Some alien species of aquatic invertebrates in the water bodies of the nature reserve fund of the Kyiv metropolis

The invasion of alien species of freshwater invertebrates and the associated changes in the faunistic composi- tion of local ecosystems are a serious threat to the conservation of biodiversity. In this work, we supplement the existing list of alien species with information about three more species of non-native freshwater invertebrates, which have formed stable populations in water bodies of Ukraine. These are two representatives of flatworms: Girardia tigrina (Girard, 1850) and Stenostomum saliens Kepner & Carter, 1931, as well as a representative of copepods, Eucyclops roseus Ishida, 1997.

Genomic Signature of Sexual Reproduction in the Bdelloid Rotifer Macrotrachella quadricornifera

Bdelloid rotifers, common freshwater invertebrates of ancient origin and worldwide distribution have long been thought to be entirely asexual, being the principal exception to the view that in eukaryotes the loss of sex leads to early extinction. That bdelloids are facultatively sexual is shown by a study of allele sharing within a group of closely related bdelloids of the species Macrotrachella quadricornifera, supporting the view that sexual reproduction is essential for long-term success in all eukaryotes.

FRESHWATER INVERTEBRATES OF LAKE ZAISAN

In this article, freshwater invertebrates are studied. Lake Zaisan is considered as an object. The article updates the list of invertebrate fauna of Lake Zaisan, which is currently relevant. The article presents steps for collecting invertebrates and determining their species composition. According to the results of the study, the species composition of thirty-nine invertebrates was determined. The author notes that the species composition of invertebrates is higher on the coast than in the lake environment, that is, the number of planktonic invertebrates is higher than that of benthos invertebrates. The author notes that the Reed thickets and kelp areas along the Lake Shore are a favorable environment for the growth of benthos organisms, that is, the predominance of benthos invertebrates, and on the sandy shores of the lake there are no invertebrates. In the course of the study, it was found that the lake is dominated by OAR-footed Scorpions, oligochetes, chironomid larvae, ashamurt Scorpions, slug worms. High-altitude Scorpions, leeches, leeches, and water mites are rare. The article considers the problem of reducing the water level of Lake Zaisan from one hundred to five hundred meters over the past year. It is worth noting that the number of benthos organisms has also decreased, as the areas of coastal reeds and algae have dried up. In addition, it is concluded that the ichthyofauna of the lake has also decreased. The result of this research work can be applied to the standard curriculum of the discipline zoology. The information contained in the article can be used by students studying at biological faculties of higher educational institutions, biology teachers in secondary schools. It will be interesting for secondary schools near Lake zaisan to use the identified invertebrates and their photos as a local component.

Morphological, calorific and nutritive characteristics of 656 freshwater invertebrates taxa

The Freshwater Animal Diversity Assessment (FADA) project estimated that freshwater animal species represent 9.5% of the 1.2 million species described. Knowing that freshwater represents only 0.01% of the earth's surface, these wetlands are suitable habitats for a great part of the world's total biodiversity. However, it has been shown that there is a lack of knowledge on these species, including freshwater invertebrates. Nevertheless, they play a key role in the majority of freshwater ecosystems and in their foodweb networks. Freshwater invertebrates are the food resource of many species, such as fish and birds. The knowledge of their morphological, energetic and nutritive characteristics allows a better understanding of their selection by predators (size, energy intake etc.), but also leads to the improvement of wetland management. Although information about freshwater invertebrates exists in literature, they are generally heterogeneous, dispersed and difficult to collect. To facilitate the accessibility of these data and, thus, optimise and accelerate research projects including freshwater invertebrates, we propose a literature review describing 14 morphological and nutritive characteristics (size, dry weight, gross energy, crude protein etc.) for 656 taxa of freshwater invertebrates. This dataset is a review from 104 publications from 1935 to 2020, compiling 14 characteristics when available (size, dry weight, gross energy, crude protein etc.) for 656 taxa of freshwater invertebrates.

A new fossil piddock (Bivalvia: Pholadidae) may indicate estuarine to freshwater environments near Cretaceous amber-producing forests in Myanmar

The lower Cenomanian Kachin amber from Myanmar contains a species-rich assemblage with numerous plant and animal fossils. Terrestrial and, to a lesser degree, freshwater species predominate in this assemblage, while a few taxa with marine affinities were also discovered, e.g. isopods, ammonites, and piddocks. Here, we describe the Kachin amber piddock †Palaeolignopholas kachinensis gen. & sp. nov. It appears to be an ancestral stem lineage of the recent Lignopholas piddocks, which are estuarine to freshwater bivalves, boring into wood and mudstone rocks. Frequent occurrences and high abundance of †Palaeolignopholas borings and preserved shells in the Kachin amber could indicate that the resin-producing forest was partly situated near a downstream (estuarine to freshwater) section of a river. Multiple records of freshwater invertebrates (caddisflies, mayflies, stoneflies, odonates, and chironomids) in this amber could also manifest in favor of our paleo-environmental reconstruction, although a variety of local freshwater environments is known to occur in coastal settings.

Demographic consequences of mitigating strategies in planktonic invertebrates facing global browning of freshwater ecosystem

Recently, it has been reported that freshwater browning has less effect on planktonic invertebrate abundances than would be expected from current knowledge regarding of the biochemical activity of dissolved organic matter. It may be that the weak responses of whole communities to browning are masked because the individual mitigating strategies of community components have disparate demographic consequences. To examine the above hypothesis, individual-, population- and community-level responses of freshwater invertebrates to varying concentrations of terrestrial dissolved organic matter (tDOM) were investigated. Common cladocerans of the Chydoridae family, Chydorus sphaericus and Acroperus harpae, were used in the experiment which revealed that species employed different strategies to cope with tDOM. C. sphaericus maintained high production of asexual offspring at the cost of individual body growth, so any decreases in the population sizes were not observed. A. harpae, conversely, invested mainly in the production of resting eggs and increased survivability, which resulted in smaller populations. Invertebrate communities showed similar resilience and temporal stability across tDOM concentrations. Therefore, the influence of tDOM was apparently negligible at community level, since the effects of the mitigating strategies of the two species complemented one another. This experiment showed that symptoms of freshwater browning might be difficult to observe at population and community level due to effective mitigating strategies performed at the level of individuals. The effects of browning on freshwater invertebrates might be better considered in the context of alterations in the demographic rates together constituting life-cycle strategies to maintain species survival.

Freshwater aquatic invertebrates on the Isle of May, Scotland

The invertebrate fauna of freshwater habitats on the Isle of May, Scotland was investigated and compared with the results from surveys undertaken in 1958. Overall, the freshwater invertebrate fauna appears to be diminished. However, several species were recorded as new to the Isle of May. Although the reasons for the apparent decline in freshwater invertebrates on the island are unclear, an increase in the temporary nature of the habitats due to climate warming may be a contributing factor.