Species Of Cladocera Research Articles

Diversity and Seasonal Variations of Zooplankton in Dudhiya Talab of Sirohi, India

In this study, the seasonal fluctuations of zooplankton and specific physico-chemical parameters were examined in Dudhiya Talab, a significant artificial reservoir located in Sirohi, Rajasthan. During the research period, a total of 41 zooplankton species were identified, comprising 12 species of Rotifera, 14 species of Cladocera, 5 species of Ostracoda, and 4 species of Copepoda. Among these, Rotifera emerged as the predominant group, with a peak abundance of 689 individuals per liter recorded in the summer, while the lowest numbers were noted during the winter season. Additionally, the zooplankton community exhibited correlations with various physico-chemical parameters. The findings of this research suggest that the distribution and density of zooplankton species are significantly affected by the prevailing physical and chemical conditions of the aquatic environment. Key words: Zooplankton, Physico-chemical factors,P Cladocera, Rotifera.

Plankton Community Stability and Drive Factor Identification Guizhou Plateau Reservoir

In order to understand the stability of the zooplankton and phytoplankton communities in the Guizhou plateau reservoir environment, the process of reservoir water quality change affecting the stability of plankton was studied. The changes in the plankton community and water quality in three different nutrient reservoirs （Huaxi Reservoir, Goupitan Reservoir, and Hailong Reservoir） were studied from October 2020 to August 2021. The stability of the zooplankton and phytoplankton communities was studied using time-lag analysis （TLA）. Variance decomposition analysis （VPA） was used to explore the response of the two communities to environmental changes. The driving factors of plankton community changes in reservoirs were also revealed. The results showed that Huaxi Reservoir and Goupitan Reservoir were mesotrophic reservoirs, and Hailong Reservoir was a eutrophic reservoir. The average comprehensive nutrition indices of the three reservoirs were 44.07, 44.68, and 50.25. A total of 51 species of zooplankton rotifers, 39 species of rotifers, three species of copepods, and nine species of cladocera were identified. Among them, the abundance of rotifers was the highest, accounting for 85.96%. A total of seven phyla and 73 species of phytoplankton were identified, including 16 species in the phylum Cyanophyta, 32 species in the phylum Chlorophyta, 16 species in the phylum Diatoma, three species in the phylum Chlorophyta, four species in the phylum Euglenophyta, and one species each in the phyla Cryptophyta and Chrysophyta. Among them, the abundance of cyanobacteria and diatoms was the highest, accounting for 66.2% and 27.35%, respectively. The median absolute deviation （MAD） of the Bray-Curtis distance of zooplankton and phytoplankton community in the three reservoirs were 0.67 and 0.65 in Huaxi Reservoir, 0.80 and 0.69 in Goupitan Reservoir, and 0.85 and 0.47 in Hailong Reservoir, respectively. The larger the value, the greater the variation in the community. The absolute value of the slope of zooplankton was greater than that of phytoplankton in the TLA results, and the absolute values of the slopes were 0.018 and 0.004, respectively. The larger the absolute value of the slope, the faster the community variability. The zooplankton community in the three reservoirs was less stable than the phytoplankton community and more sensitive to environmental changes, and the degree of variation was greater. The higher the degree of eutrophication of the reservoir, the more obvious this phenomenon. VPA showed that the changes in plankton communities in Huaxi Reservoir and Hailong Reservoir were mainly influenced by water temperature and eutrophication factors. The changes in planktonic community in Goupitan Reservoir were mainly influenced by water temperature and chemical factors. The driving factors of Huaxi Reservoir were water temperature, TP, permanganate index, and SD. The driving factors of Goupitan Reservoir were water temperature, NO3-- N, and pH. The driving factors of Hailong Reservoir were water temperature and TP. Nutrients and water temperature were the main factors affecting the stability of plankton communities in reservoirs.

The history of lake Antyukh-Lambina (Kandalaksha coast of the White Sea) based on the study of bottom sediments

We performed a comprehensive analysis of the sediment cores from lake Antyukh-Lambina. Studied area is situated on the Kandalaksha coast of the White Sea. The lake is connected to lake Kolvitskoye by a narrow strait. We have identified several stages in the lake development from brackish to freshwater conditions, since the early Holocene. The desalination and increased organic matter in the sediment have led to an increase in diversity chironomid and cladocera species. Using chironomid analysis, we performed quantitative reconstructions of mean July air temperatures and water depths. The results showed that both parameters have increased gradually since the early Holocene.

Компаративний аналіз фауністичної структури кладоцероценозів (Crustacea : Cladocera) оз. Люцимер та оз. Пулемецьке Шацького поозер’я

The taxonomic structure and fauna of Cladocera of Lakes Lucimer and Pulemetske are presented. The main work was 243 samples collected by generally accepted methods of hydrobiology during 2013–2019. There are 24 species of Cladocera registered in the lakes, which belong to 4 orders (Haplopoda, Ctenopoda, Anomopoda, Onychopoda), 7 families (Leptodoridae, Sididae, Daphniidae, Moinidae, Bosminidae, Chydoridae, Polyphemidae), 17 genera (Leptodora, Diaphanosoma, Sida, Ceriodaphnia, Daphnia, Scapholeberis, Moina, Bosmina, Alonella, Chydorus, Pseudochydorus, Pleuroxus, Acroperus, Alona, Graptoleberis, Rhynchotalona, Polyphemus) and 6 subgenera (Daphnia, Moina, Exomoina, Bosmina, Eubosmina, Alonella). One tribe (Aloninae) and 4 subfamilies (Daphniinae, Scapholeberinae, Chydorinae, Aloninae) are distinguished in the structure of cladocerocenosis. The greatest taxonomic diversity belongs to the order Anomopoda (29 taxonomic units of superspecific rank). Taking this indicator into account, the Ctenopoda order is less diverse (3 taxonomic units of superspecific rank). The smallest diversity is characteristic of the Haplopoda and Onychopoda orders (2 taxonomic units of supraspecific rank). Taking into account the taxonomic units that characterize the rank of the genus, the most diverse family is Chydoridae. It includes 9 genera (Alonella, Chydorus, Pseudochydorus, Pleuroxus, Acroperus, Alona, ​​Graptoleberis, Rhynchotalona). The family Daphniidae is characterized by a smaller diversity. It unites 3 genera: Ceriodaphnia, Daphnia, Scapholeberis, 4 families include only one genus each: Leptodoridae (genus Leptodora), Moinidae (genus Moina), Bosminidae (genus Bosmina), Polyphemidae (genus Polyphemus). The family Sididae unites 2 genera: Diaphanosoma and Sida. The 2 families contain 2 subfamilies each: Daphniidae (subfamilies Daphniinae and Scapholeberinae) and Chydoridae (subfamilies Chydorinae and Aloninae). The families Leptodoridae, Sididae, Moinidae, Bosminidae, Polyphemidae are not represented by subfamilies. The Chydoridae family is also represented by one tribe (Alonini). This taxonomic category unites related genera of this family (Acroperus, Alona, ​​Graptoleberis, Rhynchotalona). In the lake Pulemetske 19 species have been registered. In the lake Lucimer 18 species have been registered. In the cladocerocenoses of the studied lakes, 13 species are common. Jaccard, Sørensen, and Mountford fauna similarity indices calculated for lake cladocerocenoses are 54, 70, and 13, respectively.

Occurrence of Cladocera Populations in Three Treated Sewage Water Fed Ponds in CHRIST (Deemed to be University), Bangalore, Karnataka, India

Cladocerans are a ubiquitously prominent component of zooplankton and limnological systems. In aquatic ecosystems, cladocerans play a significant role in the food chain and secondary production. 620 species of cladocerans have been reported worldwide to far, making them a very old group with Palaeozoic origins. There are currently over 130 species known to exist in India, with Northeastern India having the greatest taxonomic status. A wide variety of small crustaceans known as Cladocera are found in a variety of aquatic settings, from shallow temporary ponds to deep lakes and wide rivers. Cladocerans are a vital source of food for crustaceans, tiny fish, and aquatic insects. Three treated sewage water fed ponds at CHRIST (Deemed to be University), Bengaluru, Karnataka's Main Campus (MCP: 12.555°N, 77.361° E), Bannerghatta Campus (BCP: 12.523°N, 77.354° E), and Kengeri Campus (KCP: 12.514° N, 77.261° E), have been undertaken to study the composition of and occurrence of Cladocera species. In the above study there were 3 species caldoceras observed from all the three study sites of treated sewage water.

The patchy distribution of groundwater copepods in the lowland river valley

Our research provides valuable insights into the uneven distribution of groundwater copepods in the lowland river valley ecosystem using an integrative taxonomy approach. The study was conducted in 101 wells in the Biebrza River Valley (northeastern Poland), which is one of the largest and best-preserved lowland rivers in Europe. It stands out for its exceptional biodiversity and pristine natural landscapes. Groundwater copepods were found in 49 of the 101 analyzed wells. We identified ten species of Copepoda and eight species of Cladocera. The most frequent copepods were Diacyclops bicuspidatus, Diacyclops crassicaudis, Canthocamptus staphylinus, Paracyclops cf. fimbriatus, Diacyclops bisetosus, and Eucyclops serrulatus. The aforementioned species were categorized as stygophiles, and no stygobionts were detected. Our findings suggest that the groundwater Copepoda community in this region is relatively stable and composed mostly of stygophiles along with stygoxenes. We did not find any significant impact of environmental parameters or different aquifers on the distribution of copepods, suggesting a patchy distribution of groundwater copepods in the lowland river valley. The relatively high presence of stygoxenes suggests that the exchange of organisms between surface water and groundwater plays a vital role in maintaining the diversity of microcrustaceans in lowland river valleys. Our study contributes to filling the knowledge gap regarding groundwater fauna in lowland Europe, particularly in areas affected by Pleistocene glaciations.

Spring and autumn fauna of Cladocera (Crustacea: Branchiopoda) in the center of East Asia plain: Hunan and Hubei Provinces of China.

Cladoceran (Crustacea: Branchiopoda) fauna of Hunan and Hubei provinces of China was studied in April 2014 and October 2018. 49 species of Cladocera were found, Anthalona sanoamuangae Sinev & Kotov, 2012 was recorded for China for the first time. Eight species were newly recorded for central China, taxonomic status of four species was clarified. Among the observed species, 19 taxa are predominantly Boreal, 13 species are recorded predominantly in south part of temperate zone and subtropics, and 17 species are mainly tropical. Significant difference was revealed between the spring and autumn fauna: Boreal species were the most frequent in spring, whereas subtropical and tropical species became more common in autumn. Species diversity and composition of the cladoceran fauna in the center of East Asia plain is discussed.

Structural characteristics of zooplankton communities in Hongze Lake driven by water environmental factors from 2016 to 2020.

This study investigated zooplankton species, density, biomass, and water physicochemical factors in Hongze Lake between 2016 and 2020. The correlation between zooplankton community changes and physicochemical factors was explored using canonical correspondence analysis and Spearman correlation analysis. The investigation found 48 species of protozoa, 52 species of rotifers, 36 species of cladocera, and 32 species of copepoda. The yearly mean density fluctuated between 529.01 and 2234.51 individuals per liter. The yearly mean zooplankton biomass was 950.14 mg/L, ranging from 271.92 to 1365.835 mg/L. A high diversity of zooplankton was found in the Overwater Area, with a large proportion of protozoa and copepoda. Correlation analysis revealed that nitrogen content, pH, water temperature, chemical oxygen demand, biochemical oxygen demand, water transparency, and chlorophyll a were important factors influencing the distribution of zooplankton in Hongze Lake. These factors collectively contributed to the evolution of the zooplankton community structure in Hongze Lake.

Fauna of the Cladoceran and Copepods Crustaceans (Crustacea: Cladocera, Copepoda) of Dood Tsagaan Lake (Darhad Basin, Mongolia) in Modern Times

The paper presents the results of the study the qualitative and quantitative composition of the planktonic Crustacea of Dood Tsagaan Lake (northwestern Mongolia) (Cladocera, Diaptomidae, Cyclopidae) in modern times. Comparative analysis of the species composition of crustaceans according to new data and data obtained in the last century (1962–1963) showed that during our studies the composition of crustaceans was increased by five species of Cladocera and by three species of Copepoda, 2 species of them are from the order Cyclopoida and one from the order Calanoida. Ultrastructural studies of the main morphological parts of the copepods crustaceans Mixodiaptomus incrassatus (Sars, 1903), Acanthodiaptomus paulseni (Sars, 1903) and Cyclops glacialis Flossner, 2001 were carried out for the first time using a scanning electron microscope (SEM). Detailed study of morphometric and morphological characters including the use of SEM showed that C. glacialis inhabiting Dood Tsagaan Lake is identical to the species described in lakes (Turgun Kharhiraa Uvs aimag and Nogoon nuur) in northwestern Mongolia. The biomass of M. incrassatus, an important food object for whitefish and other fish species, was found to reach 1100 mg/m3 in the modern period.

First Data on Species Composition and Development Cladocera (Crustacea: Branchiopoda) in Mire Ecosystems (Kaliningrad Region, Russia)

The original data on Cladocera fauna in standing-water and stream habitats of mire ecosystems were obtained for the first time in the Kaliningrad region during the research study on large raised bogs (Zehlau and Bolshoye) and drainage canals of 6 peatlands affected by peat extraction. In the studied wetland ecosystems, 41 species of Cladocera were recorded in total, including a number of rare and vulnerable taxa (Flavalona rustica, Scapholeberis microcephala, Streblocerus serricaudatus and Holopedium gibberum). The four species of Cladocera are new species for the Kaliningrad region which were not reported here before. Cladocera played a vital role in the studied bog pools and waterlogged habitats in peatlands as a key group of organisms that forms here a significant part of the zooplankton biomass due to the abundance and intensive production in the water bodies. The secondary filter feeders and predators were the most abundant in bog ecosystems. The cladoceran fauna in the intact bog ecosystems, especially the Zehlau raised bog, was the most diverse and unique. Nevertheless, the cladoceran assemblages in the disturbed ecosystems of drainage canals retained certain features of the natural water bodies. The latter fact is important in applied respect enabling to consider these canals as refugia that have potentials for natural restoration of the cladoceran fauna during the peatland rewetting programme on the Carbon Polygon in the Kaliningrad region.

Zooplankton in the Technogenic Aquatic Ecosystem of the North Crimean Canal, the Longest in Europe

The construction and use of navigation and irrigation canals are among the common human alterations in landscapes and ecosystems. The North Crimean Canal (NCC) is the longest in Europe; its main branch is 403 km, and the total of all its branches exceeds 10,000 km. It is a main driver of the significant environmental changes in an all-arid part of Crimea. No zooplankton studies in the canal have been carried out up to this time at all. In 2022, zooplankton was studied in different sites from May to October. Total zooplankton abundance fluctuated between 170 and 19,560 ind. m−3, and wet biomass between 0.75 and 1057 mg m−3. In total, 11 Rotifera species, 11 Cladocera species, and 15 Copepoda species, including 2 Harpacticoida, 5 Calanoida, and 8 Cyclopoida, were found in plankton. The most common Rotifera species were Brachionus calyciflorus, Euchlanis dilatate, and Keratella cochlearis. Among Cladocera, Chydorus sphaericus, Bosmina longirostris, and Coronatella rectangular have the highest frequency of occurrence. In Copepoda, these were Acanthocyclops vernalis, Eurytemora affinis, and Nitocra typica. Among the 37 species found in NCC, 10 were not previously noted in the water bodies of Crimea. Among rotifers, they were Ploesoma hudsoni, Polyarthra dolichoptera, Pompholyx complanata, Synchaeta grandis, and Synchaeta stylata. Bosminopsis zernowi, Rhynchotalona rostrata, and Scapholeberis mucronata were not noted before among Cladocera. Eurytemora lacustris and Cyclops smirnovi were first found in Crimea among Copepoda. New technogenic aquatic ecosystems such as NCC are the “gateway” for the invasion of alien species into the new regions.

The Role of Old Relicts in Structuring the Boreal/Tropical Transitional Zone: The Case of East Asian Planktonic Cladocera (Crustacea)

Previous studies provided evidence of the mixing of boreal–tropical cladocerans (Crustacea) in the Far East of Eurasia, as well as the presence of numerous pre-Pleistocene relict endemics. In this study, we hypothesize that the colonization history is reflected in the proportions of endemic/boreal/tropical taxa among different habitat types within this region. We analyzed 442 qualitative samples collected from seven sub-regions of the Far East of Russia and South Korea along a latitudinal transect of approximately 2200 km, where we identified 101 Cladocera species. Our results showed a significantly higher proportion of endemic taxa in the plankton compared to the littoral and benthic zones. The proportions of endemic/boreal/tropical taxa in the permanent and temporary waters were similar. We observed a distinct shift in dominance in benthos and littoral zone across our transect: boreal taxa were prevalent in the northern sub-regions (1–4), while tropical taxa were prevalent in the southern sub-regions (5–7), with a pronounced boreal–tropical transition zone (sub-regions 4–5). Our findings suggest that this pattern arose due to the unhindered dispersion of the two faunas in a latitudinal direction until they met at the boundary during their arrival in the Late Pleistocene. In contrast, the proportions of the boreal and tropical taxa in plankton did not exceed 16% in any of the studied sub-regions, and the proportion of boreal taxa decreased from 16% to 10%, while that of the tropical taxa increased from 0% to 10% from north to south. We propose that the lower proportions and the absence of mixing of fauna in the plankton can be explained by the strong presence (sometimes dominance) of relics that occupy these water bodies before the arrival of colonizers from the north and south. Our findings highlight the significant role of biotic interactions in the formation of biogeographic boundaries, which was previously underestimated.

Possible mediation of Cladocera species by a researcher's chest wader

Mediation of aquatic species has become an increasing problem for the last few decades. With the increasing commercial import, species’ direct or indirect spread can gain more space. There are several ways for them to land in their new home and spread through the country. Most of the aquatic species are spread by waterways, boats, vehicles, or even with the help of humans. Cladocerans have a good dispersal ability, thanks to their small size, additionally they possess good adaptation, and mechanisms to develop resting eggs. Benthic or littoral species can be mediated much more easily due to their living space, and with the help of human activities (e.g., scientists, anglers and people working in water bodies) they have a higher chance to colonize new habitats. Our goal was to explore if Cladocera species might be mediated by a scientist chest wader, while sampling in similar-sized, close-to-each other lakes, with different utilization. Most of the species were found in abandoned fishing lakes, followed by oxbow lakes (protected), and ultimately in intensively fished lakes. NMDS showed that samples from lakes with the same utilization are similar to each other. Differently utilized lakes can have various Cladocera species, even though they are closely related to each other. Based on the results, scientists can mediate species on their chest wader from lake to lake and may deteriorate the results. We recommend a necessary chest wader cleaning after every sampling process, especially when samples are taken from differently utilized lakes.

Structure of the Zooplankton Community in Sıddıklı Küçükboğaz Dam Lake, Türkiye: The Importance of Environmental Factors

The zooplankton fauna of Sıddıklı Küçükboğaz Dam Lake, located in Kırşehir city in Turkey, was researched as monthly between September 2015 and August 2016. A total of 24 major zooplankton species was determined. Zooplanktonic organisms were presented by three main groups: Rotifera (75%), Cladocera (21%) and Copepoda (4%). The minimum and maximum number of species were revealed in May (4 species) and April (12 species), respectively. Rotifera was the most abundant taxon dominated mainly by the species Keratella cochlearis, Polyarthra dolichoptera, Asplanchna priodonta and Synchaeta pectinata. Brachionus: Trichocerca quotient value of 1.00 was estimated. This result has clearly showed that the Sıddıklı Küçükboğaz Dam lake is oligotrophic. All species of Rotifera, Cladocera and Copepoda group are new records for this dam lake. The fundamental data of the Sıddıklı Küçükboğaz Dam Lake are provided, and the relationships between zooplankton and environmental parameters have researched in this study. Also, this study was supported by academic basics for monitoring a reservoir in Central Anatolia. Redundancy analysis (RDA) showed that all environmental indicators accounted for 34.1% total variance of zooplankton. Besides, RDA results demonstrated that zooplankton abundance is correlated with biological oxygen demand, water temperature, total suspended solid, ammonium and total ammonia nitrogen.

IMPACT OF SEASONAL CHANGES IN FRESHWATER PHYTOPLANKTON AND ZOOPLANKTON BIODIVERSITY AT VALANKULAM LAKE, COIMBATORE DISTRICT, TAMIL NADU, INDIA

The plankton communities are important source of food for the aquatic organisms, and if any undesirable changes in aquatic environment may affect plankton diversity and density. Therefore, assessment of planktonic communities in the freshwater ecosystems is essential because they serve as bio-indicators of water quality parameters. Hence, the present research was focused to evaluate the freshwater phytoplankton and zooplankton diversity and their abundance in Valankulam Lake (Lat. 10.59° N and Long. 76.57° E), at Coimbatore city, Tamil Nadu, India. Results from the study revealed that a total of 77 species of phytoplankton and zooplankton were recorded, under 37 families and 46 genera. In addition to that, a total of 43 phytoplankton species were recorded under 25 families and 30 genera, (which includes; 15 species of Cyanophyceae, 17 species of Chlorophyceae, 08 species of Bacillariophyceae, 03 species of Euglenophyceae). and a total of 34 species of zooplankton were recorded under 12 families and 17 genera, (which includes 13 species of Rotifera, 09 species of Cladocera, 08 species of Copepoda and 04 species of Ostracoda). The maximum plankton diversity was observed during the monsoon season and the minimum in the summer season. Results from study revealed the ecological status of the lake is categorized as moderately polluted due to the presence of municipal waste and industrial discharges into the lake water. Therefore, the assessment of planktonic communities in water bodies will be useful to monitor and maintain the water quality parameters and wealth of aquatic biota in the aquatic ecosystem.

Cladocera and Copepoda (Cyclopoida, Calanoida) of the mountain part of the Stryi river basin (Ukrainian Carpathians)

The Cladocera, Cyclopoida and Calanoida species diversity of the mountain part of the Stryi river basin is described. The objects of research were found in 48 lenthic water bodies (Zhuravlyne lake, Yavirske reservoir, numerous ponds, puddles, swamps, springs, and wells) and on 7 sections of the Stryi and Yablunka rivers. 24 species of Cladocera, 23 Cyclopoida, and 1 Calanoida are found. The most diverse is the fauna of Lake Zhuravlyne, which is located in the Skole Beskydy National Nature Park. 56% of the species diversity of the mentioned groups is noted in ponds, 42% in puddles and swamps, 8% in springs and wells, 15% in rivers, 10% in Yavirske reservoir, 44% in Zhuravlyne. The fauna of the mountain part of the Stryi river basin includes 44% of the Cladocera, Cyclopoida and Calanoida species diversity of the territory of the Ukrainian Carpathians. Only Eudiaptomus transylvanicus is noted within Calanoida. Alona protzi, Eurycercus lamellatus, Simocephalus expinosus are found only in the study area within the Ukrainian Carpathians. The most common species in this area are Chydorus sphaericus (36% frequency of occurrence in the investigated lenthic water bodies) and Eucyclops serrulatus (55%). These species are the most common in the Ukrainian Carpathians as well. The highest total density of Cladocera and Cyclopoida was 253,5 thous.ind./m3. Daphnia obtusa, Alona protzi, Eucyclops subterraneus, Paracyclops poppei та Grateriella unisetigera are rare species for Lviv region. Eurycercus lamellatus, Simocephalus expinosus, Chydorus latus together with the previous species are rare for the Ukrainian Carpathians in total. 47% of the investigated lenthic water bodies are in oligosaprobic zone. The most valuable communities of the Cladocera, Cyclopoida and Calanoida exist in the Zhuravlyne lake, springs and wells near village Verkhnia Rozhanka, pools of the Vododilnyi masiff, riverbed of Stryi and the along-river reservoirs between the villages Zavadavivka and Yavora, and ponds near the village Dovge.

A review of the Cladocera in Basrah, Iraq

Sixty-five species of freshwater Cladocera belong to twenty-two Genera are reported from Basrah city, based on 15 studies mentioned the species of Cladocera in addition to seven other studies reported only density of Cladocera group. The maximum density of Cladocera was 91225 (ind./m3) recording at Shatt Al-Arab- Al-Hartha region.

Современное состояние зоопланктона Малого Моря оз. Байкал (по данным 2022 г.)

Original results of studies of zooplankton in the Maloe More Strait of Lake Baikal in 2022 are presented. Changes in species composition, quantitative indicators of development and the structure of zooplankton in years of different water levels are analyzed. Zooplankton was collected on 5 transects in three depth zones: central about 200 m, coastal – about 10 m, shallow – less than 1 m. At deep-water stations, zooplankton includes 5 species of Rotifera and Cladocera, 2 species of Copepoda and 1 species of Amphipoda. Epischura baikalensis and Cyclops kolensis formed the basis (up to 99% of the total number) of the total population density (up to 2100 ind./m3 ) and biomass (up to 140 mg/m3). Macrohectopus branickii may also constitute a significant portion of the biomass at some stations. Coastal zooplankton is characterized by an increase in taxonomic diversity to 28 species, of which 79% are Rotifera. The population density increases to 115 thousand ind./m3 and biomass to 492 mg/m3, but the structure of zooplankton does not change due to the preservation of the dominant complex of Copepoda. A fundamentally different planktocenosis is formed at shallowwater stations, the taxonomic composition of which includes the same species as in deeper-water zones. However, non-endemic rotifers Synchaeta spp., Keratella cochlearis tecta, Polyarthra dolichoptera and others, which together make up more than 96% of the total number, become systemforming species. Of the endemic species, only the meiobenthic phytophilic crustaceans Chydorus baicalensis and Alona setosocaudata, as well as the rotifers Euchlanis ligulata, Dicranophorus sp., play some role. Zooplankton in the shallow water zone is characterized by a high abundance of up to 425 thousand ind./m3, however, taking into account the dominance of small-sized rotifers, a relatively low biomass – up to a maximum of 154.9 mg/m3. The structure and density of the population of plankton in the deep-water and coastal zones of the transects shows similarity with the zooplankton of the average water level in 2012. The taxonomic composition and quantitative characteristics of the shallow zone correspond to the zooplankton of the most warmed bays of the Maloe More Strait.

Zooplankton community structure of a tropical lake in a Northcentral State, Nigeria

One of the biological components that play a vital role in the ecological integrity of an aquatic ecosystem is zooplankton. These organisms are good indicators of stressors, especially anthropogenic stressors in their environment. Thus, there is a need to study the diversity in a diversified freshwater lake (Dangana Lake) in order to provide baseline information and knowledge on the status of the lake for proper and adequate water preservation and conservation. In addition to the zooplankton structure determination, the study also examined the physicochemical parameters of the Lake. Three sampling sites were identified with distinct characteristics where water and zooplankton samples were collected for physicochemical analyses and biotic identification using standard protocols. Sampling was conducted for a duration of eight months. The monitored physicochemical parameters, i.e., temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD5) and pH revealed no significant difference (p>0.05) among sampling sites. However, significance (p<0.05) amongst sampling sites was recorded in electrical conductivity, nitrate and phosphate. Seasonally, there was a significant difference (p<0.05) among sampling months in all the monitored parameters. A total of ten species of zooplankton were recorded with four species each of rotifera and copepoda and two species of cladocera. The order of abundance of zooplankton population was rotifera (56.39%), copepoda (29.18%) and cladocera (14.42%). Zooplankton population was significantly (p<0.05) higher during the dry season than in the rainy season. The Canonical correspondence analysis (CCA) revealed a strong correlation between the zooplankton and physicochemical parameters. Ipso-facto, the lake exhibited spatiotemporal changes in zooplankton composition and physicochemical parameters during the sampling period.

Determination of Zooplankton Fauna in the Running Waters of Arsuz District of Hatay Province

Some water quality parameters (salinity, water temperature, conductivity and dissolved oxygen) and zooplankton fauna were investigated in 4 rivers within the borders of Arsuz district of Hatay Province. Forty three (43) species of Rotifera (61.43%), 21 species of Copepoda (30%), and 6 species of Cladocera (8.57%) were recorded. In the study, 15 families from Rotifera were recorded, Lecanidae was the richest family with 12 species, Chydoridae from Cladocera represented by three families was the richest family with 4 species, and Cyclopoidae from Copepoda, represented by 10 families, was the richest family with 8 species. It was observed that Cephalodella gibba, Colurella adriatica, Eucyclops serrulatus and Paracyclops fimbriatus were the most common species recorded in all four running waters. Most species (51 species) were recorded in Arsuz Stream, followed by Gümüşkent stream with 32 species. In the study in which a total of 70 taxa were recorded, only 12 taxa were very abundant (+++) and abundant (++) levels in various seasons and rivers. Only 2 rotifer Brachionus quadridentatus and Lecane hamata were very abundant. There was a significant and positive relationship between zooplankton species diversity, abundance, and water quality parameters.