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The present study describes two occurrences of clam shrimps ("Conchostraca"). Following a formbased classification of Schneider et al. (2005, 2022) and Schneider & Scholze (2018), the conchostracans have been classified as Pseudestheria form Oberbozen and Pseudestheria form Le Fraine. They come from the Guncina and Tregiovo formations, repectivey. These units are part of the northern Athesian Volcanic Group, North Italy. All of this material were obtained from grey coloured, fine-grained siliciclastic, lacustrine deposits of Kungurian (late Cisuralian, late Early Permian) age. Their carapace valves in lateral view are marked by concentric ribs. Often, growth lines can be observed to decrease in their preservation towards the umbonal area of the valve. An open nomenclature is applied to the taxonomy at the species level herein, because of either limited number of individuals or a plastic deformation due to tectonics. So far, the records reported herein are restricted geographically and stratigraphically to respective single occurrences. Further studies are recommended to establish their full biostratigraphic ranges. [ABSTRACT FROM AUTHOR]

This study presents new data on the population-genetic polymorphism, phylogeny, and phylogeography of two vicariant species belonging to the Daphnia longispina s.lat. complex (Crustacea: Cladocera) in northern Eurasia, D. longispina s.str. and D. dentifera. Based on the variability of the fragments of noncoding 12S rRNA and the protein coding ND2 genes of mitochondrial DNA, the demographic processes that took place in populations of this vast region have been reconstructed. The previously suggested hypothesis about the different demographic history of the Siberian and European D. longispina s.str. clades has not been confirmed, since we first revealed a deep mitochondrial divergence within the Siberian clade. Moreover, a new divergent D. longispina s.str. lineage in Siberia has been identified. Nevertheless, the phylogeographic patterns of D. longispina s.str. and D. dentifera in northern Eurasia confirm the earlier conclusion that repeated, combined effects on their populations of dispersion and vicariate events occurred in different phases of the Pleistocene. [ABSTRACT FROM AUTHOR]

Notostracan branchiopods reported from the Lower Triassic Voltzia Sandstone Lagerstätte in northeastern France have previously been assigned to Triops cancriformis, making this species the longest persisting animal in earth history. Careful restudy of the splendidly preserved material indicates that the species can be well characterized but represents a notostracan genus and species that cannot be assigned to the Triopsidae. This undermines the concept of its being a 'living fossil'. The name Apudites antiquus, under which the first known specimens were described, is available and appropriate for the species. Some of the specimens of Apudites antiquus offer morphological details of a quality that ranks them among the best‐preserved fossil non‐marine arthropods. The Voltzia Sandstone specimens previously assigned to the extant species T. cancriformis include two additional, peculiar diplostracan branchiopods, Olesenocaris galli gen. et sp. nov. and Grauvogelocaris alsatica gen. et sp. nov., both with unique morphological features that characterize them as representatives of as yet unknown families. [ABSTRACT FROM AUTHOR]

Three collections of clam shrimp from the Lower Devonian (upper lower Emsian) Klerf Formation of Willwerath and Waxweiler in the western Eifel Mountains are herein studied. Four discernible morphotypes are present in the Willwerath assemblage. These morphotypes correspond to the previously described species from this locality: Pseudestheria diensti (Gross), Pseudestheria subcircularis Raymond, and Palaeolimnadiopsis? eifelensis Raymond. The fourth morphotype also closely corresponds to Pseudestheria diensti, but is slightly different in outline. Asmussia willweratica (Novozhilov) is an objective synonym of Pseudestheria subcircularis. In the Willwerath clam shrimp sample, it is difficult to disentangle taphonomic/preservational versus ontogenetic/sexual variation. If taphonomic/preservational causes could be confirmed, all the Willwerath specimens may represent just one taxon and Pseudestheria subcircularis and Palaeolimnadiopsis? eifelensis would be potential subjective synonyms of Pseudestheria diensti. However, we refrain from a formal taxonomic act, which requires a larger number of specimens to be analysed. In addition, we investigated two samples from Waxweiler, which originate from distinct centimetre-thick layers and therefore represent associations. One of these associations comprises two discernible clam shrimp morphotypes. Because of limited preservation of morphological characters, one is here left in open nomenclature as Spinicaudata incertae sedis, whereas the other is recognised as a new species of the family Palaeolimnadiopseidae, Palaeolimnadiopsis frankeorum sp. nov. The second association from Waxweiler comprises at least four, possibly six different clam shrimp taxa. In addition to Pseudestheria diensti, Palaeolimnadiopsis sp., and poorly preserved Asmussia- and Ulugkemia-like specimens, two taxa can be described as new, namely the vertexiid Cornia wasvilrensis sp. nov. and the leaiine Eicheleaia wenndorfi gen. nov. et sp. nov. Altogether, the Klerf Formation at Waxweiler yields a total of at least five (possibly eight) clam shrimp taxa. The palaeoenvironment of these early clam shrimp from the Klerf Formation is interpreted as a non-marine, relatively proximal deltaic setting with no or very minor marine influence, such as a deltaic freshwater pond or lake. The comparatively high diversity of these lower Devonian clam shrimp suggests a considerably earlier origin and cryptic evolution of the group. [ABSTRACT FROM AUTHOR]

Only a small proportion of the world's crustacean taxa is adapted to limno-terrestrial microhabitats that are disconnected from conventional surface waterbodies. In rare occasions, water films on terrestrial tropical and subtropical vegetation may also harbour specialised cladocerans. Bryospilus Frey, 1980 (Chydoridae) is the only genus within the class Branchiopoda that is specialised to living almost exclusively in water-saturated terrestrial moss patches, leaf litter, and phytotelms. The remarkable waterflea lineage, which has a suite of highly unusual characters within the family, has been found in terrestrial habitats in rainforests of West Africa, South and Central America, and New Zealand. We discovered a new moss-inhabiting chydorid from western India, Bryospilus (Indobryospilus) bharaticus n. sp. , the first representative of the genus from the Oriental Region. Its morphology and behaviour are highly unusual for a species of Bryospilus. In comparison to its congeners, the new species can swim and it has significantly less oligomerisation, with three terminal setae on the antennal endopod instead of two and seven exopod setae on the third limb instead of six, among other features. We define a new subgenus Indobryospilus nov. and we amend the genus Bryospilus. The new species is a living evolutionary connection, characterised by a phenotype which provides us with new clues about evolutionary transitions in the only terrestrial branchiopod genus. Our results are informative beyond Cladocera, as the morphology of this species provides insights about the evolution and parallelisms of aquatic crustaceans that have specialised in limno-terrestrial habitats. We revisit the morphology of the genus, the disjunct biogeographical pattern with a potential ancient signature, and discuss the functional adaptations of these cladocerans to life on land, as well as convergences with subterranean lineages. A new key to the world species of Bryospilus species is included. [ABSTRACT FROM AUTHOR]

The taxonomy of the notostracan Lepidurus Leach, 1819 is complicated by a large number of synonymised species and extensive intraspecific variability in many relevant characters. We demonstrate, based on an integrative taxonomic approach, that the Ukrainian populations of Lepidurus are not conspecific with any currently accepted Lepidurus species and assign them to the previously synonymised species Lepidurus middendorffii comp. nov. (Braem, 1893). This species exemplarily highlights the problems in the taxonomy of Lepidurus. The species was originally described as Apus extensus var. middendorffii (Braem, 1893), but L. extensus is a junior synonym of Lepidurus lubbocki (Brauer, 1873), which is currently treated as a subspecies of Lepidurus apus (Linnaeus, 1758). Our molecular genetic analyses based on mitochondrial COI, 12S, 16S, and nuclear 28S, which included published data, suggest the presence of further, possibly cryptic species that await formal recognition and stress the importance for a more extensive revision of Lepidurus. The original type specimens of L. middendorffii , previously stored at the Museum of Natural History (Wrocław University, Wrocław, Poland), are lost and a neotype is designated. Lepidurus middendorffii is characterised by the dorsal organ position between the ocular tubercle margins, the sharp carapace sulcus spines, the long supra-anal plate with many median spines, a telson length to carapace length ratio 0.18–0.35, and differs by > 9% uncorrected COI p -distances from all other Lepidurus species. [ABSTRACT FROM AUTHOR]

The current systematics of the large branchiopod crustaceans are reviewed in relation to other crustacean groups and from class to genus level. Calmanostraca and Diplostraca are raised to superorder, and †Kazacharthra and Notostraca are both treated as orders. Problems and needs regarding the systematics of large branchiopods are presented and discussed, with suggestions for moving forward, stressing the need for modern methods and defensible taxonomic definitions. Subdividing taxonomic categories may or may not be warranted, but should never be based on only one gene, or on limited taxon sampling. Furthermore, splitting species out as new genera, when the original genus is poorly defined can only lead to future problems. [ABSTRACT FROM AUTHOR]

In high-altitude (4500 m) freshwater lakes, Daphnia is the apex species and the dominant zooplankton. It frequently dwells in the same lake as the Gammarid. Branchiopoda, a class of Arthropoda, Crustacea, is a relatively primitive group in the subphylum Crustacea, which originated in the Cambrian period of the Paleozoic. The complete mitogenome sequence of Daphnia sp. (Branchiopoda: Cladocera) was sequenced and annotated in this study and deposited in GenBank. The sequence structure of this species was studied by comparing the original sequences with BLAST. In addition, we have also researched the mechanisms of their mitochondrial gene rearrangement by establishing a model. We have used the Bayesian inference [BI] and maximum likelihood [ML] methods to proceed with phylogenetic analysis inference, which generates identical phylogenetic topology that reveals the phylogenetic state of Daphnia. The complete mitogenome of Daphnia sp. shows that it was 15,254 bp in length and included two control regions (CRs) and 37 genes (13 protein-coding genes, 22 tRNAs and two ribosomal RNAs [16S and 12S]). In addition to tRNA-Ser (GCT), other tRNAs have a typical cloverleaf secondary structure. Meanwhile, the mitogenome of Daphnia sp. was clearly rearranged when compared to the mitogenome of typical Daphnia. In a word, we report a newly sequenced mitogenome of Daphnia sp. with a unique rearrangement phenomenon. These results will be helpful for further phylogenetic research and provide a foundation for future studies on the characteristics of the mitochondrial gene arrangement process in Daphnia. [ABSTRACT FROM AUTHOR]

The Cerrado is home of the headwaters of some important Brazilian basins. Such biome has a high diversity of animal and plant species with a high degree of endemism. This premise is well documented for microcrustaceans of the Superorder Cladocera, although many areas still need sampling. In this context, the objective of the present investigation was to evaluate the geographic distribution and richness of Cladocera in the Cerrado biome. The analyzed data were obtained from the authors database on Brazilian Cladocera and distributed according to the hydrographic regions comprised in the biome. Species distribution models were used to determine the areas with the highest probability of occurrence of Cladocera. We analyzed 125 publications, resulting in 2829 records. In total, we obtained 161 taxa, belonging to 48 genera and seven families. Regarding the Hydrographic Regions, Paraná presented the highest richness, followed by TocantinsAraguaia and São Francisco. Our result indicates that most studies are concentrated in certain areas. Furthermore, the species distribution models indicated that transition areas between biomes have the highest probability of occurrence of genera and families. Our results indicate significant gaps in the knowledge, making it necessary to expand inventories and ecological studies in areas still unsampled. [ABSTRACT FROM AUTHOR]

The loss of freshwater wetlands worldwide has underscored the importance of restoration to enhance biodiversity and functional objectives. While aquatic invertebrate communities within restored perennial freshwaters are well studied, few studies have occurred in the greatly reduced habitat of seasonal wetlands, such as vernal pools. California vernal pools have experienced high habitat loss and support many threatened or endangered invertebrate species. We compared 90 natural and 90 restored vernal pools of different ages across 10 sites throughout California and Southern Oregon using the Sars' method. Large branchiopod abundance, total invertebrate abundance, class richness, and community composition were assessed between pool types (natural vs. restored) and along environmental gradients (e.g. site, pool depth, surface area, age since restoration). Large branchiopod and total invertebrate abundance were 215 and 274% higher in natural pools than restored pools, but class richness was not different. Community composition was significantly different and driven by greater abundances of vernal pool fairy shrimp, San Diego fairy shrimp, Ostracoda, Cladocera, and Copepoda in natural pools. Few environmental or habitat variables explained patterns in richness or abundance. Our work demonstrates that restored pools, even those decades old, are different than natural pools. Future mitigation and monitoring guidelines for restored vernal pools should include quantitative evaluations for aquatic invertebrates. Restored pools are not adequate compensation for lost natural pools because they do not have the same ecological functions and values. [ABSTRACT FROM AUTHOR]

Introduction: The phylogenetic relationships within Pancrustacea (including Crustacea and Hexapoda) remain elusive despite analyses using various molecular data sets and analytical approaches over the past decade. The relationship between the major lineages of Allotriocarida, which includes Hexapoda, the most species-rich animal taxon, is particularly recalcitrant. Methods: To investigate and resolve the root of phylogenetic ambiguity in Pancrustacea, we re-evaluated the evolutionary relationships of major pancrustacean clades using a phylogenetically informed orthology approach and assessed the effect of systematic errors, with a major focus on long branch attraction (LBA) and incomplete lineage sorting (ILS). A data set comprising 1086 orthologs from 106 species representing all major extant classes of pancrustaceans was assembled and used in gene tree and species tree construction after various filtering processes. Results and discussion: Regardless of the filtering criteria and phylogenetic analyses, the resulting trees consistently supported (1) a sister relationship of Remipedia and Hexapoda (hence rejecting the monophyly of Xenocarida, i.e. Remipedia + Cephalocarida), and (2) refuted the monophyly of Multicrustacea, as Copepoda is either sister to or nested within Allotriocarida. Examination of gene trees reveals that the grouping of Multicrustacea and Xenocarida in previous phylogenetic studies may represent LBA artefacts. Phylogenetic signal analyses suggest a low resolution and an incidence of strong conflicting signals at the deep splits. Further analyses indicate a partial contribution of incomplete lineage sorting (ILS) to the contradictory signal in the allotriocaridan phylogeny, leading to limited support for any potential relationships between Branchiopoda, Cephalocarida and Copepoda. This study suggests the need for further examination of other potential sources of signal discordance, such as introgression and gene tree estimation error to fully understand the evolutionary history of Pancrustacea. [ABSTRACT FROM AUTHOR]

Molecular analyses based on the comparison of Chirocephalus species mtDNA cytochrome oxidase I (COI) sequences obtained from Algeria, Morocco and France with other available sequences were performed. The analysis clarified the status of the genus Chirocephalus Prévost, 1803 in Algeria and its phylogenetic links with other populations. Three lineages occur in Algeria representing three different species: Chirocephalus salinus Daday, 1910, C. sanhadjaensis Boumendjel, Rabet and Amarouayache, 2018 and a new species sampled in Reghaïa (Alger, Algeria) near Algiers. All these species, belonging to the "diaphanus" group, seem to be endemic to Algeria except C. salinus also present in France (Corsica). The new species C. algeriensis sp. n. is described and its affinities with other species of the genus are presented. This species is until now restricted to Algiers region and shares several characters with C. diaphanus Prévost, 1803. It is separated from all other species by the shape and size of the second antennal appendages of the male and the female. The resting eggs of C. algeriensis sp. n. are morphologically similar to those of many Chirocephalus but a variation of size of eggs can be used at a specific level. [ABSTRACT FROM AUTHOR]

New finds of fossil assemblages of brachiopods, mollusks, crinoids, arthropods and fishes, as well as terrestrial plants from a part of the Dyakove Group, which corresponds to the coal-bearing Mandrykyne Formation and the lower part of the Mospyne Formation and is exposed in the southern part of the Luhansk Region, were studied. For the first time, a brachiopod assemblage consisting of species of the genera Crurithyris, Tiramnia, Alphachoristites, Lissochonetes were identified in these rocks. In addition, phyllocarids and impressions of terrestrial plants of the genera Halonia, Calamites, Pinnularia, Paripteris, Eusphenopteris, Artisia and Cordaites were found in the Dyakove Group for the first time. Bivalves and gastropods in the studied collection are represented by the genera Phestia, Palaeoneilo, Nuculavus, Solenomorpha, Sanguinolites, Posidoniella, ?Euchondria, ?Nodospira, Euphemites, Retispira, Glabrocingulum, Rhineoderma, Angyomphalus, and Naticopsis. Cephalopods are represented by the species of the genera Gzheloceras, ?Pseudogzheloceras, Melvilloceras, Retites, Gastrioceras and ?Owenoceras. In addition to the above groups, the rocks also contain the crinoids Platyplateium, Platycrinites, ?Unilineatocrinus and Bicostulatocrinus as well as fragments of fin spines of acanthodians Gyracanthidae indet. and isolated unidentified fish scales. [ABSTRACT FROM AUTHOR]

The fairy shrimp Branchinectella media, because of its passive dispersal capacity and scarce and irregularly distributed habitats (temporary saline aquatic systems), is an intriguing organism from a population genomics and conservation perspective. Stochasticity of dispersal events and the irregular distribution of its habitat might lead to low levels of population connectivity and genetic diversity, and consequently, populations with limited persistence through time. Indeed, by using genomic data (SNPs), we found a strong genetic structure among some of the geographically isolated Iberian populations of B. media. Interestingly, we also obtained high estimates of effective population sizes. Lack of suitable habitat between populations (absence of a "stepping stone" network) and strong genetic differentiation suggest limited dispersal success in B. media. However, the high effective population sizes observed ensure persistence of B. media populations against genetic stochasticity (genetic drift). These results indicate that rescue-effect might not be essential for population persistence if they maintain high effective population sizes able to hold adequate levels of genetic diversity. Should high population sizes be reported in other low dispersing Anostraca, one might be optimistic with regard to their conservation status and fate, provided that their natural habitats remain undisturbed. [ABSTRACT FROM AUTHOR]

Copyright of Revista Peruana de Biología is the property of Facultad de Ciencias Biologicas, Universidad Nacional Mayor de San Marcos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Terrestrial crustaceans are represented by approximately 4,900 species from six main lineages. The diversity of terrestrial taxa ranges from a few genera in Cladocera and Ostracoda to about a third of the known species in Isopoda. Crustaceans are among the smallest as well as the largest terrestrial arthropods. Tiny microcrustaceans (Branchiopoda, Ostracoda, Copepoda) are always associated with water films, while adult stages of macrocrustaceans (Isopoda, Amphipoda, Decapoda) spend most of their lives in terrestrial habitats, being independent of liquid water. Various adaptations in morphology, physiology, reproduction, and behavior allow them to thrive in virtually all geographic areas, including extremely arid habitats. The most derived terrestrial crustaceans have acquired highly developed visual and olfactory systems. The density of soil copepods is sometimes comparable to that of mites and springtails, while the total biomass of decapods on tropical islands can exceed that of mammals in tropical rainforests. During migrations, land crabs create record-breaking aggregations and biomass flows for terrestrial invertebrates. The ecological role of terrestrial microcrustaceans remains poorly studied, while omnivorous macrocrustaceans are important litter transformers and soil bioturbators, occasionally occupying the position of the top predators. Notably, crustaceans are the only group among terrestrial saprotrophic animals widely used by humans as food. Despite the great diversity and ecological impact, terrestrial crustaceans, except for woodlice, are often neglected by terrestrial ecologists. This review aims to narrow this gap discussing the diversity, abundance, adaptations to terrestrial lifestyle, trophic relationships and ecological functions, as well as the main methods used for sampling terrestrial crustaceans. [ABSTRACT FROM AUTHOR]

The fairy shrimp genus Parartemiopsis Rogers, 2005 currently contains a single species reported from Russia and Mongolia. In 2013, an unidentified Parartemiopsis population was reported from the eastern margin of the Tibetan Plateau in China's Yunnan Province, from Patatson National Park in Shangri-La County. Here, we describe the Chinese populations as a new species, Parartemiopsis shangrilaensis sp. nov. This new species is distinguished from its congener, P. longicornis (Smirnov, 1930), by the form of the male second antennae and the gonopod. The discovery of P. shangrilaensis sp. nov. extends the known distribution of the genus, and more Parartemiopsis species may be found in the future. We present a key to the genera and species of Chirocephalidae in China as an aid to future research. [ABSTRACT FROM AUTHOR]

The enigmatic acid-resistant mesofossil genus Kuqaia is emended, a new species (Kuqaia scanicus) is instituted, and three established species are described from the Lower Jurassic (lower Pliensbachian) of the Kävlinge BH-928 core, in southern Sweden. Kuqaia has a distribution across the middle northern latitudes of Pangaea and is restricted to Lower to lower Middle Jurassic strata. Morphological characters support Kuqaia being the ephippia (resting egg/embryo cases) of Cladocera (Crustacea: Branchiopoda), and a probable early stem-group taxon of the Daphnia lineage. The paleoecology of the small planktonic crustaceans indicate purely fresh-water environments, such as lakes or ponds, all occurrences being in continental deposits, and the Kuqaia specimens possibly represent dry-season resting eggs. Chemical analyses of these and similar fossils, and of extant invertebrate eggs and egg cases are recommended to improve resolution of the biological affiliations of such mesofossil groups. [ABSTRACT FROM AUTHOR]

Branchinecta serrata Rogers, 2006 was originally thought to be limited to four localities in the central USA. We present new records of this species in prairie pools in central Canada, greatly extending its known distribution. Previous records from Canada were misidentified as the common and widespread B. paludosa (Müller, 1788). We present images emphasizing the differences between the two species, updated geochemical tolerance data, and revise the conservation status of B. serrata. Finally, we present an identification key to the Branchinecta paludosa species group. [ABSTRACT FROM AUTHOR]

Trehalose is important in activity, development, and environmental-stress response, especially in invertebrates. It is mainly synthesized by trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP), and degraded by trehalase (TRE). In the present study, the tps , tpp , and tre were identified from various crustacean species and their phylogeny, structure, network, and transcriptome were analyzed. The tps and tpp are fused in crustaceans, accompanied with multi-copies of genes to improve the synthesis capacity of trehalose, and they may be formed by whole-genome duplication (WGD) and/or segmental duplications. Phylogenetic subgroups of enzymes in the same species may be due to the different lengths and distribution positions of domains. The protein with single TPP domain in the salmon louse, the copepod Lepeophtheirus salmonis (Krøyer, 1837), probably has a depoisoning effect. Structure analyses and location predictions showed that crustacean TRE possess an α-helix-rich structure with barrel core, and are membrane-bound, cytoplasmic, and secreted. Additionally, the non-acid TRE might not be adjusted by Ca2+ because there is no binding domain in crustaceans. Expression profiles of different tissues, developmental periods, and environmental-challenge responses, as well as genes of co-expression networks suggested that TPS (including TPP) and TRE might play important roles in physiological activities including development and environmental adaptation in crustaceans. Multi-copies of tre may enhance survival ability of copepods in diverse and sometimes harsh environments. Branchiopods, copepods, and the marine shrimp Penaeus vannamei Boone, 1931 are suspected to adopt possible acid TRE as a supplementary strategy in response to stress. [ABSTRACT FROM AUTHOR]

An updated checklist of the cladoceran fauna from inland aquatic habitats in Thailand (a high-diversity hotspot in Southeast Asia), based on published cladoceran records found in literature is presented. The checklist updates nomenclature and species distributions, especially habitat preferences. A total of 138 valid recorded species is relatively high. However, the estimators indicate that more species are expected to be found with more research. The north-eastern and southern regions of Thailand are well-studied regions of high species richness with 100 and 96 cladoceran species, respectively, whereas the northern and eastern regions have large research gaps that should be studied further. Moreover, each habitat type seems to have a unique cladoceran community as the similarity values amongst them are mostly low (Sorensen similarity index < 0.50). Therefore, it is suggested that habitats with unique characteristics, such as peat swamps, stream and cave pools, are worthy of further exploration. If the current records of cladoceran diversity in Thailand confirms a high diversity of this animal in the tropical region, then the geographical distribution of each species can be properly explained. [ABSTRACT FROM AUTHOR]

Mediterranean wetlands are suitable ecosystems for studying metacommunity theory, since they are isolated ecosystems within a land matrix with well-established limits, often with watersheds destined for agricultural uses. The zooplankton community of wetlands in agricultural landscapes is the result of processes that operate in a different multiscale context. We selected 24 ponds in Alto Guadalquivir region (SE Spain) with different local environmental variables (biological, limnological and land uses). The zooplankton community of the wetlands under study consists of a total of 60 species: 38 branchiopods and 22 copepods. This community (total, branchiopods and copepods) was analysed through two different and complementary metacommunity approaches. The pattern approach determines the species distribution along environmental gradients, and the mechanistic approach considers the involved processes, such as environmental control and dispersal limitation. The results indicated a nested metacommunity, in which five limnological variables, three land uses and six spatial variables are the main drivers that explain zooplankton distribution in these wetlands. In conclusion, species sorting and dispersal processes play a role in the structuring of the zooplankton metacommunity. This conclusion has implications for the development of adequate management policies on Mediterranean wetland protection and diversity conservation in agricultural contexts. [ABSTRACT FROM AUTHOR]

Copyright of Crustaceana is the property of Brill Academic Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Very little is known about the feeding of naupliar and juvenile life stages of omnivorous fairy shrimps (Crustacea: Anostraca). Here, we aim to reveal whether the fairy shrimp Branchinecta orientalis is an ontogenetic omnivore and at which age and ontogenetic stage they gain the ability to feed on zooplankton. We assess how food uptake rates change with age until reaching maturity by providing algae (pico- and nanoplanktonic unicellular algae) and zooplankton (rotifers and copepod nauplii) as food in individual experiments. We found that the fairy shrimp B. orientalis started to feed on both types of algal prey immediately after hatching. Nanoplanktonic algae likely represented the most important food source until reaching maturity. Moreover, fairy shrimps started to feed on zooplankton already when they were 7 days old. Slow-moving rotifers gradually gained importance in the fairy shrimp diet with time. Our results reveal an ontogenetic change in the prey spectrum of fairy shrimp. The systematic shift towards omnivory likely affects both phyto- and zooplankton community composition, possibly contributing to temporal changes in food web dynamics in fairy shrimp habitats, and temporary ponds, which may warrant more detailed investigations in future studies. [ABSTRACT FROM AUTHOR]

Fossil spinicaudatan taxonomy heavily relies on carapace features (size, shape, ornamentation) and palaeontologists have greatly refined methods to study and describe carapace variability. Whether carapace features alone are sufficient for distinguishing between species of a single genus has remained untested. In our study, we tested common palaeontological methods on 481 individuals of the extant Australian genus Ozestheria that have been previously assigned to ten species based on genetic analysis. All species are morphologically distinct based on geometric morphometrics (p ≤ 0.001), but they occupy overlapping regions in Ozestheria morphospace. Linear discriminant analysis of Fourier shape coefficients reaches a mean model performance of 93.8% correctly classified individuals over all possible 45 pairwise species comparisons. This can be further increased by combining the size and shape datasets. Nine of the ten examined species are clearly sexually dimorphic but male and female morphologie strongly overlap within species with little influence on model performance. Ornamentation is commonly species-diagnostic; seven ornamentation types are distinguished of which six are species-specific while one is shared by four species. A transformation of main ornamental features (e.g. from punctate to smooth) can occur among closely related species suggesting short evolutionary timescales. Our overall results support the taxonomic value of carapace features, which should also receive greater attention in the taxonomy of extant species. The extensive variation in carapace shape and ornamentation is noteworthy and several species would probably have been assigned to different genera or families if these had been fossils, bearing implications for the systematics of fossil Spinicaudata. [ABSTRACT FROM AUTHOR]

We present the novel reference genome of the Versatile Fairy Shrimp, Branchinecta lindahli. The Versatile Fairy Shrimp is a freshwater anostracan crustacean found across the western United States from Iowa to Oregon and from Alberta to Baja California. It is an ephemeral pool specialist, living in prairie potholes, irrigation ditches, tire treads, vernal pools, and other temporary freshwater wetlands. Anostracan fairy shrimp are facing global declines with 3 species in California on the Endangered Species list. This species was included in the California Conservation Genomics Project to provide an easily accessible reference genome, and to provide whole-genome resources for a generalist species, which may lead to new insights into Anostracan resiliency in the face of climate change. The final gapped genome comprises 15 chromosome-length scaffolds covering 98.63% of the 384.8 Mb sequence length, and an additional 55 unscaffolded contigs. [ABSTRACT FROM AUTHOR]

The Taxonomic Catalog of the Brazilian Fauna (CTFB) is an initiative involving the effort of hundreds of researchers in several institutions, including international partners. Its main objective is to make public and give free access to a checklist of valid species occurring in Brazil. This catalog includes information on Cladocera, a group of microcrustaceans that occupy inland water and marine ecosystems. In this study, we evaluated the Cladocera part of the Brazilian Fauna Catalog. Among the taxa described or reported, we observed 155 valid species (37 endemic) and 61 genera (2 endemic) distributed in 11 families. European researchers represented 50% of all the authors involved in descriptions of species, and European collections keep most primary types, although many species have types that have been lost or not designed. Brazilian researchers were involved with a large number of descriptions, especially in the last 15 years. Our findings indicated that Cladocera taxa were observed in all hydrographic regions (Paraná with 119 species), biomes (Atlantic Forest with 126 species) and states, except state of Rondônia. The catalogue of Brazilian cladoceran fauna should be improved, as there are still large geographic ranges to be sampled in Brazil. [ABSTRACT FROM AUTHOR]

Daphniopsis tibetana is widely distributed in Xinjiang, Qinghai, Tibet of China, as well as in Russia and India, which is the dominant zooplankton in many high-altitude (4000 m) salt lakes. D. tibetana can adapt to saline waters, whereas the other species of the superorder Cladocera can only inhabit in freshwater. However, the phylogenetic status of D. tibetana in Branchiopoda remains unclear primarily because of limited mitogenome. In this study, complete mitochondrial genome sequences of D. tibetana were sequenced and annotated for the first time to obtain a comprehensive understanding of its phylogenetic status. The complete mitogenome of D. tibetana is 16196 bp in length. It contains 37 genes, including two ribosomal RNAs (12S and 16S rRNAs) genes, 22 transfer RNA (tRNA) genes, 13 protein-coding genes, and one non-coding region. The overall base composition is 29.6% A, 33.2% T, 19.0% G, and 18.2% C with a high AT bias (62.8%). Except for trnS1 (GCT), most tRNAs have a typical cloverleaf secondary structure. Phylogenetic analysis based on maximum likelihood and Bayesian inference generates identical phylogenetic topology and shows the phylogenetic status of D. tibetana, which reconfirm the distinction between the genera Daphniopsis and Daphnia. Meanwhile, the class Branchiopoda is clustered into three clades (Anostraca, Notostraca, and Diplostraca) with high support values. These results provide not only a comprehensive understanding of the characteristics of D. tibetana mitogenome and its phylogenetic position in Diplostraca, but also information for future research on the phylogeny of Branchiopoda. [ABSTRACT FROM AUTHOR]

The Daphnia longispina complex (Crustacea: Cladocera) contains several keystone freshwater species such as D. longispina O.F. Müller (D. rosea Sars is a junior synonym), D. galeata Sars, D. cucullata Sars, and D. dentifera Forbes. The complex is common throughout the Holarctic, but there are several geographic regions where local forms have been assigned to European species names based on a superficial morphological resemblance. Here we examine the species status of a form that was previously assigned to D. rosea from a montane bog pond on Honshu, Japan. We used two nuclear non-coding loci (nDNA), mitochondrial sequences (the ND2 protein-coding region) and morphology for evidence. The mitochondrial gene evidence supported the existence of a divergent lineage that is more closely related to D. galeata than to D. dentifera. However, morphology and the nuclear DNA data indicated a lineage that is most closely related to D. dentifera. As our evidence supported the existence of a cohesive divergent lineage, we described a new species, Daphnia japonica sp. nov. Recognition of local and subalpine diversity in this group is critical as ongoing anthropogenic disturbance has been associated with introductions, local extirpations, and hybridization. [ABSTRACT FROM AUTHOR]

Thamnocephalidae, a family of Anostraca which is widely distributed on all continents of the world except Antarctica, currently consists of six genera and approximately 63 recognized species. The relationships among genera in Thamnocephalidae and the monophyly of Thamnocephalidae, determined using morphological characteristics or gene markers, remain controversial. In order to address the relationships within Thamnocephalidae, we sequenced Branchinella kugenumaensis mitogenomes and conducted a comparative analysis to reveal the divergence across mitogenomes of B. kugenumaensis. Using newly obtained mitogenomes together with available Anostracan genomic sequences, we present the most complete phylogenomic understanding of Anostraca to date. We observed high divergence across mitogenomes of B. kugenumaensis. Meanwhile, phylogenetic analyses based on both amino acids and nucleotides of the protein-coding genes (PCG) provide significant support for a non-monophyletic Thamnocephalidae within Anostraca, with Asian Branchinella more closely related to Streptocephalidae than Australian Branchinella. The phylogenetic relationships within Anostraca were recovered as follows: Branchinectidae + Chirocephalidae as the basal group of Anostraca and halophilic Artemiidae as a sister to the clade Thamnocephalidae + Streptocephalidae. Both Bayesian inference (BI)- and maximum likelihood (ML)-based analyses produced identical topologies. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of Antarctic fairy shrimp Branchinecta gaini Daday, 1910 was sequenced, assembled and annotated using next-generation sequencing technology. The mitogenome of B. gaini is circular at 15,536 bp in length, consisting of 13 protein-coding genes, 23 tRNAs, two rRNAs and two major non-coding regions. In particular, there are two tRNA genes and one non-coding region between these two tRNA genes. A phylogenetic tree was constructed using concatenated amino acid sequences of 13 protein-coding genes. It reveals that B. gaini is clustered with the Anostraca group within the Branchiopoda clade. This study helps us understand the evolution of Anostraca. [ABSTRACT FROM AUTHOR]

Copyright of Crustaceana is the property of Brill Academic Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Crustaceana is the property of Brill Academic Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Non-indigenous species may pose a threat to native ecosystems worldwide. In aquatic environments, invasives may have a negative impact on human food security and livelihoods. Several water fleas (Crustacea: Branchiopoda: Cladocera) are notorious invasive alien species influencing large freshwater lake systems and even inland seas. In the current review, we discuss the state of knowledge regarding non-indigenous species in the Cladocera and their invasiveness potential in different continents. We argue that the potential impacts and occurrence of cladoceran exotics may be higher than generally assumed. We critically review 79 cases from literature sources, involving 61 cladoceran taxa where records outside of their natural distribution ranges were previously interpreted as invasions. We assessed the probability of natural range expansions versus human-mediated introductions and we discuss several major corridors of invasion. We estimate human-mediated transportations for at least 43 taxa (out of 61; ca 70%), while other cases can be seen as natural expansions of their distribution ranges (not necessarily/not likely human-mediated) and/or taxonomical confusion. We confirm non-indigenous presence in recipient regions for at least 41 cladoceran taxa, of which several are true invasives (i.e., with negative impacts on native ecosystems). The majority are zooplankters with effects on pelagic freshwater ecosystems, yet we also report on introductions by littoral taxa. We argue that cryptic introductions of cladocerans are taking place on a global scale, yet they remain under the radar. We highlight several striking case studies, such as the Ponto–Caspian onychopods that have invaded the Baltic Sea and the Laurentian Great Lakes, and several clones of the anomopod genera Daphnia and Bosmina that have successfully colonised new environments, causing equilibria shifts in native aquatic worlds. At the same time, we dispel some myths about taxa that were misconstrued as invasive in certain localities. Based on our review, the first of its kind for freshwater zooplankton, future environmental monitoring tools including molecular techniques and detailed surveys with rigorous and critical taxonomical assessments may help to provide a clearer picture on the extent of invasiveness of cladocerans. [ABSTRACT FROM AUTHOR]

The fairy shrimp Tanymastigites ajjeri   n. sp. is described from a temporary water body, or guelta , in the Sahara Desert near the Tadrart mountains, east of Tassili n'Ajjer National Park, Libya. Males are readily separated from congeners by the morphology of the frontal appendages, which have an undivided lateral ramus and ≥ 0.4× the length of the medial ramus, and by the second antennae, in which the medial lamellar process bears a spatulate distal lobe. The new species is most similar to congeners T. perrieri (Daday, 1910) and T. mzabica (Gauthier, 1928), and it represents the sixth described species in this genus. We provide an updated key to the genus and comments on its diagnosis and definition, particularly concerning the descriptive terminology of the second antennae. In addition, we provide a list of new records of species of Branchiopoda, Copepoda, and Ostracoda from Tassili n'Ajjer National Park. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "A new recumbirostran 'microsaur' from the lower Permian Bromacker locality, Thuringia, Germany, and its fossorial adaptations." The original article did not include the required evidence of registration in ZooBank, which is necessary for the new genus and species names to be valid. The correction provides the correct taxon name, Bromerpeton subcolossus, along with its systematic classification and diagnostic features. The document also includes information about the etymology, locality, and age of the specimen. The corrected article was authored by Mark J. MacDougall, Andréas Jannel, Amy C. Henrici, David S. Berman, Stuart S. Sumida, Thomas Martens, Nadia B. Fröbisch, and Jörg Fröbisch. [Extracted from the article]

Water fleas of the genus Daphnia have been a model system for hundreds of years and is among the best studied ecological model organisms to date. Daphnia are planktonic crustaceans with a cyclic parthenogenetic life-cycle. They have a nearly worldwide distribution, inhabiting standing fresh- and brackish water bodies, from small temporary pools to large lakes. Their predominantly asexual reproduction allows for the study of phenotypes excluding genetic variation, enabling us to separate genetic from non-genetic effects. Daphnia are often used in studies related to ecotoxicology, predator-induced defence, host–parasite interactions, phenotypic plasticity and, increasingly, in evolutionary genomics. The most commonly studied species are Daphnia magna and D. pulex, for which a rapidly increasing number of genetic and genomic tools are available. Here, I review current research topics, where the Daphnia model system plays a critical role. [ABSTRACT FROM AUTHOR]

A study of the water fleas (Crustacea: Cladocera) in man-made lakes in the northeast part of the United Arab Emirates revealed five species: Ceriodaphnia cf. cornuta Sars, 1885; Daphnia (Ctenodaphnia) arabica Neretina, Al Neyadi et Hamza, 2022; Moina cf. micrura Kurz, 1875; Anthalona mediterranea (Yalim, 2005); Coronatella anemae Van Damme et Dumont, 2008. The morphologies of the four taxa are described in detail, except that of D. Arabica, which has been described previously. The phylogenies of the C. cornuta and M. micrura species groups were reconstructed based on sequences of the COI mitochondrial gene and the possible divergence age of the Arabian clades was estimated based on molecular clocks with paleontological calibration. We concluded that the C. cornuta complex was differentiated in the Upper Jurassic to Lower Cretaceous. The splitting off of clades containing the Arabian population took place during the Oligocene to Miocene. The M. micrura species group was differentiated in the Upper Cretaceous, and the splitting off of clades including Arabian populations took place around the Oligocene. Therefore, the clades (of different hierarchical orders) in the Arabian Peninsula are very old compared to clades of similar rank in northern Eurasia, which usually have Late Pleistocene history. Most of our sampled water bodies were newly constructed man-made reservoirs. As revealed, the phylogroups are locally distributed, and we hypothesized that they are colonists from surrounding natural water bodies inhabited by the relicts of older fauna that survived after the great climate aridization and then occupied newly available (man-made) biotopes. [ABSTRACT FROM AUTHOR]

Due to the lack of a taxonomic key for the identification of Artemia species, molecular markers have been increasingly used for phylogenetic studies. The mt COI marker is a regularly considered marker for the molecular systematics of Artemia populations. The proposed universal and specific primers have mostly failed to amplify the Artemia aff. sinica mt COI marker, and on the whole, the successfully amplified products of the PCR were inefficient, primarily through the representation of poly-peak or incomplete sequences. We presumed that if a forward primer could be developed regarding the joint regions of the last part of the previous gene (tRNA Tyr ) and the beginning of the target gene mt COI , the sequence could be relevant to the target-sequence of mt COI. Thus, here, we describe a new set of primers, which could be used to amplify the mt COI barcoding region of Artemia aff. sinica Cai, 1989, with a high performance of sequencing. The new primer set worked well also for other Artemia bisexual species, as well as for parthenogenetic populations. It is recommended that joint regions between the previous/next gene(s) and the target marker, could be aimed at when designing specific primers for other markers and taxa. Résumé: En raison de l'absence d'une clé taxonomique pour l'identification des espèces d' Artemia , les marqueurs moléculaires ont été de plus en plus utilisés pour les études phylogénétiques. Le marqueur mt CO est régulièrement considéré pour la systématique moléculaire des populations d' Artemia. Les amorces proposées, universelles ou spécifiques, ont la plupart échoué à amplifier le marqueur Artemia aff. sinica mt COI , et dans l'ensemble, les produits amplifiés avec succès par PCR ont été inefficients, principalement par la représentation de poly-pic ou de séquences incomplètes. Nous supposons que si une amorce anti-sens pouvait être développée pour les régions jointives de la dernière partie du gène précédent (tRNA Tyr ) et le début du gène cible mt COI , la séquence pourrait être pertinente de la séquence cible de mt COI. Ainsi, nous décrivons ici un nouvel ensemble d'amorces qui pourraient être utilisées pour amplifier la région du code-barre mt COI d' Artemia aff. sinica Cai, 1989, avec une performance de séquençage élevée. Ce nouvel ensemble d'amorces a bien fonctionné aussi pour les autres espèces bisexuelles d' Artemia , ainsi que pour les populations parthénogénétiques. Il est recommandé que la région de jonction entre les gènes précédents et suivants et le marqueur cible, pourrait être visée dans le design d'amorces spécifiques pour d'autres marqueurs ou taxa. [ABSTRACT FROM AUTHOR]

Artemia is the most common live food that is used in aquaculture worldwide. This study reports on biometrical variation in the cysts of the introduced, originally American Artemia franciscana from 24 non-native localities and two native habitats, in Asia and the U.S.A., respectively. The results show, that the largest diameter of untreated cysts, the largest diameter of decapsulated cysts, and a thicker chorion usually are found in invasive populations. Because of the small cysts, which have an effect on an increasing quantity per unit weight and thus could be the cause of increased hatching efficiency, commercial productions of A. franciscana cysts from native sources should potentially be considered higher quality than productions from non-indigenous environments. Principal Component Analysis revealed that all cyst batches from San Francisco Bay were classified in one group and most of the invasive populations could be arranged in another, separate group. Although the diameter of the decapsulated cyst and chorion thickness showed a negative and significant correlation among invasive populations, there was no significant relationship within native populations. These observations contrast with biometrical patterns of parthenogenetic populations. Résumé: Artemia est la nourriture vivante la plus utilisée mondialement en aquaculture. Cette étude porte sur la variation biométrique des cystes de l' Artemia franciscana américaine originelle provenant de 24 localités non–indigènes en Asie et deux habitats indigènes aux U.S.A. Les résultats montrent qu'un diamètre plus grand des cystes non traités, un diamètre plus grand des cystes décapsulés et un chorion plus épais sont généralement trouvés dans les populations invasives. Du fait que les petits cystes ont un effet sur l'augmentation de la quantité par unité de poids et ainsi pourraient être la cause d'une augmentation de l'efficacité de l'éclosion, les productions commerciales de cystes à partir de sources indigènes devraient être potentiellement considérées comme de meilleure qualité que les productions à partir d'habitats non indigènes. L'analyse des composants principaux a montré que les lots de cystes de la baie de San Francisco ont été classés en un seul groupe et que la plupart des populations invasives peuvent être arrangées ensemble dans un groupe séparé. Bien que le diamètre des cystes décapsulés et l'épaisseur du chorion aient montré une corrélation négative et significative chez les populations invasives, il n'y a pas d'interrelation parmi les populations indigènes. Ces observations contrastent avec les données biométriques des populations parthénogénétiques. [ABSTRACT FROM AUTHOR]

The phylogenetic studies of clam shrimps (Branchiopoda, Crustacea) demonstrated that the significance of several morphological characters for classification of branchiopod shells should be critically re-evaluated. Such a venture is particularly important for integrating the taxonomy of fossil and extant branchiopods. One of the shell characters widely used in the branchiopod classification is the carapace ornamentation pattern. This character might, however, be significantly influenced by intraspecific variability and in particular the sexual dimorphism. In this study we investigate the pattern of ornamentation in extant branchiopods-including differences resulting from sexual dimorphism-in order to assess its value for branchiopod taxonomy. We examined 184 individuals representing 10 living species belonging to 7 genera, 5 families, and 2 suborders from China, and compared with the results of previous studies. Although some differences in ornamentation were related to reproductive modes, the basic ornamentation patterns or combinations were stable within each extant species. We found out that some taxa indeed display sexually dimorphic ornamentations, but their basic ornamentation patterns or combinations are stable within each species so they do not significantly influence the taxonomic identification. Integration of data on fossil and extant taxa indicates that similar ornamentation patterns can be observed on familial level of fossil spinicaudatan branchiopods and indicates therefore that characteristic ornamentation patterns can help to identify these taxa in the fossil record. In light of the new molecular phylogeny, we re-evaluated the phylogenetic relationship between fossil and extant spinicaudatan taxa. The resulting tree suggests: (i) paraphyly of the traditional Eosestherioidea, (ii) an affinity between Ozestheria and Triglypta, and (iii) an affinity between Cyzicus and Diestheria or Aquilonoglypta. [ABSTRACT FROM AUTHOR]

The phylogenetic studies of clam shrimps (Branchiopoda, Crustacea) demonstrated that the significance of several morphological characters for classification of branchiopod shells should be critically re-evaluated. Such a venture is particularly important for integrating the taxonomy of fossil and extant branchiopods. One of the shell characters widely used in the branchiopod classification is the carapace ornamentation pattern. This character might, however, be significantly influenced by intraspecific variability and in particular the sexual dimorphism. In this study we investigate the pattern of ornamentation in extant branchiopods--including differences resulting from sexual dimorphism--in order to assess its value for branchiopod taxonomy. We examined 184 individuals representing 10 living species belonging to 7 genera, 5 families, and 2 suborders from China, and compared with the results of previous studies. Although some differences in ornamentation were related to reproductive modes, the basic ornamentation patterns or combinations were stable within each extant species. We found out that some taxa indeed display sexually dimorphic ornamentations, but their basic ornamentation patterns or combinations are stable within each species so they do not significantly influence the taxonomic identification. Integration of data on fossil and extant taxa indicates that similar ornamentation patterns can be observed on familial level of fossil spinicaudatan branchiopods and indicates therefore that characteristic ornamentation patterns can help to identify these taxa in the fossil record. In light of the new molecular phylogeny, we re-evaluated the phylogenetic relationship between fossil and extant spinicaudatan taxa. The resulting tree suggests: (i) paraphyly of the traditional Eosestherioidea, (ii) an affinity between Ozestheria and Triglypta, and (iii) an affinity between Cyzicus and Diestheria or Aquilonoglypta. [ABSTRACT FROM AUTHOR]

The class Branchiopoda, whose origin dates back to Cambrian, includes ~ 1200 species which mainly occupy freshwater habitats. The phylogeny and systematics of the class have been debated for long time, until recent phylogenomic analyses allowed to better clarify the relationships among major clades. Based on these data, the clade Anostraca (fairy and brine shrimps) is sister to all other branchiopods, and the Notostraca (tadpole shrimps) results as sister group to Diplostraca, which includes Laevicaudata + Spinicaudata (clam shrimps) and Cladoceromorpha (water fleas + Cyclestherida). In the present analysis, thanks to an increased taxon sampling, a complex picture emerges. Most of the analyzed mitogenomes show the Pancrustacea gene order while in several other taxa they are found rearranged. These rearrangements, though, occur unevenly among taxa, most of them being found in Cladocera, and their taxonomic distribution does not agree with the phylogeny. Our data also seems to suggest the possibility of potentially homoplastic, alternative gene order within Daphniidae. [ABSTRACT FROM AUTHOR]

Base metal smelting activity around Sudbury (Ontario, Canada) has persisted for over a century, emitting metals and acidifying contaminants that affected lakes downwind of smelter stacks. Although considerable research has been directed toward the paleolimnological study of diatoms and chrysophytes in the region, relatively little comparable work has been completed on invertebrates. Here, cladoceran (Branchiopoda: Cladocera) assemblages are compared using a paleolimnological "top-bottom approach", comparing preimpact and recent assemblages. Spatiotemporal differences were likely driven by acidification-related stressors and legacy effects of metal contamination. The replacement of the Daphnia longispina complex with the Daphnia pulex complex is attributable to diminished lake-water calcium concentrations. Increased abundances of early colonist taxa demonstrate that many acidified lakes have not fully recovered. Regional stressors further complicate recovery and the interpretation of temporal changes. Finally, clustering of recent cladoceran assemblages reflects the effects of modern multiple stressors and persistent historical stressors. This study shows that acidification history partially explains differences in cladoceran assemblages, but also that multiple stressors will likely continue to influence assemblage composition and recovery in Sudbury lakes. Defining appropriate reference conditions, considering historical and modern stressors, will be important when assessing the extent and trajectory of ecosystem recovery from widespread anthropogenic impacts. [ABSTRACT FROM AUTHOR]

Transcription factor p 8 plays an important role in regulating autophagy in Daphnia pulex cells. In this experiment, 19 genes encoding 71, 271 and 117 amino acids, respectively, were obtained by RACE (Rapid Amplification of cDNA Ends). Subsequently, qPCR was used to detect the gene expression of Daphnia pulex genes for p 8 , ATG5 and ATG8 , at different time points and in different reproductive pathways. It was thus found that p 8 was significantly expressed only before the natural extrusion of resting eggs. ATG5 and ATG8 were stably expressed at a low level in the "summer eggs" produced parthenogenetically, and significantly expressed in the juvenile fleas. The mRNA expression levels in the sexual reproduction pathway gradually increased, and the mRNA expression levels of ATG5 and ATG8 reached their peaks 36 h after resting egg production, and these were significantly higher than those in other time periods. After the resting eggs are completely formed and naturally extruded, the expression levels of ATG5 and ATG8 are almost undetectable. Therefore, any expression levels of ATG5 and ATG8 can hardly be detected when the resting eggs have completely been formed and naturally discharged. Thus, by preparing Escherichia coli capable of producing p 8 dsRNA and feeding Daphnia pulex for RNAi, we found that after interfering with the expression of p 8 , the expression levels of ATG5 and ATG8 had also decreased. The results may provide a theoretical basis for further exploration of the relationship between the Daphnia pulex gene for p 8 and the formation of resting eggs. Résumé: Le facteur de transcription p 8 joue un rôle important dans la régulation de l'autophagie des cellules de Daphnia pulex. Dans cette expérience, 19 gènes codant respectivement 71, 271 et 117 acides aminés ont été obtenus par amplification rapide d'extrémités d'ADNc par réaction en chaîne par polymérase (RACE). Puis une qPCR a été utilisée pour détecter l'expression génétique des gènes p 8 , ATG5 , et ATG8 , de Daphnia pulex , et ceci à différents temps et dans différentes voies de reproduction. Ceci a montré que p 8 était exprimé significativement seulement avant l'extrusion naturelle des cystes (œufs de diapause). ATG5 et ATG8 ont été exprimés de façon stable à un faible niveau dans les œufs d'été produits par parthénogenèse, et ils ont été exprimés de façon significative chez les juvéniles. Les niveaux d'expression de l'ARNm de ATG5 et ATG8 ont atteint un pic 36 h après la production des cystes, et ils étaient significativement plus élevés qu'à d'autres périodes de temps. Après la formation complète et l'expulsion naturelle des cystes, les niveaux d'expression de ATG5 and ATG8 sont presque indétectables. Donc, aucun niveau d'expression de ATG5 et ATG8 ne peut être détecté quand les cystes sont complètement formés et libérés naturellement. En préparant des Escherichia coli capables de produire des ARN de p 8 et en nourrissant des Daphnia pulex pour des ARNi, nous avons trouvé qu'après interférence avec l'expression de p 8 , les niveaux d'expression d' ATG5 et ATG8 avaient également diminué. Ces résultats peuvent fournir une base théorique pour de futures explorations de l'interrelation entre le gène p 8 de Daphnia pulex et la formation des cystes. [ABSTRACT FROM AUTHOR]

The limnadiid clam shrimps of southern Africa are revised and the history and difficulties surrounding the taxonomy of the species in this region are discussed. Three new species are described: two of Eulimnadia Packard, 1874 and one of Gondwanalimnadia Rogers, Rabet & Weeks, 2016. The two new Eulimnadia species are distinguished from congeners by their unique egg ornamentation: dense, fine, long striae in E. striata n. sp. , broadly angular to subcylindrical with numerous rows of narrow, rectangular polygons in E. subcylindriforma n. sp. The taxonomy and identity of Gondwanalimnadia is discussed in detail and validated as a new species as Gondwanalimnadia costata n. sp. This species is readily separated from the southern African Eulimnadia by the characters of the genus and the egg, which is spherical with large, broad costae. [ABSTRACT FROM AUTHOR]

Background: Fairy shrimps belong to order Anostraca, class Branchiopoda, subphylum Crustacea, and phylum Arthropoda. Three fairy shrimp species (Eubranchipus uchidai, E. asanumai, and E. hatanakai) that inhabit snowmelt pools are currently known in Japan. Whole mitochondrial genomes are useful genetic information for conducting phylogenetic analyses. Mitochondrial genome sequences for Branchiopoda members are gradually being collated. Results: Six whole mitochondrial genomes from the three Eubranchipus species are presented here. Eubranchipus species share the anostracan pattern of gene arrangement in their mitochondrial genomes. The mitochondrial genomes of the Eubranchipus species have a higher GC content than those of other anostracans. Accelerated substitution rates in the lineage of Eubranchipus species were observed. Conclusion: This study is the first to obtain whole mitochondrial genomes for Far Eastern Eubranchipus species. We show that the nucleotide sequences of cytochrome oxidase subunit I and the 16S ribosomal RNA of E. asanumai presented in a previous study were nuclear mitochondrial DNA segments. Higher GC contents and accelerated substitution rates are specific characteristics of the mitochondrial genomes of Far Eastern Eubranchipus. The results will be useful for further investigations of the evolution of Anostraca as well as Branchiopoda. [ABSTRACT FROM AUTHOR]

Analysis of Cladocera (Crustacea: Branchiopoda) subfossil remains in lake sediments features prominently in paleolimnological studies. It is well known, however, that species composition in a taphocoenosis (assemblage of subfossil remains in sediments) does not represent perfectly that of the original living community (biocoenosis) from which it came. We analyzed the representation of different Cladocera skeletal components in sediments of 27 Russian water bodies to compare two methods of enumerating relative abundances of cladoceran remains: (1) recording the number of most abundant fragments of each taxon to represent the number of individuals, and (2) recording each fragment of a taxon as belonging to an individual specimen. Overall, for all cladoceran taxa and all water bodies sampled, proportions of different skeletal components differed from what would be expected based on those in live individuals. Carapaces were the most abundant component in 23 of 27 water bodies. Head shields were common, but predominated in only four samples, whereas postabdomens were rare, accounting for < 10% of the whole sample set. Several hypotheses are proposed to explain the different proportions of cladoceran skeletal remains in sediment samples. Both methods for counting remains yielded similar relative abundance estimates for different taxa, which can be regarded as evidence that both methods are adequate, with some exceptions. For example, Alona affinis was represented by a relatively high portion of postabdomens, a component that for other taxa was usually poorly represented. In general, recording of the total number of skeletal components, as compared to using the most abundant fragment method (MAF), slightly overestimates the significance of some taxa in the community. Disproportionate preservation of different skeletal components among cladoceran taxa does not compromise the results of cladoceran-based paleoecological analyses using either counting method, but should be considered when interpreting results. [ABSTRACT FROM AUTHOR]

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In the aquaculture of fish and crustaceans, the indoor culture of M. macrocopa constitutes a requisite to produce a more effective feed for the larviculture of the cultured commercial species. The present study examined the efficiency of different diets on population density, survival, and productivity of M. macrocopa. The cladocerans [Cladocera: currently largely referred to as Diplostraca] were fed and enriched with seven diets, including Chlorella sp., agro-industrial residues (rice bran and soybean meal), bio-organic fertilizer (chicken manure and swiftlet waste), canola oil and artificial micro pellets. The diets were provided at a concentration of 500 mg/l for each diet. The M. macrocopa fed on rice bran had a higher population density, survival, productivity, and a promising higher nutrient quality than the test groups fed on the other dietary treatments used. This study has covered the most important aspects of nutritional requirements to produce live feed organisms, which would provide a comprehensive data set for an alternative solution of the best feed for M. macrocopa propagation and their utilization in hatcheries. Résumé: En aquaculture de poissons et de crustacés, l'élevage en intérieur de M. macrocopa constitue un prérequis pour produire une nourriture plus efficace pour la production de larves des espèces commerciales élevées. Cette étude examine l'efficacité de différents régimes sur la densité de population, la survie et la productivité de M. macrocopa. Les cladocères [Cladocère : actuellement largement nommé Diplostraca] ont été nourris et enrichis avec sept régimes, incluant Chlorella sp., des résidus agro-alimentaires (riz brun et farine de soja), engrais bio-organiques (fumier de poulet et déchets de salangane), huile de canola et micro granulés artificiels. Les régimes ont été donnés à une concentration de 500 mg/l chacun. Les M. macrocopa nourris avec le riz brun ont eu une densité de population, une survie, une productivité plus élevées, et une qualité nutritive potentiellement plus élevée que les groupes nourris avec les autres régimes testés. Cette étude s'est intéressée aux aspects les plus importants des besoins nutritionnels pour produire une nourriture vivante, et pourrait fournir un ensemble de données pour une solution alternative à une meilleure nourriture pour M. macrocopa et leur utilisation généralisée en écloseries. [ABSTRACT FROM AUTHOR]