Prevalence and substrate specificity of epizoans on crustacean zooplankton were examined during an annual cycle in Tulé Reservoir, a large, shallow and polymictic waterbody in western Venezuela. Epistylis sp., a ciliate protozoan, and Synedra sp., a pennate diatom, were the most frequent epibiont taxa. The prevalence of all epibionts on 1800 individual crustaceans was only 3.3%, and the occurrence of the two epibiotic taxa together on the same substrate zooplankter was low (3.3% of total infested crustaceans). Cyclopoid copepods were preferred as substrate for Epistylis sp. Neither epibiont taxon was found on copepodids or adults of a calanoid. Both epibionts were absent in the early rainy season but appeared in mid rainy season and showed the highest prevalence in the early dry season. During the remainder of the dry season prevalence was low. Epibiont prevalence was not related to presence or absence of zooplankton taxa or water temperature. Differences from temperate epibiont communities are discussed Resumen. A lo largo de un ciclo anual, se estudió la prevalencia y la especificidad al sustrato de los epibiontes de la comunidad de crustáceos planctónicos del Embalse Tulé, un cuerpo de agua somero y polimictico del Occidente de Venezuela. Epistylis sp., un protozoario ciliado, y Synedra sp., una diatomea pennada, fueron los taxones más frecuentes. La prevalencia de ambos epibiontes en conjunto sobre los 1.800 individuos examinados fue de 3,3% y la presencia de ambos epibiontes en el mismo sustrato fue baja (3,3% del total de individuos infestados). Los copépodos ciclopoideos fueron preferidos por Epistylis como sustrato. Ningún epibionte se observó en los copépodos calanoides. Los epibiontes aparecieron a mediados del período de lluvias y alcanzaron su máxima prevalencia al principio del período de sequía. La prevalencia no se encontró relacionada ni con la presencia o ausencia de las especies zooplanctónicas ni con la temperatura del agua. En el presente trabajo se realizan comparaciones con las comunidades epibiónticas de la zona templada y se discuten explicaciones a las diferencias encontradas.

Los derrames de petróleo constituyen una fuente importante de perturbación de los macroinvertebrados bentónicos de aguas continentales. Sin embargo, los estudios referentes a estas perturbaciones en las regiones tropicales, y particularmente en el Neotrópico, son limitados. En el presente trabajo se evaluaron los efectos de un derrame de 11 700 barriles de petróleo en las comunidades de macroinvertebrados bentónicos de los ríos Santa Rosa, Quijos y Coca, amazonia ecuatoriana, mediante el uso de índices bióticos, variables de calidad de agua y sedimentos, tanto en sitios impactados como en sitios de referencia en los años 2011 y 2012. Las correlaciones de Spearman establecieron relaciones negativas significativas (p < 0.05) entre la variable “hidrocarburos totales de petróleo” y los taxa Ephemeroptera-Plecoptera-Trichoptera (índice EPT), Trichoptera, y la familia Elmidae. Se estableció una relación inversa entre el índice SIGNAL2 con los hidrocarburos totales de petróleo. El procedimiento de permutación de respuesta múltiple determinó una diferencia entre las comunidades de macroinvertebrados de estaciones de referencia e impactadas del año 2011, y entre las comunidades de macroinvertebrados de estaciones de referencia año 2011 y estaciones impactadas año 2012. El escalamiento multidimensional no-métrico implicó usar tres dimensiones, en el cual el eje dos estuvo mejor relacionado con los hidrocarburos totales de petróleo (r = 0.45). Estos resultados sugieren que factores distintos a hidrocarburos totales de petróleo son los responsables de la composición heterogénea de las comunidades de macroinvertebrados.

An annotated checklist of the free-living freshwater Copepoda recorded in different regions in Ecuador (including the Amazon, the Andes, the coastal region, and the Galapagos Islands) is here provided. We revised all published records, critically evaluated the validity of each taxon and provided short taxonomic and biogeographical remarks for each one. A total of 27 taxa have been reported, including species and records at the generic level only. The species and taxa identified only up to the generic level belong to five families and 14 genera. The Cyclopoida is the most diverse group with 16 records belonging to species (or identified to the generic level only) and eight genera, followed by the Harpacticoida with six species, one identification to the generic level only, and four genera, and Calanoida with four species belonging to two genera. A total of 18 taxa are recorded for the Andes. Six have been recorded in the Amazon, two are recorded for the coastal region, and six for the Galapagos. One species is shared between the Amazon and the Andes. One species is shared between the coastal region and the Amazon. Seventeen are only reported from the Andes and four are only reported from the Amazon. At the current status of the knowledge, any attempt to analyze and generalize distributional patterns of copepods in Ecuador is premature due to the scarcity of available information, and evidently there is an urgent need for more extensive field collections. A few working hypothesis for future studies are identified.

Diaphanosoma brachyurum is a dominant component of summer zooplankton in Central Europe. So far only this species has been known from Poland, and other species from this genus have been found in neighboring countries. The aim of the present study was to present the factual distribution of Diaphanosoma species in Central Europe. We investigated Diaphanosoma individuals in 109 water bodies in Central Europe (mostly from Poland) by combining morphological analyses and molecular methods (mtDNA COI gene). Our research confirmed the presence of three other species - D. orghidani, D. mongolianum, and D. cf. lacustris. We provided a detailed morphological description for every species and pointed out that each species can be easily distinguished morphologically by armament of postero-ventral valve margins. The results of phylogenetic analysis based on 27 haplotypes of mtDNA COI gene lead to the same conclusion as morphology. Our genetic and morphological analysis confirms a close affinity between D. mongolianum and D. lacustris, as well as the presence of hybrids between these species. Nevertheless, the most common was D. brachyurum - it was found in 97 water bodies, and other Diaphanosoma species begin to penetrate Central Europe via rivers.

We highlight the lack of researchers studying freshwater zooplankton in Latin America and contextualize it within the global extinction of taxonomists, global loss of biodiversity, and regional reality to visualize the intensity of this threat and possible strategies for addressing it. The scarcity of researchers working on freshwater zooplankton currently threatens the future of these studies in the world. This global trend of the decreasing interest of scientists and local governments in learning about this important component of freshwater biodiversity is more accentuated in Latin America by regional drivers, such as brain drain, a lack of support by stakeholders, and the absence of planning for the rational use and conservation of this essential natural resource. All these drivers interact and have more dramatic consequences for regional research due to the recent reduction in government funds for science in some of these countries. In the context of Global Change; a loss of biodiversity due to this fact; and the misuse of drainage basins, overexploitation, and regional pressures, the lack of researchers studying freshwater zooplankton and, in general, all aquatic life has emerged as a critical threat to the delicate equilibrium of these ecosystems. Within this situation, scientific integration through intra-regional and extra-regional collaboration networks has emerged as an unavoidable strategy for the survival and future strengthening of studies on biodiversity and the conservation of freshwater zooplankton in Latin America. The development of new technologies such as DNA barcoding, metabarcoding, and metagenomics has emerged as a solution to this problem. Nevertheless, they should be considered as new tools towards integrative taxonomy and not as replacements for taxonomical studies.