Factors determining the average body size of geographically separated Arctodiaptomus salinus(Daday,1885) populations

Arctodiaptomus salinus inhabits water bodies across Eurasia and North Africa.Based on our own data and that from the literature,we analyzed the influences of several factors on the intra-and inter-population variability of this species.A strong negative linear correlation between temperature and average body size in the Crimean and African populations was found,in which the parameters might be influenced by salinity.Meanwhile,a significant negative correlation between female body size and the altitude of habitats was found by comparing body size in populations from different regions.Individuals from environments with highly varying abiotic parameters,e.g.temporary reservoirs,had a larger body size than individuals from permanent water bodies.The changes in average body mass in populations were at 11.4 times,whereas,those in individual metabolic activities were at 6.2 times.Moreover,two size groups of A.salinus in the Crimean and the Siberian lakes were observed.The ratio of female length to male length fluctuated between 1.02 and 1.30.The average size of A.salinus in populations and its variations were determined by both genetic and environmental factors.However,the parities of these factors were unequal in either spatial or temporal scales.     

Salt to conserve: a review on the ecology and preservation of hypersaline ecosystems

When it comes to the investigation of key ecosystems in the world, we often omit salt from the ecological recipe. In fact, despite occupying almost half of the volume of inland waters and providing crucial services to humanity and nature, inland saline ecosystems are often overlooked in discussions regarding the preservation of global aquatic resources of our planet. As a result, our knowledge of the biological and geochemical dynamics shaping these environments remains incomplete and we are hesitant in framing effective protective strategies against the increasing natural and anthropogenic threats faced by such habitats. Hypersaline lakes, water bodies where the concentration of salt exceeds 35 g/l, occur mainly in arid and semiarid areas resulting from hydrological imbalances triggering the accumulation of salts over time. Often considered the ‘exotic siblings’ within the family of inland waters, these ecosystems host some of the most extremophile communities worldwide and provide essential habitats for waterbirds and many other organisms in already water-stressed regions. These systems are often highlighted as natural laboratories, ideal for addressing central ecological questions due to their relatively low complexity and simple food web structures. However, recent studies on the biogeochemical mechanisms framing hypersaline communities have challenged this archetype, arguing that newly discovered highly diverse communities are characterised by specific trophic interactions shaped by high levels of specialisation. The main goal of this review is to explore our current understanding of the ecological dynamics of hypersaline ecosystems by addressing four main research questions: (i) why are hypersaline lakes unique from a biological and geochemical perspective; (ii) which biota inhabit these ecosystems and how have they adapted to the high salt conditions; (iii) how do we protect biodiversity from increasing natural and anthropogenic threats; and (iv) which scientific tools will help us preserve hypersaline ecosystems in the future? First, we focus on the ecological characterisation of hypersaline ecosystems, illustrate hydrogeochemical dynamics regulating such environments, and outline key ecoregions supporting hypersaline systems across the globe. Second, we depict the diversity and functional aspects of key taxa found in hypersaline lakes, from microorganisms to plants, invertebrates, waterbirds and upper trophic levels. Next, we describe ecosystem services and discuss possible conservation guidelines. Finally, we outline how cutting-edge technologies can provide new insights into the study of hypersaline ecology. Overall, this review sheds further light onto these understudied ecosystems, largely unrecognised as important sources of unique biological and functional diversity. We provide perspectives for key future research avenues, and advocate that the conservation of hypersaline lakes should not be taken with ‘a grain of salt’.     

The Effect of Gamma Radiation on Parthenogenetic Artemia (Branchiopoda,Anostraca) Cysts: Nauplius Hatching and Postnauplial Survival under Varying Salinity

Biology Bulletin - Abstract—The effect of gamma radiation doses of 2.5, 5.5, and 7.5 Gy received by Artemia cysts on hatching of nauplii and postnauplial survival of crustaceans has been...