Ephydatia Fluviatilis Research Articles

Latitudinal distribution of freshwater sponge species across European Russia

This study provides original faunistic data on freshwater sponge dispersal across a huge territory of European Russia from north to south, highlighting the northern limits of thermophilic and north-adapted species. The holarctic species Ephydatia muelleri and, especially, Spongilla lacustris were predominant in northern areas, while the cosmopolitan Ephydatia fluviatilis and Eunapius fragilis were less prevalent. Moving to the south, E. fluviatilis took the lead. The distributional pattern of northern sponges aligns with literature data from North Europe, confirming the prevalence of the holarctic species in high latitudes. Tubella (=Trochospongilla) horrida, Eunapius carteri, and Radiospongilla cerebellata are considered to be thermophilic species that could not tolerate the conditions in northern regions. Notable findings include the extension of Eunapius carteri's known range and the first report of R. cerebellata within Russia, which is also the second record for Europe. Three potentially expected species were not found in the studied area, indicating regional rarity. We also provide molecular and morphological evidence for the synonymy of Spongilla arctica and Spongilla lacustris. Finally, we discuss the impacts of climate change and agricultural activities on northern and southern sponge habitats respectively.

Mammalian PIWI-piRNA-target complexes reveal features for broad and efficient target silencing.

The PIWI-interacting RNA (piRNA) pathway is an adaptive defense system wherein piRNAs guide PIWI family Argonaute proteins to recognize and silence ever-evolving selfish genetic elements and ensure genome integrity. Driven by this intensive host-pathogen arms race, the piRNA pathway and its targeted transposons have coevolved rapidly in a species-specific manner, but how the piRNA pathway adapts specifically to target silencing in mammals remains elusive. Here, we show that mouse MILI and human HILI piRNA-induced silencing complexes (piRISCs) bind and cleave targets more efficiently than their invertebrate counterparts from the sponge Ephydatia fluviatilis. The inherent functional differences comport with structural features identified by cryo-EM studies of piRISCs. In the absence of target, MILI and HILI piRISCs adopt a wider nucleic-acid-binding channel and display an extended prearranged piRNA seed as compared with EfPiwi piRISC, consistent with their ability to capture targets more efficiently than EfPiwi piRISC. In the presence of target, the seed gate-which enforces seed-target fidelity in microRNA RISC-adopts a relaxed state in mammalian piRISC, revealing how MILI and HILI tolerate seed-target mismatches to broaden the target spectrum. A vertebrate-specific lysine distorts the piRNA seed, shifting the trajectory of the piRNA-target duplex out of the central cleft and toward the PAZ lobe. Functional analyses reveal that this lysine promotes target binding and cleavage. Our study therefore provides a molecular basis for the piRNA targeting mechanism in mice and humans, and suggests that mammalian piRNA machinery can achieve broad target silencing using a limited supply of piRNA species.

Anomalies of Sponge Spicules: Exploring Links to Environmental Pollution

The aim of this study was to assess the frequency of spicule malformations in freshwater sponges in relation to selected environmental parameters of the streams and the presence of river pollutants. A total of 50 sponge samples were collected from ten rivers in Serbia. Selected parameters of the water varied considerably at every site where sponges were found. After spicule preparation, the samples were subjected to morphological analysis by light and scanning electron microscopy, and the number of anomalies were recorded (spicules with bulbous enlargements, sharply bent, bifurcated, scissor- and cross-like, and t-shaped). The frequencies and types of malformations within the analyzed specimens varied from 1 to 100 per 1000 spicules, with an average number of 12 per 1000. The main types of anomalies were single- and double-bent spicules. The highest number of anomalies was found in a specimen of Eunapius fragilis collected at Markovac (Velika Morava River), and the lowest number was found in a specimen of Ephydatia fluviatilis from Kanjiža (Tisa River). The sites with the lowest and the highest numbers of anomalies showed statistically significant differences in concentrations of ammonia, orthophosphates, sodium, chloride, manganese, and lead. This study indicates that several pollutants potentially affect the occurrence of spicule anomalies.

How suitable is freshwater sponge Ephydatia fluviatilis (Linnaeus, 1759) for time-integrated biomonitoring of microbial water quality?

Faecal pollution of water by bacteria has a negative effect on water quality and can pose a potential health hazard. Conventional surveillance of microbial water quality relies on the analysis of low-frequency spot samples and is thus likely to miss episodic or periodic pollution. This study aimed to investigate the potential of filter-feeding sponges for time-integrated biomonitoring of microbial water quality. Laboratory trials tested the effects of different ratios of bacterial abundance and the sequence of exposure on bacterial retention by the freshwater sponge Ephydatia fluviatilis (Linnaeus, 1759) to establish its potential to indicate bacterial exposure. Gemmule grown sponges were simultaneously exposed to Escherichia coli and Enterococcus faecalis but at different ratios (Trial 1) or individually exposed to each bacterial species but in different sequential order (Trial 2). The E. coli and E. faecalis retained in each sponge was quantified by culture on selective agars. Data analysis was conducted using the Kruskal-Wallis test and/or the Mann-Whitney U test to compare between the numbers of bacteria retained in each treatment. Additionally, the Wilcoxon matched-paired signed-rank test was used for comparison of the different bacterial abundances retained within each individual sponge. Sponges from all trials retained E. coli and E. faecalis in small numbers relative to the exposure (<0.05 % Trial 1 and <0.07 % Trial 2) but exhibited higher retention of E. coli. Higher abundance of either bacterial species resulted in significantly lower (P<0.005) retention of the same species within sponges (Trial 1). An initial exposure to E. coli resulted in significantly higher (P=0.040) retention of both bacterial species than when sponges were exposed to E. faecalis first (Trial 2).Bacterial retention by sponges was neither quantitatively representative of bacterial abundance in the ambient water nor the sequence of exposure. This implies either selective filtration or an attempt by sponges to prevent infection. However, freshwater sponges may still be useful in biomonitoring as qualitative time-integrated samplers of faecal indicator bacteria as they detect different bacteria present in the water even if their quantities cannot be estimated.

Chemolithoautotrophic Organic Matter Contributions to Subterranean Food Webs Dominated by Filter-feeders

Chemolithoautotrophic Organic Matter Contributions to Subterranean Food Webs Dominated by Filter-feeders

Morphological and molecular analysis of Ephydatia fluviatilis (Porifera: Spongillida: Spongillidae) from Nanjing, China

We present a comprehensive morphological description of Ephydatia fluviatilis collected in Nanjing for the first time in studies of freshwater sponges in China, based on scanning electron micrography of the sponge meshwork, the megascleres, the gemmules, and the delicate gemmuloscleres, in comparison with relevant data reported worldwide. The morphotype revealed in this study shows a peculiar spicular complement of the skeleton composed of two types of megascleres (the normal oxeas and occasional styles) with abundant tiny, centrally distributed microspinoses, gemmules (ca. 440 μm in diameter) bearing two types of spinose decoration on the shaft (i.e., erect long spines and microspinoses). We report the first complete ITS sequences of the morphotype of E. fluviatilis from China, which, combined with homologous sequences of related taxa from GenBank, are used in a phylogenetic analysis in order to understand the species relationship within Ephydatia and neighbouring taxa. Combining the ITS phylogeny and the gemmulosclere morphotypes, we identify three clades in the paraphyletic genus Ephydatia that are distinguished by different birotule gemmulosclere morphotypes for gemmule-bearing species. Multiple losses of gemmules within endemic taxa, as previously proposed, are confirmed in this study in a phylogenetic context obtained herein. Additionally, genetic similarities are found in some morphologically diverse species, likely indicating recent endemism leading to morphological specialization. Considering the diverse fossil record of Ephydatia from Cenozoic sedimentary strata of wide geographic ranges, we hypothesize that Ephydatia might have a deep root in the Paleogene or earlier and experienced a rapid, Quaternary radiation with emergences of specialized endemic species that lost gemmules under glacial-interglacial paleoenvironment.

Effect of alkalinity and light intensity on the growth of the freshwater sponge Ephydatia fluviatilis (Porifera: Spongillidae)

The adaptation of sponges to freshwater environments was a major event in the evolutionary history of this clade. The transition from a marine environment to freshwater ecosystems entailed a great number of adaptations to more unstable habitats, such as the ability to form resistance gemmules as a defense mechanism against environmental adversity. However, data on the parameters that modulate hatching and growth of these animals are scarce. In the present study, the growth response capacity of Ephydatia fluviatilis (Porifera: Spongillidae) has been evaluated in relation to both water alkalinity and light intensity. The results obtained revealed a positive association between the growth capacity of this freshwater sponge and high alkalinity values. On the other hand, exposure to light, regardless of its intensity, affected the development and distribution of the symbionts, which in turn, corresponds to a higher growth rate of the sponge. The obtained data suggest an explanation for the greater distribution of this species in alkaline environments. The results of this work also shed light on the importance of the symbiosis phenomenon in E. fluviatilis.

First records of Ulvella spongophila (Ulvophyceae: Ulvellaceae) for the Palaearctic region: the discovery of four populations in the SW Iberian Peninsula

During extensive Spanish river macrophyte and invertebrate surveys, the freshwater chlorophyte Ulvella spongophila was detected growing inside the freshwater sponge Ephydatia fluviatilis attached to stones. This finding is relevant from the phy¬cological, biogeographical and ecological points of view, and is the second world record of the species after one single known locality (Lake Manindjau, Sumatra, Malaysia), from which the species was collected and described around 130 years ago. The species was collected under summer base-flow conditions in four Mediterranean temporary/seasonal streams in 2018 and 2019. New information about the species’ morphological characteristics and ecological preferences in the Iberian Peninsula is presented. A comparative description of the observed specimens with previously published data, some biogeographical aspects of findings, certain biological facets of the sponge-algal association, and its conservation status, are discussed.

Addition to Sweden’s freshwater sponge fauna and a phylogeographic study of Spongilla lacustris (Spongillida, Porifera) in southern Sweden

Freshwater sponges constitute an overlooked part of the freshwater fauna in Sweden and there has been no recent systematic survey. Hitherto three species have been found in Sweden: Spongilla lacustris (Linnaeus, 1759), Ephydatia fluviatilis (Linnaeus, 1759) and E. muelleri (Lieberkühn, 1856). Neighbouring countries (Norway, Denmark, Estonia) harbour at least one additional species. We present a study on freshwater sponge diversity and distribution in the southern half of Sweden. We hypothesized dispersal within catchments to be less constrained than between, even at shorter intercatchment than intracatchment distances, and, as result, genetic distances being greater between than within catchments. We collected and identified freshwater sponges from 34 sites, using morphological and molecular data (coxI, 28S rRNA gene). We can report the presence of Eunapius fragilis (Leidy, 1851) in Sweden for the first time, and that S. lacustris is the most abundant and widely distributed freshwater sponge in Sweden. Genetic markers were tested on S. lacustris individuals for a phylogeographic study. From the 47 primers (24 markers), one pair presented successful amplification and enough variation for phylogeographic studies – i56, an intron located in a conserved gene. Seven different variants were found in the sampling area, but no clear population structure was observed.

Structural basis for piRNA targeting.

PIWI proteins use PIWI-interacting RNAs (piRNAs) to identify and silence transposable elements and thereby maintain genome integrity between metazoan generations1. The targeting of transposable elements by PIWI has been compared to mRNA target recognition by Argonaute proteins2,3, which use microRNA (miRNA) guides, but the extent to which piRNAs resemble miRNAs is not known. Here we present cryo-electron microscopy structures of a PIWI-piRNA complex from the sponge Ephydatia fluviatilis with and without target RNAs, and a biochemical analysis of target recognition. Mirroring Argonaute, PIWI identifies targets using the piRNA seed region. However, PIWI creates a much weaker seed so that stable target association requires further piRNA-target pairing, making piRNAs less promiscuous than miRNAs. Beyond the seed, the structure of PIWI facilitates piRNA-target pairing in a manner that is tolerant of mismatches, leading to long-lived PIWI-piRNA-target interactions that may accumulate on transposable-element transcripts. PIWI ensures targeting fidelity by physically blocking the propagation of piRNA-target interactions in the absence of faithful seed pairing, and by requiring an extended piRNA-target duplex to reach an endonucleolytically active conformation. PIWI proteins thereby minimize off-targeting cellular mRNAs while defending against evolving genomic threats.

Effects of freshwater sponge Ephydatia fluviatilis on conjugative transfer of antimicrobial resistance in Enterococcus faecalis strains in aquatic environments.

Filter feeding is a biotic process that brings waterborne bacteria in close contact with each other and may thus support the horizontal transfer of their antimicrobial resistance genes. This laboratory study investigated whether the freshwater sponge Ephydatia fluviatilis supported the transfer of vancomycin resistance between two Enterococcus faecalis strains that we previously demonstrated to exhibit pheromone responsive plasmid conjugation. Microcosm experiments exposed live and dead colonies of laboratory-grown sponges to a vancomycin-resistant donor strain and a rifampicin-resistant recipient strain of Ent. faecalis. Enterococci with both resistance phenotypes were detected on double selection plates. In comparison to controls, abundance of these presumed transconjugants increased significantly in water from sponge microcosms. Homogenized suspensions of sponge cells also yielded presumed transconjugants; however, there was no significant difference between samples from live or dead sponges. Fluorescent in situ hybridization analysis of the sponge cell matrix using species-specific probes revealed the presence of enterococci clusters with cells adjacent to each other. The results demonstrated that sponge colonies can support the horizontal transfer of antimicrobial resistance although the mechanism underlying this process, such as binding of the bacteria to the sponge collagen matrix, has yet to be fully elucidated.

Distribution of freshwater sponges in Serbia

As data on the distribution of freshwater sponges (Porifera, Demospongiae, Spongillida) in Serbia are extremely scarce, we investigated the main Serbian rivers and lakes with respect to Porifera occurrence, for which 17 lotic and 11 lentic water bodies were selected. Sponges were found in 11 of 17 rivers (62 specimens in total) and in 3 of 11 lakes/reservoirs (seven specimens in total). Classical morphological spicule analysis was coupled with polymerase chain reaction (PCR) and gene sequencing for species identification. Among the 69 collected speci- mens, five sponge species of the family Spongillidae have been identified: Ephydatia fluviatilis (Linnaeus, 1759), Spongilla lacustris (Linnaeus, 1759), Ephydatia muelleri (Lieberkühn, 1856), Trochospongilla horrida Weltner, 1893, and Eunapius fragilis (Leidy, 1851). The most frequently found sponge in Serbian rivers was E. fluviatilis (45% of all specimens), while the least frequent was E. fragilis (6 % of all specimens). The Tisa river has the highest sponge diversity (four species). In lentic water bodies, only E. fluviatilis (four specimens) and S. lacustris (three specimens) were found. In general, sponges were infrequent and their abundance was low in Serbian fresh waters. While sponges seem to tolerate significant variations of physical and chemical parameters, some optimal values can be established.

Having the balls to colonize – The Ephydatia fluviatilis group and the origin of (ancient) lake “endemic” sponge lineages

Spongillida (freshwater sponges) constitute an integral part of the world's lacustrine ecosystems. Their radiation and worldwide distribution into nearly every freshwater habitat is predominantly facilitated by the formation of so-called gemmules, i.e., globular endurance and propagation stages. Widespread species produce gemmules in a wide array of morphs, while in (ancient) lake endemic lineages gemmules are absent. Contrary to current classification, earlier molecular studies on non-type material indicated that gemmule-lacking lineages are unrelated, and endemic taxa were derived from a cosmopolitan (and paraphyletic) founder lineage. In this study we investigate this hypothesis with type material, particularly focussing on endemic taxa potentially derived from common ancestor shared with the widespread Ephydatia fluviatilis. We demonstrate that taxa regarded as endemic from Lake Ohrid (Ochridaspongia), Lake Kinneret/Tiberias (Cortispongilla) and Lake Titicaca (Balliviaspongia) are derived from the founder lineage, but unrelated to other, particularly Afrotropical, ancient lake sponges, and discuss implications for understanding freshwater sponge phylogeny and evolution.

Study of microsatellite cross-species specificity in freshwater sponge families Lubomirskiidae and Spongillidae

Abstract. The endemic Baikal sponges of the Lubomirskiidae family are a unique bouquet of closely related species formed from a common ancestor with the present-day cosmopolitans, Ephydatia muelleri, facing today are big ecological problems that require careful study. It is necessary to analyze the genetic structure of endemic freshwater sponge populations for a better understanding of the influence of such adaptive features on permanent habitat conditions as the loss of the ability to form gemmules. Microsatellite markers are best suited for analyzing population structure. The closest species to them, for which microsatellite markers have been developed to date, is Ephydatia fluviatilis. In this article, we check the suitability of these markers for population genetic analysis of Lubomirskia baikalensis and E.muelleri species using bioinformatic and molecular genetic methods of analysis, since the cross-species specificity of microsatellite markers has been shown for many closely related species. Despite the revealed 45.5% cross-species specificity for both L.baikalensis and E.muelleri at the level of genomic data, qualitative population genetic analysis requires the development of specific microsatellite markers de novo based on the genomic data of L.baikalensis and E.muelleri.

Study of variability of ITS1 and ITS2 spacers of rDNA of freshwater sponges (Porifera, Spongillida)

Molecular methods are especially important in the study of the taxonomy of sponges of ancient lakes, since when living at great depths, sponges lose their ability to form gemmules, and the structure of gemmules is an important taxonomic feature. However, the number of species and samples of freshwater sponges analyzed by molecular methods is insignificant today. In this work, we analyzed the variability of ITS1 and ITS2 of rDNA spacers of several species of freshwater sponges from geographically distant regions - Eastern Siberia, European Russia, Japan, and India. Our results confirmed the cosmopolitanism of the species Ephydatia fluviatilis and Spongilla lacustris and the adequacy of using ITS rDNA spacers for analyzing the phylogeny of freshwater sponges.

Climacia californica Chandler, 1953 (Neuroptera: Sisyridae) in Utah: taxonomic identity, host association and seasonal occurrence

We provide a record of spongillaflies (Sisyridae) with an associated host sponge from a population found in Spring Creek, Utah. We monitored the population for the 2016 field season to identify the insect and its associated host sponge and to establish the seasonal period of the insect’s presence in the adult stage. We also evaluated the commonly used sampling techniques of sweeping and light trapping and made natural history observations. We identified the spongillaflies as Climacia californica Chandler, 1953 and the sponge to be Ephydatia fluviatilis (Linnaeus, 1758). We collected 1726 adults, and light trapping proved to be the superior collecting method. The population was characterised by a two-week emergence peak occurring at the end of July to beginning of August followed by a steep decline. Other habitats within the state contained E. fluviatilis and should be sampled using light traps at times when peak abundances are predicted to further understand the distribution of C. californica across the state and the Intermountain West. urn:lsid:zoobank.org:pub:F795281F-0042-4F5F-B15B-F6C584FACF2B

Freshwater sponge (Porifera: Spongillidae) distribution across a landscape: Environmental tolerances, habitats, and morphological variation

AbstractFreshwater sponges are important to ecosystem functioning; however, information about their biogeography and interspecific variation is fragmentary, limiting our ability to assess their role. Although the specific epithets of two common species suggest that sponges found in lentic habitats are Spongilla lacustris, and those found in lotic habitats are Ephydatia fluviatilis, the number of sponge species in the UK is unresolved. We sampled sponges in a variety of habitats and used both morphological and molecular (D3 domain of 28S rDNA) methods to identify six species, including the first record of Trochospongilla horrida. We contrasted species in terms of their environmental tolerances, habitats, and variation, and we expanded on the limited information available about the geographic distributions of these sponges. In our study, most sponge species colonized a variety of substrates, but exhibited different distributions. The most widespread sponge, S. lacustris, was present at lower mean water temperatures and was more often located above a latitude of 55°N. Ephydatia fluviatilis was the most common species in rivers, but was also located in lentic habitats. Salinity in anthropogenic habitats was not a significant factor for the presence of E. fluviatilis or the more patchily distributed species Eunapius fragilis. Instead, these species occurred more frequently at sites with negative oxidation–reduction potential. Sponge biodiversity may be affected by substrate availability in anthropogenic habitats, invasive species, and improved ability to recognize sponge taxa. Crucially, we provide foundation data as a prerequisite for future ecological evaluation.

АНАЛИЗ ПРОДУКТИВНОСТИ ГУБКИ ИЗ СЕМЕЙСТВА SPONGILLIDAE, ПРОИЗРАСТАЮЩЕЙ В ВОДОЕМАХ РЕКИ ВОЛГИ, В ПЕРИОД РЕГРЕССИИ КАСПИЙСКОГО МОРЯ

The article describes the habitat, systematics and species of freshwater sponge ( Badiaga spongia fluviatilis ) inhabiting water bodies of Russia. There have been characterized the hydrological features of water bodies - sponges’ habitats, and their ecological function has been characterized. In freshwater bodies of the central Russia there occur two most common and numerous types of sponges - lake badiaga ( Spongilla lacustris ) and river badiaga ( Ephydatia fluviatilis ) presenting a valuable raw material for the pharmaceutical and cosmetic industry. The attention is focused on the fact that sponge colonies can reach the commercial volumes only in the floodplain waters and the delta of the Volga River. Retrospective data on volumes of sponge fishery in the Astrakhan region suggest the reason for decreasing sponge productivity and volume of the sponge industry: a lack of reclamation works in small rivers in the Volga delta. There has been given a comparative analysis of the data on microscopic studies of sponge structure caught on experimental zones in the water bodies of the Astrakhan region and the information found in the scientific literature. Characteristics of soils where significant sponge plantations were found are analyzed. It has been stated that in the watercourses of the Astrakhan region there prevail species of lake sponge ( Spongilla lacustris ), whose biomass should increase tenfold taking into account the cyclicity of the regression processes of the Caspian Sea, carrying out complex ameliorative works on the waterways of the Volga and development of agriculture and livestock breeding. It has been recommended to prepare a scientific and production base for the rational and effective development of the potential of this natural resource for pharmaceutical and cosmetic purposes.

Spiculous skeleton formation in the freshwater sponge Ephydatia fluviatilis under hypergravity conditions.

Successful dispersal of freshwater sponges depends on the formation of dormant sponge bodies (gemmules) under adverse conditions. Gemmule formation allows the sponge to overcome critical environmental conditions, for example, desiccation or freezing, and to re-establish as a fully developed sponge when conditions are more favorable. A key process in sponge development from hatched gemmules is the construction of the silica skeleton. Silica spicules form the structural support for the three-dimensional filtration system the sponge uses to filter food particles from ambient water. We studied the effect of different hypergravity forces (1, 2.5, 5, 10, and 20 × g for 48 h)—as measure for environmental stress—on the ability of developing sponges to set-up their spiculous skeleton. Additionally, we assessed whether the addition of nutrients (i.e., dissolved 13C- and 15N-labeled amino acids) compensates for this stress. Our results show that freshwater sponges can withstand prolonged periods of hypergravity exposure and successfully set-up their skeleton, even after 48 h under 20 × g. Developing sponges were found to take up and assimilate dissolved food before forming a functional filtering system. However, fed and non-fed sponges showed no differences in skeleton formation and relative surface area growth, suggesting that the gemmules’ intrinsic energy fulfills the processes of skeleton construction. Additionally, non-fed sponges formed oscula significantly more often than fed sponges, especially under higher g-forces. This suggests that the eventual formation of a filtration system might be stimulated by food deprivation and environmentally stressful conditions. These findings indicate that the process of spiculous skeleton formation is energy-efficient and highly resilient. The uptake of dissolved food substances by freshwater sponges may contribute to the cycling of dissolved organic matter in freshwater ecosystems where sponges are abundant.

Mesoscale investigations based on microsatellite analysis of the freshwater sponge Ephydatia fluviatilis in the River-Sieg system (Germany) reveal a genetic divergence

Freshwater sponges play a major role in freshwater ecological system as important filter-feeding organisms and bioindicators. There are only few data about their ecological diversity and population genetic structure available, though a deeper knowledge is needed to propose proper conservation and effective management. The aim of this study was to assess data on distribution patterns of freshwater sponges to study the connectivity of genotypes of Ephydatia fluviatilis in a river system. We sampled specimens from River-Sieg system (River Agger and River Sieg, Germany). We hypothesized that strong anthropogenic influence would cause a uniform distribution of population structures. The genetic structure of E. fluviatilis populations was analysed with a set of eleven microsatellite loci from seven locations in River-Sieg system. Besides of E. fluviatilis, three other species co-occurred (Ephydatia mulleri, Spongilla lacustris, Eunapius fragilis). In contrast to our hypothesis, we observed an overall correlation between genetic and geographic distances among populations of this sessile species, which follows a clear isolation-by-distance pattern. A significant microsatellite polymorphism and high levels of genetic divergence between populations (FST) in upstream reaches were present. These results will provide important information for conservation management of populations with limited dispersal ability in connected river systems.