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Esteban Barreraoro - One of the best experts on this subject based on the ideXlab platform.
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new insights into the autecology of the two sympatric fish species Notothenia coriiceps and n rossii from western antarctic peninsula a trophic biomarkers approach
Polar Biology, 2021Co-Authors: Esteban Barreraoro, Eugenia Moreira, Katja Mintenbeck, Manuel Novillo, Gaston Alurralde, Marleen De TrochAbstract:Biomarker analysis, especially fatty acids (FA) and stable isotopes (SI), has become a useful tool to elucidate the flow of energy and trophic interactions in an ecosystem and to analyse the diet of species that are hard to observe whilst feeding. Herein we compare FA profiles and SI composition (nitrogen, δ15N and carbon, δ13C) of muscle tissue from two sympatric Antarctic fish species—Notothenia rossii and N. coriiceps—that are key components in the inshore ecosystem of the South Shetland Islands. For both nototheniids, potential benthic food sources (algae, amphipods, polychaetes and gastropods) were screened in order to re-evaluate their trophic position (TP) and the energy flow. Significant differences in FA and SI composition between the two fish species were found. Notothenia rossii showed a higher total FA concentration, with high levels of polyunsaturated FA. Conversely, the potential food sources tested showed low concentrations of these FAs. This could indicate that both nototheniids are feeding mainly on another food source or that FA bioconversion takes place. While the FA results might suggest a possible trophic niche segregation between N. rossii and N. coriiceps, both species occupy a similar trophic position. Furthermore, we found a 50-times higher total concentration of monounsaturated FA in N. rossii than in N. coriiceps that can be related to the higher buoyancy capacity of the former. Trophic biomarkers did not elucidate the main prey item as lipid source for N. rossii and N. coriiceps, suggesting that other food sources and potential fatty acid bioconversion should be further investigated.
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the importance of macroalgae and associated amphipods in the selective benthic feeding of sister rockcod species Notothenia rossii and n coriiceps nototheniidae in west antarctica
Polar Biology, 2019Co-Authors: Esteban Barreraoro, Eugenia Moreira, Meike Anna Seefeldt, Mariano Valli Francione, Maria Liliana QuartinoAbstract:Studies on feeding selectivity in Antarctic fish with comparison between diet organisms and those available in the wild are scarce. We explored this issue in Notothenia rossii (NOR) and N. coriiceps (NOC) at Potter Cove in summer 2016 to test: (1) their preference among different benthic groups, primarily species of algae and amphipods and (2) differences between these nototheniids given their distinct morphology but their known similar general ecology in the fjords. The methodology included a comparative analysis of benthic organisms identified in the stomachs and those collected on macroalgal beds (Ivlev Index). Benthic amphipods, mainly Gondogeneia antarctica and Cheirimedon femoratus, followed by macroalgae, mainly Palmaria decipiens and Desmarestia spp., were the most important and frequent dietary items (IRI%) for both nototheniids. However, NOC was more herbivorous and fed more intensively on a wider diversity of benthic organisms such as certain algal-associated groups like gastropods and bivalves, whereas NOR fed on a greater proportion of epibenthic amphipods and other epibenthic prey. Although in the last three decades the physiognomy of the inner cove has been changed due to the retreat of the Fourcade Glacier, at our sampling site in the outer cove the abundance and vertical distribution of macroalgae did not show substantial changes compared with those reported in the literature in 1994–1996. Temporal differences in the feeding selectivity of NOC on amphipod species, between contemporary and historical samples, may be explained by variations in the assemblage of the algal-associated epifauna. We suggest factors that may have produced these changes.
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changing status of three notothenioid fish at the south shetland islands 1983 2016 after impacts of the 1970 80s commercial fishery
Polar Biology, 2017Co-Authors: Esteban Barreraoro, Enrique Marschoff, David G AinleyAbstract:Owing to commercial fishing during the late 1970s/early 1980s, targeted notothenioid species had become depleted around the South Shetland Islands. Herein we report subsequent changes in the prevalence of three species, Notothenia rossii, Gobionotothen gibberifrons and Notothenia coriiceps in Potter Cove, King George Islands/Isla 25 de Mayo, in a 33-year effort to monitor recovery. N. rossii and G. gibberifrons had been severely impacted by industrial fishing but in offshore waters N. coriiceps had never been commercially fished; however, all three species exhibit similar nearshore habitats and life history. We examined composition in trammel net catches during 2012–2016, augmenting a time series started in 1983. Our inshore results were consistent with those from offshore bottom trawl sampling in 2007 and 2012 around the South Shetland Islands: (1) continued increase in the abundance of N. rossii; (2) further decline in G. gibberifrons recruitment evidenced by low proportions of juvenile fish; and (3) a high abundance of N. coriiceps. Reasons for lack of recovery in G. gibberifrons remain obscure but seemingly relate to the dramatically changing ecosystem of the region due in part to climate as well as recovery among previously depleted upper trophic level species. Our results are also consistent with trends reported in seabirds that feed on juveniles of these notothenioids: decrease in the areas commercially fished. Under the regulation of CCAMLR, commercial fishing for finfish in the South Shetland Islands region (FAO Subarea 48.1) remains prohibited since 1991; results indicate that it cannot be reinstated.
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linking population trends of antarctic shag phalacrocorax bransfieldensis and fish at nelson island south shetland islands antarctica
Polar Biology, 2016Co-Authors: Esteban Barreraoro, Ricardo CasauxAbstract:This study aims to provide consistent information to explain the steady declining trend in the number of breeding pairs of Antarctic shag Phalacrocorax bransfieldensis in two colonies on Nelson Island, South Shetland Islands, southern Atlantic sector of Antarctica, which was observed during the 1990s up to the mid 2000s over an overall monitoring period of over two decades. It addresses correspondence between long-term population trends of inshore demersal fish and inshore-feeding Antarctic shags of this area, where an intensive commercial fishery for shag prey once operated. The analysis also includes comparable information on diet (by examination of regurgitated pellets), foraging patterns, and breeding output of shags from the Danco Coast, western Antarctic Peninsula, an area where no commercial finfish fishery has ever existed. Integral study of these parameters there showed that, in Antarctic shags, low breeding success and high foraging effort might imply low recruitment and high adult mortality, respectively, with both factors adversely affecting the population trends of this bird. In line with these premises, the declining trend observed in shag colonies on the South Shetland Islands appears to have been influenced by the concomitant decrease in abundance of two of their main prey, the nototheniids Notothenia rossii and Gobionotothen gibberifrons, due to intensive industrial fishing in the area in the late 1970s. In comparison, no such pattern occurred for the Danco Coast colonies.
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dietary overlap among early juvenile stages in an antarctic notothenioid fish assemblage at potter cove south shetland islands
Polar Biology, 2014Co-Authors: Esteban Barreraoro, Eugenia Moreira, Mariana A JuaresAbstract:To date, studies of food overlap in Antarctic fish have been performed on a mixture of late juvenile and adult stages, leaving the young immature specimens (TL ≤ 10 cm) practically unexplored. We studied diet overlap and potential competition among early juvenile individuals in a coastal notothenioid community at Potter Cove, by analysing the stomach contents of 225 fish of 5 species collected in the summer of 2009–2010. We used frequency of occurrence (F %) and the coefficient “Q” for diet evaluation and the method of Tyler and the similarity index “S” for food overlap. Amphipods of the suborder Gammaridea were the main (Q > 2.900) and most frequent (% F) prey for all species, although Notothenia coriiceps also consumed gastropods of the family Littorinidae, mostly Laevilitorina antarctica. Secondary prey were algae for Notothenia rossii and N. coriiceps, calanoid (pelagic) and harpacticoid (benthic) copepods for Trematomus newnesi and the latter copepods and isopods of the family Munnidae for Lepidonotothen nudifrons. The reoccurrence of prey among fish species was 39.6 % and food overlap between 90 % of species pairs was under 58 %. Because similarly low values of diet overlap were reported for intermediate/advanced juveniles and adults of the same species at the same site, we conclude that there is no difference in the degree of interspecific food overlap and therefore potential competition between the immature and mature fraction of the fish community. Food competition is avoided by resource partitioning along a depth gradient or by different prey species.
Lucélia Donatti - One of the best experts on this subject based on the ideXlab platform.
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Effect of gradual temperature increase on the carbohydrate energy metabolism responses of the Antarctic fish Notothenia rossii.
Marine environmental research, 2019Co-Authors: Angela Carolina Guillen, Maria Rosa Dmengeon Pedreiro De Souza, Tatiana Herrerias, Priscila Krebsbach Kandalski, Marcelo Eduardo Borges, Elen De Arruda Marins, Douglas Viana, Letícia Oliveira Do Carmo Daloski, Lucélia DonattiAbstract:Abstract The warming of the Southern Ocean waters may affect the biological processes and the performance of the fish inhabiting it. The notothenioid group is metabolically specialized to low-temperature environments and may be vulnerable to the climatic changes imposed on the Antarctic continent. However, gradual temperature changes potentially allow an opportunity for plasticity adjustments. The present study evaluated the effect of gradual increase of temperature on the enzymatic and nonenzymatic parameters of energy metabolism in renal, branchial, hepatic, and encephalic tissue of Notothenia rossii subjected to a gradual temperature change of 0.5 °C/day until reaching 2 °C, 4 °C, 6 °C, and 8 °C. Under the effect of an acclimation rate of 0.5 °C/day, the gill tissue showed increased phosphofructokinase (PFK) enzyme activity. In the kidney, there was increased activity of the malate dehydrogenase (MDH), glucose-6-phosphatase (G6PDH), and glycogen phosphorylase (GP) enzymes. There was an increase in lactate concentration in the liver and an increase in GP enzyme activity in the brain. The specific tissue responses indicate the presence of thermal plasticity and an attempt to regulate energy metabolism to mitigate thermal stress in this species under these experimental conditions, possibly through the activation of glycolysis, gluconeogenesis, and glycogenolysis.
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Effect of long-term thermal challenge on the Antarctic notothenioid Notothenia rossii.
Fish physiology and biochemistry, 2019Co-Authors: Priscila Krebsbach Kandalski, Cintia Machado, Tânia Zaleski, Maria Rosa Dmengeon Pedreiro De Souza, Mariana Forgati, Claudio Adriano Piechnik, Flávia Baduy, Danilo Santos Eugênio, Luís Fernando Fávaro, Lucélia DonattiAbstract:The thermal stability of the Antarctic Ocean raises questions concerning the metabolic plasticity of Antarctic notothenioids to changes in the environmental temperature. In this study, Notothenia rossii survived 90 days at 8 °C, and their condition factor level was maintained. However, their hepatosomatic (0.29×) index decreased, indicating a decrease in nutrient storage as a result of changes in the energy demands to support survival. At 8 °C, the plasma calcium, magnesium, cholesterol, and triglyceride concentrations decreased, whereas the glucose (1.91×) and albumin (1.26×) concentrations increased. The main energy substrate of the fish changed from lipids to glucose due to a marked increase in lactate dehydrogenase activity, as demonstrated by an increase in anaerobic metabolism. Moreover, malate dehydrogenase activity increased in all tissues, suggesting that fish acclimated at 8 °C exhibit enhanced gluconeogenesis. The aerobic demand increased only in the liver due to an increase (2.23×) in citrate synthase activity. Decreases in the activities of superoxide dismutase, catalase, and glutathione-S-transferase to levels that are most likely sufficient at 8 °C were observed, establishing a new physiological activity range for antioxidant defense. Our findings indicate that N. rossii has some compensatory mechanisms that enabled its long-term survival at 8 °C.
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Heat stress in the heart and muscle of the Antarctic fishes Notothenia rossii and Notothenia coriiceps: Carbohydrate metabolism and antioxidant defence.
Biochimie, 2017Co-Authors: Maria Rosa Dmengeon Pedreiro De Souza, Cintia Machado, Tânia Zaleski, Tatiana Herrerias, Mariana Forgati, Priscila Krebsbach Kandalski, Dilza Trevisan Silva, Claudio Adriano Piechnik, Mauricio Osvaldo Moura, Lucélia DonattiAbstract:Carbohydrate metabolism and the antioxidant defence system of heart and muscle of the Antarctic notothenioids Notothenia rossii and Notothenia coriiceps were evaluated in response to heat stress (8 °C) over 144 h. N. rossii heart exhibited decreased glycolysis and aerobic metabolism after up to 12 h of exposure to 8 °C, and anaerobiosis was inhibited within 24 h. However, these pathways were stimulated after 72 h at 8 °C. The consumption of glucose-6-phosphate, derived from hexokinase (HK), by glucose-6-phosphate dehydrogenase (G6PDH) decreased in N. rossii heart within 6 h at 8 °C, with a subsequent increase at 72 h. In N. rossii muscle at 8 °C, glycolysis was stimulated within 2 h by an increase in pyruvate kinase (PK), and aerobic metabolism was stimulated at 144 h, together with anaerobiosis. In N. coriiceps heart at 8 °C, glucose break down by HK decreased within 2 h and subsequently increased at 12 and 24 h. Increased glucose-6-phosphate consumption by G6PDH occurred within 6 h at 8 °C. In N. coriiceps muscle at 8 °C, glycolysis was stimulated at 2 and 6 h, with subsequent inhibition within 24 h, as indicated by HK activity. Aerobic metabolism was inhibited at 72 and 144 h at 8 °C through the inhibition of citrate synthase (CS). Heat stress caused responses were only occasional and transient in antioxidant defence system of both species in the heart and muscle, leading to increased glutathione (GSH) and decreased levels of lipoperoxidation in the heart of both species. The results obtained in this study in the heart and muscles indicate that under heat stress at 8 °C, N. rossii is more responsive than N. coriiceps with respect to carbohydrate metabolism.
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Metabolic responses of the Antarctic fishes Notothenia rossii and Notothenia coriiceps to sewage pollution
Fish physiology and biochemistry, 2015Co-Authors: Edson Rodrigues, Lucélia Donatti, Mariana Feijó-oliveira, C. N. K. Suda, Gannabathula Sree Vani, Helena Passeri LavradoAbstract:The present study aimed to assess the sewage effects of the Brazilian Antarctic Station Comandante Ferraz, Admiralty Bay, King George Island, on the hepatic metabolism (energetic, antioxidant, and arginase levels) and levels of plasma constituents of two Antarctic fish species Notothenia rossii and N. coriiceps. The bioassays were conducted under controlled temperature (0 °C) and salinity (35 psu), exposing the fish for 96 h, to sewage effluent diluted in seawater to 0.5 % (v/v). Liver homogenates were tested for the specific activities of the enzymes glucose-6-phosphatase (G6Pase), glycogen phosphorylase (GPase), hexokinase, citrate synthase, lactate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, superoxide dismutase, glutathione reductase, catalase, and arginase. Plasma levels of glucose, triacylglycerides, cholesterol, total protein, albumin, chloride, magnesium, calcium, and inorganic phosphate were also determined. In N. rossii, the decrease in citrate synthase and the increase in G6Pase and GPase suggested that the sewage effluent activated glycogenolysis and hepatic gluconeogenesis, whereas is N. coriiceps, only G6Pase levels were increased. In N. rossii, sewage effluent induced hypertriglyceridemia without modulating glucose plasma levels, in contrast to N. coriiceps, which developed hypoglycemia without elevating plasma triglyceride levels. The decrease in glutathione reductase levels in N. coriiceps and in superoxide dismutase and catalase in N. rossii suggest that these two species are susceptible to oxidative stress stemming from the production of reactive oxygen species. An increase in magnesium in N. rossii and a decrease in N. coriiceps showed that sewage effluent compromised the control of plasma levels of this cation. Although phylogenetically close, both species of Antarctic fish exhibited different metabolic responses to the sewage effluent, with N. coriiceps showing greater susceptibility to the toxic effects of the pollutants. The present study suggests that the biochemical responses of these two species are potential indicators of metabolic changes caused by sewage effluents.
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Ecological and physiological aspects of the antarctic fishes Notothenia rossii and Notothenia coriiceps in Admiralty Bay, Antarctic Peninsula
Environmental Biology of Fishes, 2015Co-Authors: Gabriela Raga, Cintia Machado, Edson Rodrigues, Helen Audrey Pichler, Tânia Zaleski, Flavia Baduy Vaz Silva, Helena Gonçalves Kawall, Flavia Sant’anna Rios, Lucélia DonattiAbstract:The well-being, feeding habits and energetic and plasmatic parameters of the notothenioids Notothenia rossii and Notothenia coriiceps were assessed in specimens collected at a depth of up to 25 m in the Admiralty Bay region, King George Island, Antarctic Peninsula. The population structure of N. rossii ( n = 221) was composed of juveniles, and that of N. coriiceps ( n = 151) was composed of adults. The greatest mean length and weight measurements of N. coriiceps may be related to warming waters in the Antarctic Peninsula region. Salps were the dominant item in the diet of both species responsible for high protein quantity item found in muscle tissues and liver. The krill and amphipods were an important food item and related to lipid reserves. Among the indices evaluated, greater variation was observed in the hepatosomatic index of N. coriiceps and was related to the greater sizes and ages attained by this species. The liver and muscle energetic components showed great variability between different months may be related by the variability in diet. The plasma components did not exhibit seasonal patterns but displayed large monthly variation. Long-term analysis of the biological parameters evaluated in this study should be continued to monitor the species present in Admiralty Bay, a region with great biological diversity.
Barrera Oro Esteban - One of the best experts on this subject based on the ideXlab platform.
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Changing status of three notothenioid fish at the South Shetland Islands (1983–2016) after impacts of the 1970–80s commercial fishery
'Springer Science and Business Media LLC', 2017Co-Authors: Barrera Oro Esteban, Marschoff, Enrique Ricardo, Abramson DavidAbstract:Owing to commercial fishing during the late 1970s/early 1980s, targeted notothenioid species had become depleted around the South Shetland Islands. Herein we report subsequent changes in the prevalence of three species, Notothenia rossii, Gobionotothen gibberifrons and Notothenia coriiceps in Potter Cove, King George Islands/Isla 25 de Mayo, in a 33-year effort to monitor recovery. N. rossii and G. gibberifrons had been severely impacted by industrial fishing but in offshore waters N. coriiceps had never been commercially fished; however, all three species exhibit similar nearshore habitats and life history. We examined composition in trammel net catches during 2012–2016, augmenting a time series started in 1983. Our inshore results were consistent with those from offshore bottom trawl sampling in 2007 and 2012 around the South Shetland Islands: (1) continued increase in the abundance of N. rossii; (2) further decline in G. gibberifrons recruitment evidenced by low proportions of juvenile fish; and (3) a high abundance of N. coriiceps. Reasons for lack of recovery in G. gibberifrons remain obscure but seemingly relate to the dramatically changing ecosystem of the region due in part to climate as well as recovery among previously depleted upper trophic level species. Our results are also consistent with trends reported in seabirds that feed on juveniles of these notothenioids: decrease in the areas commercially fished. Under the regulation of CCAMLR, commercial fishing for finfish in the South Shetland Islands region (FAO Subarea 48.1) remains prohibited since 1991; results indicate that it cannot be reinstated.Fil: Barrera Oro, Esteban. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Marschoff, Enrique Ricardo. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Abramson, David. H.T. Harvey and Associates; Estados Unido
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Dietary overlap in inshore notothenioid fish from the Danco Coast, western Antarctic Peninsula
Co-action Publishing, 2016Co-Authors: Casaux, Ricardo Jorge, Barrera Oro EstebanAbstract:We carried out a dietary overlap analysis between notothenioid species by examining the stomach contents of more than 900 specimens collected in a fish assemblage at the Danco Coast, western Antarctic Peninsula, in the summer of 2000. Prey reoccurrences among fish species were 32.2%, with krill Euphausia superba, salps and the gammaridean Prostebeingia longicornis the most reoccurring prey. The diet similarity between species pairs was lower than 55%, in accordance with similar fish assemblages in the South Orkney Islands, the South Shetland Islands and the Antarctic Peninsula. Whereas at those localities the higher prey overlap was between krill-feeding fish species, at the Danco Coast it was between Trematomus bernacchii and Lepidonotothen nudifrons, Notothenia coriiceps and Notothenia rossii, Notothenia coriiceps and Parachaenichthyis charcoti, and Trematomus newnesi and Notothenia rossii, which shared primarily gammaridean amphipods, algae, fish and krill, respectively. Krill is normally the main prey of fish in summer in inshore waters of the western Antarctic Peninsula, but its density in January/February 2000 was notably lower than in previous years. Therefore, at the Danco Coast, under conditions of krill shortage, most of the notothenioid species foraged more intensively on alternative prey, such as gammarideans, fish and algae. The difference between areas in the pattern of dietary overlap might be related to differences in prey availability between years and to the degree of competition for targeted prey.Fil: Casaux, Ricardo Jorge. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barrera Oro, Esteban. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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Linking population trends of Antarctic Shag (Phalacrocorax bransfieldensis) and fish at Nelson Island, South Shetland Islands (Antarctica)
'Springer Science and Business Media LLC', 2015Co-Authors: Casaux, Ricardo Jorge, Barrera Oro EstebanAbstract:This study aims to provide consistent information to explain the steady declining trend in the number of breeding pairs of Antarctic shag Phalacrocorax bransfieldensis in two colonies on Nelson Island, South Shetland Islands, southern Atlantic sector of Antarctica, which was observed during the 1990s up to the mid 2000s over an overall monitoring period of over two decades. It addresses correspondence between long-term population trends of inshore demersal fish and inshore-feeding Antarctic shags of this area, where an intensive commercial fishery for shag prey once operated. The analysis also includes comparable information on diet (by examination of regurgitated pellets), foraging patterns, and breeding output of shags from the Danco Coast, western Antarctic Peninsula, an area where no commercial finfish fishery has ever existed. Integral study of these parameters there showed that, in Antarctic shags, low breeding success and high foraging effort might imply low recruitment and high adult mortality, respectively, with both factors adversely affecting the population trends of this bird. In line with these premises, the declining trend observed in shag colonies on the South Shetland Islands appears to have been influenced by the concomitant decrease in abundance of two of their main prey, the nototheniids Notothenia rossii and Gobionotothen gibberifrons, due to intensive industrial fishing in the area in the late 1970s. In comparison, no such pattern occurred for the Danco Coast colonies.Fil: Casaux, Ricardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Barrera Oro, Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentin
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Early life history timings in marbled rockcod (Notothenia rossii) fingerlings from the South Shetland Islands as revealed by otolith microincrement
'Springer Science and Business Media LLC', 2014Co-Authors: Barrera Oro Esteban, La Mesa Mario, Moreira, María EugeniaAbstract:Although it has been reported that Notothenia rossii elsewhere hatches in spring, our daily increment back-counting from the capture date in otoliths of fingerlings caught in Potter Cove, South Shetland Islands, in the 2000s, showed two main periods of larval hatching, one in summer (February–March) and another in winter (July). In concordance, the simultaneous presence of two cohorts born the same year was identified in the age/length frequency distribution of fish sampled in spring 2010, which belonged to biological ages 0+ and 1+ and hatched, respectively, in summer and winter–spring. Maximum and minimum ages of pelagic blue-phase and demersal brown-phase fingerlings were, respectively, 227 and 240 days, indicating a demersal settlement after about 8 months from hatching. The estimated growth rate was 0.23–0.33 mm/day, equivalent to that of South Georgia fingerlings and higher than those of other nototheniids of similar size range. Based on early life events associated with the hatching periods, two types of life cycles are hypothesised for South Shetland fingerlings. The pelagic blue-phase fingerlings (6.5–7.6 cm TL, age group 0+) hatched in July (winter cohort), entering in Potter Cove in February–March. The brown-phase fingerlings (6.3–10.6 cm, mostly of age group 0+) hatched in February–March (summer cohort) and were collected in the cove in spring (the smaller specimens) or in summer (the larger ones). Finally, early juveniles (10.7–15.5 cm, age group 1+) hatched in winter, mainly in July (winter cohort), entering in the cove the following year to spend the second winter inshore.Fil: Barrera Oro, Esteban. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: La Mesa, Mario. Consiglio Nazionale delle Ricerche. Istituto Di Scienze Marine; ItaliaFil: Moreira, María Eugenia. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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Dietary overlap among early juvenile stages in an Antarctic notothenioid fish assemblage at Potter Cove, South Shetland Islands
'Springer Science and Business Media LLC', 2014Co-Authors: Moreira, María Eugenia, Juares, Mariana Alejandra, Barrera Oro EstebanAbstract:To date, studies of food overlap in Antarctic fish have been performed on a mixture of late juvenile and adult stages, leaving the young immature specimens (TL ≤ 10 cm) practically unexplored. We studied diet overlap and potential competition among early juvenile individuals in a coastal notothenioid community at Potter Cove, by analysing the stomach contents of 225 fish of 5 species collected in the summer of 2009–2010. We used frequency of occurrence (F %) and the coefficient “Q” for diet evaluation and the method of Tyler and the similarity index “S” for food overlap. Amphipods of the suborder Gammaridea were the main (Q > 2.900) and most frequent (% F) prey for all species, although Notothenia coriiceps also consumed gastropods of the family Littorinidae, mostly Laevilitorina antarctica. Secondary prey were algae for Notothenia rossii and N. coriiceps, calanoid (pelagic) and harpacticoid (benthic) copepods for Trematomus newnesi and the latter copepods and isopods of the family Munnidae for Lepidonotothen nudifrons. The reoccurrence of prey among fish species was 39.6 % and food overlap between 90 % of species pairs was under 58 %. Because similarly low values of diet overlap were reported for intermediate/advanced juveniles and adults of the same species at the same site, we conclude that there is no difference in the degree of interspecific food overlap and therefore potential competition between the immature and mature fraction of the fish community. Food competition is avoided by resource partitioning along a depth gradient or by different prey species.Fil: Moreira, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Juares, Mariana Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Barrera Oro, Esteban. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin
Eugenia Moreira - One of the best experts on this subject based on the ideXlab platform.
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new insights into the autecology of the two sympatric fish species Notothenia coriiceps and n rossii from western antarctic peninsula a trophic biomarkers approach
Polar Biology, 2021Co-Authors: Esteban Barreraoro, Eugenia Moreira, Katja Mintenbeck, Manuel Novillo, Gaston Alurralde, Marleen De TrochAbstract:Biomarker analysis, especially fatty acids (FA) and stable isotopes (SI), has become a useful tool to elucidate the flow of energy and trophic interactions in an ecosystem and to analyse the diet of species that are hard to observe whilst feeding. Herein we compare FA profiles and SI composition (nitrogen, δ15N and carbon, δ13C) of muscle tissue from two sympatric Antarctic fish species—Notothenia rossii and N. coriiceps—that are key components in the inshore ecosystem of the South Shetland Islands. For both nototheniids, potential benthic food sources (algae, amphipods, polychaetes and gastropods) were screened in order to re-evaluate their trophic position (TP) and the energy flow. Significant differences in FA and SI composition between the two fish species were found. Notothenia rossii showed a higher total FA concentration, with high levels of polyunsaturated FA. Conversely, the potential food sources tested showed low concentrations of these FAs. This could indicate that both nototheniids are feeding mainly on another food source or that FA bioconversion takes place. While the FA results might suggest a possible trophic niche segregation between N. rossii and N. coriiceps, both species occupy a similar trophic position. Furthermore, we found a 50-times higher total concentration of monounsaturated FA in N. rossii than in N. coriiceps that can be related to the higher buoyancy capacity of the former. Trophic biomarkers did not elucidate the main prey item as lipid source for N. rossii and N. coriiceps, suggesting that other food sources and potential fatty acid bioconversion should be further investigated.
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the importance of macroalgae and associated amphipods in the selective benthic feeding of sister rockcod species Notothenia rossii and n coriiceps nototheniidae in west antarctica
Polar Biology, 2019Co-Authors: Esteban Barreraoro, Eugenia Moreira, Meike Anna Seefeldt, Mariano Valli Francione, Maria Liliana QuartinoAbstract:Studies on feeding selectivity in Antarctic fish with comparison between diet organisms and those available in the wild are scarce. We explored this issue in Notothenia rossii (NOR) and N. coriiceps (NOC) at Potter Cove in summer 2016 to test: (1) their preference among different benthic groups, primarily species of algae and amphipods and (2) differences between these nototheniids given their distinct morphology but their known similar general ecology in the fjords. The methodology included a comparative analysis of benthic organisms identified in the stomachs and those collected on macroalgal beds (Ivlev Index). Benthic amphipods, mainly Gondogeneia antarctica and Cheirimedon femoratus, followed by macroalgae, mainly Palmaria decipiens and Desmarestia spp., were the most important and frequent dietary items (IRI%) for both nototheniids. However, NOC was more herbivorous and fed more intensively on a wider diversity of benthic organisms such as certain algal-associated groups like gastropods and bivalves, whereas NOR fed on a greater proportion of epibenthic amphipods and other epibenthic prey. Although in the last three decades the physiognomy of the inner cove has been changed due to the retreat of the Fourcade Glacier, at our sampling site in the outer cove the abundance and vertical distribution of macroalgae did not show substantial changes compared with those reported in the literature in 1994–1996. Temporal differences in the feeding selectivity of NOC on amphipod species, between contemporary and historical samples, may be explained by variations in the assemblage of the algal-associated epifauna. We suggest factors that may have produced these changes.
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dietary overlap among early juvenile stages in an antarctic notothenioid fish assemblage at potter cove south shetland islands
Polar Biology, 2014Co-Authors: Esteban Barreraoro, Eugenia Moreira, Mariana A JuaresAbstract:To date, studies of food overlap in Antarctic fish have been performed on a mixture of late juvenile and adult stages, leaving the young immature specimens (TL ≤ 10 cm) practically unexplored. We studied diet overlap and potential competition among early juvenile individuals in a coastal notothenioid community at Potter Cove, by analysing the stomach contents of 225 fish of 5 species collected in the summer of 2009–2010. We used frequency of occurrence (F %) and the coefficient “Q” for diet evaluation and the method of Tyler and the similarity index “S” for food overlap. Amphipods of the suborder Gammaridea were the main (Q > 2.900) and most frequent (% F) prey for all species, although Notothenia coriiceps also consumed gastropods of the family Littorinidae, mostly Laevilitorina antarctica. Secondary prey were algae for Notothenia rossii and N. coriiceps, calanoid (pelagic) and harpacticoid (benthic) copepods for Trematomus newnesi and the latter copepods and isopods of the family Munnidae for Lepidonotothen nudifrons. The reoccurrence of prey among fish species was 39.6 % and food overlap between 90 % of species pairs was under 58 %. Because similarly low values of diet overlap were reported for intermediate/advanced juveniles and adults of the same species at the same site, we conclude that there is no difference in the degree of interspecific food overlap and therefore potential competition between the immature and mature fraction of the fish community. Food competition is avoided by resource partitioning along a depth gradient or by different prey species.
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Early life history timings in marbled rockcod (Notothenia rossii) fingerlings from the South Shetland Islands as revealed by otolith microincrement
Polar Biology, 2014Co-Authors: Esteban Barrera-oro, Mario La Mesa, Eugenia MoreiraAbstract:Although it has been reported that Notothenia rossii elsewhere hatches in spring, our daily increment back-counting from the capture date in otoliths of fingerlings caught in Potter Cove, South Shetland Islands, in the 2000s, showed two main periods of larval hatching, one in summer (February–March) and another in winter (July). In concordance, the simultaneous presence of two cohorts born the same year was identified in the age/length frequency distribution of fish sampled in spring 2010, which belonged to biological ages 0+ and 1+ and hatched, respectively, in summer and winter–spring. Maximum and minimum ages of pelagic blue-phase and demersal brown-phase fingerlings were, respectively, 227 and 240 days, indicating a demersal settlement after about 8 months from hatching. The estimated growth rate was 0.23–0.33 mm/day, equivalent to that of South Georgia fingerlings and higher than those of other nototheniids of similar size range. Based on early life events associated with the hatching periods, two types of life cycles are hypothesised for South Shetland fingerlings. The pelagic blue-phase fingerlings (6.5–7.6 cm TL, age group 0+) hatched in July (winter cohort), entering in Potter Cove in February–March. The brown-phase fingerlings (6.3–10.6 cm, mostly of age group 0+) hatched in February–March (summer cohort) and were collected in the cove in spring (the smaller specimens) or in summer (the larger ones). Finally, early juveniles (10.7–15.5 cm, age group 1+) hatched in winter, mainly in July (winter cohort), entering in the cove the following year to spend the second winter inshore.
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Age validation of juvenile Notothenia rossii at Potter Cove, South Shetland Islands, using mark-recapture data
Polar Biology, 2013Co-Authors: Eugenia Moreira, Esteban Barrera-oro, Mario La MesaAbstract:Among all validation methods of age determination in fish, release of known age and marked specimens gives the most reliable information. We carried out a tag-recapture experiment on Notothenia rossii at Potter Cove, to validate, for first time for this species using this method, the principle of annual deposition of an annulus in scales and otoliths. Of 132 juvenile specimens (TL = 22.1–38.1 cm) tagged and released in successive years from 2004 to 2010, 7 were recaptured at the same site after periods of 1–13 months. In scales of five specimens recovered after 10–13 months, one extra annulus was laid down, exhibiting an additional winter zone of closely spaced sclerites. Consistently, the same analysis in two individuals marked and recaptured during the same summer, after 1–3 months at liberty, did not show the deposition of an additional annulus. All the fish tagged or recaptured during the experiment period (December to March) showed in their scales an edge zone of widely spaced sclerites, in agreement with the known pattern of growth in summer. Likewise, an analysis in selected specimens showed good consistency between the numbers of sclerites deposited in scales and the time of fish release. The comparative analysis between scales taken at recapture and otoliths of the same individual allowed a simultaneous counting of the annuli with complete correspondence. The growth in length of fish ranged from 0.5 to 6.1 cm, depending on the time of release.
Felix Christopher Mark - One of the best experts on this subject based on the ideXlab platform.
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mitochondrial acclimation capacities to ocean warming and acidification are limited in the antarctic nototheniid fish Notothenia rossii and lepidonotothen squamifrons
PLOS ONE, 2013Co-Authors: Anneli Strobel, Martin Graeve, Hans O Poertner, Felix Christopher MarkAbstract:Antarctic notothenioid fish are characterized by their evolutionary adaptation to the cold, thermostable Southern Ocean, which is associated with unique physiological adaptations to withstand the cold and reduce energetic requirements but also entails limited compensation capacities to environmental change. This study compares the capacities of mitochondrial acclimation to ocean warming and acidification between the Antarctic nototheniid Notothenia rossii and the sub-Antarctic Lepidonotothen squamifrons, which share a similar ecology, but different habitat temperatures. After acclimation of L. squamifrons to 9°C and N. rossii to 7°C (normocapnic/hypercapnic, 0.2 kPa CO2/2000 ppm CO2) for 4–6 weeks, we compared the capacities of their mitochondrial respiratory complexes I (CI) and II (CII), their P/O ratios (phosphorylation efficiency), proton leak capacities and mitochondrial membrane fatty acid compositions. Our results reveal reduced CII respiration rates in warm-acclimated L. squamifrons and cold hypercapnia-acclimated N. rossii. Generally, L. squamifrons displayed a greater ability to increase CI contribution during acute warming and after warm-acclimation than N. rossii. Membrane unsaturation was not altered by warm or hypercapnia-acclimation in both species, but membrane fatty acids of warm-acclimated L. squamifrons were less saturated than in warm normocapnia−/hypercapnia-acclimated N. rossii. Proton leak capacities were not affected by warm or hypercapnia-acclimation of N. rossii. We conclude that an acclimatory response of mitochondrial capacities may include higher thermal plasticity of CI supported by enhanced utilization of anaplerotic substrates (via oxidative decarboxylation reactions) feeding into the citrate cycle. L. squamifrons possesses higher relative CI plasticities than N. rossii, which may facilitate the usage of energy efficient NADH-related substrates under conditions of elevated energy demand, possibly induced by ocean warming and acidification. The observed adjustments of electron transport system complexes with a higher flux through CI under warming and acidification suggest a metabolic acclimation potential of the sub-Antarctic L. squamifrons, but only limited acclimation capacities for N. rossii.
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Elevated temperature and PCO2 shift metabolic pathways in differentially oxidative tissues of Notothenia rossii.
Comparative biochemistry and physiology. Part B Biochemistry & molecular biology, 2013Co-Authors: Anneli Strobel, Hans-otto Pörtner, Elettra Leo, Felix Christopher MarkAbstract:Mitochondrial plasticity plays a central role in setting the capacity for acclimation of aerobic metabolism in ectotherms in response to environmental changes. We still lack a clear picture if and to what extent the energy metabolism and mitochondrial enzymes of Antarctic fish can compensate for changing temperatures or PCO2 and whether capacities for compensation differ between tissues. We therefore measured activities of key mitochondrial enzymes (citrate synthase (CS), cytochrome c oxidase (COX)) from heart, red muscle, white muscle and liver in the Antarctic fish Notothenia rossii after warm- (7 degrees C) and hypercapnia- (0.2kPa CO2) acclimation vs. control conditions (1 degrees C, 0.04kPa CO2). In heart, enzymes showed elevated activities after cold-hypercapnia acclimation, and a warm-acclimation-induced upward shift in thermal optima. The strongest increase in enzyme activities in response to hypercapnia occurred in red muscle. In white muscle, enzyme activities were temperature-compensated. CS activity in liver decreased after warm-normocapnia acclimation (temperature-compensation), while COX activities were lower after cold- and warm-hypercapnia exposure, but increased after warm-normocapnia acclimation. In conclusion, warm-acclimated N. rossii display low thermal compensation in response to rising energy demand in highly aerobic tissues, such as heart and red muscle. Chronic environmental hypercapnia elicits increased enzyme activities in these tissues, possibly to compensate for an elevated energy demand for acid-base regulation or a compromised mitochondrial metabolism, that is predicted to occur in response to hypercapnia exposure. This might be supported by enhanced metabolisation of liver energy stores. These patterns reflect a limited capacity of N. rossii to reorganise energy metabolism in response to rising temperature and PCO2.
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metabolic shifts in the antarctic fish Notothenia rossii in response to rising temperature and pco2
Frontiers in Zoology, 2012Co-Authors: Anneli Strobel, Elettra Leo, Swaantje Bennecke, Katja Mintenbeck, Hans O Portner, Felix Christopher MarkAbstract:Ongoing ocean warming and acidification increasingly affect marine ecosystems, in particular around the Antarctic Peninsula. Yet little is known about the capability of Antarctic notothenioid fish to cope with rising temperature in acidifying seawater. While the whole animal level is expected to be more sensitive towards hypercapnia and temperature, the basis of thermal tolerance is set at the cellular level, with a putative key role for mitochondria. This study therefore investigates the physiological responses of the Antarctic Notothenia rossii after long-term acclimation to increased temperatures (7°C) and elevated P CO2 (0.2 kPa CO2) at different levels of physiological organisation. For an integrated picture, we analysed the acclimation capacities of N. rossii by measuring routine metabolic rate (RMR), mitochondrial capacities (state III respiration) as well as intra- and extracellular acid–base status during acute thermal challenges and after long-term acclimation to changing temperature and hypercapnia. RMR was partially compensated during warm- acclimation (decreased below the rate observed after acute warming), while elevated P CO2 had no effect on cold or warm acclimated RMR. Mitochondrial state III respiration was unaffected by temperature acclimation but depressed in cold and warm hypercapnia-acclimated fish. In both cold- and warm-exposed N. rossii, hypercapnia acclimation resulted in a shift of extracellular pH (pHe) towards more alkaline values. A similar overcompensation was visible in muscle intracellular pH (pHi). pHi in liver displayed a slight acidosis after warm normo- or hypercapnia acclimation, nevertheless, long-term exposure to higher P CO2 was compensated for by intracellular bicarbonate accumulation. The partial warm compensation in whole animal metabolic rate indicates beginning limitations in tissue oxygen supply after warm-acclimation of N. rossii. Compensatory mechanisms of the reduced mitochondrial capacities under chronic hypercapnia may include a new metabolic equilibrium to meet the elevated energy demand for acid–base regulation. New set points of acid–base regulation under hypercapnia, visible at the systemic and intracellular level, indicate that N. rossii can at least in part acclimate to ocean warming and acidification. It remains open whether the reduced capacities of mitochondrial energy metabolism are adaptive or would impair population fitness over longer timescales under chronically elevated temperature and P CO2.
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metabolic shifts in the antarctic fish Notothenia rossii in response to rising temperature and pco2
Frontiers in Zoology, 2012Co-Authors: Anneli Strobel, Elettra Leo, Swaantje Bennecke, Katja Mintenbeck, Hans O Portner, Felix Christopher MarkAbstract:Introduction: Ongoing ocean warming and acidification increasingly affect marine ecosystems, in particular around the Antarctic Peninsula. Yet little is known about the capability of Antarctic notothenioid fish to cope with rising temperature in acidifying seawater. While the whole animal level is expected to be more sensitive towards hypercapnia and temperature, the basis of thermal tolerance is set at the cellular level, with a putative key role for mitochondria. This study therefore investigates the physiological responses of the Antarctic Notothenia rossii after long-term acclimation to increased temperatures (7°C) and elevated PCO2 (0.2 kPa CO2) at different levels of physiological organisation. Results: For an integrated picture, we analysed the acclimation capacities of N. rossii by measuring routine metabolic rate (RMR), mitochondrial capacities (state III respiration) as well as intra- and extracellular acid–base status during acute thermal challenges and after long-term acclimation to changing temperature and hypercapnia. RMR was partially compensated during warm- acclimation (decreased below the rate observed after acute warming), while elevated PCO2 had no effect on cold or warm acclimated RMR. Mitochondrial state III respiration was unaffected by temperature acclimation but depressed in cold and warm hypercapnia-acclimated fish. In both cold- and warm-exposed N. rossii, hypercapnia acclimation resulted in a shift of extracellular pH (pHe) towards more alkaline values. A similar overcompensation was visible in muscle intracellular pH (pHi). pHi in liver displayed a slight acidosis after warm normo- or hypercapnia acclimation, nevertheless, long-term exposure to higher PCO2 was compensated for by intracellular bicarbonate accumulation. Conclusion: The partial warm compensation in whole animal metabolic rate indicates beginning limitations in tissue oxygen supply after warm-acclimation of N. rossii. Compensatory mechanisms of the reduced mitochondrial capacities under chronic hypercapnia may include a new metabolic equilibrium to meet the elevated energy demand for acid–base regulation. New set points of acid–base regulation under hypercapnia, visible at the systemic and intracellular level, indicate that N. rossii can at least in part acclimate to ocean warming and acidification. It remains open whether the reduced capacities of mitochondrial energy metabolism are adaptive or would impair population fitness over longer timescales under chronically elevated temperature and PCO2.
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Response of the stenothermal Antarctic fish Notothenia rossii to ocean warming and acidification
2012Co-Authors: Felix Christopher Mark, Anneli Strobel, Elettra Leo, Swaantje Bennecke, Martin Graeve, Hans-otto PörtnerAbstract:Ongoing ocean warming and acidification have been found to particularly affect polar marine ecosystems. However, few data exist about the ability of Antarctic fish to respond to environmental change. We therefore studied the acclimatory capacities of the Antarctic fish Notothenia rossii after 4-6 weeks of acclimation to 7°C, hypercapnia (0.2 kPa CO2) and the combination of both. We analysed routine metabolic rate (RMR) during acute thermal challenge and after acclimation, extra- and intracellular acid-base status, mitochondrial as well as enzymatic capacities and lipid composition. Our results showed partially compensated RMR after warm acclimation and no effect of increased PCO2 on the RMR. Hypercapnic acclimation led to a general overcompensation of extracellular pH. Intracellular pH displayed a slight acidosis in liver after warm normocapnic/hypercapnic acclimation, whereas white muscle remained well buffered under hypercapnia. Mitochondrial state III respiration in liver was unaffected by temperature acclimation, but depressed in the hypercapnia acclimated animals, which went along with reduced rates of proton leak. The activities of the mitochondrial enzymes citrate synthase and cytochrome c oxidase increased during hypercapnia acclimation in red and white muscle, but not in liver and heart. Furthermore, there was a trend towards an enrichment of poly-unsaturated fatty acids in liver mitochondria towards the warm hypercapnic conditions. We conclude that N. rossii possesses basic acclimatory capacities towards ocean warming and acidification. However, these capacities are confined within strict limits, becoming obvious in metabolically more active organs like heart and liver that show less plasticity than muscle and ultimately define animal survival.
