Habitats for large branchiopods in the agricultural landscape of the Mureş Floodplain Natural Park: how long will they last?

In the last two hundred years, the Mureş River Floodplain has suffered major changes caused by dike constructions, meander cutting, and by the transformation of the natural landscape into an agricultural one. In this environmental context, we wanted to find out the degree to which large branchiopod species still survive in the Mureş Floodplain area. Every stagnant aquatic habitat encountered in 2019 in the Mureş Floodplain Natural Park was sampled. For the habitats where more species co-occur, urgent preservation actions must be taken. Most of the species prefer open habitats and have survived in the wheel ruts on agricultural lands. In the absence of natural habitats, the importance of this habitat type becomes a major one. The forest advantages species related to shady habitats, such as Chirocephalus diaphanus. We have found several individuals in the park that showed black spots on their bodies, characteristic of the black disease of fairy shrimp. The presence of the disease only in the populations from wheel ruts suggests that vehicles which make these ruts, could be the carriers of the disease.

A Review of Recently Discovered Remains of the Pleistocene Branchiopods (Anostraca, Notostraca) from NE Siberia and Arctic Canada

In this study, we examine, identify, and discuss fossil remains of large branchiopod crustaceans collected from six sites across the Beringian region (north-eastern Asia and north-western North America). Eggs and mandibles from Anostraca and Notostraca, as well as a notostracan telson fragment and a possible notostracan second maxilla, were collected from both paleosediment samples and also from large mammal hair. The remains of large branchiopods and other species that are limited to seasonally astatic aquatic habitats (temporary wetlands) could be useful indicator organisms of paleoecological conditions. Different recent large branchiopod species have very different ecological preferences, with each species limited to specific geochemical component tolerance ranges regarding various salinity, cation, and gypsum concentrations. Our purpose is to bring the potential usefulness of these common fossil organisms to the attention of paleoecologists.

On the Biodiversity Hotspot of Large Branchiopods (Crustacea, Branchiopoda) in the Central Paroo in Semi-Arid Australia

Biodiversity is central to the structure and functioning of communities including those of temporary water bodies. Worldwide the large branchiopod component commonly consists up to about six species instantaneously per site and twice that number across the surrounding district. Where these figures reach eight to ten species per site and about twice that number per district, the term diversity hotspot is sometimes used. In eastern Australia, biogeographical factors have facilitated a rich large branchiopod fauna ca 80 species and locally within 500 km2 of the central Paroo in northwestern New South Wales where a rarely diverse and abundant array of habitats supports at least 38 species, though the maximum per site syntopically is still near 10 species — we suggest it be termed a super hotspot.

Key environmental factors for the conservation of large branchiopods in farmland vernal pools — a case from a Central European diversity hotspot

Large branchiopod crustaceans are among the most threatened freshwater invertebrates of the world. They are regarded as a flagship group in the conservation of temporary waters, and knowledge of their ecology and conservation has developed rapidly in recent years, especially in the Mediterranean region. Little is known, however, about population functioning in species associated with vernal pools in cooler temperate areas, despite recent data showing a significant decline in their localities. The present study was conducted in western Poland, on a cluster of vernal pools known to host a Central European diversity hotspot of large branchiopods. We collected data on water and sediment quality, as well as hydroperiod length, to determine their effect on the occurrence of four large branchiopod species present in the ponds during our samplings: Eubranchipus grubii (Anostraca), Lynceus brachyurus (Laevicaudata), Cyzicus tetracerus (Spinicaudata) and Lepidurus apus (Notostraca). According to the statistical analyses, the presence or absence of particular species was affected by hydroperiod length, heavy metal content in the sediments of the marginal zone of the pond, total water phosphorus content, and pH value. Since previous studies show that deep and relatively small kettle-hole ponds seem to be the most vulnerable to human-induced changes in water nutrient contents and acidification, large branchiopod populations of this type of pools should be the first target for monitoring and active forms of protection, with the aim of maintaining the good water quality. Shallow shore-bursting type ponds are subject to increased heavy metal contamination and require activities reducing the influx of these elements from their agricultural catchment. Possible forms of protection are suggested, and the use of large branchiopods as an umbrella group in temporary waters of temperate climate is also discussed.

Streptocephalus sangoensis n. sp. (Anostraca, Streptocephalidae), a new large branchiopod species for southern Africa

Recent collections from the south-eastern Lowveld of Zimbabwe yielded an undescribed species of the freshwater branchiopod genus Streptocephalus. The species was formerly published as Streptocephalus cf. bidentatus by Brendonck & Riddoch (1997), indicating that more research was needed to prove its valid species status, distinct from S. bidentatus sensu stricto. The new species can be distinguished from S. bidentatus sensu stricto, mainly by its cercopods. The cercopods of S. bidentatus sensu stricto have spines in the distal third region of the furcal rami, while those of S. sangoensis n. sp. are setiferous up to the tips. All other morphological features are the same. The occurrence of the two species in syntopy further validates that they are different species. As with S. bidentatus sensu stricto, the new species S. sangoensis n. sp. was collected from ephemeral habitats. This region is a hotspot of large branchiopod diversity with a total of 16 known species occurring there.

Cyst morphology of large branchiopod crustaceans (Anostraca, Notostraca, Laevicaudata, Spinicaudata) in western Poland

The morphology of resting eggs was studied in Polish populations of 7 large branchiopod species:Branchipus schaefferi,Chirocephalus shadini,Eubranchipus grubii(Anostraca),Lepidurus apus,Triops cancriformis(Notostraca),Lynceus brachyurus(Laevicaudata), andCyzicus tetracerus(Spinicaudata). Scanning electron microscope photographs for each species are also provided. In some species (especiallyE. grubii), the ornamentation and size of cysts from Polish populations significantly differ from literature data for populations from other parts of Europe. We also present a key to determination of the studied species based on cyst morphology and discuss whether those traits are useful in surveys of new localities of endangered large branchiopods.