Reproductive traits of Macrobiotus hufelandi during a long-term field study with notes on Paramacrobiotus richtersi and Diphascon pingue (Eutardigrada)

Abstract

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Effect of lifespan and age on reproductive performance of the tardigrade Acutuncus antarcticus: minimal reproductive senescence

“…Large variation in body size of individuals developing eggs was present in a natural population of another eutardigrade species Pseudobiotus kathmanae (Kathman & Nelson, 1987). A positive correlation between the body length of females and the number of oocytes was reported in three species of eutardigrades in a natural population field study of Macrobiotus hufelandi, Paramacrobiotus richtersi and Diphascon pingue in a moss carpet (Schuster & Greven, 2013). While no body size data were recorded in our study, a rapid increase in clutch size of A. antarcticus at the beginning of the reproductive period might also suggest that it is a relationship with the growth phase of animals.…”

Temperature (latitude) and nutrient (seabird guano) effects on limno-terrestrial Tardigrada (Testechiniscus spitsbergensisandPilatobius recamieri) body size

“…Tardigrades are invertebrates having a number of instars during their life history and many generations during a year (Franceschi et al 1962(Franceschi et al -1963Ramazzotti & Maucci 1983;Schuster & Greven 2013;Kosztyła et al 2016). Multi-voltinism and seasonality in terrestrial arthropods have been discussed as factors that may be related to body size changes along temperature and latitudinal gradients (Horne et al 2015(Horne et al , 2017.…”

“…Although seasonal variability may result in shifts of body size, such effect has not been widely accepted. Schuster & Greven (2013) sampled monthly (over a period of 4.5 years) a lawn covered by a moss carpet and reported that two of the three tardigrade species studied were larger during springtime following a period of cryobiosis in winter. The authors hypothesized that reduced exposure to sunlight negatively affected the body lengths of these two tardigrade species.…”

“…Locally they can reach very high densities, up to hundreds of individuals per gram of dry plant or soil sample (e.g., Zawierucha, Zmudczyńska-Skarbek et al 2016). Nonetheless, detailed experimental (field or laboratory) data are scarce for tardigrade morphometry (e.g., Ramazzotti & Maucci 1983;Schuster & Greven 2013;Kosztyła et al 2016). Recent studies conducted under laboratory conditions have shown that tardigrade morphometric traits may be influenced by the environment (Kosztyła et al 2016), genetics (Stec et al 2016) and individual development/ontogeny .…”

Simultaneous Metabarcoding of Eukaryotes and Prokaryotes to Elucidate the Community Structures within Tardigrade Microhabitats

“…Ecological studies of tardigrades thus far have been predominantly focused on biogeographic scales [5][6][7], and studies on interspecies interactions and community structures within the microenvironments of tardigrade habitats are still limited; however, factors within the tardigrade habitat, such as humidity, food source, and the presence of antagonists, are suggested to play important roles in determining tardigrade distributions, possibly more so than geographical or abiotic factors such as altitude or substrate and plant type [8][9][10]. Humidity is also reported to sometimes affect the reproductive traits of tardigrades [11].…”