Revision of the guttata-group of Alona s. lato leads to its translocation to Prendalona Sousa, Elmoor-Loureiro & Santos, 2018 (Cladocera: Anomopoda: Chydoridae).

Revision of the guttata-group of Alona s. lato justifies its translocation to the genus Prendalona Sousa, Elmoor-Loureiro & Santos, 2018. Emended diagnosis of the genus and diagnoses for all its species are provided. Prendalona belong to the Hexalona-clade of Alona s. lato, it is a sister-group of genus Flavalona Sinev & Dumont, 2016, but differs from the latter in: (1) minute lateral head pores without any pockets below, (2) absence of the genital process on male postabdomen, and (3) absence of inner setae on endites 1-2 of thoracic limb I. Morphology of North American P. barbulata (Megard, 1967) and widely distributed P. guttata (Sars, 1862) is investigated in detail for the first time. Prendalona julietae sp. nov.,sibling-species of P. guttata, is described from Brazil. Global diversity and distribution patterns of Prendalona are discussed.

The first record of Bergamina lineolata (Chydoridae; Aloninae) from Colombia / O primeiro registro de Bergamina lineolata (Chydoridae; Aloninae) na Colômbia

The Neotropical freshwater cladoceran Bergamina lineolata (Sars, 1901) was found in a small temporal pond in the Magdalena department. Hitherto, it has been reported in Brazil and El Salvador. It was originally described as Alonella lineolata by Sars, 1901 from Brazil and then placed to the genus Bergamina by Elmoor-Loureiro et al. (2013). This is the first record of this species in Colombia. B. lineolata can be identified by a unique combination of characters including: 1) a remarkably large and oblong postabdomen, with three denticles on distal corner; 2) basal spine of the claw very short, length less than the half claw diameter at base; 3) IDL with two setae shorter than ODL seta, armed with fine setules unilaterally in terminal half; 4) endite 1 of trunk limb I with a long smooth seta between endites 1 and 2.

O cladócero neotropical de água doce Bergamina lineolata (Sars, 1901) foi encontrado em uma pequena lagoa temporária no departamento de Magdalena, na Colômbia. Até o momento, havia sido relatado no Brasil e em El Salvador. Foi originalmente descrito como Alonella lineolata por Sars, 1901 no Brasil, e, em seguida, colocado no gênero Bergamina por Elmoor-Loureiro et al. (2013). Esse é o primeiro registro dessa espécie na Colômbia. B. lineolata pode ser identificada por uma combinação única de caracteres, incluindo: 1) um pós-abdômen notavelmente grande e oblongo, com três dentículos no ângulo distal; 2) espinho basal da garra muito curto, comprimento menor que o diâmetro da metade da garra na base; 3) IDL com duas cerdas mais curtas que cerdas ODL, armadas com sétulas finas unilateralmente na metade terminal; e 4) endito 1 do toracópodo I com uma longa cerda lisa entre os enditos 1 e 2.

A new species of Bosmina (Liederobosmina) Brték, 1997 (Cladocera: Bosminidae) from high mountain lakes of Colombia.

Insufficient attention has been recently paid by the taxonomists to the family Bosminidae Baird (Crustacea: Cladocera). Here we describe a new species of Bosmina (Liederobosmina) Brték from high mountain water bodies of Colombia which is unique among all bosminids having heavily striated valves. Most probably, this taxon has a narrow distribution area in the Andean high mountains. It is obvious that the Andean highlands must be studied in detail, i.e. using molecular methods, and more new taxa might be detected in the future.

Ceriodaphnia smirnovi (Crustacea: Cladocera), a new species from the Mediterranean Region, and a phylogenetic analysis of the commonest species.

Species of the genus Ceriodaphnia Dana, 1853 (Crustacea: Cladocera: Daphniidae) are present in the plankton of many freshwater bodies all around the World. However, the taxonomy of the genus is still poorly developed. Most species have been described in the nineteenth century and data on their morphology and distribution should be revised according to current standards. Currently, due to lack of reliable morphological and genetic data, almost all nominal species of Ceriodaphnia are considered as species groups rather than separate biological species, complicating the detection and description of new species of the genus. Here, we redescribe the morphology of Ceriodaphnia quadrangula (O.F. Müller, 1785) based on material close to the type locality in Denmark, and describe a new species of Ceriodaphnia from the Mediterranean region. Also, we provide a phylogenetic analysis using existing and novel sequences of mitochondrial DNA of the commonest species of the genus. Ceriodaphnia smirnovi sp. nov. can be easily distinguished from C. quadrangula via presence of the head pore and the structure of the second thoracic limb, the postabdomen and the ephippium. From other species of Ceriodaphnia known to date C. smirnovi sp. nov. can also be separated on ephippium structure and some other fine morphological features. Although distribution range of C. smirnovi sp. nov. must be clarified in the future based on analysis of more sampling points, most likely, it is restricted to the Mediterranean region. The phylogenetic analyses showed high divergence among 16 different clades (mean clade separation of 13±2.3 % (mean ± SD) and 20.7±2.1% for 16S and COI respectively). These clades belonged to 11 described species and 5 undescribed. The high intraspecific variability of some species indicates the possible existence of more undescribed species within present species groups.

Phylogenetic analysis of eight species of Anomopoda based on transcriptomic and mitochondrial DNA sequences.

Anomopoda is the widespread planktonic microcrustacean, which plays a crucial role in aquatic ecosystem. There are few studies about the evolutionary relationships among various Anomopoda basing on molecular data. In the present study, phylogenetic analysis of eight Anomopoda was carried out. Firstly, the culture system was developed to breed cladocerans. By using this system, eight species (Daphnia magna, D. pulex, D. sinensis, Ceriodaphnia reticulata, Moina micrura, Scapholeberis kingi, Simocephalus vetulus and Eurycercus lamellatus) were purified and cultured stably in the laboratory. Then, transcriptomic sequences and partial mitochondrial DNA sequences were both used to reconstruct the phylogenetic tree among 8 species. Transcriptomic sequences were sequenced on Illumina Hiseq 2500 platform. After assembly and annotation, transcriptomic sequences were spliced together and aligned for phylogenetic analysis. Basing on the orthologous genes derived from transcriptomic sequences, the phylogenetic analysis showed that 4 genera of Daphniidae were clustered into one group, and among the 4 genera, Ceriodaphnia was closer to Daphnia than Simocephalus, while Scapholeberis was farthest from other species. In addition, Eurycercidae was closer to Daphniidae than Moinidae. The phylogenetic trees based on both 12S rRNA and 16S rRNA sequences were similar with that based on transcriptomic sequences. Meanwhile, the phylogenetic tree based on 16S rRNA sequences was more suitable than that based on 12S rRNA sequences. These results suggested that the phylogenetic analysis basing on the transcriptomic sequences was available in cladocerans, which will help us to effectively understand the phylogenetic relationships among various cladocerans.

Temporal and spatial variations in zooplankton communities in relation to environmental factors in four floodplain lakes located in the middle reach of the Yangtze River, China.

A comparative limnological study of the zooplankton communities and their relationship with environmental factors was conducted to test the temporal and spatial changes among lake groups. In our study of four lakes, the lowest gamma (γ) diversity was recorded in January 2017, with a total of 25 zooplankton taxa. The highest γ diversity was recorded in May 2016, with a total of 55 zooplankton taxa. Species turnover in space (ß) were from 14.98 to 25.81. Markedly temporal and spatial variations were observed in the zooplankton community. The higher mean cladocera density (57.70 ind. L-1 and 39.85 ind. L-1) was observed in May and August, then decreased gradually with the lowest in January. The mean copepoda density ranged from 8.71 ind. L-1 in January 2017 to 32.04 ind. L-1 in August 2016. The mean rotifera density was significantly higher than that of the other two crustacean zooplankton (p < 0.01), within the range of 89.36-1139.2 ind. L-1. We also observed that zooplankton density exhibited significant seasonal changes from NMDS (Nonmetric multidimensional scaling analysis). Redundancy analysis revealed that environmental factors, such as water temperature and transparency, have significantly influenced the zooplankton community structure.

New lineages and old species: Lineage diversity and regional distribution of Moina (Crustacea: Cladocera) in China.

The distribution and genetic diversity of freshwater zooplankton is understudied in the Eastern Palearctic. Here, we explored the lineage diversity and regional distribution of the genus Moina in China. Members of this genus are often keystone components of freshwater ecosystems and have been frequently subjected to toxicological and physiological studies. Four species of Moina were identified, based on morphology, in 50 of 113 Chinese water bodies examined, and their phylogenetic position was analyzed using both a mitochondrial (mitochondrial cytochrome c oxidase subunit I; COI) and a nuclear marker (the nuclear internal transcribed spacer; ITS-1). Both molecular markers identified four clades corresponding broadly to the morphological species. Mitochondrial DNA analysis showed the presence of four species complexes with eleven lineages across China, five of which were new. However, some lineages (and even individual haplotypes) were widespread in Eurasia, suggesting an ability to disperse over long distances. In contrast, a few lineages exhibited restricted distributions. The nuclear phylogeny also recognized four species of Moina within China and seven very distinct clades. Interestingly, one specimen possessing Moina cf. micrura mtDNA had ITS-1 alleles of the M. cf. brachiata clade. This discordance between mtDNA and nuclear ITS-1 phylogenies is indicative of interspecific introgression and hybridization. Additionally, our COI phylogeny showed apparent paraphyly in two Moina species groups, suggesting introgression of their mitochondrial genomes. Our data shows the regional distribution/diversity of the Moina species complex in a Eurasian context.

Evidence for a species complex in Indialona ganapati (Chydoridae).

Indialona ganapati (Petkovski 1966 ), is one of the three known cladoceran endemic species from India. It is also the only one of these species that is monotypic and endemic to central India. In this study we report on habitat shifts for this species as well as presence of parthenogenetic and ephippial females throughout the year, phenomena that are uncommon in most species of the family Chydoridae. These factors prompted us to undertake a study evaluating the taxonomic status of this species in collections from India using morphological and molecular methods. This included recognition of some degree of morphometric diversity based on sexual differentiation and reproductive patterns which were not correlated with speciation events. Analysis of our data does, however, suggest that I. ganapati can be split into two recent clades. Also, phylogenetic as well as haplotype network analysis of our data suggests the presence of a sibling species complex of I. ganapati in the river Godavari. This suggests that reconsideration of taxonomic status of this species may be appropriate. In addition, this study underscores the potential utility of using COI gene based 'barcode' DNA sequences for recognizing the existence of cryptic species among the cladocera.

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Shallow lakes, sensitive to environmental changes due to low environmental carrying capacity, generally experience decreases in ecosystem function and even regime shifts after over-exploitation. Surface sediments of 18 shallow lakes in Yunnan were collected and analyzed to identify the spatial pattern and the influencing factors of cladoceran communities. The results showed that there was significant heterogeneity in the spatial distribution of cladocera in those lakes. For example, the cladoceran community was generally dominated by benthic taxa in alpine lakes, while there was a clear replacement of benthic cladocerans by planktonic ones with increasing nutrient levels across lakes from Southeast Yunnan. Altitude and total phosphorus were the main driving factors, which independently explained 22.0% and 7.7% of the change in cladocera communities, respectively. The altitude gradient and related changes in climate and catchment features were the main factors in structuring cladocerans for shallow lakes of Yunnan, while the anthropogenic impacts on cladoceran distribution was significant via the processes such as catchment development, pollutant input and macrophyte changes. Meanwhile, the interaction between elevation and total phosphorus explained 26.3% of the total variance in cladoceran community shift, indicating that the increase in human activity intensity in lakes at lower altitudes would have stronger impact on cladocerans through anthropogenic nutrient inputs.

Impact of habitat heterogeneity on zooplankton assembly in a temperate river-floodplain system.

Dissimilar life features of Rotifera, Cladocera and Copepoda enable these organisms to respond differently to changes in the hydrological regime which influence alterations in environmental characteristics. We investigated the effect of habitat heterogeneity (e.g. eupotamal, parapotamal, palaeopotamal) on individual zooplankton group assemblages and biodiversity indices (α, ß and γ diversity) during hydro regime change in floodplain waterbodies. Dissolved oxygen and organic nitrogen concentrations changed significantly among hydrological states while water depth was affected by both site and hydro regime replacement. Each studied site supported different zooplankton assemblage that highly depended on species-specific responses to hydro regime change. Also, individual zooplankton groups exhibited different correlations with specific environmental parameters regarding site change. Throughout the study, rotifers' local (α) and among-community (ß) diversities were susceptible to the site and inundation change while the microcrustacean biodiversity pattern diverged. Copepods highly discriminated different habitat types and hydrological phases at the regional scale (γ diversity), while we found a complete lack of biodiversity dependence on both site and hydrology for Cladocera. Our results show that heterogeneous environments support the development of different zooplankton assemblages that express the within-group dissimilarities. They also point to the importance of identifying processes in hydrologically variable ecosystems that influence biodiversity patterns at an individual zooplankton group level. Our results suggest the use of appropriate zooplankton groups as biological markers in natural habitats and stress the importance of proper management in preserving biodiversity in floodplain areas.

Species and hybrids in the genus Diaphanosoma Fischer, 1850 (Crustacea: Branchiopoda: Cladocera).

Cladocerans are well-studied planktonic crustaceans, especially those of the genus Daphnia in which interesting evolutionary questions have been addressed on speciation processes. The aim of the present study is to demonstrate that other genera of cladocerans show similar levels of cryptic diversity, intraspecific gene flow, and thus become useful model systems for comparison. In order to do so, we chose the genus Diaphanosoma, widespread in tropical and temperate areas. We started with a survey of species diversity in the genus Diaphanosoma in Asia using a morphological approach, then obtained sequences from a mitochondrial and a nuclear marker from multiple individuals of different species, performed tests on DNA taxonomy and molecular phylogenies, and assessed the role of hybridization in explaining the cases of mitonuclear discordance. The results are that cryptic diversity occurs in Diaphanosoma, and mitonuclear discordance was found in about 6% of the sequenced animals. Past hybridization is supported as the most likely explanation for the discordance: no evidence was found of first generation hybrids with heterozygous sequences. Our analysis on patterns of genetic diversity in Diaphanosoma supports similarities and differences with what is known in Daphnia.

Invisible Parasites and Their Implications for Coexisting Water Fleas.

The top-down effects of consumers, such as predators, are known to affect abundances, size structure, and species composition in aquatic ecosystems. Parasites are also important in shaping the ecology of free-living species; however, their effects are often overlooked because parasites can be difficult to detect. Parasites can be particularly challenging to observe in zooplankton hosts because of their small size and ephemeral infection periods. To overcome these challenges, we used a quarantine approach combined with high-magnification microscopy to increase detection of parasites of the tropical Cladoceran, Ceriodaphnia cornuta, in Lake Gatun, Panamá. Using this approach, we were able to demonstrate that competing morphs of Ceriodaphnia experience differential rates of infection, where the subordinate competitor suffered higher parasite prevalence than did the dominant morph. Predation by fishes on the dominant morph is considered the principal mechanism for their coexistence, but we hypothesize that parasites may also play a role in maintaining morphotype diversity of Ceriodaphnia.

Key for identification of Cladocera of the subfamily Aloninae (Anomopoda: Chydoridae) from South-East Asia.

An identification key for Cladocera of subfamily Aloninae (Anomopoda: Chydoridae) of South-East Asia is provided. The key includes 42 species known from the region to date, and encompass all recent changes in taxonomy of the subfamily Aloninae. Drawings and descriptions of diagnostic characters for each species are provided. This is the first identification key for Aloninae of the region published in the last forty years.

Endemism and long distance dispersal in the waterfleas of Easter Island.

Easter Island is known for a depauperate terrestrial and aquatic biota. The discovery of new taxa is unusual, even among the island's micro-invertebrates. A new cladoceran, Ovalona pascua sp. nov. (Crustacea: Cladocera: Anomopoda: Chydoridae), is described from freshwater environments. The chydorid, the only known extant cladoceran on the island, is the dominant aquatic invertebrate in the surface waters. Based on detailed morphological comparison, including a character similarity matrix applied across the species in the genus (12 characters/17 spp), the new taxon is proposed here as an insular endemic with affinities in the East (New World). The revision challenges the theory that invasive zooplankton species were introduced from the subantarctic islands during the 18th century. Human introduction is not the main mechanism through which cladocerans could have arrived on Easter Island. Late Pleistocene - Early Holocene fossils in Cañellas-Boltà et al. (2012) from cores in Rano Raraku Lake are identified here as Daphnia O.F. Müller, 1785 (subgenus Ctenodaphnia Dybowski & Grochowski, 1895). The establishment of Daphnia before human colonization on Easter Island provides strong proof of successful long distance dispersal by ephippia over thousands of kilometers of open sea.

A revision of the subgenus Eurycercus (Teretifrons) Frey, 1975 (Crustacea: Cladocera) in the Holarctic with description of a new species from Russian Arctic.

Our study is aimed at a taxonomic revision of the subgenus Eurycercus (Teretifrons) Frey, 1975 (Crustacea: Cladocera: Eurycercidae) in the Holarctic based on the morphology of parthenogenetic females. Three species were revealed and described: (1) E. glacialis Lilljeborg, 1887 which is relatively widely distributed in the north portion of Atlantic and Pacific regions; (2) E. nigracanthus Hann, 1990 which is apparently present in Labrador and Newfoundland, Cape Breton Island and Nova Scotia and (3) Eurycercus chernovi sp. nov. from Taimyr Peninsula in Siberia, Russia. Main differences of the latter taxon from other species are: (1) more proximal position of sensory seta on the antenna I and (2) surface of cuticle of major head pore forms a low projection in middle. A revision of this subgenus in Arctic Siberia and Canada needs to be continued.

A new species of the genus Anthalona Van Damme, Sinev & Dumont, 2011 (Cladocera: Anomopoda: Chydoridae) from North-East Thailand.

A new species of Cladocera, Anthalona spinifera sp. nov., is described from North-East Thailand. A. spinifera differs from most species of the genus in the setae of the inner distal lobe on limb I armed by long thin spines and in limb II having very short scraping spines 6-8, a character that is shared only with the South American Anthalona brandorffi (Sinev & Hollwedel, 2002). A. brandorffi differs from A. spinifera sp. nov. in the shape of postabdomen, in much longer posterior setae of valves, in posteroventral angle of valves armed with about 25 setules only, and in shortened setae of endite 2 of limb I. These two species form a separate advanced clade within Anthalona with Amphi-Pacific distribution.

DNA Barcoding Reveals High Cryptic Diversity in the North Eurasian Moina Species (Crustacea: Cladocera).

Species of the genus Moina Baird (Cladocera: Moinidae) often dominate freshwater crustacean communities in temporary water bodies. Several species of Moina are used as food for fish larvae in aquaculture, as bioindicators in toxicological studies, and as common subjects for physiological studies. The aim of this paper is to estimate biodiversity of Moina in northern Eurasia using the standard DNA barcoding approach based on the cytochrome c oxidase subunit I (COI) gene. We analysed 160 newly obtained and 157 existing COI sequences, and found evidence for 21 phylogroups of Moina, some of which were detected here for the first time. Our study confirmed the opinion that the actual species diversity of cladocerans is several times higher than is presently accepted. Our results also indicated that Moina has the second richest species diversity among the cladoceran genera (with only Daphnia O. F. Mueller having a greater diversity of species). Our study strongly supports division of Moina into two faunistic groups: European-Western Siberian and Eastern Siberian-Far Eastern, with a transitional zone at the Yenisey River basin (Eastern Siberia). Here, we refrain from taxonomic descriptions of new species, as this requires a thorough morphological and taxonomic study for each putative taxon.

A revision of the genus Leberis Smirnov, 1989 (Cladocera: Chydoridae) in the Old World and Australia.

A comparison between populations of the diaphanus-group of Leberis Smirnov, 1989 from Australia and India confirmed that Australian L. diaphanus (King, 1853) and Indian L. punctatus (Daday, 1898) are separate species. Morphology of parthenogenetic females of L. punctatus is redescribed for the first time. Some fine details of morphology are re-examined in other species of Leberis, taxonomically significant features and their variability are studied. In the Old World L. punctatus could be confused with L. diaphanus, but the former differs from the latter mainly in the details of thoracic limbs I and IV. Both species have relatively broad distribution ranges: L. punctatus inhabits South Asia, Africa and penetrates Southeast Asia, L. diaphanus is a widespread taxon in the water bodies of Australia, Southeast Asia and South China. Diversity of the genus in the Old World is underestimated yet, and further investigations are desirable.

Redescription of Bythotrephes arcticus Lilljeborg, 1901 (Crustacea:Cladocera: Onychopoda) and confirmation of an independent species status of the distant Transcaucasian populations of the genus Bythotrephes Leydig.

Two species of the genus Bythotrephes Leydig, B. arcticus Lilljeborg and B. transcaucasicus Behning, forming a group of close species, are redescribed on the basis of type material and other materials from Northern Eurasia. They were investigated with the application of detailed morphological analysis, including intra- and interpopulation variability and the original scheme of morphometric measurements. The lectotypes and paralectotypes of the species were selected. B. arcticus compared with other species of the genus, seem more evolutionary primitive and less specialized, judging from its large body size, comparatively short tl I, short and straight caudal process, well developed distal setae on two proximal endopodital segments of tl I, and large number of claws. B. arcticus tends to occur in small and shallow water bodies, while B. transcaucasicus was predominantly found in pelagic zone of large and deep Transcaucasian lakes. B. arcticus is probably mainly distributed along the tundra and northern forest area of the Eurasian continent and the nearest islands from Scandinavia to Eastern Siberia. Its documented easternmost locality is situated near the northern part of the Yenisei River, whereas B. transcaucasicus was recorded in the second half of 19th-first half of 20th century in three closely situated mountain lakes in Turkey, Georgia, and Armenia. The presence of B. arcticus in Northern Kazakhstan and B. transcaucasicus in the distant Transcaucasia is linked with their (or their ancestor) hypothetical displacement to the south in the period of ice ages. More recent surveys of Transcaucasian lakes have not revealed the presence of B. transcaucasicus. The rare findings of this species in the past can imply that it could also be missed in the process of collecting but, on the other hand, it cannot be excluded that B. transcaucasicus become extinct as a result of an anthropogenic or other impact on Transcaucasian lakes.

Not "Alona" monacantha Sars, 1901, but Coronatella hardingi (Brehm, 1957) Crustacea: Branchiopoda: Cladocera) in the Afrotropics.

Many taxa formerly housed in the lump genus Alona Baird, 1843 remain data-deficient. These species are often overlooked or wrongly identified during faunistic and ecological studies. "Alona" hardingi (Brehm, 1957) is a lesser known taxon, hidden for decades under records of "Alona" monacantha Sars, 1901. Both taxa have recently been allocated to the genus Coronatella Dybowski & Grochowski, 1894, yet without revision of the former. The morphology of Coronatella hardingi (Brehm, 1957), a widespread and abundant species in Afrotropical freshwater habitats, is examined here for the first time, including the first description of the male. The species is redescribed, based on populations from Southern Africa and confirmed as a good species and a valid sibling of the Neotropical C. monacantha (Sars, 1901) and the SE Asian C. acuticostata (Sars, 1903). The study of the Afrotropical C. hardingi allows a better understanding of this small tropical species complex, for which a diagnosis is included.