Published articles
*indicate corresponding authorship
1. Christodoulou M, Paraskevopoulou S, Syranidou E, Koukouras A (2013). The amphipod fauna of the Aegean Sea and comparison with those of the neighbouring areas. Journal of the Marine Biological Association of the UK, 93, 1303–1327
My first manuscript was the outcome of an effort to collect and record all the existing information about the amphipod fauna of the Mediterranean Sea that is present in literature. The main effort was to create a catalog with the species reported in different places in the Mediterranean Sea and make comparisons among them. I tried to answer questions regarding the amphipod species richness and how this changes from west to east Mediterranean Sea. We also tried to trace species with an Indo-Pacific origin in the Mediterranean See. If you are interested to learn more about this, you can read our article here. Any comments or suggestions are very welcomed.
2. Paraskevopoulou* S, Monokrousos N, Kappas I, Abatzopoulos J. Th. (2014). Spatio-temporal variability of benthic macrofauna in a coastal lagoon assessed by ecological interaction networks. Community Ecology, 16, 10-22.
My second manuscript was a result of my master thesis which was conducted in a costal lagoon. The area is of high interest as it is the first ecotouristic aquatic park in Greece. We sampled different areas in the lagoon in to estimate differences in the biodiversity. To do so we applied ecological networks, a technique which provides additional information on the quality of interactions among the different species. Knowledge generated by network analysis should provide a valuable tool in order to assess potential environmental changes and inform management decisions. Do you want to learn more about the uniqueness of the research place? Are you curious how ecological networks can be applied to ecological studies? Do not hesitate and visit the link.
3. Paraskevopoulou* S, Tiedemann R, Weithoff G (2018). Differential response to heat-stress among evolutionary lineages of an aquatic invertebrate species complex. Biology Letters, 14, 20180498.
After 3 years of hard work the first manuscript of my PhD research was published. Here, we speak about very small organisms, zooplankton and how they respond to increasing temperature. Are they stressed? How much heat they tolerate? Are there differences between species? We also address the issue of cryptic diversity (species which have the same appearance, however, are different genetically) and the necessity of a sound species assignment, when organismal responses to environmental change are investigated. Are you curious which species perform the best? You can read our manuscript here.
4. Paraskevopoulou* S, Dennis AB, Weithoff G, Hartmann S, Tiedemann R (2019). Within species expressed genetic variability and genes associated with sustained thermal stress in the rotifer Brachionus calyciflorus sensu stricto. PLoS ONE, 14(9): e0223134.
Are you curious to see which genes are associated with sustained thermal stress in these tinny planktonic organism, then you are in the right place. Comparison of expressed genes allows us to assess the impact of stressors on both expression and sequence divergence among disparate populations within a single species. Here, we have used RNA-seq to explore expressed genetic diversity in B. calyciflorus s.s. in two mitochondrial DNA lineages with different phylogenetic histories and differences in thermotolerance. We identify a suite of candidate genes that may underlie local adaptation, with a particular focus on the response to sustained high or low temperatures. To identify variants between our two lineages we developed a new method for non model species. Interested?? Visit the link of our paper link here.
5. Paraskevopoulou* S, Dennis AB, Weithoff G, Tiedemann R (2020). Temperature-dependent life history and transcriptomic responses in heat-tolerant versus heat-sensitive Brachionus. Scientific Reports, 10: 13281.
More about thermal stress and gene expression in rotifer species. Are you interested to learn more? Here, we compared temperature-related demography and gene expression difference in closely related heat-tolerant and heat sensitive rotifer species. Comparative transcriptomic analyses identified shared and opposing responses to heat. Interestingly, expression of heat shock proteins (hsps) was strikingly different in the two species and mirrored differences in population growth rates, showing that hsp genes are likely a key component of a species’ adaptation to different temperatures. Want to learn more and what the consequences might be? Visit our paper link!!!
6. Romero-Mujalli D, Rochow M, Kahl S, Paraskevopoulou S, Folkertsma R, Jeltsch F, Tiedemann R (2021). Adaptive and nonadaptive plasticity in changing environments: Implications for sexual species with different life history strategies. Ecology and Evolution, 11, 6341-6357.
Our effort to model phenotypic plasticity in now online!! Populations adapt to novel environmental conditions by genetic changes or phenotypic plasticity, however, plastic responses are generally faster and can buffer fitness losses under variable conditions. Here we present an individual-based model and study the relative importance of adaptive and non-adaptive plasticity for populations of sexual species with different life history strategy experiencing directional stochastic climate change. If you want to learn more visit our paper link. If you want to use our PanModel33, you will find the github here.
7. De Cahsan B, Westbury MV, Paraskevopoulou S, Drews H, Ott M, Gollmann G, Tiedemann R (2021). Genomic consequences of human-mediated translocations in margin populations of an endangered amphibian. Evolutionary Applications, 14, 1623-1634.
Are translocations a benefit or a loss for biodiversity? Human-mediated translocations of southern lineage specimens into northern German populations of the endangered European fire-bellied toad (Bombina bombina) provide an unexpected experimental set up to test the genetic consequences of an intraspecific introgression from central population individuals into populations at the species range margin. If you are interested to see the answer to the question visit our paper link here.
8. Kiemel K, De Cahsan B, Paraskevopoulou S, Weithoff G, Tiedemann R. (2022). Mitochondrial genomes of the freshwater monogonont rotifer Brachionus fernandoi and of two additional B. calyciflorus s.s. lineages from Germany and the USA (Rotifera, Brachionidae). Mitochondrial DNA Part B: Resources, 14, 646-648.
In this paper we provide two complete mitochondrial (mt) genomes from B. calyciflorus sensu stricto (Germany, USA) and the mt coding sequences (cds) from a German B. fernandoi. Phylogenetic analysis placed our B. calyciflorus sensu stricto strains close to the published genomes of B. calyciflorus, forming the putative sister species to B. fernandoi. If you wanna learn more about Brachnionus cryptic species or you are interested in bioinformatic pipelines to analyze genomic data you can visit our paper link here.
9. Paraskevopoulou* S, Gattis S, Ben-Ami F. (2022). Parasite resistance and parasite tolerance: insights on transgenerational immune priming in an invertebrate host. Biology Letters, 18, 20220018.
Parental challenge with parasites can enhance the immune response of their offspring, a phenomenon termed in invertebrates as transgenerational immune priming. We exposed two parental generations of the model organism Daphnia magna to the horizontally transmitted parasitic yeast Metschnikowia bicuspidata and recorded resistance- and tolerance-related traits in the offspring generation. Our susceptibility assays revealed contradictory results regarding parasite tolerance and parasite resistance. Our findings emphasize that transgenerational immune responses may not be consistent even within the same host species. If you are interested to see the answer to the question visit our paper link here.
10. Kiemel K, Gurke M, Paraskevopoulou S, Weithoff G, Tiedemann R (2022). Variation in heat shock protein 40 kDa relates to divergence in thermotolerance among cryptic rotifer species. Scientific Reports, 12, 22626.
Genetic divergence and the frequency of hybridization are central for defining species delimitations, especially among cryptic species where morphological differences are merely absent. Here, we used the recently resolved Brachionus calyciflorus species complex to investigate whether between species differences in thermotolerance and gene expression are also reflected in their genomic footprint. We identified a Heat Shock Protein gene (HSP 40 kDa) which exhibits cross species pronounced sequence variation. This gene exhibits species-specific fixed sites, alleles, and sites putatively under positive selection. By comparing three genetic markers (ITS, COI, HSP 40 kDa), we also revealed hybridization events between the cryptic species. The low frequency of introgressive haplotypes/alleles suggest a tight, but not fully impermeable boundary between the cryptic species. For more information on findings and methods used please visit the link.
11. Walczyńska A, Fontaneto D, Kordbacheh A, Hamil S, Jimenez-Santos M-A, Paraskevopoulou S, Pociecha A, Zhang W (2024). Niche differentiation in rotifer cryptic species complexes: a review of environmental effects. Hydrobiologia, 851, 2909–2926.
Adaptation to different ecological niches is considered one of the main drivers of species diversification, also in cryptic species complexes, notwithstanding their morphological stasis. We here review all the published information on ecological differentiation within cryptic species complexes within the phylum Rotifera. We found 177 instances of cryptic species identified genetically, published in 101 papers. Only a subset of the papers contained available information on ecological differences and only for two of the 54 known complexes, namely Brachionus calyciflorus s.l. and Brachionus plicatilis s.l., sufficient data were available for analyses of ecological differences. Our aim is to showcase this interesting field of research spurring further detailed studies to focus on the mechanisms of ecological speciation using rotifer cryptic species as a model system. For more information on the finsings for each complex species separately please read the article here.
Pre-prints
P1. Hirshberg O, Paraskevopoulou S, Kiemel k, Ben-Ami F (2024). The gems of the Middle-East: Unravelling the biodiversity of Monogonont rotifers in temporary waterbodies of Israel. BioRxiv, DOI: 10.1101/2023.10.25.563682 (under review, Freshwater Biology).
Freshwater ponds are critical ecosystems, yet the diversity of microscopic invertebrates like monogonont rotifers remains underexplored. For the first time, we compiled all available data on rotifer biodiversity in Israel and conducted a large-scale survey using rehydrated sediments from 30 freshwater ponds across diverse climatic and geographic regions. We identified 39 species, with 26 (≈64%) newly recorded for Israel, increasing the known rotifer diversity by 41%. These findings reveal that much of Israel’s rotifer fauna had previously gone undocumented. Environmental analysis showed that altitude and temperature negatively affect species richness, while spatial factors (e.g., dbMEMs) strongly influence community composition. Spatial structure explained more variation (7.3%) than environmental variables (1.4%), highlighting the role of dispersal and landscape configuration in rotifer metacommunities. For more information please visit the link.
P2. Paraskevopoulou* S, Gattis S, Ben-Ami F (2025). Transcriptomic landscape reveals immunity related trade-offs in an invertebrate-fungal host-parasite system, BioRxiv, DOI:10.1101/2025.03.28.645961v1 (submitted in Molecular Ecology, 01/06/25).
What happens when an invertebrate fights back?
While vertebrates have complex immune systems, invertebrates rely solely on innate immunity, and we still know surprisingly little about how this works, especially outside of insects. In this study, we took a fresh look at immune defense in an aquatic invertebrate infected by a natural yeast parasite. By combining life-history analysis with transcriptomics, we uncovered previously unknown genetic and physiological responses to infection. We identified novel candidate genes involved in hemocyte recruitment and gut barrier reinforcement, likely key mechanisms of parasite resistance. Exposed but uninfected individuals delayed reproduction, revealing a temporary cost of immune activation, but no long-term fitness loss. Infected hosts shifted their metabolism in a way that supports the terminal investment hypothesis, investing in immediate reproduction at the cost of survival. This is one of the first integrative studies to link molecular immune responses to life-history strategies in a non-insect invertebrate. Our findings open up new perspectives on how innate immunity shapes host-parasite dynamics and offer a deeper understanding of evolutionary trade-offs in immunity. Visit our article here.
P3. Gattis S, Paraskevopoulou* S, Ben-Ami F (2025). Decoding host responses: How a freshwater invertebrate defends against a parasitic bacterium. BioRxiv, DOI: 10.1101/2025.03.28.645445
Using the Daphnia magna–Pasteuria ramosa model, we explored how an aquatic invertebrate mounts an immune response against a natural bacterial parasite. We infected 800 Daphnia with 20,000 P. ramosa spores each, monitoring infection stages and sampling hosts at key points during the infection. RNA sequencing across infection stages, from early to terminal, uncovered dynamic gene expression shifts tied to parasite development. We identified key immune genes, including those in the Toll signaling pathway, and observed strong regulation of pathways linked to immunity, metabolism, and resource allocation. Interestingly, we found evidence for iron sequestration as a potential nutritional immunity strategy, a novel mechanism for limiting parasite growth. Genes related to infection-driven traits, like host castration, stunted growth, and red pigmentation, were also significantly upregulated, showing how deeply the parasite manipulates host physiology. This is one of the most detailed molecular dissections of host-parasite interaction in an aquatic invertebrate, offering new insights into coevolution, immune strategy, and how parasites hijack host biology. Visit the link for more information.
P4. Bereza E, Rotter I, Paraskevopoulou S, Ben-Ami F (2025). Light pollution affects the behavior and life-history traits of aquatic invertebrates. BioRxiv, DOI: https://doi.org/10.1101/2025.10.09.679630.
Many living things, from humans to tiny plankton, follow circadian rhythms, internal “clocks” that control activities like feeding and reproduction. When these rhythms are disturbed, it can affect behavior, and even survival. One growing concern is artificial light at night (ALAN) sourcing from human activities (e.g., streetlights, skyglow), which spreads beyond cities and changes natural light cycles. In this context, aquatic ecosystems are especially sensitive. In our study, we looked at how light pollution affects survival, reproduction, and behavioral of rotifers, microscopic animals that play key roles in freshwater food webs. We found that light had strong and species-specific effects. Green light boosted survival and reproduction in B. calyciflorus s.s., but reduced reproduction in B. fernandoi. In B. rubens, white light changed both reproductive timing and how individuals attached to hosts. Overall, our findings show that artificial light doesn’t affect all rotifers in the same way. Some may even benefit while others are harmed. This complexity highlights why we need more research to understand how increasing night-time light pollution could impact freshwater ecosystems and biodiversity. Visit our paper for more information.
Selected Conference Presentations
| Paraskevopoulou S, Vizitiu M, Brask N, Carr P, Pereira R, Shepherd J-N, Horton A, Leys S, Stairs C (2025). Freshwater sponges acquired anaerobic cofactor biosynthesis genes from microbes. World Sponge Conference, Porto, 9-13 September, Portugal. |
| Paraskevopoulou S, Vizitiu M, Brask N, Carr P, Pereira R, Shepherd J-N, Horton A, Leys S, Stairs C (2025). Symbiosis-mediated gene transfer in early-diverging Metazoan. ESEB, 17-22 August, Barcelona, Spain |
| Paraskevopoulou S, Vizitiu M, Aguilera Campos KI, …, Stairs C. (2025). Have sponges stolen genes to survive without oxygen? Evolution in Sweden, 13-15 January, Linköping, Sweden. |
| Paraskevopoulou S, Gattis S, Ben-Ami F. (2022). Transgenerational evolution of immunity in an invertebrate-yeast system. ESEB, 14-19 August, Prague, Czech Republic (oral presentation) |
| Hirshberg O, Paraskevopoulou S, Ben-Ami F. (2022). Little rotifer tales from the Middle East. 16th International Rotifer Symposium, 6-10 September, Zagreb, Croatia. |
| Paraskevopoulou S, Dennis AB, Weithoff G, Tiedemann R. (2022). Disentangling the physiological heat boundaries among species of the Brachionus calyciflorus species complex, 16th International Rotifer Symposium, 6-10 September, Zagreb, Croatia. |
| Paraskevopoulou S, Denis AB, Weithoff G, Tiedemann R (2019). Cross-temperature comparisons of gene expression between heat tolerant and heat sensitive Brachionus species. ESEB, 19 – 24 August, Turku, Finland. |
| Paraskevopoulou S, Tiedemann R & Weithoff G (2018). Differential response to heat-stress among evolutionary lineages of an aquatic invertebrate species complex. 15th International Rotifer Symposium, 3-9 June, Texas, USA. |