Branchiopoda Research Articles

Comparative analysis of the population of the brachiopod belonging to Artemia genus in the hypersaline lakes of Crimea based on its morphometric characteristics

Systematic and regular long-term observations of Crimean artemia populations have not been carried out, and therefore, there is little data in the literature on the size and weight characteristics and morphometric features of artemia at different stages of development. It is obvious that the water-salt regime of many lakes is changing and new observations of the peculiarities of its biology and the study of its morphometric indicators are required for a reliable assessment of stocks and forecasting of catch volumes of artemia. Aim of this work is to study the morphometric characteristics of the brine shrimp, a branchiopod crustacean (gen. Artemia) of the saline lakes within Kransnoperekopsk, Chernomorsk, Saky and Lenino Districts of the Republic of Crimea. The correlation analysis of morphometric (9 morphological and 3 meristic) parameters of Artemia males and females has been conducted. New data on the length, weight and morphometric characteristics of the brine shrimp at various stages of its development have been obtained for the hypersaline water bodies of the Republic of Crimea. In the hyperhaline lakes of the Republic of Crimea, parthenogenetic and bisexual Artemia populations have been found. Investigated morphological features of male and female individuals have shown a different degree of contingency. The furca parameters in females and the abdomen parameters in males are found to be the most variable. Based on the morphometric characteristics of the investigated Artemia populations, a similarity dendrogram for the saline lakes has been created. The morphometric and cluster analysis made it possible to categorize the investigated lakes into three groups with differing salinity. Mineralization of these water bodies exerts a morphogenetic influence on the growth and development of Artemia.

Large branchiopods (Anostraca, Notostraca, Laevicaudata, Spinicaudata) from the semi-arid regions of western India

Abstract Large branchiopod crustaceans are flagship species of temporary water bodies, especially in arid and semi-arid regions. Less information is available about the large branchiopods of tropical Asia compared to other parts of the world such as the Americas. To reduce this disparity, we surveyed large branchiopods from the semi-arid region of Maharashtra state, India. Sampling at 29 sites over four years revealed nine species representing four orders. This is the highest diversity ever reported from a single regional study in India. Anostracans were the most commonly occurring group, whereas the spinicaudatans Leptestheria cf. nobilisSars, 1900, L. jaisalmerensisTiwari, 1962, and Eulimnadia michaeliNayar & Nair, 1968 were very rare. Leptestheria jaisalmerensis had been known previously only from its type locality nearly 1,200 km north of our study region. Congeneric assemblages of the anostracans Streptocephalus dichotomusBaird, 1860 + S. simplexGurney, 1906 and the spinicaudatans Leptestheria cf. nobilis + L. jaisalmerensis were collected. Temporary aquatic habitats are threatened due to adverse anthropogenic activities, especially in developing countries like India. The endemic species of large branchiopods in the Indian subcontinent should be red-listed, as is done elsewhere.

Comparative transcriptomics suggests a potential realizator gene for carapace expansion in longtail tadpole shrimp, Triops longicaudatus (Branchiopoda: Notostraca).

The origin of morphological innovation has been extensively studied within evolutionary developmental biology (evo-devo). Recent studies have demonstrated that the developmental module for double-layered epithelial outgrowths is conserved between the insect wings and branchiopod crustacean carapace, thereby introducing homology among these diverse structures. However, evo-devo studies on the branchiopod crustacean carapace have been primarily limited to a single species, the water flea Daphnia magna, leaving the gene regulatory network governing carapace development not comprehensively understood. Furthermore, realizator genes downstream of the character identity mechanism (ChIM) for bilayered epithelial development remain inadequately described. In this study, we analyzed tissue-specific transcriptional profiles in the developing longtail tadpole shrimp, Triops longicaudatus. We observed significant upregulation of papilin in the carapace-bearing head, along with its expression in both the carapace and the trunk limb lobes. Based on these results, we hypothesize that differential expression of papilin is involved in the disproportional growth of Triops carapace. Our findings will contribute to elucidating the diversification of double-layered epithelial outgrowths across distant arthropod lineages.

Current status of the systematics of large branchiopod crustaceans (Branchiopoda: Anostraca, Notostraca, Laevicaudata, Spinicaudata, Cyclestherida)

Abstract 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.

Bison Act as Habitat Engineers for Large Branchiopod Crustaceans in the Great Plains

Bison Act as Habitat Engineers for Large Branchiopod Crustaceans in the Great Plains

Local Faunistic Association of the Water Fleas (Crustacea: Cladocera) in the Water Bodies of Left Bank of the Lena River near Town of Yakutsk and Its Vicinities (Yakutia Russia)

In this study, we investigated a species composition of the water fleas (Crustacea: Cladocera) in the water bodies of the left bank of the Lena River near Yakutsk and its vicinities. Local faunistic associations characteristics of this region were identified using a statistical approach based on the binomial distribution function. As a result of the study, 68 taxa were identified and eight very distinct groups of taxa constituting the cores of local faunistic associations of the branchiopod crustaceans in various water bodies and/or various biotopes within one water body were drawn out. We have demonstrated that the water bodies of the Lena River valley and the watershed differ both in species composition and in associations of the Cladocera. At least one species association of the Cladocera is confined to the ponds with a visible anthropogenic influence. Thus, it is possible to identify not only species that are typical for urban water bodies, but also local faunistic associations, the presence of which in the city indicates a significant anthropogenic pressure. At the same time, the identified clusters can be interpreted in terms of our knowledge of the individual species preferences to water bodies of different types and different ecological zones of a certain water body.

Phylogenetic analysis of problematic Asian species ofArtemiaLeach, 1819 (Crustacea, Anostraca), with the descriptions of two new species

AbstractSpecies of Artemia are regionally endemic branchiopod crustaceans composed of sexual species and parthenogenetic lineages, and represent an excellent model for studying adaptation and speciation to extreme and heterogeneous hypersaline environments. We tested hypotheses of whether populations from the Tibetan Plateau belong to A. tibetianaAbatzopoulos, Zhang & Sorgeloos,1998 and whether a population from Kazakhstan is a new species, using other Asian species of Artemia as outgroups. We conducted a multitrait phylogenetic study based on the complete mitogenome, mitochondrial (COI, 12S, 16S) and nuclear (microsatellites, ITS1) markers, and a suit of uni- and multivariate morphological traits. Our results led to the discovery of two new species, one from the Tibetan Plateau (Haiyan Lake) in China (Artemia sorgeloosin. sp.) and a second from Kazakhstan (Artemia amatin. sp.). Our analysis demonstrate that A. tibetiana and A. amatin. sp. are monophyletic, whereas A. sorgeloosin. sp., and A. tibetiana are polyphyletic. Evolutionary relationships based on mitochondrial and nSSR markers suggest that A. tibetiana may have arisen from a past hybridization event of a maternal ancestor of A. tibetiana with A. sorgeloosin. sp. or its ancestor. We present the complete mitogenome of A. tibetiana, A. amatin. sp., and A. sorgeloosin. sp. We also provide a novel taxonomic identification key based on morphology, emphasizing the phenotype as a necessary component of the species concept.

New Data on the Distribution of Southern Forests for the West Siberian Plain during the Late Pleistocene: A Paleoentomological Approach

Subfossil remains of insects and branchiopod crustaceans (Cladocera and Notostraca) found in three late Pleistocene deposits in the Novosibirsk region in the vicinity of the village of Suzun have been described. The calibrated radiocarbon dates for these deposits were 24,893–25,966 cal BP (Suzun-1), 20,379–20,699 cal BP (Suzun-2), and 27,693–28,126 cal BP (Nizhny Suzun), which correspond to the onset of marine isotope stage 2 (MIS 2). The insect assemblages of these deposits are mainly represented by Coleoptera, which are noteworthy for high taxonomic and ecological diversity. At least 194 beetle species from 21 families have been found altogether. Of them, 74 species were found in the Pleistocene deposits of Western Siberia for the first time. All deposits were similar in species composition of beetles; Carabidae and Curculionidae prevailed everywhere. The ecological composition was dominated by steppe and tundra-steppe species; aquatic and riparian groups were also well represented. The Cladoceran and notostracan taxa revealed in Suzun-1 and Suzun-2 are characteristic of recent steppes rather than the forest zone of Western Siberia. The studied entomocomplexes are congruent with the periglacial “Otiorhynchus-type” fauna that inhabited the southern part of the West Siberian Plain at the end of the Pleistocene and had no close contemporary analogues. Cold and dry conditions, as well as the prevailing open landscapes of the tundra-steppe type, were the reconstructed conditions for this fauna. At the same time, the Suzun-1 and Suzun-2 entomocomplexes had a distinctive feature, namely a high proportion of forest species associated with both coniferous and deciduous trees. According to these data, at the beginning of MIS 2 in the Upper Ob region, spruce forests with the participation of small-leaved species (birch) were present. They were probably confined to river valleys and were not widely distributed.

APPLICATION OF BIOSURFACTANTS IN WASTEWATER BIOFILTRATION TECHNOLOGY USING DAPHNIA MAGNA

When solving water purification problems, including for the needs of industrial fish farming, biofiltration methods involving planktonic organisms, in particular branchiopod crustaceans, deserve special attention. A specific filtration apparatus feeding daphnia can provide highly efficient wastewater treatment from suspended fine particles that have a low settling velocity and are not able to be retained on mechanical filters. An important advantage of this method of water treatment is the ability to use the resulting zooplankton biomass as live feed for fish farming. The filtration properties of zooplankton can be improved by growing it in the presence of surfactants of biological origin, which, in addition, improve the absorption of nutrients by cladocerans and intensify their growth. In this study, the possibility of using a preparation of trehalosolipid biosurfactants obtained from the culture fluid of Rhodococcus erythropolis AU-1 for intensive growth of Daphnia magna culture for the purpose of biological treatment of water bodies was evaluated. It was established that the toxicity of trehalosolipids is dose-dependent, in particular, their minimum concentration at which the death of daphnia was observed within 24 hours of exposure was 300 mg/l, and the LC50 at the same duration of exposure was 479 mg/l. The maximum non-toxic concentration of the trehalosolipid biosurfactant is 200 mg/l. Concentrations of trehalosolipids in the range of 1-3 mg/l provide an increase in the density of daphnia culture by 1.3-1.7 times compared to the control. To evaluate the efficiency of biofiltration of Daphnia magna in the model experiment, water from the mechanical filter of the experimental recirculation system of the Yuriy Fedkovych Chernivtsi National University was used. The value of the optical density of the discharge water decreases by more than half after one day of daphnia presence in it, and after 4 days - by 7 times. The addition of biosurfactants leads to a more efficient filtration process, with the best results obtained when using the preparation with a concentration of 1 mg/l. The use of biosurfactants in concentrations of 1, 2 and 3 mg/l leads to a decrease in electrical conductivity and total mineralization compared to the control. At the same time, the pH and soluble oxygen content did not change compared to the control.

A draft reference genome of the Vernal Pool Fairy Shrimp, Branchinecta lynchi.

We present the reference genome of the Vernal Pool Fairy Shrimp Branchinecta lynchi. This branchiopod crustacean is endemic to California's freshwater ephemeral ponds. It faces enormous habitat loss and fragmentation as urbanization and agriculture have fundamentally changed the vernal pool landscape over the past 3 centuries. The assembled genome consists of 22 chromosome-length scaffolds that account for 96.85% of the total sequence. One hundred and ninety-five unscaffolded contigs comprise the rest of the genome's 575.6 Mb length. The genome is substantially complete with a BUSCO score of 90.0%. There is no immediately identifiable sex chromosome, typical for this class of organism. This new resource will permit researchers to better understand the adaptive capacity of this imperiled species, as well as answer lingering questions about anostracan physiology, sex determination, and development.

Review of the large branchiopod crustacean fauna of Qatar (Anostraca, Notostraca, Spinicaudata) and adjacent countries

The large branchiopod crustaceans (Anostraca, Notostraca, and Spinicaudata) of Qatar have only been examined recently. Although 15 nominal species have been reported for the Arabian Peninsula, there is confusion surrounding the determinations of previously collected taxa from Qatar, and the validity of some spinicaudatan taxa is in question. Most spinicaudatan clam shrimp taxa are poorly described; some lack type material or the type material has been lost. We provide a review of the taxa from Qatar and some records from adjacent Saudi Arabia. We recognise five large branchiopod crustacean taxa from Qatar (two anostracans, one notostracan, and two spinicaudatans) and provide new locality records from Umm Alshkoot and correct some previous literature statements. In addition, we comment on the likelihood of another ten taxa to occur in or near Qatar.

Whole-Genome Phylogenetic Reconstruction as a Powerful Tool to Reveal Homoplasy and Ancient Rapid Radiation in Waterflea Evolution.

Although phylogeny estimation is notoriously difficult in radiations that occurred several hundred million years ago, phylogenomic approaches offer new ways to examine relationships among ancient lineages and evaluate hypotheses that are key to evolutionary biology. Here, we reconstruct the deep-rooted relationships of one of the oldest living arthropod clades, the branchiopod crustaceans, using a kaleidoscopic approach. We use concatenation and coalescent tree-building methods to analyze a large multigene data set at the nucleotide and amino acid level and examine gene tree versus species tree discordance. We unequivocally resolve long-debated relationships among extant orders of the Cladocera, the waterfleas, an ecologically relevant zooplankton group in global aquatic and marine ecosystems that is famous for its model systems in ecology and evolution. To build the data set, we assembled eight de novo genomes of key taxa including representatives of all extant cladoceran orders and suborders. Our phylogenetic analysis focused on a BUSCO-based set of 823 conserved single-copy orthologs shared among 23 representative taxa spanning all living branchiopod orders, including 11 cladoceran families. Our analysis supports the monophyly of the Cladocera and reveals remarkable homoplasy in their body plans. We found large phylogenetic distances between lineages with similar ecological specializations, indicating independent evolution in major body plans, such as in the pelagic predatory orders Haplopoda and Onychopoda (the “Gymnomera”). In addition, we assessed rapid cladogenesis by estimating relative timings of divergence in major lineages using reliable fossil-calibrated priors on eight nodes in the branchiopod tree, suggesting a Paleozoic origin around 325 Ma for the cladoceran ancestor and an ancient rapid radiation around 252 Ma at the Perm/Triassic boundary. These findings raise new questions about the roles of homoplasy and rapid radiation in the diversification of the cladocerans and help examine trait evolution from a genomic perspective in a functionally well understood, ancient arthropod group. [Cladocera; Daphnia; evolution; homoplasy; molecular clock; phylogenomics; systematics; waterfleas.]

Insights into the genetic regulatory network underlying neurogenesis in the parthenogenetic marbled crayfish Procambarus virginalis.

Nervous system development has been intensely studied in insects (especially Drosophila melanogaster), providing detailed insights into the genetic regulatory network governing the formation and maintenance of the neural stem cells (neuroblasts) and the differentiation of their progeny. Despite notable advances over the last two decades, neurogenesis in other arthropod groups remains by comparison less well understood, hampering finer resolution of evolutionary cell type transformations and changes in the genetic regulatory network in some branches of the arthropod tree of life. Although the neurogenic cellular machinery in malacostracan crustaceans is well described morphologically, its genetic molecular characterization is pending. To address this, we established an in situ hybridization protocol for the crayfish Procambarus virginalis and studied embryonic expression patterns of a suite of key genes, encompassing three SoxB group transcription factors, two achaete-scute homologs, a Snail family member, the differentiation determinants Prospero and Brain tumor, and the neuron marker Elav. We document cell type expression patterns with notable similarities to insects and branchiopod crustaceans, lending further support to the homology of hexapod-crustacean neuroblasts and their cell lineages. Remarkably, in the crayfish head region, cell emigration from the neuroectoderm coupled with gene expression data points to a neuroblast-independent initial phase of brain neurogenesis. Further, SoxB group expression patterns suggest an involvement of Dichaete in segmentation, in concordance with insects. Our target gene set is a promising starting point for further embryonic studies, as well as for the molecular genetic characterization of subregions and cell types in the neurogenic systems in the adult crayfish brain.

Dentition and feeding in Placodontia: tooth replacement in Henodus chelyops

BackgroundPlacodontia is a Triassic sauropterygian reptile group characterized by flat and enlarged crushing teeth adapted to a durophagous diet. The enigmatic placodont Henodus chelyops has numerous autapomorphic character states, including extreme tooth count reduction to only a single pair of palatine and dentary crushing teeth. This renders the species unusual among placodonts and challenges identification of its phylogenetic position.ResultsThe skulls of two Henodus chelyops specimens were visualized with synchrotron tomography to investigate the complete anatomy of their functional and replacement crushing dentition in 3D. All teeth of both specimens were segmented, measured, and statistically compared to reveal that H. chelyops teeth are much smaller than the posterior palatine teeth of other cyamodontoid placodonts with the exception of Parahenodus atancensis from the Iberian Peninsula. The replacement teeth of this species are quite similar in size and morphology to the functional teeth.ConclusionAs other placodonts, Henodus chelyops exhibits vertical tooth replacement. This suggests that vertical tooth replacement arose relatively early in placodont phylogeny. Analysis of dental morphology in H. chelyops revealed a concave shape of the occlusal surface and the notable absence of a central cusp. This dental morphology could have reduced dental wear and protected against failure. Hence, the concave teeth of H. chelyops appear to be adapted to process small invertebrate items, such as branchiopod crustaceans. Small gastropods were encountered in the matrix close to both studied skulls.

Dancing on the top: phylogeography and genetic diversity of high-altitude freshwater fairy shrimps (Branchiopoda, Anostraca) with a focus on the Tibetan Plateau

Fairy shrimp are the most divergent taxon of large branchiopod crustaceans and have a worldwide distribution. Yet the diversity and distribution of fairy shrimps in the “Roof of the World” remain poorly known. Here, based on morphology, we identified three species of fairy shrimp (Branchinecta orientalis, Chirocephalus graziellae and Branchipodopsis affinis), among 14 fairy-shrimp populations from the Tibetan Plateau, China. Their phylogenetic relationships were verified based on mitochondrial DNA sequences (cytochrome c oxidase subunit I gene) and two nuclear markers (18S ribosomal RNA gene and internal transcribed spacer 2). Syntopy of different species of fairy shrimp was observed. Some haplotypes were shared among populations, and sequences from B. affinis exhibited a star-like pattern in haplotype networks, suggesting a recent rapid expansion. Finally, a high genetic diversity of fairy shrimp was detected on the Tibetan Plateau. Obtained results contribute to a better knowledge of the diversity of high-altitude fairy shrimps.

The complete mitogenome of Leptestheria brevirostris Barnard, 1924, a rock pool clam shrimp (Branchiopoda: Spinicaudata) from Central District, Botswana

Spinicaudatan clam shrimp are a widespread and diverse group of branchiopod crustaceans, yet few mitochondrial genomes have been published for this taxonomic group. Here, we present the mitogenome of Leptestheria brevirostris from a rock pool ecosystem in Botswana. Massively parallel sequencing of a single specimen facilitated the reconstruction of the species’ 15,579 bp circularized mitogenome. The reconstructed phylogenetic tree confirms that L. brevirostris forms a monophyletic group with other diplostracan branchiopods, and that these are the sister taxon to Notostraca. The mitogenome reconstructed here is the first to be reported from a leptestherid clam shrimp.

A Review of Recently Discovered Remains of the Pleistocene Branchiopods (Anostraca, Notostraca) from NE Siberia and Arctic Canada

In this study, we examine, identify, and discuss fossil remains of large branchiopod crustaceans collected from six sites across the Beringian region (north-eastern Asia and north-western North America). Eggs and mandibles from Anostraca and Notostraca, as well as a notostracan telson fragment and a possible notostracan second maxilla, were collected from both paleosediment samples and also from large mammal hair. The remains of large branchiopods and other species that are limited to seasonally astatic aquatic habitats (temporary wetlands) could be useful indicator organisms of paleoecological conditions. Different recent large branchiopod species have very different ecological preferences, with each species limited to specific geochemical component tolerance ranges regarding various salinity, cation, and gypsum concentrations. Our purpose is to bring the potential usefulness of these common fossil organisms to the attention of paleoecologists.

Egg morphology may underpin the successful distribution of large branchiopods in temporary waters

Invertebrate species from temporary aquatic ecosystems produce resistant dormant stages (i.e. eggs) that accumulate in long lived mixed egg banks in the sediment. These dormant eggs not only bridge dry phases but also act as propagules for passive dispersal. Large branchiopod crustaceans (e.g. Notostraca, Anostraca and Spinicaudata) produce dormant eggs of variable shapes, sizes and external ornamentation. While these characteristics are often species-specific and have been used in taxonomy, little is known about their ecological significance, for example, their contribution to colonisation success. Here, we explore the idea that variation in egg morphology may impact vector-mediated dispersal and colonisation success of large branchiopods. We studied egg banks from 98 temporary waters across the Northern Cape, South Africa and assessed whether distribution and densities of eggs carried a morphological signal. Overall, our results imply that both size and external structures may impact dispersal to and successful colonisation of temporary waters by large branchiopods. Specifically, our results show that small propagules ( 400 µm), smooth eggs and medium sized (200–300 µm), polygonal eggs were most widely distributed. Ultimately, our approach provides insight in actual colonisation success of species with different egg types and not only on the propensity of the eggs to be picked up and transported by vectors.

<p><strong>Discovery of <em>Pemphilimnadiopsis cheni</em> (Branchiopoda: Diplostraca: Spinicaudata) from the Benxi Formation in Taiyuan, North China and its stratigraphic significance</strong></p>

Clam shrimp (Spinicaudata) are worldwide distributed branchiopod crustaceans specialised in ephemeral freshwater habitats. The Carboniferous is an important period for the early evolution and diversification of clam shrimp. Compared with the rare and geographically confined fossil record of the Devonian, clam shrimp in the Carboniferous have a much wider geographical distribution and higher biodiversity. Over 20 genera of clam shrimp have been recorded in the Carboniferous all over the world, but they are sparse in China. To date, five records of Carboniferous clam shrimp have been reported from China (Pruvost, 1927; Zhang et al., 1976; Wang, 1987; Zheng et al., 1988; Liu & Fan, 1995; Liao et al., 2019). Among them, four species Lioestheria? mathieui Pruvost, 1927, Protomonocarina huixianensis Wang, 1987, Retrofractus lingyuanensis Liu & Fan, 1995, and Pemphilimnadiopsis cheni Liao, Shen & Huang, 2019, are found in the Pennsylvanian Benxi Formation in North China (Pruvost, 1927; Zhang et al., 1976; Wang, 1987; Liu & Fan, 1995; Liao et al., 2019).

A New Glance at Old Samples: Remains of Freshwater Invertebrates Associated with Mummified Carcasses of Large Quaternary Mammals

Carcasses of mammals with well-preserved soft tissues from the permafrost of Siberia and northern North America are among the most important sources of our knowledge on Quaternary environments. However, the potential of this information source is far from being exhausted. The objective of this study is to reveal and describe the remains of freshwater invertebrates in the hair and gut contents of large Pleistocene mammals stored for a long time in museum collections. We have studied the gut contents of two mammoths, as well as the hair of two other mammoths, one woolly rhinoceros, four bison, and two horses. Remains of invertebrates were found in the gut contents of both mammoths, as well as in the hair of two mammoths and the woolly rhinoceros, while no remains were detected in the bison and horse hair. Among the remains of microscopic invertebrates, the most common are branchiopod crustaceans, namely the ephippia of Daphnia sp., Simocephalus sp., the head shields and valves of Chydoridae (Cladocera), and the mandibles of tadpole shrimps (Notostraca). Based on our current level of knowledge, we are able to identify only a limited number of Pleistocene branchiopods. Studies on Recent taxa with the aim to develop identification keys to the aforementioned groups are needed, as they could significantly expand the potential of palaeoecological analysis.