Anemochory of diapausing stages of microinvertebrates in North American drylands

Abstract

Dry, ephemeral, desert wetlands are major sources of windblown sediment, as well as repositories for diapausing stages (propagules) of aquatic invertebrates. Zooplankton propagules are of the same size range as sand and dust grains. They can be deflated and transported in windstorm events. This study provides evidence that dust storms aid in dispersal of microinvertebrate propagules via anemochory (aeolian transport). We monitored 91 windstorms at six sites in the southwestern U.S.A. over a 17‐year period. The primary study site was located in El Paso, Texas in the northern Chihuahuan Desert. Additional samples were collected from the Southern High Plains region. Dust carried by these events was collected and rehydrated to hatch viable propagules transported with it. Using samples collected over a 6‐year period, 21 m above the ground, which included 59 storm events, we tested the hypothesis that transport of propagules is correlated with storm intensity by monitoring meteorological conditions such as storm duration, wind direction, wind speed, and particulate matter (PM10; fine dust concentration). An air quality monitoring site located adjacent to the dust samplers provided quantitative hourly measurements. Rehydration results from all events showed that ciliates were found in 92% of the samples, rotifers in 81%, branchiopods in 29%, ostracods in 4%, nematodes in 13%, gastrotrichs in 16%, and tardigrades in 3%. Overall, four bdelloid and 11 monogonont rotifer species were identified from rehydrated windblown dust samples. Principal component analysis indicated gastrotrichs, branchiopods, nematodes, tardigrades, and monogonont rotifer occurrence positively correlated with PM10 and dust event duration. Bdelloid rotifers were correlated with amount of sediment deposited. Non‐metric multidimensional scaling showed a significant relationship between PM10 and occurrence of some taxa. Zero‐inflated, general linear models with mixed‐effects indicated significant relationships with bdelloid and nematode transport and PM10. Thus, windstorms with high PM10 concentration and long duration are more likely to transport microinvertebrate diapausing stages in drylands.

Patterns of Rotifer Diversity in the Chihuahuan Desert

“…Comprehensive studies of rotifer distributions are common, but vary widely in their focus. For example, many emphasize long-term, ecological questions across several water bodies [125][126][127][128], the dynamics in a particular lake [129][130][131][132][133][134] or region [13,14,117,[135][136][137][138][139][140], or examine a single taxon [141][142][143][144][145][146][147][148]. Collectively, such studies provide insight into the biogeography of the phylum.…”

“…While they comprise an important component of freshwater ecosystems and contribute to both the microbial loop and typical aquatic food webs, it is unclear whether their distribution follows ubiquity theory [4,5], or whether they exhibit some level of endemicity [6][7][8][9]. Due to their ability to produce small resting stages that are easily transported by hydrochory [10], zoochory [11,12], or anemochory [13,14], it has been assumed that most rotifers were widely dispersed by passive means and that the majority of species would have cosmopolitan distributions [8,15,16]. However, recent studies have shown that the distribution of rotifer species encompasses the range from cosmopolitanism to biogeographies that are restricted to certain biogeographic realms, hotspots of biodiversity [7,17,18], or habitat types [4,[17][18][19].…”

Integrative description of a new Dactylobiotus (Eutardigrada: Parachela) from Antarctica that reveals an intraspecific variation in tardigrade egg morphology

“…nov. Taking into account high dispersal abilities of tardigrades by wind [87][88][89] as well as birds 35,90 , wide dispersal (2020) 10:9122 | https://doi.org/10.1038/s41598-020-65573-1 www.nature.com/scientificreports www.nature.com/scientificreports/ of resting forms being transported between Antarctic islands is plausible. Hence, the similarity of morphology of egg type described for Signy Island Dac.…”

Water bears dominated cryoconite hole ecosystems: densities, habitat preferences and physiological adaptations of Tardigrada on an alpine glacier

“…A similar phenomenon on glaciers in Austria was suggested by Dastych et al (2003). However, tardigrade adaptations for dispersal as well as their distribution and habitat preferences still remain a topic of debate (Guil et al 2009;Gąsiorek et al 2019;McInnes and Pugh 2019;Rivas et al 2019;Zawierucha et al 2018b). Until now, tardigrades in glacial habitats were mostly investigated in cryoconite holes with scarce data on other glacial habitats (Dastych et al 2003;Coulson and Midgley 2012).…”