Paramysis Lacustris Research Articles

Functional responses correspond to stable isotope-based trophic positions among four invasive Ponto-Caspian mysid species (Crustacea, Mysida)

Determining the consumptive effects of non-native predators, for which several direct and indirect methods have been applied, is a common goal in invasion biology. Functional responses and stable isotope analysis are among the most widely used approaches; however, they are rarely used in combination. In this study, we used these two complementary methods to compare the predatory impacts of four invasive Ponto-Caspian mysids on zooplankton in a habitat (Danube River) where all four species coexist. The order of the species based on the attack rates of the functional response models matched with their mean δ15N values, indicating a correspondence between their predatory potentials and trophic positions in their invaded habitat. Hemimysis anomala had the highest attack rate on zooplankton presumably due to its higher degree of specialization linked to its pelagic lifestyle. Contrary to our expectations, the largest species, Paramysis lacustris, had an intermediate predatory efficiency and trophic position, similar to those of Limnomysis benedeni but higher than those of the smallest species, Katamysis warpachowskyi. Nevertheless, all of the four species exhibited a considerable predatory potential, suggesting that any of them can contribute significantly to their combined predatory impact depending on their densities. The congruence between the results of the two methods shows that the species can realize their different predatory potentials in their invaded environment, indicating favorable conditions (i.e., food availability and spatial heterogeneity) which allowed dietary differentiation. We recommend the combined use of functional responses and stable isotope analysis, which might allow robust conclusions to be drawn on the trophic ecology of the species and also provide further insights into the studied ecosystem.

SPREAD RATE OF ALIEN AMPHIPODS AND MYSIDS IN THE MAIN RIVERS OF BELARUS

The spread rates of alien species of Amphipoda and Mysida were calculated for the Dnieper, Pripyat and Neman rivers in the territory of Belarus. The maximal values of spread rate were obtained for Dikerogammarus villosus (in the Pripyat River - 37.8 km/year, in the Dnieper River - 17 km/year) and Dikerogammarus haemobaphes (in the Pripyat River - 53.6 km/year, in the Dnieper River - 17 km/year), while the minimal values of spread rate were calculated for mysids Paramysis lacustris (in the Dnieper River - 0.4 km/year) and Limnomysis benedeni (in the Dnieper River - 0.6 km/year), also for amphipods Chelicorophium robustum (in the Dnieper River - 0.5 km/year) and Echinogammarus trichiatus (in the Dnieper River - 1.3 km/year). The differences in the spread rates of species connected with the time of their first records at the monitoring points and the intensity of economic activities in the studied rivers.

Native and alien species of macrozoobenthos in rivers of the Belarusian part of the Dnieper River basin

The Dnieper River basin in Belarus was studied in 2016-2019. In total, 201 species and forms of macro-zoobenthos were found and 146 of them were identified to the species level. New habitats of several protected species (Unio crassus Philipsson, 1788, Anax imperator Leach, 1815, Ophiogomphus cecilia (Fourcroy, 1785) and Gomphus flavipes Char-pentier, 1825) and one alien species (Paramysis lacustris (Czerniavsky, 1882)) have been recorded in Belarus.

Экологическая валентность к кислороду северокаспийских мизид и кумовых ракообразных

The paper focuses on the problems of violation of the ecological balance, changes in the nutrient load, undermining the ecosystem’s biopotential, caused by anthropological pressure and resulting in deterioration of the oxygen regime in the bottom layer of water. The purpose of the research was to determine the environmental oxygen tolerance in bottom invertebrates, representatives of the orders Mysidacea and Cumacea, which are forage objects for beluga, sturgeon, stellate sturgeon, bream and pike perch. The research was conducted in 2013-2017 in the western part of the North Caspian. Developing of oxygen deficiency in the studied water area was due to thermohaline stratification of water masses. Hypoxia was formed in local areas. Representatives of Mysidacea predominantly inhabiting the bottom layers have a low frequency of occurrence, because they live in a narrow range of oxygen content (about 5-7 mg/l). A low oxygen concentration (less than 3.95 ml/l (74%)) inhibits the development of Mysidacea. Paramysis ullskyi prevailed in the total number of samples taken from macrozoobenthos, and Paramysis lacustris prevailed in the total biomass. Limnomysis benedeni and Paramysis ullskyi were the most resistant to oxygen deficiency. These species have a maximum ecological valence to oxygen. Representatives of the order Cumacea are characterized by a high frequency of occurrence. The species Schizorhynchus bilamellatus dominated in the surveyed water area, both in abundance and biomass. Cumacea live in a wide variability of oxygen content. Schizorhynchus bilamellatus and Stenocuma graciloides are most resistant to oxygen deficiency. These species have a maximum ecological valence to oxygen. The minimum oxygen recorded over the entire research period (1.29 ml/l; 21%) is not critical for Stenocuma graciloides. The results of the study are of practical value for assessing the condition of the food supply of benthos-eating fish that are commercialized in the western part of the North Caspian

The impact of introduced Ponto-Caspian mysids (Paramysis lacustris) on the trophic position of perch (Perca fluviatilis) in European mesotrophic lakes

Paramysis lacustris was introduced into Lithuanian lakes in the middle of the 20th century. It was assumed that P. lacustris will enhance efficiency of primary production utilization and channelling of primary production towards higher trophic levels, i.e. commercially important fish species. However, at the time of P. lacustris introduction, there were no reliable data about its trophic position in lakes. Thus, P. lacustris was considered to have no or little impact on native ecosystems. Until now, there is a gap in the knowledge of the trophic role and potential impacts of P. lacustris on local food webs in lakes. Here we investigated the impact of P. lacustris on the food chain length of its potential predator Perca fluviatilis in temperate lakes. In this study, gut contents and stable isotope analyses were performed to assess the diet and trophic position of P. lacustris and P. fluviatilis in lakes with and without invasive mysids. The results obtained revealed that P. lacustris consumes a significant amount of animal prey and occupies the third trophic level in lake littoral zones. Furthermore, our results showed that P. lacustris might enhance the food chain length for at least some zooplanktivorous fishes. Overall, the assumption that P. lacustris invasion has no whole-ecosystem consequences, as it was thought before its introduction, is not correct.

The Ponto-Caspian mysid Paramysis lacustris (Czerniavsky, 1882) has colonized the Middle Danube

In 2017, the mysid Paramysis lacustris (Czerniavsky, 1882) was found for the first time in the Hungarian Danube section, representing the first psammo-pelophilous Ponto-Caspian peracarid colonizing the Middle Danube. In 2018, a brief survey focusing on this species revealed its presence in a more than 500-km-long river section spanning from Austria (Vienna, river km 1926) to Croatia (Batina, river km 1425). The largest populations of P. lacustris might be formed in reservoirs and slow-flowing stretches, where the appearance of the species might imply a considerable impact in connection with its zooplanktivorous feeding and important role in the diet of fish. Similar to all the other Ponto-Caspian peracarids that have crossed the Middle Danube, P. lacustris can reasonably be expected to continue its spread toward Western Europe in the future.

Human-mediated lineage admixture in an expanding Ponto-Caspian crustacean species Paramysis lacustris created a novel genetic stock that now occupies European waters

Identifying the origins and colonization routes of alien species is critical to understanding the mechanisms, consequences and management of invasions. This study aims to demonstrate and explain conflicting genetic signals in a widespread invasive Ponto-Caspian mysid Paramysis lacustris using mitochondrial DNA and microsatellite markers. Native Black Sea populations of P. lacustris are divided into three distinct phylogeographic groups: Danube–Dniester region, coastal Danube lakes, and Dnieper River delta. In the 1950s–1970s the species has been extensively used for relatively well documented transplantations in Eastern Europe. However, the populations in the newly established distribution area do not match any of the known native groups, and their genetic signal does not correspond with the recorded transplantation history. Using Bayesian Approximate Computation we explore alternative scenarios that could explain the unexpected mitochondrial and nuclear signals in the introduced populations. We suggest that reservoir construction and break-up of natural dispersal barriers on the River Dnieper have brought about a novel stock, probably admixed from a previously isolated and unknown “relict” population in the middle Dnieper and the genetically distinct Dnieper delta lineage. Through further intentional transfers this new P. lacustris lineage is now widely present in Eastern Europe and is likely to have new gene and trait combinations. The conflicting mitochondrial-nuclear signal in non-native populations also highlights the importance of using multiple genetic markers when tracing invasion sources and pathways.

Non-indigenous amphipods and mysids in coastal food webs of eastern Baltic Sea estuaries

The study analyses the role of non-indigenous invertebrates in the food webs of two eutrophic brackish estuarine ecosystems of the Baltic Sea: the Neva River estuary and the Curonian Lagoon, with the aim of clarifying several questions such as what trophic levels were occupied by newly established species (mainly amphipods and mysids) and whether they can affect the native benthic invertebrates as a result of their possible carnivorous nature. Stable isotope analysis (δ15N values) and gut contents analysis of field-collected specimens were used to estimate trophic level and trophic links of the newly established malacostracan crustaceans, while their consumption rates when feeding as carnivores were measured experimentally. The δ15N analysis allocated four trophic levels (TL) in the coastal food webs of both studied ecosystems with the lowest δ15N (2–4‰) for detritus and algae and the highest for fish (12–14‰). Through their high abundance, non-indigenous crustaceans (Pontogammarus robustoides, Gmelinoides fasciatus, Obessogammarus crassus, Gammarus tigrinus, Limnomysis benedeni and Paramysis lacustris) have become important members of food chains of the studied ecosystems. Their trophic position varied significantly within species during ontogenesis. This suggests that they turned from being typically detritivores/plantivorous (TL 2–2.4) at juvenile stages to omnivores (2.5–3) or to carnivores (>3) as adults. Assessment of the predation pressure by the adult amphipods on other coexisting invertebrates (in the example of the Neva Estuary) showed a low or medium impact, depending on species of predator and productivity of its potential prey organisms.

Characterization of ten polymorphic microsatellite markers in an invasive Ponto-Caspian mysid crustacean Paramysis lacustris

Paramysis lacustris is a Ponto-Caspian mysid crustacean species. It inhabits coasts, estuaries and lower parts of rivers in the Black, Azov and Caspian seas and shows high levels of genetic structuring and cryptic diversity. The species has been introduced into the Baltic Sea basin and is considered to be a high risk invader. We developed ten microsatellite loci and tested their polymorphism in 70 individuals from four wild populations. The number of alleles per locus ranged from 4 to 23; none of the loci showed consistent deviations from Hardy–Weinberg equilibrium. These microsatellite markers will be useful to trace potential invasions and understand dynamics of native P. lacustris populations.

Range expansion of Ponto-Caspian mysids (Mysida, Mysidae) in the River Tisza: first record of Paramysis lacustris (Czerniavsky, 1882) for Hungary

In the River Tisza, the longest tributary of the Danube,Limnomysis benedeniCzerniavsky, 1882 had been the only mysid recorded until recently. In 2011, we found a few juvenile specimens ofHemimysis anomalaG. O. Sars, 1907 in two daytime samples taken from the Hungarian river section. During the overnight survey in 2012 aimed at revealing the actual distribution of this nocturnally active species, its most upstream occurrence was detected at Szolnok (river km 334).Paramysis lacustris(Czerniavsky, 1882) was also found at every sampling site of the river downstream of Tiszabercel (rkm 568), representing the first record of the species for the fauna of Hungary, and its most upstream self-sustaining population in the basin of the River Danube (1759 rkm from the Danube mouth).P. lacustrisis the fourth Ponto-Caspian mysid that has begun to expand its range spontaneously in the Danube catchment afterL. benedeni,H. anomala, andKatamysis warpachowskyiG. O. Sars, 1893. Due to its zooplanktivory it can be anticipated to have a considerable effect on the composition and abundance of the zooplankton assemblages and it may also become an important food source for certain fish species, especially in the impounded reaches and in stagnant or slow-flowing backwaters.P. lacustris — similarly toH. anomala — shows a diel vertical migration, moving to shallow waters only by night, which calls for increased attention in order to reveal its possible future range expansions. Although the River Tisza itself is not connected directly to other river basins via canals, it may potentially contribute to the further spread of the species (e.g., via fish stocking).

Initial and long-term consequences of attempts to improve fish-food resources in Lithuanian waters by introducing alien peracaridan species: a retrospective overview

Summary In this overview, we consider the rationale and practice of invertebrate introductions into Lithuanian waters, the current distribution of introduced species, test the theoretical expectations of introduction of peracaridan species into lakes, and summarize the large-scale consequences of these translocations. After some early attempts to transfer locally available species within the country, peracaridan species from the Ponto-Caspian region were introduced into Lithuanian waters during the 1960s (Pontogammarus robustoides, Obesogammarus crassus, Chaetogammarus warpachowskyi, Paramysis lacustris, Limnomysis benedeni and Hemimysis anomala). After their establishment at the site of first introduction in a newly constructed water reservoir on the Nemunas River, further deliberate introductions into Lithuanian lakes and water reservoirs, as well as into more distant areas, were undertaken. These introduced species soon contributed to fish diet and a subsequent increase in the production of commercially important fish was envisaged. However, our collation of available data does not support the enhancement of fish production in Lithuanian lakes. Although perch (selected as a model fish species) assimilated the introduced species into diet and sometimes in large quantities, there was no subsequent influence on somatic growth rates when compared with perch from lakes devoid of alien peracaridans. Comparisons of littoral fish communities of different lakes, and commercial catches in the lake with the most numerous populations of introduced species also indicate no significant effect on fish production. Negative consequences of introduction are more than obvious in contrast. To date, most of the introduced Ponto-Caspian amphipod and mysid species occur in different sites of the Baltic Sea basin outside Lithuania, and their further dispersal may be expected. These species, especially amphipods, have proved to be highly ecologically aggressive, inducing change in resident macroinvertebrate communities and causing increase of biological contamination (i.e. detract from naturalness). Thus, the introduction of alien fodder species was ill advised from an economic, and even adverse from an environmental perspective.

Role of mysid seasonal migrations in the organic matter transfer in the Curonian Lagoon, south-eastern Baltic Sea

We investigated population dynamics, growth and feeding of an omnivorous mysid, Paramysis lacustris, performing seasonal horizontal migrations in the Curonian Lagoon. In autumn, increased predation pressure and deteriorated feeding conditions, due to zooplankton and phytoplankton decline in the open water, forces mysids to migrate to the shoreline, where large amounts of decaying submersed vegetation occur at the end of plant growth season. Using stable isotope analysis and mixing models, we evaluated relative importance of decaying submersed macrophytes, lagoon phytoplankton and mesozooplankton in the diet of mysids during this period. In September–November, mysids actively grew and produced three cohorts. Specific growth rates of adults (10.9 ± 1.9 mm) and subadults (6 ± 0.5 mm) were 3 and 9% DW d −1, respectively, resulting in population somatic production of 36 g DW m −2. Both δ 15N and δ 13C of mysids varied in concert with those in suspended and bottom particulate organic matter (POM) and mesozooplankton. The mixing models estimated that 45% of mysid diets were composed of bottom POM originated from the decaying macrophyte Potamogeton perfoliatus, 45% by suspended POM largely consisting of phytoplankton, while mesozooplankton contributed less than 10% of the diet. This diet composition differs from that in summer, when mysids rely mostly on zooplankton and phytoplankton. Therefore, mysid horizontal migrations and their ability to efficiently utilize littoral detritus improve the efficiency of macrophyte detritus transfer up the food chain and inshore/offshore habitat coupling in the Curonian Lagoon.

Isotopic evidence for zooplankton as an important food source for the mysid Paramysis lacustris in the Curonian Lagoon, the South-Eastern Baltic Sea

To evaluate the contribution of mesozooplankton to the diet of a coastal mysid Paramysis lacustris in the Curonian Lagoon, stable isotope analysis of mysids and mesozooplankton was conducted from July to October 2004. Nitrogen isotopic composition ( δ 15N) of both mysid bodies and dissected stomachs was analyzed and their δ 15N values were compared to those in ambient mesozooplankton. We also evaluated changes in phyto- and mesozooplankton assemblages during the study period and related the community dominance structure to the isotopic composition of the mesozooplankton and mysids. Stable isotope data suggest that during the ontogenetic development, mysid diet changes to include a larger proportion of mesozooplankton and that mysids need to attain a threshold size of 8.7 ± 0.7 mm to feed on mesozooplankton. In adult mysids, δ 15N values of the dissected stomachs and stomach content were indistinguishable from those of ambient mesozooplankton, indicating nearly complete reliance on mesozooplankton prey. A significant depletion of 15N in both mesozooplankton and mysids occurred during the study period, correlating with cyanobacteria abundance in the lagoon. These findings contribute to the understanding of P. lacustris' feeding biology, and the pelagic food web structure and functioning in the coastal environment.

Comparative phylogeography of Ponto‐Caspian mysid crustaceans: isolation and exchange among dynamic inland sea basins

The distributions of many endemic Ponto-Caspian brackish-water taxa are subdivided among the Black, Azov and Caspian Sea basins and further among river estuaries. Of the two alternative views to explain the distributions, the relict school has claimed Tertiary fragmentation of the once contiguous range by emerging geographical and salinity barriers, whereas the immigration view has suggested recolonization of the westerly populations from the Caspian Sea after extirpation during Late Pleistocene environmental perturbations. A study of mitochondrial (COI) phylogeography of seven mysid crustacean taxa from the genera Limnomysis and Paramysis showed that both scenarios can be valid for different species. Four taxa had distinct lineages related to the major basin subdivision, but the lineage distributions and depths of divergence were not concordant. The data do not support a hypothesis of Late Miocene (10-5 Myr) vicariance; rather, range subdivisions and dispersal from and to the Caspian Sea seem to have occurred at different times throughout the Pleistocene. For example, in Paramysis lacustris each basin had an endemic clade 2-5% diverged from the others, whereas Paramysis kessleri from the southern Caspian and the western Black Sea were nearly identical. Species-specific ecological characteristics such as vagility and salinity tolerance seem to have played important roles in shaping the phylogeographic patterns. The mitochondrial data also suggested recent, human-mediated cryptic invasions of P. lacustris and Limnomysis benedeni from the Caspian to the Sea of Azov basin via the Volga-Don canal. Cryptic species-level subdivisions were recorded in populations attributed to Paramysis baeri, and possibly in P. lacustris.

Habitat-Induced Heterogeneity in the Curonan Lagoon Littoral Assemblages: Mysids, Juvenile Fish and Plankton Crustaceans

Zooplankton, juvenile fish and mysid assemblages were investigated in adjacent vegetated and un-vegetated littoral habitats of the Curonian Lagoon (SE Baltic Sea). Juvenile perch (Perca fluviatilis) showed significant habitat partitioning while roach (Rutilus rutilus) did not. The proportion of perch was higher in vegetated habitats, and its foraging on Daphnia was lower in open areas. Roach preferred frequent shifting between habitats, and foraged more intensely on Daphnia and copepods in un-vegetated areas or fed on small-sized chydorids regardless of habitat facilitation. Two omnivorous Ponto-Caspian mysids (Limnomysis benedeni and Paramysis lacustris) tend to aggregate in vegetation during nocturnal migrations. However, their hypothetically increased predatory potential did not show a clear structuring effect on zooplankton distribution in littoral habitats at night. In contrast, the research cases showed that zooplankton distribution heterogeneity is more pronounced during the day. We suggested sever...

Patterns of Reproduction of Pontocaspian Relict Paramysis lacustris within Distribution Area

AbstractReproduction has been studied of Paramysis lacustris, pontocaspian relict, in the centre of its natural area, and in southern and northern zones of acclimatisation. Life cycles of the animals are identical in the distribution area. The effect of female size on fecundity is only slightly expressed within each generation. Significant correlations of these indices were obtained in seasonal aspect. Specific fecundity is represented by maximum values in the centre of the area and declines in the north‐western direction of introduction. The relation of fecundity to egg weight reflecting correlation of K‐r reproduction strategy is reduced in the regions of introduction. Reproduction effort, i.e. ratio of eggs weight to female weight, is the most stable index within the distribution area. Cumulative potential growth, including soma as well as generative products, was nearer in spite of considerable temperature difference in animal growth.