Search Results (6)

Alien species constitute one of the main threats to freshwater ecosystems, negatively impacting biodiversity, economy, and ecosystem services. Here, we use morphological and genetic data to show the presence of a new alien freshwater sponge in Europe, Rosulaspongilla rhadinaea, a Ponto-Caspian species which recently has been found in the fluvial port of Seville (Guadalquivir River, Spain). We also reviewed the mechanisms and adaptations of freshwater sponges for dispersal. The gemmule is the key structure for understanding their life history, evolution, and dispersal capacity, since their high salinity tolerance may have made possible the spreading of these sponges on the hulls of ocean-going ships that frequent freshwater ports. Once established, they are dispersed via river currents and intraregional boat traffic through the network of interconnected channels, which act as invasion corridors. Transport via phoresy attached to mobile animal vectors such as birds (especially migrating birds) has also been demonstrated in several sponge species. Gemmules may be attached on the feathers and scales, or even to be transported in the guts of these animals, followed by defecation of viable gemmules. Transport associated with other invasive freshwater species, such as mussels, cannot be ruled out. The scarcity of taxonomic studies of freshwater sponges in the Iberian Peninsula might explain why the species had not been recorded. Full article

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. Full article

Freshwater sponges (Spongillida: Demospongiae), including more than 240 described species, are globally distributed in continental waters (except for Antarctica), where they cover both natural and artificial surfaces. However, fragmentary studies have targeted their microbiome, making it difficult to test hypotheses about sponge-microbe specificity and metabolic relationships, along with the environmental factors playing key roles in structuring the associated microbial communities. To date, particular attention has been paid to sponges (family Lubomirskiidae) that are endemic to Lake Baikal. Few other freshwater sponge species (e.g., Ephydatia spp., Eunapius spp., and Spongilla lacustris), from lakes and rivers spanning from Europe to South and North America, have been targeted for microbiological studies. Representatives of the phyla Proteobacteria, Bacteroidetes, and Actinobacteria largely predominated, and high differences were reported between the microbiome of freshwater and marine sponges. Several bacterial strains isolated from freshwater sponges can produce bioactive compounds, mainly showing antibiotic activities, with potential application in biotechnology. Understanding the roles played by sponge microbiomes in freshwater ecosystems is still in its infancy and has yet to be clarified to disentangle the ecological and evolutionary significance of these largely under-investigated microbial communities. This review was aimed at providing the main available information on the composition and biotechnological potential of prokaryotic communities associated with healthy freshwater sponges, as a neglected component of the global sponge microbiome, to stimulate researchers interested in the field. Full article

A number of reports on sponge diseases, including from Lake Baikal, have increased dramatically all over the world in recent years. Herewith, there are various hypotheses for sponge mortality. Lubomirskia baikalensis (phylum Porifera, order Spongillida) is a unique endemic freshwater sponge of Lake Baikal that contains a complex community of eukaryotic and prokaryotic endosymbiotic microorganisms. In this work, we present the first results for the effect of anionic surfactants viz. linear alkylbenzene sulphonates (LAS) at low 10 and 20 µg L⁻¹ concentrations on Baikal sponge species and their symbiotic community as an experimental model. A new toxicity test protocol under conditions close to natural is proposed. It uses the sponge amoebocytes called as SA1-cells, which contain eukaryotic green microalgae Chlorella sp. These SA1-cells are shown to be representative indicator in assessing the impact of anionic surfactants. The acute toxic effect resulted in 97–100% sponge cell death in less than 48 h, as well as 100% symbiotic microalgae Chlorella sp. death over 72 h was noted under LAS solution (20 μg L⁻¹) exposure during in vivo experiments. This includes the cell membrane fatty acid changes, change in the cell sizes, cell swelling, and lysis. Long term exposure to LAS solution (10 μg L⁻¹) reflected in cellular stress (oxidative stress) and accompanied by malondialdehyde formation (0.16–2.0 μg g⁻¹ of dry weight) during 14-day exposure was noted. Oxidative stress and mortality of L. baikalensis are associated with their low antioxidant activity. Trolox-equivalent antioxidant capacity (TEAC) found in the range from 0.00031 to 0.00077 Trolox equivalents for these freshwater sponges. Full article

Sponges (Porifera, Spongillida) make up the bulk of the benthic biomass in Lake Baikal and are represented by the family Lubomirskiidae, a collection of endemic species, and several species of the cosmopolitan family Spongillidae. We conducted an analysis of the D3 domain of the 28S rDNA of 16 freshwater sponge species. Based on molecular data, we were able to identify all of the collected Spongillidae specimens whose identification was difficult due to the lack of gemmules. Phylogenetic trees have shown that Ephydatia muelleri, Spongilla lacustris, and Eunapius fragilis formed monophyletic clades, and the D3 domain of the 28S rDNA can be used for their DNA barcoding. For the Baikal sponges, the use of this marker is important since the gemmule-less Spongillidae and Lubomirskiidae are, in some cases, indistinguishable from each other in morphology. The 28S rDNA has been shown to be useful for family and species-level identification of freshwater sponges within the Spongillida. Full article

Shallow water sponges settled on a raft along the Pong River (Lower Mekong Basin, Thailand) were investigated to highlight the taxonomic richness, composition, relative abundance and lifestyle of sponge-dwelling aquatic Insecta. The three-dimensional biogenic structures of the model sponges hosted 4 orders of Insecta, belonging to 10 families and 19 genera/species, able to strictly coexist at the level of the sponges in aquiferous canals and/or at the body surface, and/or dwelling in the extracellular matrix. On the basis of the identified 379 larvae and pupae, Trichoptera and Diptera were found to be the dominant inhabitants of Corvospongilla siamensis (Demospongiae: Spongillida), endemic to Southeast Asia. In the focused lotic ecosystem, dominated by soft bottoms, sponges play a functional role. Insecta use sponges as a substratum, nursery ground, food source, and shelter microhabitat, protecting them from predation and environmental aggression. Moreover, their feeding behavior indicates the insects’ adaptive traits to recycle sponge siliceous spicules as a source of exogenous material to strengthen the larval–pupal cases and the digestive system. The results of the Thai sponge model contribute to the inventory of global engineering species richness, ecosystem types, and biogeographic diversity, thus raising awareness for freshwater biodiversity conservation. In this regard, the present data, along with the worldwide inventory, focus on sponges as (a) key habitat-forming species for aquatic insect assemblages, (b) ecosystem engineers in river/lake/wetland ecosystems, providing water purification, the processing of organic matter, recycling of nutrients, and freshwater–terrestrial coupling, and (c) promising candidates in restoration projects of tropical freshwater ecosystems by bioremediation. Full article