Abstract Introduction: Reservoirs are conceived as a set of interactions in which physical, chemical, and biological instability determines changes in the density of planktonic communities. Objective: To evaluate the instability of phytoplankton and zooplankton, and their interactions with environmental factors in four tropical Andean reservoirs with different trophic status. Methods: Physical and chemical variables and phytoplankton and zooplankton densities were measured between 2010-2018 in the oligotrophic reservoirs Punchiná and San Lorenzo and between 2013 and 2015 in the hypereutrophic reservoir Porce II and in the eutrophic Porce III reservoir (total N = 248). The Factor Shaping Community Assemblages (FCA) was used to calculate environmental and biotic instability as well as their interaction. Results: High environmental and biological instability was observed in the studied reservoirs. Oxygen saturation, pH, total nitrogen, water temperature, nitrites, total phosphorus (only for zooplankton), and total solids were the abiotic variables with the greatest contribution to planktonic instability, regardless of trophic state. Particularly, Cryptomonas sp., Aulacoseira sp., Cyclotella sp., Dinobryon sp., Nephrocytium sp., Tetraëdron caudatum and Oscillatoria sp. had the greatest influence on the instability of various rotifer taxa and some copepods. Conclusions: Regardless of trophic state, pH dynamics, nutrients availability, amount of suspended solids and the availability of gases, such as dissolved oxygen, mainly determined the instability of phytoplankton and to a lesser extent that of zooplankton. In the oligotrophic reservoirs, zooplankton instability was mainly influenced by highly palatable algae with no toxicity, and in reservoirs highly enriched, the instability was influenced by algae with low nutritional quality and difficult to ingest and manipulate.

Resumen Introducción: los embalses deben ser concebidos como un conjunto de interacciones, donde la inestabilidad física, química y biológica determinan cambios en la densidad de las comunidades planctónicas. Objetivo: Evaluar la inestabilidad del fitoplancton y zooplancton y su interacción con factores ambientales en cuatro embalses tropicales andinos con diferente estado trófico. Métodos: Se analizaron datos de variables físicas y químicas y de las densidades del fitoplancton y del zooplancton, medidas entre 2010-2018, en los embalses oligotróficos Punchiná y San Lorenzo y, entre 2013 y 2015, en el embalse hipereutrófico Porce II y en el embalse eutrófico Porce III (total N = 248). Se empleó el Factor Shaping Community Assemblages (FCA), para calcular la inestabilidad biótica y ambiental y la interacción entre estas. Resultados: En los embalses estudiados hubo una alta inestabilidad ambiental y biológica. El pH, la saturación de oxígeno, el nitrógeno total, la temperatura del agua, los nitritos, el fósforo total (solo para el zooplancton) y los sólidos totales, son las variables abióticas con mayor aporte a la inestabilidad planctónica, independientemente del estado trófico. Particularmente, Cryptomonas sp., Aulacoseira sp., Cyclotella sp., Dinobryon sp., Nephrocytium sp., Tetraëdron caudatum y Oscillatoria sp., tuvieron mayor influencia sobre la inestabilidad de diferentes taxones de rotíferos y de algunos copépodos. Conclusión: Independiente del estado trófico, la dinámica del pH, la disponibilidad de nutrientes, la cantidad de sólidos suspendidos y la disponibilidad de gases como el oxígeno disuelto determinaron principalmente la inestabilidad del fitoplancton, y en menor medida la del zooplancton. En los embalses oligotróficos la inestabilidad del zooplancton es influenciada principalmente por algas altamente apetecibles con toxicidad nula, y en embalses altamente enriquecidos la inestabilidad fue influenciada por algas con baja calidad nutricional y de difícil ingestión y manipulación.

ABSTRACT The present study aimed to evaluate the ecology considering distribution, abundance, population structure, and fecundity of the marine diplostraceans Penilia avirostris and Pseudevadne tergestina in the Veracruz Reef System National Park, southwest Gulf of Mexico. Surface samples were collected with a 300 μm mesh plankton net at 26 sampling sites in June, August, October (2011), May (2012) and June (2013). Temperature, salinity, and dissolved oxygen were measured in situ. The temperature range was 26.53 ± 0.41 and 29.29 ± 0.27°C, salinity between 33.43 ± 0.49 and 35.91 ± 0.09, and dissolved oxygen between 2.92 ± 0.08 and 6.56 ± 0.08 mg L-1. P. avirostris and P. tergestina presented the highest density, with 2200 ind 100 m-3 in June and 5980 ind 100 m-3 in October, respectively. Four stages were determined in P. avirostris. In P. tergestina, there were five instars, with males in August and October. The size of parthenogenic females of P. avirostris was 773.4 ± 20.08 μm. In P. tergestina, it was 637.6 ± 49.28 μm. The number of embryos in P. avirostris was 2 to 7, and in P. tergestina, 2 to 8 embryos. The correlations between body length and the number of embryos in both species were statistically significant under the potential model (r > 0.68 for both species, P < 0.001). The transects with the highest abundance were the northern and the southern zones because they are far from the influence of the Jamapa River. The density of these crustaceans is related to optimal temperature, salinity, and dissolved oxygen values. The low proportions obtained from gamogenic individuals of P. avirostris and P. tergestina suggest that in tropical and subtropical regions, gamogenesis is not crucial for the life cycle of these organisms.

ABSTRACT Marine pollution caused by microplastics (MPs) in the ocean has been very high research in recent years, and their effects over different marine organisms such as zooplankton have been recognized. The crescent literature requires review and harmonization of the methodologies to unify criteria of comparison. Literature on microplastic ingestion in marine organisms is just beginning to be published, so it is of great importance to establish unified techniques for the extraction methodologies of microplastics ingested by zooplankton to determine the abundance and characteristics of MPs. Databases were used to find specific techniques for digestion of organic material from marine organisms, and four specific techniques were chosen for zooplankton degradation. Samples collected at one station in the Corales del Rosario and San Bernardo National Natural Park, Colombia were done. The chosen techniques were evaluated in four aspects: 1) The efficiency of digestions was evaluated on zooplankton samples, 2) The efficiency of digestion different duration and temperature conditions was assessed, 3) Evaluate the effect physics of digestions on microplastics, 4) Quantifying MPs from the ingestion rate. Fifty individuals were chosen from the sample to evaluate each technique. The most abundant groups corresponding to the families Paracalanidae, Corycaedae and Oncaeidae, and the phylum Chaetognatha were used. The best technique obtained was Md Amin et al (2020) with our modifications, this technique uses HNO3 65 % at 80 °C of temperature during one hour, in bottles of 2 mL lid with heat resistant. The organic matter was totally degraded, not changes on the physic integrity of MPs were observed, and the ingestion rates were similarly reported for other authors in these organisms.

RESUMEN Existe un incremento de publicaciones por conocer la problemática de la contaminación marina por microplásticos (MPs), donde ya se reconocen algunos de los efectos que pueden tener en el zooplancton. Este aumento de publicaciones requiere que se revisen las metodologías para unificar criterios de comparación, por lo que es de gran importancia unificar técnicas para las metodologías de extracción de los microplásticos ingeridos por el zooplancton para determinar la abundancia y las características de los MPs. A partir de una búsqueda en bases de datos, se escogieron cuatro técnicas específicas para la degradación de la materia orgánica representada por el zooplancton. Las técnicas fueron evaluadas en cuatro aspectos: 1) Eficiencia de la degradación de la materia orgánica, 2) Duración y condiciones de temperatura para el procesamiento, 3) Efecto físico de la digestión sobre los microplásticos, 4) cuantificar los MPs a partir de la tasa de ingestión. Se emplearon cincuenta individuos para cada uno de los grupos más abundantes correspondientes a las familias Paracalanidae, Corycaeidae y Oncaeidae, y al filo Chaetognatha. Los resultados obtenidos mostraron que la mejor técnica fue la de Md Amin et al (2020) con modificaciones, en la que no se observaron alteraciones en la integridad de los MPs y la tasa de ingestión fue similar a la que se reporta para estos organismos.

ABSTRACT The semi-permanent coastal upwelling system within the Humboldt Current System (HCS) off northern Chile provides nutrient-rich, oxygen-poor water to the euphotic zone that contributes to high levels of primary production and restricts the vertical distribution of most zooplankton species according to their tolerance to hypoxia within this highly heterogeneous environment. The day/night vertical distributions of two calanoid copepods, Eucalanus inermis and Nannocalanus minor, were studied concerning the presence of oxygen-poor water associated with the Oxygen minimum zone (OMZ) at a coastal and an offshore station off northern Chile (∼20°S), by stratified sampling from the surface to a depth of 600 m. At the coastal station, most of the population of both species remained above the OMZ, whereas at the offshore station, most populations remained at the edge of the OMZ. Both species exhibited reverse diel vertical migration between day and night and were positively correlated with dissolved oxygen and chlorophyll-a, suggesting that both species may prefer oxygenated waters and avoid the OMZ. However, E. inermis and N. minor exhibited distinct behavior, with E. inermis displaying significant variations among stations and strata and N. minor showing differences only among strata, particularly in the upper strata where it was more aggregated. The results helped us understand the behavior and distribution of zooplankton related to OMZ and how they may change as ocean temperature increases worldwide.

ABSTRACT The ecology, distribution, and taxonomy of bopyrid isopod species are often omitted from studies not systematically addressed to crustaceans. From a wider study of zooplankton in coastal and reef waters of the Mexican Caribbean Sea, two bopyrid species were collected, Probopyrinella latreuticola, attached to the branchial chamber of Latreutes fucorum andProbopyrus pandalicola parasitizing the branchial chamber of Palaemon northropi. For both parasite-host associations, these records represent a new locality and the southernmost record in the Mexican Caribbean. A map and a list of the bopyrid species belonging to Bopyridae recorded in the Mexican Caribbean are provided.

ABSTRACT: The zooplankton species present in Argopecten purpuratus “fan shell” culture areas were determined in Vichayo, Sechura, Piura; The physical and chemical parameters were related to the composition of the zooplankton; The sampling unit was 100 ml of water, in which zooplankton, temperature, pH, oxygen and salinity were evaluated. 180 samples were collected from 5 sampling points, chosen at random, using drag and vertical sampling, for six months. ; species are determined using taxonomic keys and the appropriate equipment to evaluate physical and chemical factors. The data obtained were analyzed using descriptive and inferential statistics, with decisions of 95% confidence. The results indicate that the phyllum Arthropoda predominates in the zooplankton and within it, the Copepoda class; The physical and chemical values were within the established ranges. Concluding that of 100% of individuals of the zooplankton species community present in the evaluated areas, 69.84% of them belong to the Phylum Arthropoda; and that the zooplankton community remains in dynamic equilibrium due to low dominance and high values of species richness, diversity and equitability.

RESUMEN: Se determinaron las especies de zooplancton presentes en áreas de cultivo de Argopecten purpuratus “concha de abanico” Vichayo, Sechura, Piura; se relacionaron los parámetros físicos y químicos con la composición del zooplancton; la unidad muestral fue de 100 ml de agua, en la que se evaluó zooplancton, temperatura, pH, oxígeno y salinidad, fueron colectadas 180 muestras en 5 puntos de muestreo elegidos al azar, muestreos por arrastre y vertical durante seis meses; determinándose las especies con el uso de claves taxonómicas y oxímetro, peachímetro y refractómetro para evaluar factores físicos y químicos. Los datos obtenidos fueron analizados mediante estadística descriptiva e inferencial, con decisiones de 95% de confianza. Los resultados indican que en el zooplancton predomina el phyllum Arthropoda y dentro de él, la clase Copepoda; los valores físicos y químicos se hallaron dentro de los rangos establecidos. Concluyéndose que del 100% de las especies de zooplancton presentes en las áreas evaluadas, el 69,84% pertenecen al phylum Arthropoda; y que, la comunidad de zooplancton se mantiene en equilibrio dinámico debido a una baja dominancia y valores elevados de riqueza de especies, diversidad y equitabilidad.

ABSTRACT Harmful algal blooms (HABs) can negatively affect coastal water quality, aquatic fauna, and human health from the consumption of toxin-contaminated seafood. Estuaries are especially prone to the incidence of these noxious events and sensitive to the associated damage. This study represents a comprehensive overview of previous investigations reporting the occurrence of harmful algae and/or phycotoxins in the Paranaguá Estuarine Complex (CEP), in Southern Brazil. Secondary data from 2002 to 2021 were combined with new results obtained from widely spaced sampling campaigns performed from 2018 to 2019 to assess the periods and estuarine sectors at greater risk for the incidence of HABs. In total, about 600 water/sediment samples containing harmful microalgae and 675 tissue samples of phycotoxin-contaminated fauna were analyzed. The most frequent and abundant species of potentially toxic microalgae were dinoflagellates belonging to the species complexes Dinophysis acuminata and Prorocentrum lima, producers of diarrhetic shellfish toxins (DSTs), and diatoms of the genus Pseudo-nitzschia, producers of amnesic shellfish toxins (ASTs). Okadaic acid, a DST, was by far the most common toxin in the fauna, reaching higher levels in primary consumers such as bivalve mollusks (mussels, oysters, and clams), zooplankton, and suspension-feeding crustaceans (ghost shrimps), and moderate to low levels in cephalopods, fishes, gastropods, echinoderms, sea turtles, seabirds, and cetaceans. Less rainy periods (winter-early spring) were associated with the highest incidence of DSTs and blooms of their producing algae P. lima and Dinophysis spp., mainly in the middle region of Paranaguá Bay and on the shallow continental platform adjacent to the estuarine mouth. However, certain HAB-forming species may be more successful in inner estuarine areas ( Prorocentrum cordatum) and during different periods, such as late summer—early fall ( Pseudo-nitzschia spp.). Continuous monitoring of harmful algae and toxins is therefore highly recommended to mitigate the effects of HABs in the entire estuary. (HABs quality toxincontaminated contaminated seafood damage andor or CEP, CEP , (CEP) Brazil 200 202 201 total 60 watersediment sediment 67 phycotoxincontaminated phycotoxin analyzed DSTs, (DSTs) Pseudonitzschia, Pseudonitzschia Pseudo nitzschia, nitzschia ASTs. ASTs . (ASTs) acid DST mussels, mussels (mussels oysters clams, clams clams) zooplankton suspensionfeeding suspension feeding ghost shrimps, shrimps shrimps) cephalopods fishes gastropods echinoderms turtles seabirds cetaceans winterearly winter early spring P spp spp. mouth However HABforming HAB forming cordatum summerearly summer spp.. spp.) estuary (CEP 20 6 (DSTs (ASTs 2

Abstract: Aim The zooplankton community is used as a bioindicator of environmental changes and can be an indicator of trophic status in aquatic environments through changes in the composition of the community. The objective of this work was to study the variation of shallow reservoir systems in an urban park, evaluating the relationships between physical, chemical, and biological variables. Methods The collections were conducted monthly for a year in the surface of reservoirs. The physical and chemical variables of the water were measured using a multiparametric probe on the surface. Nutrient analysis was performed using spectrophotometry in the laboratory. Zooplankton was collected using a plankton net (60 µm mesh size). Principal Coordinate Analysis (PCoA) was used to verify whether the three reservoirs present differences in zooplankton community composition. Results Altogether, 43 taxa belonging to 16 families were collected. Rotifera was the most representative group, with 27 taxa, Cladocera had 13 taxa, and Copepoda had only three taxa. The environmental variables indicated different trophic status between the reservoirs, demonstrating greater eutrophication in reservoirs 1 and 3. An association between the composition of the zooplankton community and the trophic state of the reservoirs was verified. Conclusions The composition of the zooplankton community shows differences among three of the shallow urban reservoirs studied. Reservoir 1 exhibited Filinia terminalis and Asplanchna herrick as indicator species. As for reservoir 2, with a lower trophic status, the indicative species were Bosmina freyi and Diaphanosoma polyspina, correlated with lower concentrations of nitrate, nitrite, total phosphorus, pH, and lower values of electrical conductivity. Reservoir 3 exhibited Brachionus angularis and Brachionus calyciflorus as indicator species, demonstrating a similar nutrient profile to R1, but with higher nitrate concentrations. Abstract park laboratory 60 (6 size. size . size) PCoA (PCoA Altogether 4 group 2 verified studied polyspina nitrite phosphorus pH conductivity R1 R 6 (

Resumo: Objetivo A comunidade zooplâncton é utilizada como bioindicador de mudanças ambientais e pode ser um indicador do estado trófico em ambientes aquáticos através de mudanças na composição da comunidade. O objetivo deste trabalho foi estudar a variação de sistemas de reservatórios rasos em um parque urbano, avaliando as relações entre variáveis físicas, químicas e biológicas. Métodos As coletas foram realizadas mensalmente durante um ano na superfície dos reservatórios. As variáveis físicas e químicas da água foram medidas por meio de sonda multiparamétrica na superfície. A análise dos nutrientes foi realizada por espectrofotometria em laboratório. O zooplâncton foi coletado com rede de plâncton (malha de 60 µm). A Análise de Coordenadas Principais (PCoA) foi utilizada para verificar se os três reservatórios apresentam diferenças na composição da comunidade zooplanctônica. Resultados Ao todo foram coletados 43 táxons pertencentes a 16 famílias. Rotifera foi o grupo mais representativo, com 27 táxons, Cladocera teve 13 táxons e Copepoda teve apenas três táxons. As variáveis ambientais indicaram diferentes estados tróficos entre os reservatórios, demonstrando maior eutrofização nos reservatórios 1 e 3. Foi verificada associação entre a composição da comunidade zooplanctônica e o estado trófico dos reservatórios. Conclusões A composição da comunidade zooplanctônica apresenta diferenças entre três dos reservatórios urbanos rasos estudados. O reservatório 1 exibiu Filinia terminalis e Asplanchna herrick como espécies indicadoras. Já no reservatório 2, com menor status trófico, as espécies indicativas foram Bosmina freyi e Diaphanosoma polyspina, correlacionadas com menores concentrações de nitrato, nitrito, fósforo total, pH e menores valores de condutividade elétrica. O reservatório 3 exibiu Brachionus angularis e Brachionus calyciflorus como espécies indicadoras, demonstrando perfil nutricional semelhante ao R1, mas com maiores concentrações de nitrato. Resumo urbano biológicas laboratório malha 6 µm. µm . µm) PCoA (PCoA 4 famílias representativo 2 estudados indicadoras polyspina nitrato nitrito total elétrica R1 R

ABSTRACT Functional traits, short life cycles, and the pivotal role in the ocean make copepod diversity a solid foundation for assessing the effect of global changes in marine food webs and ecosystem functioning. Climate change and extreme events, particularly El Niño, can affect coastal ecosystems. The Arvoredo Marine Biological Reserve (MPA), located in highly productive coastal waters of the Southern Brazilian Bight, presents complex climate and oceanographic conditions. This study investigates the influence of oceanographic processes and El Niño 2015-2016 on the copepod functional diversity from 2014 to 2016 in the Arvoredo MPA. Horizontal tows were performed using a WP2 net with a mesh size of 200 µm. The 41 species accounted for 19 functional entities and four functional groups. Our findings reveal that the seasonal intrusion of water masses influenced copepod functional diversity. During summer, the upwelling of South Atlantic Central Water increased nutrient availability and favored large herbivore-omnivores and carnivores. The Plata Plume Water enrichment during winter coincided with a decline in functional richness and abundance, leading to the predominance of the Oithona nana, a small-sized omnivore. Compensatory mechanisms were observed as functional equivalence and species composition shifts. Acartia lilljeborgii and Temora turbinata exhibited functional equivalence and compensated for each other in response to salinity changes associated with upwelling and El Niño. The copepod assemblage demonstrated the ability to maintain functional diversity despite changes in copepod abundance. However, the decline in functional diversity and abundance during the intense winter indicated potential disruption in trophic dynamics and ecosystem functioning. Maintaining balance and compensating for disturbances such as El Niño is crucial for marine food web resilience. The functional trait approach provided a comprehensive understanding of the copepod assemblage in Arvoredo MPA, contributing to a broader knowledge of the impact of oceanographic processes intensification. Monitoring functional diversity and abundance is crucial for evaluating the effects of copepod assemblage changes in ecosystem functionings. traits cycles functioning events ecosystems MPA , (MPA) Bight conditions 20152016 2015 2015-201 201 WP 20 µm 4 1 groups summer herbivoreomnivores herbivore omnivores carnivores nana smallsized small sized omnivore shifts However resilience intensification functionings (MPA 2015201 2015-20 2 201520 2015-2 20152 2015-

Abstract Bioseston is a heterogeneous assemblage of bacterioplankton, phytoplankton, zooplankton, and planktonic debris. A detailed knowledge of biosestons is essential for understanding the dynamics of trophic flows in marine ecosystems. The distributional features of seston biomass in plankton (micro- and mesoplankton) in the Southwest Atlantic Ocean (Rio de Janeiro State, Brazil) were analyzed using stratified samples gathered to a depth of 2,400 m during night time. The horizontal pattern of biomass distribution was analyzed vis-a-vis station depth during both wet and dry periods, with higher values recorded in the continental shelf than in the slope, confirming the terrestrial contribution of nutrient sources to the marine environment. This horizontal variation reinforces the occurrence of seasonal vortices in Cabo Frio and Cabo de São Tomé on the central coast of Brazil. Environmental variables reflect the hydrological signatures of the water masses along the Brazilian coast. The largest seston biomass was related to high temperatures, salinities, and low inorganic nutrient concentrations in tropical and South Atlantic central waters. The observed distribution patterns suggest that seston biomass in plankton in the region may be structured based on partitioned horizontal and vertical habitats and food resources. bacterioplankton phytoplankton zooplankton debris ecosystems micro (micro mesoplankton Rio State Brazil 2400 2 400 2,40 time visavis vis periods slope environment temperatures salinities waters resources 240 40 2,4 24 4 2,

Abstract: Aims This study aims to analyze the efficiency of two novel methods for ex situ zooplankton hatching experiments, compared with a traditional one. Both proposed methods were specifically designed to minimize sediment resuspension during the sampling of hatched individuals when no previous egg isolation is performed. Methods Sediment samples were collected from shallow lakes, homogenized, and incubated for 18 days under stable laboratory conditions. The traditional method (1M) involved simple water filtration from incubated sediments. The so called “inverted funnel filtering” method (2M) includes an inverted funnel located above the sediment to trap zooplankton that passes through the funnel aperture, and the “levels filtering” method (3M) involves perforated plates above the sediment. The efficiency of each method was evaluated by analyzing the cumulative abundance and number of taxa in hatched total zooplankton, rotifers, and microcrustaceans, as well as the overall composition. Results The new proposed methods significantly favored higher abundances than 1M for total zooplankton and rotifers. Even more, 3M outperformed 2M in the case of microcrustacean hatching abundances. Conclusions Our findings suggest that despite all analyzed methods being suitable for studying zooplankton hatchings, the newly proposed methods incorporating internal structures to minimize sediment resuspension displayed increased capture efficiency. Abstract experiments one performed lakes homogenized 1 conditions M (1M sediments filtering (2M aperture levels (3M rotifers microcrustaceans composition more hatchings

Resumo: Objetivo Este estudo tem como objetivo analisar a eficiência de dois novos métodos para experimentos de eclosão de zooplâncton ex situ, comparados com um método tradicional. Ambos os métodos propostos foram especificamente projetados para minimizar a ressuspensão de sedimentos durante a amostragem de indivíduos eclodidos quando não há isolamento prévio dos ovos. Métodos Amostras de sedimentos foram coletadas de lagos rasos, homogeneizadas e incubadas por 18 dias em condições laboratoriais estáveis. O método tradicional (1M) envolveu uma simples filtração da água dos sedimentos incubados. O método chamado “filtragem por funil invertido” (2M) inclui um funil invertido localizado acima do sedimento para capturar zooplâncton que passasse pela abertura do funil, e o método “filtragem por níveis” (3M) envolveu placas perfuradas acima do sedimento. A eficiência de cada método foi avaliada analisando a abundância cumulativa e o número de táxons no zooplâncton total eclodido, rotíferos e microcrustáceos, bem como a composição geral. Resultados Os novos métodos propostos favoreceram significativamente uma maior abundância do que 1M para zooplâncton total e rotíferos. Além disso, 3M superou 2M no caso das capturas de eclosão de microcrustáceos. Conclusões: Nossos resultados sugerem que, apesar de todos os métodos analisados serem adequados para estudar eclosões de zooplâncton, os novos métodos propostos que incorporam estruturas internas para minimizar a ressuspensão de sedimentos apresentaram maior eficiência de captura. Resumo situ ovos rasos 1 estáveis M (1M incubados filtragem (2M níveis (3M eclodido microcrustáceos geral disso Conclusões captura

Resumo Objetivo Este estudo tem como objetivo contribuir para elucidar a importância da pesquisa experimental sobre a comunidade zooplanctônica de água doce no Brasil através de uma análise cienciométrica. Métodos As bases de dados Web of Science, SciELO e Scopus foram utilizadas para compilar 249 trabalhos científicos publicados entre 1978 e 2023. Os dados extraídos dos artigos foram o ano de publicação, localização geográfica, características do experimento (tipo, escala, duração), espécies ou táxons estudados e os temas de pesquisa. Sínteses quantitativas e qualitativas foram realizadas para fornecer uma compreensão sistematizada dos estudos experimentais sobre zooplâncton de água doce. Resultados A análise revelou um aumento significativo no número de publicações experimentais ao longo do tempo, com uma maior concentração de estudos na região Sudeste do Brasil. Experimentos de laboratório, principalmente microcosmos foram realizados com mais frequência do que experimentos de campo. Predação, poluentes químicos e eutrofização surgiram como os temas de pesquisa frequentemente abordados. Por outro lado, certos tópicos, como dinâmicas de metapopulação e microplásticos, foram relativamente sub-representados na literatura. Apesar da pesquisa experimental sobre o zooplâncton de água doce no Brasil desempenhar um papel crucial no avanço da compreensão ecológica, há uma distribuição desigual desses estudos pelo país, indicando a necessidade de investimentos e mais pesquisadores preparados para trabalhar com experimentos em certas regiões. Abordar as lacunas identificadas nesta revisão, como dinâmicas de metapopulação e dispersão, juntamente com ameaças emergentes como invasões, microplásticos, patógenos, estressores cumulativos, contaminantes emergentes e nanomateriais, será essencial para gerar conhecimento científico que informe estratégias de manejo eficazes para preservar a biodiversidade do zooplâncton de água doce em meio às mudanças ambientais em curso. Conclusões Esta revisão destaca a importância de expandir a pesquisa experimental por diversas regiões e tópicos pouco explorados para melhorar nossa compreensão ecológica e melhor gerenciar a biodiversidade do zooplâncton de água doce no Brasil. cienciométrica Science 24 197 2023 publicação geográfica tipo, tipo (tipo escala duração, duração , duração) tempo laboratório campo Predação abordados lado microplásticos subrepresentados sub representados literatura país dispersão invasões patógenos cumulativos nanomateriais curso 2 19 202 1 20

Abstract Aim This study aims to contribute to elucidating the importance of experimental research on freshwater zooplankton communities in Brazil through a scientometric analysis. Methods Web of Science, SciELO, and Scopus databases were used to compile 249 scientific papers published between 1978 and 2023. The extracted data included the year of publication, geographical location, experiment characteristics (type, scale, duration), species or taxa studied, and research topics. Quantitative and qualitative syntheses were performed to provide a systematic understanding of experimental studies on freshwater zooplankton. Results The analysis revealed a significant increase in the number of experimental papers over time, with a higher concentration of studies in the Southeastern region of Brazil. Laboratory experiments were conducted with greater frequency than field experiments, mainly microcosms. Predation, chemical pollutants, and eutrophication emerged as frequently addressed research topics. On the other hand, certain topics, such as metapopulation dynamics and microplastics, were relatively underrepresented in the literature. Despite the crucial role of experimental research on freshwater zooplankton in advancing ecological understanding in Brazil, there is an unequal distribution of these studies across the country, indicating the need for investment and more researchers prepared and interested in studying with experiments in certain regions. Addressing the gaps identified in this review, such as metapopulation dynamics and dispersion, along with emerging threats like invasions, microplastics, pathogens, cumulative stressors, emerging contaminants, and nanomaterials, will be essential for generating scientific knowledge to inform effective management strategies to preserve freshwater zooplankton biodiversity amidst ongoing environmental changes. Conclusions This review underscores the importance of expanding experimental research across diverse regions and underexplored topics to enhance our ecological understanding and better manage freshwater zooplankton biodiversity in Brazil. Science SciELO 24 197 2023 publication location type, type (type scale duration, duration , duration) studied time microcosms Predation pollutants hand microplastics literature country dispersion invasions pathogens stressors contaminants nanomaterials changes 2 19 202 1 20

Resumo Objetivo Nós investigamos a relação entre atributos ecológicos da comunidade zooplanctônica e a produção secundária. Métodos Amostras foram coletadas em lagos da planície de inundação do Alto Rio Paraná (Brasil), em períodos de águas baixas e altas, e em um experimento manipulativo realizado em mesocosmos. Resultados A maior produção secundária esteve relacionada à dominância de poucas espécies. A produção secundária de organismos de maior tamanho e maior ciclo de vida, como os copépodes, foi mais associada à biomassa, enquanto os menores, como os rotíferos, à abundância. Conclusões Esses atributos da comunidade zooplanctônica (biomassa e densidade) podem ser usados como proxies para estimar a produção secundária de zooplâncton na planície de inundação, subsidiando os estudos de monitoramento e conservação desses ecossistemas. Brasil, Brasil , (Brasil) altas mesocosmos espécies vida copépodes biomassa menores rotíferos abundância densidade ecossistemas (Brasil

Abstract Aim We investigated the relationship between ecological attributes of the zooplankton community and its secondary production. Methods Samples were taken from lakes in the floodplain of the Upper Paraná River (Brazil), in low and high-water periods, and in a manipulative experiment realized in mesocosms. Results The highest amount of production was related to the dominance of few species. Secondary production of larger and long-lived organisms, such as copepods, had been most associated with the biomass, whereas smaller ones, such as rotifers, with the abundance. Conclusions These attributes of the zooplankton community (biomass and abundance) can be used as proxies to estimate the zooplankton secondary production in the floodplain, supporting the studies on monitoring and conservation of these ecosystems. Brazil, Brazil , (Brazil) highwater high water periods mesocosms species longlived long lived organisms copepods biomass ones rotifers abundance ecosystems (Brazil

Maldonado Bay is situated on the northeastern shore of the River Plate estuary. Some hydrological and biological characteristics of the area were investigated during a complete year. The survey encompassed the characterization and circulation of main water masses in the bay, water quality, zooplankton composition and dynamics, and settlement and growth of the mussel Mytilus. The sample strategy was designed to cope with the high spatial and temporal variability of the estuary.

Abstract. The population structure of Centropages furcatus associated with hydrographic structures in late spring 2004 was analyzed. The distribution of the different copepodite stages of C. furcatus was analyzed from zooplankton samples obtained with a bongo net. The hydrography and geostrophic velocity in Bay of La Paz relative to the bottom depth revealed the presence of a cyclonic gyre in the Alfonso basin area and a thermohaline front near Boca Grande. The distribution of vertically integrated chlorophyll a concentration showed maximum values at the center of the gyre and in the region of the front, making evident that both hydrographic structures stimulated biological productivity because of the flux of nutrients into the euphotic layer in the gyre and the nutrient accumulation in the thermohaline front. The results showed that the spatial variation of C. furcatus was influenced by both hydrographic structures. The differential distribution of the copepodite stages was noticeable in the cyclonic gyre, with the highest density for the first copepodite stages at the center of the gyre because of the high chlorophyll a concentration due to the nutrient enrichment in the euphotic layer, as a result of Ekman pumping. Copepod density was higher in the thermohaline front than inside the cyclonic gyre because the front serves as a reproductive spot for the species, maintaining a stable adult population density inside the bay and in the Gulf of California.

Resumen. Se analizó la estructura poblacional de Centropages furcatus asociada a estructuras hidrográficas a finales de la primavera de 2004. La distribución de los diferentes estadios de copepoditos de C. furcatus fue analizada a partir de las muestras de zooplancton obtenidas con una red bongo. En la bahía de La Paz, la hidrografía y la velocidad geostrófica relativa al fondo revelaron la presencia de un giro ciclónico en la cuenca Alfonso y un frente termohalino cerca de Boca Grande. La distribución de la concentración de clorofila a integrada verticalmente mostró valores máximos en el centro del giro y en la región del frente, lo que evidenció que ambas estructuras hidrográficas favorecen la productividad biológica debido al flujo de nutrientes hacia la capa eufótica en el giro y a la acumulación de nutrientes en el frente termohalino. Los resultados mostraron que la variación espacial de C. furcatus estuvo influenciada por ambas estructuras hidrográficas. En el giro ciclónico se observó una distribución diferencial por etapa de desarrollo, con mayor densidad poblacional de los primeros estadios de copepoditos en el centro del giro, como consecuencia de la alta concentración de clorofila a por el enriquecimiento de nutrientes en la capa eufótica, debido al bombeo de Ekman. La densidad poblacional de copépodos fue mayor en el frente termohalino que en el interior del giro ciclónico, debido a que el frente actúa como una zona reproductiva de la especie que mantiene una densidad poblacional estable para los adultos de la bahía y del golfo de California.