Biological control of invasive zebra mussel (Dreissen polymorpha) in a freshwater ecosystem through Potamon ibericum

In the present study, possible effects of using Potamon ibericum for the prevention of zebra mussel (Dreissena polymorpha) invasion in a freshwater ecosystem were investigated. In a recirculating aquaculture system (RAS) supplied with aerated freshwater, 3 individuals of P. ibericum were placed in each of 3 aquariums provided by 100 zebra mussels. Throughout the 90-day monitoring study, mussel consumption was visually counted and then new mussels were introduced daily to complete the number of mussels to hundred, repeatedly each day. Throughout the monitoring study, growth rates, number of mussels consumed, and the number of broken mussel shell pieces were determined. Daily consumption rate of mussels by each crab was recorded as 11.115, 11.104, and 11.107 mussel/crab in the 3 experimental groups, respectively. The consumption rate of mussels per crab was counted as 999.78 over the 90-days experiment. As a result, the findings of this study provide strong evidence that P. ibericum can be used for

The Genome of the Zebra Mussel, Dreissena polymorpha: A Resource for Comparative Genomics, Invasion Genetics, and Biocontrol

The zebra mussel, Dreissena polymorpha, continues to spread from its native range in Eurasia to Europe and North America, causing billions of dollars in damage and dramatically altering invaded aquatic ecosystems. Despite these impacts, there are few genomic resources for Dreissena or related bivalves. Although the D. polymorpha genome is highly repetitive, we have used a combination of long-read sequencing and Hi-C-based scaffolding to generate a high-quality chromosome-scale genome assembly. Through comparative analysis and transcriptomics experiments we have gained insights into processes that likely control the invasive success of zebra mussels, including shell formation, synthesis of byssal threads, and thermal tolerance. We identified multiple intact Steamer-Like Elements, a retrotransposon that has been linked to transmissible cancer in marine clams. We also found that D. polymorpha have an unusual 67 kb mitochondrial genome containing numerous tandem repeats, making it the largest observed in Eumetazoa. Together these findings create a rich resource for invasive species research and control efforts.

Cellular Responses Induced by Zinc in Zebra Mussel Haemocytes. Loss of DNA Integrity as a Cellular Mechanism to Evaluate the Suitability of Nanocellulose-Based Materials in Nanoremediation

Zinc environmental levels are increasing due to human activities, posing a threat to ecosystems and human health. Therefore, new tools able to remediate Zn contamination in freshwater are highly recommended. Specimens of Dreissena polymorpha (zebra mussel) were exposed for 48 h and 7 days to a wide range of ZnCl2 nominal concentrations (1–10–50–100 mg/L), including those environmentally relevant. Cellulose-based nanosponges (CNS) were also tested to assess their safety and suitability for Zn removal from freshwater. Zebra mussels were exposed to 50 mg/L ZnCl2 alone or incubated with 1.25 g/L of CNS (2 h) and then removed by filtration. The effect of Zn decontamination induced by CNS has been verified by the acute toxicity bioassay Microtox®. DNA primary damage was investigated by the Comet assay; micronuclei frequency and nuclear morphological alterations were assessed by Cytome assay in mussels’ haemocytes. The results confirmed the genotoxic effect of ZnCl2 in zebra mussel haemocytes at 48 h and 7-day exposure time. Zinc concentrations were measured in CNS, suggesting that cellulose-based nanosponges were able to remove Zn(II) by reducing its levels in exposure waters and soft tissues of D. polymorpha in agreement with the observed restoration of genetic damage exerted by zinc exposure alone.

Hitchhiking Exotic Clam: Dreissena polymorpha (Pallas, 1771) Transported via the Ornamental Plant Trade

Ornamental aquaculture is one of the main sources of non-native species worldwide. Unintentionally transported “hitchhiking” organisms have been previously recorded; although most of these species are transported from tropical regions, here we report on the first accidental transport of the zebra mussel (Dreissena polymorpha) in a shipment of ornamental Aegagropila linnaei (Chlorophyta) from Russia to the Czech Republic. This invasive mussel is listed on the national blacklist of alien species in the Czech Republic and can be easily released in outdoor garden ponds together with A. linnaei. Since the Czech Republic is known to be a gateway for aquatic ornamental species from a European perspective, re-export to other European countries is also possible. Thus, the spread of D. polymorpha via this pathway cannot be excluded. This finding should be of importance to conservationists, traders, decision-makers and other stakeholders.