of B. glabrata, modifying the TNLE, hatching time and embryonic survival.

Environmental Science and Pollution Research, Mar 13, 2017

We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), whi... more We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), which had not been informed up to now, such as silver and bromine and others listed as hazardous by the United States Environmental Protection Agency as arsenic, cobalt, chromium, and mercury. Analyses of the element concentrations in feathers, adult and chicken, from Barton Peninsulas at 25 de Mayo (King George) Island, South Shetlands, were made by Instrumental Neutron Activation Analysis. Samarium, lanthanum a, thorium, and uranium concentrations in Chinstrap penguin feathers were below 0.1 mg/kg. This suggests that the elements in feather do not come from atmospheric particles surface deposition. Arsenic (0.120 ± 0.050 mg/kg) and cobalt (0.030 ± 0.020 mg/kg) concentrations were lower than the reports for other colony of Chinstrap penguins, and essential elements as iron (26 ± 12 mg/kg), zinc (78.0 ± 5.3 mg/kg), and chromium (0.51 ± 0.27 mg/kg) were in the same range while Se (2.90 ± 0.65 mg/kg) content were the lowest reported. Mercury (0.43 ± 0.21 mg/kg), chromium (0.210 ± 0.060 mg/kg), and silver (0.083 ± 0.003 mg/kg) in chicks tended to be lower than in adults. Iron, cobalt, and arsenic concentrations in feathers found in this study were the lowest compared to measurements were in several penguin species in Antarctica. These results confirm to feathers like effective indicators for the trace elements incorporated in the penguins and it provide a data set which can adds to the baseline for bioindication studies using feathers.

Polar Biology, Mar 15, 2016

Several fish species of the suborder Notothenioidei (Perciformes) predominate in the Antarctic Co... more Several fish species of the suborder Notothenioidei (Perciformes) predominate in the Antarctic Convergence Zone; nevertheless, reproductive studies are scarce due to difficulties on regular sampling. This study takes the research area of reproductive biology of notothenioids to a new level by providing, for the first time, data on sex hormone and vitellogenin detection in the blood of females of Notothenia rossii and N. coriiceps and correlates this data with morphological maturity indices as well as ovarian histology. Fish were captured during the Antarctic summer at Potter Cove, 25 de Mayo (King George) Island, and blood and ovary were collected. Histological analysis revealed that females of both fish possess group synchronous ovarian development with two distinct clutches of oocytes: a more advanced batch of vitellogenic oocytes ready for spawning and a second batch of previtellogenic oocytes for the next spawning event. Since liver vitellogenin synthesis is stimulated by estradiol produced by the ovaries, gonadal development, estradiol levels, and vitellogenin showed that both species were at a more advanced stage of maturation in March than in January. On the other hand and irrespectively of the month, gonadosomatic index and plasma estradiol levels of N. coriiceps were higher than those of N. rossii. Furthermore, females of N. coriiceps showed an advanced stage of vitellogenesis or were ready for spawn, contrary to results of previous studies. Our results indicate the successful use of gonadal morphology, estradiol, and vitellogenin detection for the estimation of sexual maturity stage of female adults.

Polar Science, Mar 1, 2018

Antarctica: mucilage and glucan storage as a C-source for limpets.

Comparative Biochemistry and Physiology Part A: Physiology, Jul 1, 1997

Haemolymphatic PO 2 , PCO 2 , and pH, and ionic concentrations of haemolymph and branchial chambe... more Haemolymphatic PO 2 , PCO 2 , and pH, and ionic concentrations of haemolymph and branchial chamber water were measured in submerged and emersed crabs. Hypercapnia and respiratory acidosis were recorded after 15 min of air exposure, then P CO 2 remained constant and pH was compensated. Sodium concentration increased in haemolymph and decreased in branchial water. The difference between haemolymph Na ϩ and Cl Ϫ increased dramatically. Acid-base balance is restored by two mechanisms: a) increase of the P CO 2 gradient across the gills and consequently the rate of CO 2 excretion; b) the increase in the strong ion difference, caused by branchial sodium uptake, compensates the hypercapnic acidosis. comp biochem physiol 117A;3:407-410, 1997.

Comparative Biochemistry and Physiology C-toxicology & Pharmacology, Jul 1, 2007

In Tierra del Fuego (Southern South America), the stone or false king crab, Paralomis granulosa r... more In Tierra del Fuego (Southern South America), the stone or false king crab, Paralomis granulosa represents one of the most important crab fisheries. After capture, animals are kept in baskets and exposed to dryness for several hours, when the water flow through the gills is interrupted. As a consequence a concomitant increase of reactive oxygen species begins, triggering oxidative stress. The aim of this study was to determine oxidative stress and antioxidant enzyme activities due to air exposure in different tissues of P. granulosa. Fifty crabs (carapace length >82 mm) were captured in Beagle Channel (54 degrees 50'S, 68 degrees 20'W) during winter 2004. Five groups of 10 crabs each were exposed to dryness at 6 degrees C for 0, 3, 6, 12 or 24 h, respectively. Activity of superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST) protein and lipid oxidation were measured in gills, muscle, hepatopancreas and haemolymph samples. Almost all analyzed tissues showed antioxidant enzymes activity, which varied with time of air exposure. The maximum enzyme activity was measured after 6 h of air exposure. Protein oxidation levels varied significantly in gills. Lipid peroxidation levels increased significantly in muscle and hepatopancreas. The critical time of air exposure probably occurs at 6 h. Thereafter animals were unable to induce the synthesis of antioxidant enzymes or proteins. This should be taken into account to minimize the stress generated by the commercial capture process.

Marine Environmental Research, May 1, 2005

The aim of this work was to investigate the activity of antioxidant enzymes and oxidative damage ... more The aim of this work was to investigate the activity of antioxidant enzymes and oxidative damage in the digestive gland of the limpet Nacella concinna, and their suitability as biomarkers for hydrocarbon pollution in Antarctic coasts. Three groups of 30 individuals each were kept in seawater containing 0%, 0.05% or 0.1% diesel. Superoxide dismutase, catalase, glutathione S transferase and glutathione peroxidase activities, as well as lipid peroxidation and protein oxidation were studied in 18 animals of each group after 24, 48 and 168 h of exposure. The activity levels of most enzymes were increased by diesel in a dose-dependent manner. Glutathione peroxidase showed the most clear effect; its activity significantly increased in the 0.1% diesel group respect to the control. Lipid peroxidation and protein oxidation were significantly increased by diesel after 168 h. Both variables were higher in the group exposed to the lowest dose.

Canadian Journal of Physiology and Pharmacology, Jun 1, 1989

Comparative Biochemistry and Physiology C-toxicology & Pharmacology, Jul 1, 2007

In a previous study we analysed the effect of diesel seawater contamination in the digestive glan... more In a previous study we analysed the effect of diesel seawater contamination in the digestive gland of the Antarctic limpet Nacella concinna. We observed that antioxidant enzyme activities decreased after one-week starvation prior to the experiment, and this was considered in the analysis of the obtained results. To know whether the digestive gland oxidant-antioxidant status may be altered by starvation and experimental conditions, we evaluated the food deprivation effect in limpets from the nearshore shallow waters of Potter Cove, Antarctica. Organisms were acclimated to laboratory conditions and were divided in fed and starved groups, and maintained in these conditions during one month. Every week 20 limpets were sampled from each group. Digestive glands were dissected and kept frozen until they were processed. Superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) measured as thiobarbituric reactive substances (TBARS), protein oxidation (PO) and reduced glutathione (GSH) were measured. For both groups of limpets, SOD increased its activity in the first week of the exposure period, with a maximum in the second week. CAT activity increased significantly in the second week, only for the starved group. Similarly, GST activity also increased for starved group in the second week; but maintained this tendency for both groups until the fourth week. In fed and starved limpets, TBARS values increased significantly, during the first week and then returned to normal values. The PO levels in the starved group increased only during the first week. The GSH content, for the fed group, increased significantly after the third week. The obtained results indicate that biochemical or physiological studies conducted with N. concinna should consider the effects of food deprivation and time spent under experimental conditions.

Aquatic Toxicology, 2013

Endosulfan (ES), a persistent organochlorine pesticide, is widely used despite its toxicity to no... more Endosulfan (ES), a persistent organochlorine pesticide, is widely used despite its toxicity to non-target animals. Upon reaching water bodies, ES can cause negative effects on aquatic animals, including disruption of hormonal systems. However, the action of ES on fish reproductive axis has been hardly studied thus far. The aim of the present work was to assess the endocrine disruptive potential of endosulfan on the pituitary gonadotropins levels and on the testes function due to ES in the South American freshwater fish Cichlasoma dimerus, using in vitro and in vivo approaches. In vitro experiments showed that ES inhibited the LH-stimulated steroidogenesis in gonads; no change was observed in gonadotropins release from pituitaries in culture. Laboratory waterborne ES (0.1, 0.3 and 1 g/L) exposure for two months caused decrease in ␤FSH pituitary content and ␥GT activity in the testes (Sertoli cell function marker). Testicular histology revealed pathologies such as scarce intermediate stages of spermatogenesis, release of immature germ cells into the lobular lumen, presence of foam cells and interstitial fibrosis. As FSH and FSH-mediated steroidogenesis regulate spermatogenesis and Sertoli cell function, the effect of ES on FSH could be responsible for the morphological alterations observed in testes. In vitro, ES disrupted steroidogenesis in gonads, therefore similar effects in vivo cannot be ruled out. Based on this evidence, ES exhibits an endocrine disruptive action on the reproductive axis of C. dimerus, causing disruption at the pituitary and/or at the gonad level. These effects could acquire ecological significance under prolonged exposure to the pesticide in nature.

Polar Biology, Mar 24, 2018

The limpet Nacella concinna is one of the most widely distributed gastropods along the Antarctic ... more The limpet Nacella concinna is one of the most widely distributed gastropods along the Antarctic Peninsula. This species has been a useful tool in ecological and physiological studies for understanding Antarctic trophic interactions. Although the reproduction of limpets has been thoroughly studied, very little is known about gametogenesis in the genus Nacella. The purpose of this study is to describe the gonadal morphology and gametogenesis in N. concinna observed by light microscopy and to determine its chromosome complement. All the limpets were sexually mature at the time of sampling. Oocytes were separated by trabeculae with abundant glycogen reserves. There was a predominance of late vitellogenic oocytes. Many previtellogenic oocytes were pyriform in shape. Oogonia were clustered near the ovary wall or the trabeculae. Only two meiotic stages were found: metaphase I and anaphase I, both of which showed a regular arrangement of chromosomes. The oviduct contained mature oocytes surrounded by sperm. Testicular tubules were filled with spermatozoa. The elongated head of the spermatozoon resembles that of other Nacellidae members. One of the bivalents is heteropycnotic. The haploid complement is n = 4 and the sex determination system is XO/XX. Although N. concinna has been commonly characterized as a broadcast-spawner, its unique spawning behavior, the presence of oocytes at anaphase I and spermatozoa within the oviduct suggests internal fertilization.

Environmental Pollution, Mar 1, 2016

Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine a... more Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine and terrestrial organisms. This work reports the elements incorporated by Usnea sp thalli in Potter Peninsula, 25 de Mayo (King George) Island, South Shetlands, Antarctica. Geological origin was analyzed as possible sources of elements. For this purpose, correlations were done using a geochemical tracer, principal component analysis and enrichment factors were computed. Lithophile elements from particulate matter were present in most of the sampling sites. Bromine, Se and Hg showed the highest enrichment factors suggesting other sources than the particulate matter. Mercury values found in Usnea sp were in the same range as those reported for Deception Island (South Shetlands) and remote areas from the Patagonia Andes.

Polar Biology, Feb 23, 2000

Brazilian Journal of Medical and Biological Research, Apr 1, 1997

Comparative Biochemistry and Physiology C-toxicology & Pharmacology, May 1, 2011

The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarb... more The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarbons (WSF) on the antioxidant status of the freshwater prawn Macrobrachium borellii. First, seasonal variations were studied in a non-polluted area. Hepatopancreas and gills showed season-related fluctuations in catalase (CAT), glutathione-S-transferase (GST) activities and in lipid peroxidation levels (LPO), but not in superoxide dismutase (SOD). Then, adults were exposed semi-statically to sublethal doses for 7 days. CAT, SOD, GST, and glutathione peroxidase (GPx) activities and LPO, reduced glutathione (GSH) and protein oxidation (PO) levels were determined. Exposed individuals showed significant increases in CAT, SOD, and GST activities in hepatopancreas and CAT activity in gills. GPx activity did not vary in either tissues. While LPO levels increased, GSH levels decreased significantly in hepatopancreas of exposed animals, but PO levels showed no variation. Induction of SOD was also assessed by Real-time PCR mRNA expression in hepatopancreas. The nonenzymatic antioxidant activity was also tested; ABTS 2,2′-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) was higher in hemolymph of treated-prawns compared to controls, but ferric reducing activity of plasma assay (FRAP) values did not change. Taken together, the present results indicated that the antioxidant defenses of M. borellii, mainly in hepatopancreas, were significantly affected by aquatic hydrocarbon contamination, regardless of the season.

Aquaculture, Sep 1, 2011

In the Southern South America, the stone or false king crab Paralomis granulosa constitutes the m... more In the Southern South America, the stone or false king crab Paralomis granulosa constitutes the main crab fishery. One of the extremely stressful situations to fished crustaceans is the air-exposure handling once they are on deck. The aims of this study were to determine effects of air-exposure and re-submersion on: (1) the antioxidant enzyme activities and lipid peroxidation in different tissues; and (2) changes in the meat palatability in Paralomis granulosa. One hundred and twenty male crabs were captured in Beagle Channel (54°S, 68°W) and randomly assigned to the two planned experiments. For the air-exposure, four groups of 8 animals each were exposed to dryness at 7°C for 6 h, and then re-submerged for 0.5, 1, 2 and 24 h respectively, whereas a fifth group was used as control. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST), as well as lipid peroxidation were measured in gills, muscle, hepatopancreas and haemolymph. Almost all tissues showed a significant increase of antioxidant enzyme activities until 2 h of recovery (α = 0.05). The highest antioxidant enzyme activities were found in gills, in which SOD, CAT and GST activities were similar to the control values after 24 h of recovery. Moreover, gills and hepatopancreas showed significantly increased (α = 0.05) lipid peroxidation at 0.5 h of re-submersion. For the palatability assay, three groups of twenty crabs each were air-exposed at 7°C for: 6, 12 and 18 h and then re-submersed for 24 h, whereas a fourth group was used as control. Four dishes of~10 g meat each were offered to 30 judges who performed a taste ranking with the meat samples. Even if differences in the meat flavor of P. granulosa were detected, participants could not rank samples according to the increasing air exposure of animals. Live transportation of P. granulosa is promising and crabs can be re-submerged and offered alive.

Anais Da Academia Brasileira De Ciencias, 2022

Human activities are increased in Antarctica during decades, primarily due to the logistic and to... more Human activities are increased in Antarctica during decades, primarily due to the logistic and tourism operations, which consequent negative impact on penguin populations, altering their physiological responses. Therefore, we aimed to assess the blood biochemistry and oxidant/antioxidant balance of Adélie penguins (Pygoscelis adeliae) inhabiting two selected colonies: Potter Peninsula, considered as a low impacted colony, and Esperanza/Hope Bay as a high impacted colony. The levels of calcium, uric acid, and fructosamine, showed significant high values (p<0.05) for the Potter Peninsula´s penguins. Besides, this population showed high levels of plasma protein oxidation and erythrocyte lipid peroxidation (p<0.005) while the Esperanza/ Hope Bay population presented high levels of erythrocyte protein oxidation and plasma lipid peroxidation (p<0.005). The oxidative damage values were similar in the Potter Peninsula population and slightly lower in the Esperanza/Hope Bay penguins if the results were compared to previous reports. The enzymes superoxide dismutase and glutathione peroxidase had significantly (p<0.005) high activity in the Esperanza/Hope Bay population, which also showed high reduced glutathione levels. The glutathione S-transferase activity was significantly high (p<0.005) in the Potter Peninsula population. The obtained results might take into account for making decisions about management and protection plans for the different penguin nesting areas in Antarctica.

Polar Biology, May 15, 2020

Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Gmb... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag GmbH Germany, part of Springer Nature. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Marine Biology, Apr 24, 2021

The capacity of seabirds to shape their physiological and immune phenotypes may often be constrai... more The capacity of seabirds to shape their physiological and immune phenotypes may often be constrained by the ecological context. While phenotypic plasticity in physiological traits has been previously studied, the molecular mechanisms underlying phenotype plasticity in response to environmental stress have been little explored. This prompted us to enquire about how the nutritional and immune status are involved in physiological adaptations in breeding seabirds under anthropogenic pressure. At Esperanza (Hope) Bay, Antarctic Peninsula exists one of the biggest breeding penguin colony of Pygoscelis adeliae (Adélie). At this location, penguins nest nearby the Argentinian Esperanza Station and, therefore, are exposed to high levels of disturbance, whereas there is a low disturbed area, where penguins also breed far away from the Station. In both areas, the nutritional and immune status in breeding individuals was addressed and serum protein expression level was analyzed using a proteomic approach. Body mass, proteins, albumin, and triacylglycerol were higher in penguins from the low disturbance area, whereas uric acid increased in individuals from the disturbed area, indicating a poorer body condition of penguins under anthropogenic pressure. Immune responses were elevated in penguins from the disturbed area (IgY, γ-globulins and hemagglutinating activity). Finally, individuals breeding under anthropogenic pressure overexpressed proteins with immune, antioxidant, and metabolic functions. The poor nutritional status of penguins under disturbance may be the consequence of the reallocation of resources to the immune system. Altogether, this would constitute a potential strategy to preserve an adequate immune phenotype under stressed environments.

Ecotoxicology, Sep 24, 2022

Deschampsia antarctica Desv. (Poaceae) is the only native grass described so far for Antarctica, ... more Deschampsia antarctica Desv. (Poaceae) is the only native grass described so far for Antarctica, with a distribution mainly centered on the Antarctic Peninsula. The plants were collected at Argentinian Scienti c Station Carlini, 25 de Mayo (King George) Island, to determine and evaluate in their leaves: the stomatic index (SI), density (SD), and area (SA) as pollution biomarkers. Samples were taken within the Station's in uence area: (A) Supply Area (loading and unloading of fuel and supplies), (B) the area adjacent to the Electric Power Station, and (C) area of Fuel Tanks. Besides, other samples were taken from a pristine area called Peñon 7 (D). The results of SD showed signi cant differences only on the leaf abaxial face from the plants of the 4 studied sites: Peñón 7 (57.36 ± 2.03), Supply Area (61.30 ± 2.32), Electric Power Station adjacent area (69.56 ± 2.23) and Fuel Tanks area (80.11 ± 2.42). The SI as well as the SA did not have signi cant differences (p > 0.05) for all the analyzed sites. However, correlation analyses between SD and SI showed a positive and signi cant association only for the leaf adaxial face from all sites. From the obtained results, we could suggest that the correlation (SD-SI) on the adaxial side of the leaves was a good biomarker to estimate the degree of anthropogenic impact in each studied area.

Science of The Total Environment, Mar 1, 2009

Biomphalaria glabrata is a widespread freshwater gastropod mollusc. The easy aquaculture of these... more Biomphalaria glabrata is a widespread freshwater gastropod mollusc. The easy aquaculture of these organisms allow its use as an accessible tool for contamination bioassays. B. glabrata showed marked metabolic responses when exposed to cadmium, lead and arsenic. Those responses could also affect the reproduction of the snails. Taking into account this hypothesis, B. glabrata were exposed for 96 h (acute laboratory bioassays) to different concentrations of cadmium (0.1, 0.05 and 0 mg/L), lead (0.5, 0.1, 0.05 and 0 mg/L) and arsenic (0.5, 0.1, 0.05 and 0 mg/L). Snails were removed from the aquaria while eggs were left in the same contaminant concentrations. The effect of the assayed toxicants on snail reproduction was registered as the alterations of the total number of laid eggs (TNLE), hatching time and embryonic survival. At 0.10 mg/L cadmium significantly decreased the TNLE (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) and no embryos survived. The lowest assayed level (0.05 mg/L) of cadmium, delayed the hatching time twice when it was compared with the control group (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). Lead decreased the TNLE at 0.5 mg/L level (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). The other assayed doses (0.05 and 0.10 mg/L) also decreased embryonic survival significantly (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05 and p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01 respectively) and extended twice the time to hatching (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.01). The 0.50 mg/L level killed all embryos. Arsenic at all studied concentrations decreased the TNLE (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) while the hatching time was increased by 50%. Embryo survival only decreased at the highest level (0.5 mg/L) of arsenic assayed. In summary, the acute exposure (96 h) to cadmium lead and arsenic, altered the reproduction of B. glabrata, modifying the TNLE, hatching time and embryonic survival.

Environmental Science and Pollution Research, Mar 13, 2017

We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), whi... more We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), which had not been informed up to now, such as silver and bromine and others listed as hazardous by the United States Environmental Protection Agency as arsenic, cobalt, chromium, and mercury. Analyses of the element concentrations in feathers, adult and chicken, from Barton Peninsulas at 25 de Mayo (King George) Island, South Shetlands, were made by Instrumental Neutron Activation Analysis. Samarium, lanthanum a, thorium, and uranium concentrations in Chinstrap penguin feathers were below 0.1 mg/kg. This suggests that the elements in feather do not come from atmospheric particles surface deposition. Arsenic (0.120 ± 0.050 mg/kg) and cobalt (0.030 ± 0.020 mg/kg) concentrations were lower than the reports for other colony of Chinstrap penguins, and essential elements as iron (26 ± 12 mg/kg), zinc (78.0 ± 5.3 mg/kg), and chromium (0.51 ± 0.27 mg/kg) were in the same range while Se (2.90 ± 0.65 mg/kg) content were the lowest reported. Mercury (0.43 ± 0.21 mg/kg), chromium (0.210 ± 0.060 mg/kg), and silver (0.083 ± 0.003 mg/kg) in chicks tended to be lower than in adults. Iron, cobalt, and arsenic concentrations in feathers found in this study were the lowest compared to measurements were in several penguin species in Antarctica. These results confirm to feathers like effective indicators for the trace elements incorporated in the penguins and it provide a data set which can adds to the baseline for bioindication studies using feathers.

Polar Biology, Mar 15, 2016

Several fish species of the suborder Notothenioidei (Perciformes) predominate in the Antarctic Co... more Several fish species of the suborder Notothenioidei (Perciformes) predominate in the Antarctic Convergence Zone; nevertheless, reproductive studies are scarce due to difficulties on regular sampling. This study takes the research area of reproductive biology of notothenioids to a new level by providing, for the first time, data on sex hormone and vitellogenin detection in the blood of females of Notothenia rossii and N. coriiceps and correlates this data with morphological maturity indices as well as ovarian histology. Fish were captured during the Antarctic summer at Potter Cove, 25 de Mayo (King George) Island, and blood and ovary were collected. Histological analysis revealed that females of both fish possess group synchronous ovarian development with two distinct clutches of oocytes: a more advanced batch of vitellogenic oocytes ready for spawning and a second batch of previtellogenic oocytes for the next spawning event. Since liver vitellogenin synthesis is stimulated by estradiol produced by the ovaries, gonadal development, estradiol levels, and vitellogenin showed that both species were at a more advanced stage of maturation in March than in January. On the other hand and irrespectively of the month, gonadosomatic index and plasma estradiol levels of N. coriiceps were higher than those of N. rossii. Furthermore, females of N. coriiceps showed an advanced stage of vitellogenesis or were ready for spawn, contrary to results of previous studies. Our results indicate the successful use of gonadal morphology, estradiol, and vitellogenin detection for the estimation of sexual maturity stage of female adults.

Polar Science, Mar 1, 2018

Antarctica: mucilage and glucan storage as a C-source for limpets.

Comparative Biochemistry and Physiology Part A: Physiology, Jul 1, 1997

Haemolymphatic PO 2 , PCO 2 , and pH, and ionic concentrations of haemolymph and branchial chambe... more Haemolymphatic PO 2 , PCO 2 , and pH, and ionic concentrations of haemolymph and branchial chamber water were measured in submerged and emersed crabs. Hypercapnia and respiratory acidosis were recorded after 15 min of air exposure, then P CO 2 remained constant and pH was compensated. Sodium concentration increased in haemolymph and decreased in branchial water. The difference between haemolymph Na ϩ and Cl Ϫ increased dramatically. Acid-base balance is restored by two mechanisms: a) increase of the P CO 2 gradient across the gills and consequently the rate of CO 2 excretion; b) the increase in the strong ion difference, caused by branchial sodium uptake, compensates the hypercapnic acidosis. comp biochem physiol 117A;3:407-410, 1997.

Comparative Biochemistry and Physiology C-toxicology & Pharmacology, Jul 1, 2007

In Tierra del Fuego (Southern South America), the stone or false king crab, Paralomis granulosa r... more In Tierra del Fuego (Southern South America), the stone or false king crab, Paralomis granulosa represents one of the most important crab fisheries. After capture, animals are kept in baskets and exposed to dryness for several hours, when the water flow through the gills is interrupted. As a consequence a concomitant increase of reactive oxygen species begins, triggering oxidative stress. The aim of this study was to determine oxidative stress and antioxidant enzyme activities due to air exposure in different tissues of P. granulosa. Fifty crabs (carapace length &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;82 mm) were captured in Beagle Channel (54 degrees 50&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;S, 68 degrees 20&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;W) during winter 2004. Five groups of 10 crabs each were exposed to dryness at 6 degrees C for 0, 3, 6, 12 or 24 h, respectively. Activity of superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST) protein and lipid oxidation were measured in gills, muscle, hepatopancreas and haemolymph samples. Almost all analyzed tissues showed antioxidant enzymes activity, which varied with time of air exposure. The maximum enzyme activity was measured after 6 h of air exposure. Protein oxidation levels varied significantly in gills. Lipid peroxidation levels increased significantly in muscle and hepatopancreas. The critical time of air exposure probably occurs at 6 h. Thereafter animals were unable to induce the synthesis of antioxidant enzymes or proteins. This should be taken into account to minimize the stress generated by the commercial capture process.

Marine Environmental Research, May 1, 2005

The aim of this work was to investigate the activity of antioxidant enzymes and oxidative damage ... more The aim of this work was to investigate the activity of antioxidant enzymes and oxidative damage in the digestive gland of the limpet Nacella concinna, and their suitability as biomarkers for hydrocarbon pollution in Antarctic coasts. Three groups of 30 individuals each were kept in seawater containing 0%, 0.05% or 0.1% diesel. Superoxide dismutase, catalase, glutathione S transferase and glutathione peroxidase activities, as well as lipid peroxidation and protein oxidation were studied in 18 animals of each group after 24, 48 and 168 h of exposure. The activity levels of most enzymes were increased by diesel in a dose-dependent manner. Glutathione peroxidase showed the most clear effect; its activity significantly increased in the 0.1% diesel group respect to the control. Lipid peroxidation and protein oxidation were significantly increased by diesel after 168 h. Both variables were higher in the group exposed to the lowest dose.

Canadian Journal of Physiology and Pharmacology, Jun 1, 1989

Comparative Biochemistry and Physiology C-toxicology & Pharmacology, Jul 1, 2007

In a previous study we analysed the effect of diesel seawater contamination in the digestive glan... more In a previous study we analysed the effect of diesel seawater contamination in the digestive gland of the Antarctic limpet Nacella concinna. We observed that antioxidant enzyme activities decreased after one-week starvation prior to the experiment, and this was considered in the analysis of the obtained results. To know whether the digestive gland oxidant-antioxidant status may be altered by starvation and experimental conditions, we evaluated the food deprivation effect in limpets from the nearshore shallow waters of Potter Cove, Antarctica. Organisms were acclimated to laboratory conditions and were divided in fed and starved groups, and maintained in these conditions during one month. Every week 20 limpets were sampled from each group. Digestive glands were dissected and kept frozen until they were processed. Superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) measured as thiobarbituric reactive substances (TBARS), protein oxidation (PO) and reduced glutathione (GSH) were measured. For both groups of limpets, SOD increased its activity in the first week of the exposure period, with a maximum in the second week. CAT activity increased significantly in the second week, only for the starved group. Similarly, GST activity also increased for starved group in the second week; but maintained this tendency for both groups until the fourth week. In fed and starved limpets, TBARS values increased significantly, during the first week and then returned to normal values. The PO levels in the starved group increased only during the first week. The GSH content, for the fed group, increased significantly after the third week. The obtained results indicate that biochemical or physiological studies conducted with N. concinna should consider the effects of food deprivation and time spent under experimental conditions.

Aquatic Toxicology, 2013

Endosulfan (ES), a persistent organochlorine pesticide, is widely used despite its toxicity to no... more Endosulfan (ES), a persistent organochlorine pesticide, is widely used despite its toxicity to non-target animals. Upon reaching water bodies, ES can cause negative effects on aquatic animals, including disruption of hormonal systems. However, the action of ES on fish reproductive axis has been hardly studied thus far. The aim of the present work was to assess the endocrine disruptive potential of endosulfan on the pituitary gonadotropins levels and on the testes function due to ES in the South American freshwater fish Cichlasoma dimerus, using in vitro and in vivo approaches. In vitro experiments showed that ES inhibited the LH-stimulated steroidogenesis in gonads; no change was observed in gonadotropins release from pituitaries in culture. Laboratory waterborne ES (0.1, 0.3 and 1 g/L) exposure for two months caused decrease in ␤FSH pituitary content and ␥GT activity in the testes (Sertoli cell function marker). Testicular histology revealed pathologies such as scarce intermediate stages of spermatogenesis, release of immature germ cells into the lobular lumen, presence of foam cells and interstitial fibrosis. As FSH and FSH-mediated steroidogenesis regulate spermatogenesis and Sertoli cell function, the effect of ES on FSH could be responsible for the morphological alterations observed in testes. In vitro, ES disrupted steroidogenesis in gonads, therefore similar effects in vivo cannot be ruled out. Based on this evidence, ES exhibits an endocrine disruptive action on the reproductive axis of C. dimerus, causing disruption at the pituitary and/or at the gonad level. These effects could acquire ecological significance under prolonged exposure to the pesticide in nature.

Polar Biology, Mar 24, 2018

The limpet Nacella concinna is one of the most widely distributed gastropods along the Antarctic ... more The limpet Nacella concinna is one of the most widely distributed gastropods along the Antarctic Peninsula. This species has been a useful tool in ecological and physiological studies for understanding Antarctic trophic interactions. Although the reproduction of limpets has been thoroughly studied, very little is known about gametogenesis in the genus Nacella. The purpose of this study is to describe the gonadal morphology and gametogenesis in N. concinna observed by light microscopy and to determine its chromosome complement. All the limpets were sexually mature at the time of sampling. Oocytes were separated by trabeculae with abundant glycogen reserves. There was a predominance of late vitellogenic oocytes. Many previtellogenic oocytes were pyriform in shape. Oogonia were clustered near the ovary wall or the trabeculae. Only two meiotic stages were found: metaphase I and anaphase I, both of which showed a regular arrangement of chromosomes. The oviduct contained mature oocytes surrounded by sperm. Testicular tubules were filled with spermatozoa. The elongated head of the spermatozoon resembles that of other Nacellidae members. One of the bivalents is heteropycnotic. The haploid complement is n = 4 and the sex determination system is XO/XX. Although N. concinna has been commonly characterized as a broadcast-spawner, its unique spawning behavior, the presence of oocytes at anaphase I and spermatozoa within the oviduct suggests internal fertilization.

Environmental Pollution, Mar 1, 2016

Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine a... more Several pollutants, which include metals, are present in the Antarctic atmosphere, snow, marine and terrestrial organisms. This work reports the elements incorporated by Usnea sp thalli in Potter Peninsula, 25 de Mayo (King George) Island, South Shetlands, Antarctica. Geological origin was analyzed as possible sources of elements. For this purpose, correlations were done using a geochemical tracer, principal component analysis and enrichment factors were computed. Lithophile elements from particulate matter were present in most of the sampling sites. Bromine, Se and Hg showed the highest enrichment factors suggesting other sources than the particulate matter. Mercury values found in Usnea sp were in the same range as those reported for Deception Island (South Shetlands) and remote areas from the Patagonia Andes.

Polar Biology, Feb 23, 2000

Brazilian Journal of Medical and Biological Research, Apr 1, 1997

Comparative Biochemistry and Physiology C-toxicology & Pharmacology, May 1, 2011

The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarb... more The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarbons (WSF) on the antioxidant status of the freshwater prawn Macrobrachium borellii. First, seasonal variations were studied in a non-polluted area. Hepatopancreas and gills showed season-related fluctuations in catalase (CAT), glutathione-S-transferase (GST) activities and in lipid peroxidation levels (LPO), but not in superoxide dismutase (SOD). Then, adults were exposed semi-statically to sublethal doses for 7 days. CAT, SOD, GST, and glutathione peroxidase (GPx) activities and LPO, reduced glutathione (GSH) and protein oxidation (PO) levels were determined. Exposed individuals showed significant increases in CAT, SOD, and GST activities in hepatopancreas and CAT activity in gills. GPx activity did not vary in either tissues. While LPO levels increased, GSH levels decreased significantly in hepatopancreas of exposed animals, but PO levels showed no variation. Induction of SOD was also assessed by Real-time PCR mRNA expression in hepatopancreas. The nonenzymatic antioxidant activity was also tested; ABTS 2,2′-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) was higher in hemolymph of treated-prawns compared to controls, but ferric reducing activity of plasma assay (FRAP) values did not change. Taken together, the present results indicated that the antioxidant defenses of M. borellii, mainly in hepatopancreas, were significantly affected by aquatic hydrocarbon contamination, regardless of the season.

Aquaculture, Sep 1, 2011

In the Southern South America, the stone or false king crab Paralomis granulosa constitutes the m... more In the Southern South America, the stone or false king crab Paralomis granulosa constitutes the main crab fishery. One of the extremely stressful situations to fished crustaceans is the air-exposure handling once they are on deck. The aims of this study were to determine effects of air-exposure and re-submersion on: (1) the antioxidant enzyme activities and lipid peroxidation in different tissues; and (2) changes in the meat palatability in Paralomis granulosa. One hundred and twenty male crabs were captured in Beagle Channel (54°S, 68°W) and randomly assigned to the two planned experiments. For the air-exposure, four groups of 8 animals each were exposed to dryness at 7°C for 6 h, and then re-submerged for 0.5, 1, 2 and 24 h respectively, whereas a fifth group was used as control. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST), as well as lipid peroxidation were measured in gills, muscle, hepatopancreas and haemolymph. Almost all tissues showed a significant increase of antioxidant enzyme activities until 2 h of recovery (α = 0.05). The highest antioxidant enzyme activities were found in gills, in which SOD, CAT and GST activities were similar to the control values after 24 h of recovery. Moreover, gills and hepatopancreas showed significantly increased (α = 0.05) lipid peroxidation at 0.5 h of re-submersion. For the palatability assay, three groups of twenty crabs each were air-exposed at 7°C for: 6, 12 and 18 h and then re-submersed for 24 h, whereas a fourth group was used as control. Four dishes of~10 g meat each were offered to 30 judges who performed a taste ranking with the meat samples. Even if differences in the meat flavor of P. granulosa were detected, participants could not rank samples according to the increasing air exposure of animals. Live transportation of P. granulosa is promising and crabs can be re-submerged and offered alive.

Anais Da Academia Brasileira De Ciencias, 2022

Human activities are increased in Antarctica during decades, primarily due to the logistic and to... more Human activities are increased in Antarctica during decades, primarily due to the logistic and tourism operations, which consequent negative impact on penguin populations, altering their physiological responses. Therefore, we aimed to assess the blood biochemistry and oxidant/antioxidant balance of Adélie penguins (Pygoscelis adeliae) inhabiting two selected colonies: Potter Peninsula, considered as a low impacted colony, and Esperanza/Hope Bay as a high impacted colony. The levels of calcium, uric acid, and fructosamine, showed significant high values (p<0.05) for the Potter Peninsula´s penguins. Besides, this population showed high levels of plasma protein oxidation and erythrocyte lipid peroxidation (p<0.005) while the Esperanza/ Hope Bay population presented high levels of erythrocyte protein oxidation and plasma lipid peroxidation (p<0.005). The oxidative damage values were similar in the Potter Peninsula population and slightly lower in the Esperanza/Hope Bay penguins if the results were compared to previous reports. The enzymes superoxide dismutase and glutathione peroxidase had significantly (p<0.005) high activity in the Esperanza/Hope Bay population, which also showed high reduced glutathione levels. The glutathione S-transferase activity was significantly high (p<0.005) in the Potter Peninsula population. The obtained results might take into account for making decisions about management and protection plans for the different penguin nesting areas in Antarctica.

Polar Biology, May 15, 2020

Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Gmb... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag GmbH Germany, part of Springer Nature. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Marine Biology, Apr 24, 2021

The capacity of seabirds to shape their physiological and immune phenotypes may often be constrai... more The capacity of seabirds to shape their physiological and immune phenotypes may often be constrained by the ecological context. While phenotypic plasticity in physiological traits has been previously studied, the molecular mechanisms underlying phenotype plasticity in response to environmental stress have been little explored. This prompted us to enquire about how the nutritional and immune status are involved in physiological adaptations in breeding seabirds under anthropogenic pressure. At Esperanza (Hope) Bay, Antarctic Peninsula exists one of the biggest breeding penguin colony of Pygoscelis adeliae (Adélie). At this location, penguins nest nearby the Argentinian Esperanza Station and, therefore, are exposed to high levels of disturbance, whereas there is a low disturbed area, where penguins also breed far away from the Station. In both areas, the nutritional and immune status in breeding individuals was addressed and serum protein expression level was analyzed using a proteomic approach. Body mass, proteins, albumin, and triacylglycerol were higher in penguins from the low disturbance area, whereas uric acid increased in individuals from the disturbed area, indicating a poorer body condition of penguins under anthropogenic pressure. Immune responses were elevated in penguins from the disturbed area (IgY, γ-globulins and hemagglutinating activity). Finally, individuals breeding under anthropogenic pressure overexpressed proteins with immune, antioxidant, and metabolic functions. The poor nutritional status of penguins under disturbance may be the consequence of the reallocation of resources to the immune system. Altogether, this would constitute a potential strategy to preserve an adequate immune phenotype under stressed environments.