Eugenia Moreira

Instituto Antártico Argentino / CONICET - BIOLAB UNCPBA

The trophic ecology of several cryonotothenioid species has been well studied, but scarcely on the juvenile fraction of their populations. Particularly, till date the inter-annual variation of the diet composition and feeding habits of these young notothenioid stages has not been explored. Herein, we analysed the trophic ecology of 755 specimens of...

Durante el análisis parasitológico de individuos de Chaenocephalus aceratus (pez de hielo) provenientes de las Islas Shetland del Sur se hallaron en la vesícula biliar mixosporidios. El material obtenido fue fotografiado y medido. Parte del mismo se utilizó para MET y otra parte fue fijada en alcohol 96% para identificación molecular. Se secuenció...

Parental care and nest guarding behaviors have been described for all major clades of Antarctic notothenioid fishes. In possible association with this reproductive behavior, there is no evidence of significant fish egg predation in notothenioids so far. Here, we report a recently ingested fish egg mass in the stomach of a large specimen of the vora...

Prior understanding of Harpagifer antarcticus reproductive biology was based exclusively on macroscopic observations of its gonadal maturation cycle. Our present study with H. antarcticus specimens collected in summer of 2019 at Paradise Bay (PB), Western Antarctic Peninsula (WAP), provides a) additional reproductive parameters, and b) for first ti...

Concentrations of polybrominated diphenyl ethers (PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs); are reported in specimens of fish notothenioids Chaenocephalus aceratus (SSI), Trematomus bernacchii (ERN), and Nototheniops nudifrons (NOD) from the South Shetland Islands, Antarctica. Significant differences in the accumulation of...

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 fr...

The spatio-temporal delimitation of fish reproduction is essential for the appropriate management and conservation strategies in populations. Assessing this feature in Antarctic Ichthyology is particularly difficult because harsh environmental conditions limit sample collection. This study shows how physiology can contribute compelling evidence to...

In agricultural soils, fungi constitute most of the total microbial biomass in the environment contributing with more than 50% of the soil biomass. The fungi should be considered as a link in the production not only by their attributes but also for their potential pathogenicity on crops chains. We aim to determine in what extent the combination of...

We analyzed the effect of different tillage systems on soils under different land-use histories, on biological properties of soil during one year. The experiment was carried out at a Petrocalcic Argiudoll of Tres Arroyos (Buenos Aires, Argentina). The specific aim was to describe and compare the soil organic carbon (SOC), the soil basal respiration...

Although many notothenioid fishes are primarily carnivorous, some species consistently feed on macroalgae and are therefore omnivorous. Among fish, the degree of herbivory is usually reflected in the morphology of the gastrointestinal system especially intestine length. We examined a large number of juvenile and adult specimens of nine sympatric no...

The knowledge of the reproductive biology of blackfin icefish Chaenocephalus aceratus in the southern Scotia Arc has been based, primarily on macroscopic observations of its maturation cycle, and lately, on histological analysis of ovaries in developing phase exclusively. Our study on reproduction of C. aceratus collected at Potter Cove (PC), South...

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 while feeding. Herein we compare FA profiles and SI composition (nitrogen, δ15N and carbon, δ13C) of muscle tissue fro...

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) diff...

Studies on reproduction of the dragonfishes, Bathydraconidae, are scarce, and within this family, the reproductive biology of Parachaenichthys charcoti was poorly understood. Herein we present a histologic analysis of P. charcoti ovaries together with data on reproductive effort using fish collected with trammel nets in austral summer at Potter Cov...

At Potter Cove, King George Island/Isla 25 de Mayo, South Shetland Islands, significant ichthyological research has been conducted in the last three decades, mainly on the general ecology of notothenioid species in demersal stages from young juveniles to adults. Nevertheless, the knowledge of the ichthyoplankton composition in the cove, necessary f...

It is reported the first record of early stages of Antarctic notothenioids collected in pelagic hauls at Potter Cove in summers of 2014 and 2016 at depths of 6-9 m from the surface, where total bottom depth ranged 30-190 m. The ichthyoplankton consisted of a), 37 larval stages (preflexion and postflexion) of the species Harpagifer antarcticus (the...

Although many notothenioid fishes are primarily carnivorous, some species consistently feed on macroalgae and are therefore omnivorous. The degree of herbivory is reflected in the morphology of the digestive tract especially intestine length. We examined a large number of juvenile and adult specimens of eight sympatric notothenioid species collecte...

Knowledge of the food web structure and complexity are central to better understand ecosystem functioning. A food-web approach includes both species and energy flows among them, providing a natural framework for characterizing species’ ecological roles and the mechanisms through which biodiversity influences ecosystem dynamics. Here we present for...

Knowledge of the food web structure and complexity are central to better understand ecosystem functioning. A food-web approach includes both species and energy flows among them, providing a natural framework for characterizing species’ ecological roles and the mechanisms through which biodiversity influences ecosystem dynamics. Here we present for...

In the present study, the possible associations between selected persistent organic pollutants (POPs) and biological factors were assessed in different tissues of two Antarctic notothenioid fish: Notothenia rossii (NOR) and Trematomus newnesi (TRN) collected at Potter Cove, King George Island/Isla 25 de Mayo, South Shetland Islands. Specifically, asso...

The study of food web structure and complexity is central to better understand ecosystem functioning. A food-web approach includes both species and energy flows among them, providing a natural framework for characterizing species’ ecological roles and the mechanisms through which biodiversity influences ecosystem dynamics. Here we present for the f...

The crustacean amphipod superfamily Lysianassoidea plays an important role in Southern Ocean benthic food webs due to high biomass and abundance and their predominantly scavenging mode of feeding. However, their poorly differentiated morphology and their unsolved phylogenetic relationships impede our understanding of the lysianassoid fauna even in...

Amphipoda from the superfamily Lysianassoidea Dana, 1849 play an important role in Southern Ocean benthic food webs due to their high biomass, abundance and predominantly scavenging mode of feeding. Our knowledge on the lysianassoid fauna, even in well-studied areas of the Western Antarctic Peninsula, is incomplete. Here we report the findings of a...

Certain wild animals represent excellent models, or sentinels, to address issues related to environmental pollution [1]. Wild trout present several biological characteristics (including being at top of the food web, having lipid-rich tissues, pollutant concentration capacity, and a wide geographic distribution [2]), that position it as a potentiall...

We studied diet overlap and potential competition among early juvenile individuals in a coastal notothenioid community at Potter Cove, by analyzing 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 (1973) and th...

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 B 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 stoma...

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, th...

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 otolit...

King penguin (Aptenodytes patagonicus Miller; hereafter KP) is a circumpolar species that breeds on sub-Antarctic islands, between 458 and 558S. Although vagrant individuals can be found in the Antarctic region (south of 608), these sites are not included in the historic breeding range of the species (Williams 1995). However, Petry et al. (2013) re...

Antarctic marine ecosystems are increasingly threatened by climate change and are considered to be particularly sensitive because of the adaptation of most organisms to cold and stable environmental conditions. Fishes play a central role in the Antarctic marine food web and might be affected by climate change in different ways: (i) directly by incr...

Commercial fishing of finfish in the Antarctic began in the 1960s just as decades of sealing and whaling were ending. Around the South Shetland Islands, where our study was focused, heavy fishing was reported mainly from its northern-most island, Elephant Island, during 1977-1980. N. rossii and Champsocephalus gunnari were the target species, but a...

Trematomus newnesi is a common inshore species with a circum-Antarctic distribution. It provides the only known example of phenotypic plasticity in Antarctic notothenioid fish, existing as populations of typical, large mouth and intermediate morphs that can be difficult to identify. Using specimens from both Potter Cove, King George/25 de Mayo Isla...

We studied the buoyancy of 263 specimens of the sympatric sister species Notothenia coriiceps and N. rossii captured at King George Island. In these species without a swim bladder, we expressed measurements of buoyancy as percentage buoyancy (%B = weight in water/weight in air × 100), with smaller numbers reflecting more buoyant (i.e. less dense) s...

The radiation of notothenioid fishes in Antarctic waters has led to a level of habitat dominance by this single taxon that is unparalleled in other marine environments. Although lacking a swim bladder, notothenioids inhabit pelagic and benthic habitats and diversification in buoyancy is the ecological hallmark of their radiation. We studied the buo...

Scales and whole otoliths were read for age determination in early stages of Notothenia rossii caught in Potter Cove, South Shetland Islands, in summer seasons 2003–2006 and 2008. The sample comprised blue-phase pelagic fingerlings of 7.0–7.6 cm (TL) of age group 0 year and demersal brown-phase fingerlings/juveniles of 8.5–20.9 cm and predominant a...

We report herein the southernmost record of the Hudsonian Godwit (Limosa haemastica), at two localities inthe Antarctic: Esperanza/Hope Bay (January 2005) and 25 de Mayo/King George Island (October 2008). On both occasionsa pair of specimens with winter plumage was observed.

Three decades after the offshore commercial fishery in the South Shetland Islands in the late 1970s, the inshore population of Notothenia rossii recovered to levels comparable to those observed in 1983, while fjord Gobionotothen gibberifrons disappeared from the catches.

Scales and whole otoliths were read for age determination of early stages of Notothenia rossii caught in Potter Cove, South Shetland Islands, in summer of years 2003-2006 and 2008. The sample was composed by blue phase fingerlings of 7-7.6 cm (TL) and age group 0 year and demersal young brown phase juveniles of 8.5-20.9 cm and predominant age group...