Impact of Hindiya Dam on Rotifera Community of Euphrates River on the Northern of Babil Governorate, Iraq

This study was the first of its kind on the Hindiya Dam, which is considered one of the important dams in Euphrates River. Five sites were chosen on the north of Babil Governorate in order to know the rotifers biodiversity features and the impact of the Hindiya Dam on it's during the 2019. Site2(S2) was located near the dam to reflect the rotifers diversity of this site, whereas , S1 was located at the upstream of the dam as a control site, and S3, S4 and S5 were located down the dam. Rotifers showed higher density average at Hindiya Dam site compared with sites downstream the dam which was 9164 Ind./m3, whereas density average at the site downstream the dam was 5540 Ind./m3, site (downstream the dam ) decreased clearly compared with the dam site. It was showing the relative abundance index of rotifers: Keratella cochlearis was with the highest percentages followed by Rotaria neplunia, Syncheta oblonga and K. valga at the sites of study area. The study confirmed that the dam reservoir was the source of pelagic rotifers for the outflowing river which led to increase species numbers about 104 species of rotifers. The average values of species richness index of rotifers declined from 1.64 at Hindiya Dam site to 1.58 at site below the dam. Euphrates River rotifers were considered generally from moderate richness to disturbed during 2019 in study area. Site 3(downstream the dam) had the lowest similarity values with site 5 which was 47.5% in rotifers group. Whereas, the highest Jaccard similarity index percentage was between sites 1 with 4 which reached to 76.2%. The Shanon- Weiner index of rotifers reported average values at the dam site 1.7 and 1.8 bit/Ind. at site below the dam. Also, the average values uniformity index of rotifers increased from 0.6 at Hindiya Dam site to 0.7 at site downstream the dam. Euphrates River rotifers were considered generally as little diversified because of index value was ranged from 1 to 2 during 2019 in study area. According to uniformity index values, Euphrates River rotifers were considered generally from unbalanced to moderate balanced in study area. The constant species of rotifers showed that constant species were 8 at the dam site. While, it decreased to 7 constant species at site (downstream the dam). It was concluded that Hindiya Dam had a great effect on the spatial composition of the rotifers community related to the change in the hydrological conditions from current water in site1 to limnetic basins in site 2 (the dam reservoir) then again to current water at site 3, 4 and 5 downstream the dam.

ZIPLAS: Zooplankton Index for Polish Lakes’ Assessment: a new method to assess the ecological status of stratified lakes

Zooplankton is widely recognized as a key component of pelagic ecosystems and forms the basis for major trophic webs. Although zooplankton has often been used as an indicator of trophic state, it has not been included as an obligatory element of the water assessment systems compliant with the Water Framework Directive. This article introduces the Zooplankton Index for Polish Lakes’ Assessment (ZIPLAS) as a new method to assess the ecological status of stratified lakes based on the zooplankton community. The ZIPLAS evaluates three aspects of zooplankton communities, namely, taxonomic composition and abundance, diversity of the zooplankton community, and stressor-sensitive species, which are combined into a multimetric index. Following are the metrics used to compose multimetric ZIPLAS: percentage share of the Rotifer species indicative of high trophy in the indicative group’s number (IHTROT; %), ratio of Calanoida to Cyclopoida individual numbers (CA/CY), percentage of tecta form in the population of Keratella cochlearis (TECTA; %), Margalef’s index (d), and zooplankton abundance (NZOL; ind./L). ZIPLAS responds clearly to eutrophication indicators—the strongest with Secchi disc visibility (Spearman’s rank correlation R = 0.86) and slightly weaker with the expressed by total phosphorus (R = -0.74), total nitrogen (R = 0.68) and the catchment pressure expressed by the nutrient loads generated by different types of land use (R = -0.58).

Can zooplankton species be used as indicators of trophic status and ecological potential of reservoirs?

The European Water Framework Directive implements the policies to achieve a good ecological status of all European waterbodies. To determine the ecological potential in freshwater environments, abiotic (morphology, physical and chemical variables) and biotics (algae, fishes, etc.) metrics are used. Despite their importance in trophic web, zooplankton was not included as one of the Biological Quality Elements (BQE) to determine the water quality. In the present research, we studied the zooplankton species that can be considered as indicators of trophic status and ecological potential for more than 60 water reservoirs. The data were obtained from more of 300 samples collected during 10 years from reservoirs at Ebro River watershed, which is the largest basin in Spain. According to their physicochemical and biological elements, the trophic status and ecological potential of these reservoirs were established. More than 150 zooplankton species were identified during the study. The results from this research indicate that species that are related with low water quality are: Acanthocyclops americanus, Ceriodaphnia spp., Daphnia cucullata, Daphnia párvula, Diaphanosoma brachyurum, Brachionus angularis, Keratella cochlearis and Phompolyx sulcata. An indicator of moderate quality was Bosmina longirostris, while Daphnia longispina, Ascomorpha ovalis and Ascomorpha saltans were considered as indicators of good water quality. The data obtained suggest that zooplankton species can be used as a valuable tool to determine the water quality status and should be considered, in a near future, as one more of the BQE within the WFD metrics.

Application of COI Primers 30F/885R in Rotifers to Regional Species Diversity in (Sub)Tropical China

Rotifers are the most diverse group in freshwater zooplankton and play an important role in food webs and ecosystems. DNA barcoding has become a useful approach to investigate species diversity at local and regional scales, but its application is still limited by efficient primers for the group. To test a pair of primers 30F/885R recently designed for rotifers, we applied them to investigating regional species diversity in the freshwater of South China. We sequenced the cytochrome c oxidase subunit I (COI) gene of rotifers collected from the investigated 23 reservoirs in a large river basin and obtained 145 COI sequences from 33 species in 14 genera. The mean PCR success rate for all tested species was 50%. The 145 sequenced mtCOI in this study covered 33 of 64 identified morphological taxa, including most of the common species in the basin. The intraspecific genetic distance was calculated with a K2P model for 24 rotifer species occurring in the quantitative samples, in which 15 rotifers, such as Keratella cochlearis and Brachionus calyciflorus, had a genetic distance higher than 5%. The high intraspecific genetic differentiation indicates that cryptic species are probably common in (sub)tropical China.

Were there any changes in zooplankton communities due to the limitation of restoration treatments?

Zooplankton is a good indicator of water quality state. Analysing the species composition and abundance, it is possible to assess the condition of the water body and predict the direction of changes. The aim of the study was to analyse the zooplankton in a shallow urban lake, in which restoration was limited to one method, i.e. wind-aeration. The results were compared with the earlier data obtained during sustainable restoration (three methods: wind-aeration, phosphorus inactivation, biomanipulation) and before the restoration period. The zooplankton was sampled monthly in 2015 and 2016 in the deepest place of the lake from the surface to the bottom. The trophic state was determined based on rotifer trophic state index for lakes (TSIROT). Although the species composition of zooplankton communities varied very little among the restoration periods (Keratella cochlearis f. tecta mainly dominated), significant changes in the abundance of zooplankton were found in the analysed lake. The maximum of total abundance was noted in 2015, almost 5500 ind. L−1, and in the next year its decrease was almost 3-fold, to ca. 1800 ind. L-1. Based on TSIROT, the water was still eutrophic. Leaving only one method of restoration (namely, oxygenation of the bottom waters) proved insufficient to support the development of crucial organisms as cladocerans. The changes in the abundance could have resulted more from seasonal changes than from the effects of aeration. A reduction in species number and maintaining a high proportion of rotifers typical for a high trophic state indicated a return of the ecosystem to its pre-restoration state. High variability in the rotifer abundance indicated a continuous imbalance of the ecosystem. Previous restoration treatments using several methods simultaneously showed better effectiveness. The change of strategy of restoration before obtaining a stable improvement of water quality destroyed previously achieved effects.

Dung analysis of the East Milford mastodons: dietary and environmental reconstructions from central Nova Scotia at ~75 ka yr BP.

To reconstruct a mastodon diet and provide a ‘snapshot’ view of environmental conditions in eastern Canada prior to the onset of the Wisconsinan glaciation, we analysed the faunal and floral components of dung associated with juvenile mastodon remains from East Milford, Nova Scotia, dated to 74.9 ± 5.0 ka cal BP. The diverse assemblage of pollen, non-pollen palynomorphs, plant macrofossils and macroinvertebrate remains in the dung suggests that the mastodons lived in a spruce-dominated mixed coniferous-deciduous forest with a strong boreal aspect interspersed with wetlands rich in charophytes, sedges, cattails, bulrushes and bryophytes. The abundance of spruce needles and birch samaras in the dung sample is consistent with an inferred browsing behaviour, having been reported for other mammutid species previously. The limited diversity and near-absence of coprophilous fungi, such as <i>Sporormiella</i>, in the dung could have an impact on understanding the influence of feeding strategies on the presence of coprophilous taxa in sedimentary records, and thus interpretations of megafaunal abundance. The dung also yielded the earliest known Canadian remains of the bark beetle <i>Polygraphus </i>cf. <i>rufipennis</i>, gemmulae of the freshwater sponge <i>Eunapius </i>cf. <i>fragilis </i>and loricae of the rotifer <i>Keratella cochlearis</i>.

ROTÍFEROS Y OTRAS ESPECIES ZOOPLANCTÓNICAS LITORALES DE LA LAGUNA DE PACA Y ÑAHUINPUQUIO, JUNÍN, PERÚ

Este trabajo tuvo como objetivo evaluar los rotíferos y otras especies zooplanctónicas litorales de las lagunas altoandinas (~3400 msnm) de Paca (75°30´LW; 11°40¨LS) y Ñahuinpuquio (75°32´LW; 11°46´LS), Junín, Perú. En agosto de 1994 fueron evaluados cuantitativamente los rotíferos y otras especies zooplanctónicas litorales en las lagunas de Paca y Ñahuinpuquio empleando una red de plancton de 45 um. Los valores son expresados en N° org·L-1. En las 16 estaciones de la laguna de Paca fueron registradas un total de 22 especies, un promedio de seis especies (0-12), 30 org·L-1 (0-164) y un valor del índice de Shannon-Wiener de 2,11 bits·ind-1. Los rotíferos registrados fueron: Keratella cochlearis (Gosse, 1851) (37,5% de las estaciones) y Rotaria sp. (12,5% de las estaciones). En las 17 estaciones de la laguna de Ñahuinpuquio fueron registradas un total de 34 especies, un promedio de 12 especies (0-27), 22 org·L-1 (0-53) y un valor del índice de Shannon-Wiener de 2,95 bits·ind-1. Los rotíferos encontrados fueron: K. cochlearis (58,88% de las estaciones), Rotaria sp. (5,88% de las estaciones), Platyias quadricornis (Ehrenberg, 1832) (5,88% de las estaciones) y Trichocerca bicristata (Gosse, 1887) (5,88% de las estaciones). La diversidad beta empleando el índice de similitud cualitativo de Jaccard (I ) y el J cuantitativo de Bray-Curtis (I ) señalaron para el zooplancton de las lagunas de Paca y B-C Ñahuinpuquio valores de 50% y 59,7%, respectivamente. Los estimadores del número de especies zooplanctónicas para la laguna de Paca y Ñahuinpuquio fueron según Chao-1 (22,5; 52), Jacknife-1 (22; 50) y Bootstrap (22; 45), respectivamente.

ZOOPLANKTON OF SMALL LAKES IN THE EASTERN PART OF THE CATCHMENT AREA OF LAKE VOZHE (VOLOGDA OBLAST)

In the summer period of 2017–2020, the authors studied the composition, dominant complex and the abun-dance of zooplankton in 23 small lakes in the eastern part of the Lake Vozhe catchment area (Vologda oblast). The lakes are located in lacustrine-glacial, moraine-hilly and moraine-plain landscapes. A total of 121 species are recorded in zooplankton of the lakes (Rotifera – 38, Cladocera – 56, Copepoda – 27) including Holopedium gibberum, Daphnia pulex, Bunops serricaudata, Paralona pigra, Chydorus ovalis, Acanthodiaptomus denticornus denticorn that are relatively rare species for the region. The highest occurrence is typical for eurybiontic species. The planktonic fauna of the waterbodies of lacustrine-glacial terrains is sui generis (the index of similarity with other lakes is 0.4). The level of similarity in the composition of zooplankton in moraine lakes is 0.7 on average. Zooplankton in the lakes of different landscape types differs in the structure of dominant complex. The set of dominants in the reservoirs of the lacustrine-glacial terrains is sui generis (Keratella cochlearis, Daphnia galeata, Eudiaptomus graciloides, Heterocope appendiculata). The composition of zooplankton dominants in moraine lakes is more diverse. Most of these waterbodies are dominated by Kellicottia longispina, Keratella cochlearis, Bosmina longirostris, Thermocyclops oithonoides. In the lakes of the moraine-hilly landscape, the set of dominants also includes Eudiaptomus gracilis and E. graciloides, and in the moraine-plain water bodies Asplanchna priodonta, Diaphanosoma brachyurum, Ceriodaphnia pulchella, Polyphemus pediculus are dominant. The highest average abundance (137.7 thousand ind./m3) and biomass (1.8 g/m3) are typical for the lakes in moraine-plain landscapes. The morphology of the depressions of these lakes contributes to the development of macrophyte thickets. The abundance and biomass of zooplankters in waterbodies of the lacustrine-glacial landscapes are 58.9 thousand ind./m3 and 0.8 g/m3, respectively. The development of macrophytes in these reservoirs is limited by a rapid increase in depth and the predominance of peat and peat-silt soils.

STUDY ON ZOOPLANKTON DIVERSITY DURING SPRING SEASON IN CHASHMA LAKE, PAKISTAN

The present study was conducted to know the zooplankton species diversity in Chashma Lake during spring (March 2016 to May 2016). Various physico-chemical parameters like Temperature, PH, Salinity, conductivity, Total dissolved solids (TDS), Turbidity, Dissolved Oxygen, Alkalinity, Chloride and Carbon dioxide which effect the distribution of zooplankton were also analyzed during this study. Zooplankton community was dominated by different species of rotifers. Those rotifers were Asplanchna herricki, Asplanchna brightwelli, Polyarthra remata, Brachionus angularis, Keratella cochlearis, Keratella tecta and Keratella valga tropica. Among these Keratella valga tropica was most common. Some species of copepods were recorded such as, Diacyclops thomasi, Acanthocyclops robustus, Mesocyclops edax, Tropocyclops prasinus mexicanus and Orthocyclops modestus. Among these Diacyclops thomasi was most abundant. Among copepods some nauplii and copepodid stages were also observed. Different species of cladocerans such as, Bosmina longirostris, Daphnia pulex, Chydorus sphaericus, Alona bicolor, Alonella exigua and Simocephalus serrulatus were also recorded.

DEDEYOLU GÖLETİ (ELAZIĞ–TÜRKİYE) ZOOPLANKTONU

In this study, it is aimed to determine the zooplankton and species diversity of Dedeyolu Pond. Zooplankton samples were taken from 3 stations in monthly periods between May 2011 and April 2012. In the research, 17 species belonging to Rotifera, 6 species belonging to Cladocera and 2 species belonging to Copepoda were identified in Dedeyolu Pond. Among all zooplankton, it was represented Rotifera with 81%, Cladocera with 14% and Copepoda with 5%. Species diversity reached its highest value in April (H'=2.34) in the 3rd station, and the Margalef species richness index value reached its highest value in the first station (D=3.84) in October. There were a strong positive correlation between the number of individuals and the temperature in Dedeyolu Pond (r=0.674), a weak positive relationship between the number of individuals and the pH value (r=0.370), and a weak positive relationship between the number of individuals and the dissolved oxygen value (r=0.290). Keratella cochlearis species was recorded as the dominant species in all seasons in the pond.