We carried out a literature review to investigate the taxonomic and functional β diversity of zooplankton and its species replacement (βrepl) and richness difference (βrich) components in Brazilian rivers. In addition, the taxonomic (LCBD-t) and functional ecological uniqueness (LCBD-f) were also measured. We tested the following hypotheses: (i) The βrepl component is the main driver of taxonomic β diversity, while βrich is most important for functional β diversity, due to functional simplification; (ii) Sites with lower taxonomic and functional richness are the ones that most contribute to LCBD. Contrary to expectations, βrich drove the taxonomic and functional β diversity. This may have occurred due to environmental constraints and geographic distance, thus causing a loss or gain of species and traits between hydrographic regions. For just two regions, the sites with the lowest functional richness were the ones that most contributed to LCBD-f. This reinforces that sites with lower richness can support species that perform unique functions in the ecosystem. As studies involving zooplankton from lotic systems are still limited in Brazil, we suggest that future research should consider the patterns of β diversity in these dynamic, diverse, and threatened aquatic ecosystems.

Tragic incidents involving mine tailings spills have impacted many aquatic ecosystems around the world. The massive mine tailings dam collapse of Fund & atilde;o, which occurred in Brazil in 2015, affected several aquatic ecosystems, including shallow and deep lakes in the lower Doce River basin. Until now, the effects of mine tailings on the functional diversity of zooplankton remain poorly understood. We investigated the functional diversity of zooplankton (functional groups, functional richness [FRic] and functional evenness [FEve]) in shallow and deep lakes, exploring the influence of environmental variables and metals. In addition, trends in functional redundancy and functional vulnerability were also assessed to understand patterns of resilience in mining-impacted ecosystems. Surveys were performed monthly on three deep and three shallow lakes affected by the dam failure, from October 2018 to September 2019. In the deep lakes, the zooplankton community was dominated by smaller filter-feeders and omnivorous species, associated with cyanobacteria density and chlorophyll-a. Medium-sized filters were associated to iron, suspended particulate organic matter and total organic carbon in shallow lakes. The smaller filter-feeders and omnivorous trophic groups had a higher contribution to increasing the functional diversity of zooplankton than medium-sized filter-feeders in both deep and shallow lakes. FRic and FEve were higher in deep lakes than in shallow lakes. Shallow lakes were highly vulnerable to species loss and functional diversity was modulated by environmental changes and metal pollution. Tropical shallow lakes impacted by mining tailings should receive particular attention in conservation plans, as a consequence of their high level of pollutant retention in comparison with deep lakes. In addition, we highlight the importance of using a functional approach to better understand the ecosystem changes resulting from the impacts of mine tailings on aquatic environments.

A review was carried out on the freshwater zooplankton in Brazil, between 1900 and 2021, based on 1014 studies, and the main trends were pointed. There was an increase of studies from the 1990 s onwards, especially between 2016 and 2020. Most of them addressed ecological research, followed by taxonomical research in the past (mid-1970 s). Field studies were also more numerous than experimental and review ones, but the latter type also increased between 2016 and 2020. Most studies were developed in limnetic regions and in artificial and natural lakes, in contrast to littoral regions, streams and wetlands. Studies on cladocerans were the most numerous in all environments, followed by Copepoda and Rotifera. Protozooplankton was the least studied group, with a predominance of testate amoebae, followed by ciliates, flagellates and naked amoeba studies. We also discuss some aspects of the ecological traits, such as life cycles and life history, population and community dynamics, interactions with the environment, influence of environmental and anthropogenic factors and interspecific interactions. Studies on populations biomass, secondary production, functional ecology, long term duration and molecular analyzes were the main gaps and the next challenges. Finally, it is also necessary to understand the diversity and related variables in different environments that have few or never been studied.

The effects of exposure to mining tailings on water quality and biota of tropical lacustrine ecosystems remain poorly understood. We tested the hypothesis that after mining tailing spills, shallow lakes should retain higher metal concentrations in comparison with deep lakes, which might contribute to differentiating species sorting and community structure of zooplankton in both ecosystems. Surveys were performed in 6 Brazilian lakes affected by the Fundão dam failure from October 2018 to September 2019. The shallow lakes showed higher values of turbidity (19.4 ± 12.9 NTU), conductivity (846.5 ± 1727.1 μS.cm-1), total organic carbon (11.6 ± 4.6 mg.L-1), total nitrogen (2688.7 ± 2215.6 μg.L-1), iron (2507.5 ± 726.9 μg.L-1), aluminum (419.9 ± 166.5 μg.L-1) and manganese (150.8 ± 146.2 μg.L-1) and lower zooplankton richness (9.2 ± 3.2) compared to the deep lakes (13.4 ± 3.0), which showed higher cyanobacteria density (84.7 103 ± 69.3 103 cel.mL-1). We recorded negative relationships between zooplankton richness and turbidity, conductivity, iron, zinc and vanadium, indicating that as well as morphometric characteristics of lakes (area and depth) have an important role in zooplankton richness, the coupling between metals and limnological variables represent decisive environmental filters for species sorting of zooplankton. The variation-partitioning analysis showed that limnological variables and metals explained zooplankton composition, highlighting that metals play major influence on zooplankton composition. We suggest that the shallowness of the lakes should had promoted often resuspension of mining tailings that caused increases in metal concentrations in water column. The results indicate that the shallow lakes presented higher vulnerability to mining tailings exposure than the deep lakes, which may have substantially contributed for differentiating zooplankton communities in both ecosystems. This study reveals the need for considering shallow lakes as priority target for conservation among freshwater ecosystems affected by mining tailings.

In the last five years, two colossal environmental disasters involving iron-enriched mine tailings have occurred in Brazil, affecting many aquatic ecosystems over the short, medium and long-terms. This study investigated whether these iron-enriched mine tailings affect the main biotic strategy to restore zooplankton populations affected by severe stress, i.e., hatching of dormant stages. A 30 day hatching experiment was conducted, using a resting egg bank from a natural lake, exposed to 3 concentrations of mine tailings: control (0 g), T25 (25 g) and T50 (50 g). A total of 22, 15 and 16 species hatched in the control, T25 and T50, respectively. Conochilus sp., Filinia terminalis, Hexartha mira, Bosmina longirostris and Ceriodaphnia silvestrii hatched only in the control, which suggests that these species are sensitive to any concentration of mine tailings. A gradual decrease in richness and hatchling abundance was recorded, from the control (8.0 ± 1.0 SE species and 1597 ± 73.9 hatchlings) to T25 (4.6 ± 1.2 species and 1279 ± 136.5 hatchlings) and then to T50 (2.3 ± 1.2 species and 603.3 ± 61.9 hatchlings). Our results suggest that exposure of zooplankton resting eggs to iron-enriched mine tailings may negatively impact these egg banks in natural ecosystems, with potential impacts on the restoration of zooplankton communities after even short-term exposures.

In recent decades, riparian vegetation has been removed from important ecosystems around the world, in spite of its high ecological importance for aquatic biota. Nevertheless, the effects of catchment land use on zooplankton have been little studied. The present study investigated if replanting riparian vegetation in a tropical reservoir influences the richness and abundance of cladoceran communities, by addressing the question of whether cladocerans show differences in richness and abundance among four levels of riparian vegetation conditions: 1) native forest (NF); 2) 30 years after forest replanting (R1); 3) 10 years after forest replanting (R2); and 4) no forest (No-F). Zooplankton samples were obtained from 9 stations in the Volta Grande Reservoir, Minas Gerais, Brazil. Cladocerans in zones NF and R1 showed higher levels of richness and abundance than in zones No-F and R2. Ceriodaphnia reticulata, Ceriodaphnia laticaudata, and Diaphanosoma spinulosum showed higher abundances in zones NF and R1. Cladoceran community structure was influenced by the different levels of riparian vegetation. This study showed that the presence and age of riparian forest positively influence the abundance, richness and diversity of cladoceran assemblages. Furthermore, our results indicated that C. reticulata, C. laticaudata and D. spinulosum are more efficient than other cladocerans in exploiting allochthonous resources provided by riparian forest. Functional diversity was higher in zones NF and R1, suggesting that the trait composition of cladoceran assemblages responds positively to recovery of riparian forest. Overall, our research suggests that cladocerans are good indicators of riparian vegetation conditions and that restoration of riparian forest positively affects cladoceran assemblages of tropical reservoirs.

Interaction between Epistylis sp. and copepods was investigated in 3 tropical lakes. Epibiont load was higher in Thermocyclops minutus compared to Notodiaptomus ssp. at light compensation depth. No difference was found at surface. Infestation of Epistylis sp. seems to respond to copepod species densities. Attaching to more abundant copepods may increase encounter rates of epibionts with its hosts, raising biological efficiency of it even if attaching to smaller hosts when rare larger ones are present.

Tropical reef ecosystems are generally considered to be sinks of marine zooplankton, mainly due to the predation by scleractinian corals and other planktivores. The present study aims to evaluate the zooplankton community of a coastal reef in two specific environments: the reef edge and open-water channels between patch reefs. Sampling was carried out at two patch reefs that border the Tamandaré coastal lagoon system (Pernambuco State, Brazil). Two passive stationary nets (64 μm mesh size) were used: the Reef Edge Net (REN) and the Channel Midwater Neuston Net (CMNN). Sampling was performed simultaneously at both reefs during eight nocturnal sampling campaigns, always at new moon ebb tides. Zooplankton was classified by “origin” (estuarine, reef, neritic and neritic/estuarine). During all campaigns and at both sites, a significant buildup of zooplankton at the reefs was observed. Reef edges showed significantly higher abundance (77,579 ± 73,985 ind. m −3 ) and biomass (48.9 ± 45.5 mg C m −3 ) of zooplankton compared to open-water channels (9982 ± 11,427 ind. m −3 and 11.4 ± 21.9 mg C m −3 , respectively). A total of 65 taxonomic groups were identified. Copepods were the most abundant group with a contribution of 69% for total zooplankton abundance, followed by foraminiferans, gastropod veligers, appendicularians, cirripedians nauplii, and polychaete larvae. Copepods from neritic/estuarine environments dominated the reef edges in both relative abundance and relative biomass (91% and 88%, respectively). The unexpectedly high abundance of copepods and other holoplankton at the reef edges, when compared to Indo-Pacific and Caribbean reefs, is probably due to very low cover of corals and other zooplanktivorous sessile animals (< 0.2%) on these coastal reefs, which leads to a very low predation mortality for zooplankters. Also, we propose that the reduced water column above the reef top leads to a buildup of very high densities in these environments.

In Brazil, although, high-altitude shallow lakes comprise large parts of conservation units and are considered highly important environments for biodiversity studies, little is known about the factors that regulate the zooplankton community. In the present study, we sought to identify the effect of regional (hydroperiod and altitude) and local (lake area and macrophyte cover) factors on the zooplankton communities in eight shallow high-altitude lakes (from 1080 m a.s.l. to lakes above 1200 m a.s.l.) in the Espinhaço Mountain Range (Brazil). Of the 116 zooplankton species identified, 66 (56%) showed a high degree of spatial aggregation, occurring in only a few lakes. Accessory species occurred predominantly in small lakes, while rare species were better represented in the larger lakes, suggesting species sorting associated with the niche effect. Zooplankton richness was strongly influenced by hydroperiod, indicating that temporary lakes can congregate species resistant to the environmental filter of the drought, playing an important role in the diversification of the zooplankton community. We identified environmental heterogeneity (macrophyte cover) as the factor that most influenced the species diversity: zooplankton responded positively to increased macrophyte cover, confirming that the presence of aquatic plants constitutes a strong environmental filter to explain the variation of the zooplankton community. Zooplankton species composition and abundance differed among lakes, indicating a certain degree of heterogeneity in assemblage structure, but no influence on zooplankton diversity was observed. Our results provide evidences that altitude did not influence zooplankton diversity and this may affect the regional diversity (ß diversity) of tropical high-altitude lakes, and merits further study.

In spite of the paramount ecological and socioeconomic relevance of tropical reef ecosystems, the dynamics of their meroplankton abundance remain poorly characterized. The small-scale distribution and detailed analysis of individual biomass of mesozooplankton were studied in the coastal reefs of Tamandaré (Brazil). Mesozooplankton (> 300 μm) was collected during nocturnal ebb tides at new moon, using three different devices to sample at three different environments: a standard ring net that was towed at subsurface, the Channel Midwater Neuston Net that collected at midwater in channels between patch reefs and the Reef Edge Net that captured organisms that are washed by ebb currents from reef tops toward the reef edge. Samples were analyzed using a ZooScan to obtain abundances and biovolume of each taxonomic group. Specific biomass measurements were taken to obtain allometric equations used to calculate zooplankton biomass from biovolume. The mesozooplankton were significantly more abundant at subsurface and at the reef edge compared to channel environments. The high abundance of organisms at reef edges suggests a low predation pressure on zooplankton at near-bottom areas, since the reefs of Tamandaré present a low coverage of planktivorous corals, being dominated by macroalgae. These results show that rather than sinks these ecosystems may be considered important sources of zooplankton available for planktivorous species. Regarding zooplankton composition, we found large amounts of initial stages of meroplanktonic larvae and newly hatched fish eggs, which presented consistently greater abundances compared to holoplankton and emergent benthic taxa. Decapod larvae were the most abundant group of the meroplankton, but cirripedian nauplii, stomatopod larvae, fish larvae and fish eggs were also abundant. More than 50% of the total biomass was due to meroplankton taxa, mainly composed of decapod larvae. This study indicates that the contribution of meroplankton to mesozooplankton composition and biomass off tropical reefs may have been underestimated.

Abstract In the present work, spatial and seasonal fluctuations of the abundance and diversity of mesozooplankton are presented, with special attention being given to copepod assemblages from coastal area of the Fernando de Noronha Archipelago (FNA) (3°50'24''S and 32°24'48''W). Sampling was carried out during the dry and rainy seasons of two consecutive years (July and December 2013) and (June and November 2014). A total of 37 mesozooplankton taxa were recorded, being the copepods the most diversified group (15 taxa). The Subclass Copepoda dominated in both periods sampled, comprising 53% and 86% of the total abundance in the dry and rainy season respectively. The species considered abundant were: Calanopia americana, Undinula vulgaris, Oithona plumifera and Corycaeus speciosus. The rainy season favored a significant increase in the abundance of mesozooplankton and copepods. However, a low value of the Shannon-Wiener diversity index was observed in this same seasonal period. This was explained by the dominance of the species C. americana and U. vulgaris in the studied area. Spatial differences have not been verified. The copepod assemblages was composed mostly by species considered as predator-carnivours of greater importance on the pelagic trophic web, indicators of oligotrophic conditions and components of a major portion of fish food items. Thus, we suggest that a spatially homogeneous mesozooplankton community characterizes the coastal area of Fernando de Noronha Archipelago with variations related mainly to the seasonal factor.

O enriquecimento ambiental é utilizado por zoológicos para estimular a interação dos animais cativos com o ambiente para elevar o bem-estar e diversificar as oportunidades comportamentais. Este estudo de caso investigou o efeito do enriquecimento ambiental no orçamento de atividades do macho de jaguatirica adulto cativo no Parque Estadual Dois Irmãos, Brasil. O experiment foi realizado de agosto de 2011 a junho de 2012 e foi dividido em três fases denominadas: Pré-enriquecimento, Enquecimento, e Pós-enriquecimento. Os métodos de análise utilizados foram Animal-focal e Ad libitum. As observações sugerem um aumento do comportamento de locomoção e uma significante redução nas estereotipias do animal. As técnicas de enriquecimento aplicadas nesse estudo provaram ser efetivas para a redução das estereotipias e aumento do repertório comportamental da espécie no cativeiro.

Sampling mobile zooplankton on reefs is a major challenge, mainly due to the problems faced when towing plankton nets inside complex reef mosaics. This study presents two new systems that permit precise point sampling of micro- and mesozooplankton and larvae of invertebrates and fish: the Channel Midwater Neuston Net (CMNN) and the Reef Edge Net (REN). Both are moored systems that are equipped with 64- and 300-μm mesh nets. The CMNN system was designed for continuous sampling in tidal channels between reef patches. It samples at three precise depth layers (epineuston: 0 m to 0.075 m, hyponeuston: 0.075 m to 0.225 m, 1 m layer: 0.925 m to 1.075 m depth). The REN system allows sampling at precise, adjustable depths at given distances from the reef edge. The objective of the REN is to collect organisms that are washed from reef tops and reef edges with the ebb flow. The performance of these two new systems was evaluated and compared with results obtained by using common Ring nets in horizontal subsurface tows. Fieldwork was performed at two reef patches of the Tamandaré reef system (Brazil) in November 2015. The CMNN and REN showed similar performance in comparison with Ring net tows, capturing microzooplankton communities as well as veliger, polychaete, decapod and barnacle larvae in similar abundances. For the mesozooplankton, the REN presented a similar performance to the Ring net tows, efficiently capturing decapod crustacean and fish larvae as well as fish eggs. The CMNN showed lower abundance of decapod larvae and fish eggs but showed a good performance for the quantification of fish larvae. The two new passive nets showed a high effectiveness in collecting larvae and advantages over tows with Ring nets since they stay for several hours continuously capturing larval aggregations during spawning events. This high capturing efficiency is probably related to the avoidance of sample reflux in the long nets that sink and close at slack tide for the CMNN, and due to the long, trap-like design with funnel-shaped internal "anti-reflux" nets, for the REN. Navigation safety and easy handling are further advantages of these moored systems, as compared to towing plankton nets at nighttime between reefs. CMNN and REN may become useful tools for the study of zooplankton and larval ecology and for integrated long-term studies in marine protected areas and reefs under multiple human impacts.

The present study tested the hypothesis that endosymbionts of the zoanthid Palythoa caribaeorum show specific responses in cell density, size, and mitotic index (as proxy for cell population growth) under different environmental conditions (water depth, position within the reef and within the colony). Colony fragments were sampled at the nearshore coastal reefs of Porto de Galinhas and at the oceanic St. Peter and St. Paul's archipelago (SPSP), Brazil. At the coastal reefs, zooxanthellae showed higher density on the reef flat (mean: 2.99 × 106 cm−2) than at the back reef (mean: 2.07 × 106 cm−2). Zooxanthellae were larger at the center of the colonies (mean: 10.61 µm) than at the edges (mean: 10.11 µm), where younger polyps were found. At SPSP, zooxanthellae showed smaller cell diameters at 3 m depth, than at 5–15 m. Cell size increased with depth, thus enhancing the photosynthetic efficiency of colonies in deeper environments. Strategies and adaptations of these endosymbionts to environmental stressors are discussed. Symbiont distribution patterns shown in this study have fundamental implications for the monitoring of the health of tropical reef ecosystems.

The study of zooplankton biomass is an important and simple tool to evaluate the trophic status of aquatic ecosystems, e.g., providing information on the availability of food to upper trophic levels. Samples were collected on the continental shelf off Tamandare, Pernambuco, in the context of the INCT AmbTropic project. Samples were taken bimonthly (every two lunar months, always during new moon), from June 2013 to March 2014 at 5 sampling stations from the coastal ​​coral reef area to the central continental shelf (maximum local depth: 30 m). Sampling was carried out at daytime, with subsurface hauls during flood tide, lasting 5 minutes, using cylindrical-conical nets (200 micron / 30 cm and 300 micron / 60 cm), equipped with flowmeters. Biomass was estimated by wet weight and ZooScan. The biomass obtained with 200 micron mesh ranged from 19.7 to 306.8 mg m-3 (mean: 94.9 mg m-3). The biomass in the 300 micron mesh nets ranged from 2.01 to 55.14 mg m-3 (mean: 15.7 mg m-3). For both nets, higher values occurred ​​in the rainy season (March to October, strong winds) and lower values ​​in the months of December and January (dry season, weak winds ). This seasonality was significant for the 300 micron net (p = 0.0063, Kruskal-Wallis ANOVA, n = 38). The spatial distribution showed higher biomass values ​​in the deeper stations and far from the coast. This pattern was especially clear for the 200 micron nets, for which we observed an increase with distance from the coast (p = 0.048, Kruskal-Wallis ANOVA, n = 37). Biomass found in this study was considerably lower than in other studies on the continental shelf. Higher values ​​observed offshore support the hypothesis that the area is influenced by the offshore branch of the Una river plume, which feeds a bank of silt and clay on the central shelf. Nutrients are then resuspended from this offshore bank by seasonal winds, an important regulator of plankton in this area. This study was the first to evaluate the seasonal dynamics of zooplankton biomass on the continental shelf in a tropical coastal area off northeastern Brazil.

Tropical reefs are used for intensive tourism in various parts of the world. However, few studies have investigated the effect of regular trampling on these fragile ecosystems. The aim of this study was to assess the effect of different conservation strategies (open access, partial protection, and total long-term closure) on intertidal reef tops in Porto de Galinhas and Tamandaré, Pernambuco State, Brazil. Analysis of the macrobenthic community was performed with photo transects and image analysis (CPCe). Twenty-seven transects were surveyed from January to August 2012, in intensively impacted (I) open-access sites, in partially protected (P) sites with occasional, illegal trampling, and in a permanently closed (C) site. In I sites, total live cover was half the cover found in adjacent P sites. The area of bare rock averaged 53.6 and 25.0 % in I and P sites, respectively. In the C site, the area of bare rock was only 19.8 %. In I and P sites, macroalgae ( Palisada perforata ) were dominating, while in the C site, the zoanthid Zoanthus sociatus was most abundant. Shell-bearing vermetids ( Petaloconchus varians ) and bivalves ( Isognomon bicolor ) were more abundant at the C site, being possible bioindicators for areas with zero or little trampling. Twelve years of total closure produced near-pristine communities in the C site, dominated by zoanthids and fragile mollusks. This study showed that trampling has severe and long-lasting consequences for the structure of these ecosystems.

O objetivo do presente trabalho foi avaliar se as áreas de cobertura de Zoanthus sociatus (Ellis, 1768) e de macroalgas no topo da área fechada de Tamandaré apresentam associação e se juntas influenciam na variação da área de cobertura da comunidade macrobentônica séssil. As amostragens foram realizadas no topo dos recifes da área fechada de Tamandaré (PE, Brasil) em janeiro e de março a agosto de 2012. A fauna macrobentônica séssil foi avaliada através do fototransecto. Foram realizados 9 transectos fixos de 10 m de extensão, e em cada um deles foram fotografados dez quadrados de 50 x 50 cm, totalizando 630 fotografias. A comunidade macrobentônica séssil apresentou como grupos com maior área de cobertura o zoantídeo Zoanthus sociatus (Ellis, 1768) e as macroalgas (principalmente a rodófita Palisada perforada). A área de cobertura viva total variou de 3,3 % a 100%, com uma média de 80,26%. Já Z. sociatus apresentou uma variação de 3,3 % a 80% (média: 26,37%) de área de cobertura e as macroalgas variaram de 3,3% a 93% (média: 29,98%). Houve uma correlação positiva entre a área de cobertura total e a de macroalgas e uma correlação negativa entre a área de cobertura de macroalgas e de Z. sociatus. O grupo que mais influenciou nas mudanças da comunidade macrobentônica séssil dos ambientes de estudo é o das macroalgas. O fato das macroalgas e o zoantídeo Z. sociatus apresentarem áreas de cobertura inversas, ao longo dos meses, pode estar relacionado à estratégias competitivas regidas pelas mudanças ambientais. Palavras-chave: área de cobertura, fototransecto, Tamandaré

Island environments drastically modify the hydrodynamics of ocean currents and generate strong vertical turbulence. This leads to an upward transport of nutrient-rich waters, thus increasing the biomass of plankton in these oceanic marine environments. The objective of this study was to assess the biomass and density of the zooneuston communities in relation to the upper and lower layers (epi-/hyponeuston), the nycthemeral variation (day/night), the currents in relation to the island (downstream vs upstream), and the distance from the island, focusing on the spatial variability. Samples were taken in July and August 2010 with a David-Hempel neuston net (Hydro-Bios) with a mesh size of 500 µm. Twenty-one taxa were recorded. The most abundant taxa were Copepoda, Chaetognatha, Teleostei (eggs) and Hydrozoa. This is the first record of phoronid larvae for the waters of the Tropical Atlantic. For both layers, density and biomass were significantly higher at night. Density and biomass were always significantly higher in the upper (epineuston) layer than in the lower (hyponeuston) layer. This was probably due to a zooneuston aggregation at the surface and massive vertical migration from deep waters at night, leading to increased abundances at night in both neuston layers.

Volume 47 (2), February 1983, p 221 B. Silvstrine, G.M. Hahn, V. Cioli and C. De Martino "Effects of lonidamine alone or combined with hyperthermia in some experimental cell and tumour systems." The correct affiliation of Dr V. Cioli is: F. Angelini Research Institute, Viale Amelia 70 00181, Rome, Italy, and of Dr G. M. Hahn: Stanford University Medical Centre, Stanford, California, U.S.A.