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

Abstract

Surveys of terrestrial microinvertebrate morphometry, especially spatial patterns of body size at wider geographical scales, including the polar regions, are very scarce. In this study, we focused on Tardigrada, common limno-terrestrial microinvertebrates. Considering Bergmann's rule, originally formulated for endothermic animals, we tested the hypothesis that body length of limno-terrestrial tardigrades augments with increasing latitude and decreasing temperature. Since some of our sampling areas adjoined seabird colonies, we also explored the effects of nutrients from seabird guano deposits. Individual body length of Testechiniscus spitsbergensis was measured in populations obtained from seven localities distributed along a latitudinal gradient extending from 45°N (northern Italy) to 79°N (northern Svalbard), and for Pilatobius recamieri from three localities in Svalbard (77°N-80°N). Considering both latitude and proximity to a seabird colony there were significant effects of locality on the body length of T. spitsbergensis; however, no clear pattern of increasing individual body size with increasing latitude could be detected. Immense differences in body size may be a signal for cryptic species diversity within this genus. No effect of latitude, or proximity to a seabird colony, on the body length of Arctic populations of P. recamieri was documented. Evidently, there is no tendency towards body size increase along the latitudinal gradient in either T. spitsbergensis or P. recamieri. Our study, and recent literature, indicates that larger body size in polar regions reported for several groups of micro-fauna may be a taxon-dependent response, and cannot be taken as a universally applicable rule for limnoterrestrial animals.

Tips and tricks how to culture water bears: simple protocols for culturing eutardigrades (Tardigrada) under laboratory conditions

“…But, of course, the impact of temperature is strongly species-dependent, which has been confirmed by other authors (e.g. Sømme & Meier 1995;Ramlov & Westh 2001;Li & Wang 2005a, 2005bHengherr et al 2009;Zawierucha et al 2018;Neves et al 2020). Nevertheless, as shown in Table I, some tardigrade species have been cultured with success at different temperatures.…”

The terrestrial invertebrate fauna of Edgeøya, Svalbard: Arctic landscape community composition reflects biogeography patterns

“…However, there has been considerable sampling effort along the west coast, particularly around Isfjord (Longyearbyen and Barentsburg) and Kongsfjord (Ny-Ålesund). From these studies, projects and campaigns a large number of articles have arisen (Coulson et al 2014a;Gillespie et al 2016;Luoto et al 2016;Kolicka 2017;Zawierucha et al 2018). It is curious then that with limited sampling undertaken during this project that such a large percent of the species identified were new records if these species do indeed occur in habitats in the west of the archipelago.…”

The impact of marine vertebrates on polar terrestrial invertebrate communities

“…Based on data assessing springtails, mites and tardigrades from sites affected by marine vertebrates and nonimpacted control sites (Zawierucha et al 2015b(Zawierucha et al , 2016(Zawierucha et al , 2017(Zawierucha et al , 2018Zmudczyńska-Skarbek et al 2015, 2017Bokhorst and Convey 2016;Bokhorst et al 2019a, b), we found significant vertebrate influence on terrestrial invertebrate community composition regardless of their taxonomic affiliation or geographic location (Model 1, factor: Vertebrates; F = 111.65, df = 1, p < 0.001; Suppl. Table 1, Fig.…”

“…Datasets available from the Arctic included the taxonomic composition of springtail communities (35 species) from Hamburgbukta (NW Spitsbergen), Isfjorden (central Spitsbergen) and Bjørnøya (Zmudczyńska-Skarbek et al 2015, 2017, mites (Oribatida, Mesostigmata, in total 48 species) from Hamburgbukta and Isfjorden (Zmudczyńska-Skarbek et al, unpublished data), and Bjørnøya (Zmudczyńska-Skarbek et al 2017), and tardigrades (43 species) from Svalbard (Hornsund, Kongsfjorden, Nissenfjella, Nordaustlandet, Amsterdamøya, Danskøya, Fuglesongen, Phippsøya, Parrøya, and Prince Karl Forland, Zawierucha et al 2015bZawierucha et al , 2016Zawierucha et al , 2017Zawierucha et al , 2018. The Antarctic datasets contained records of springtails (6 species) and mites (Oribatida, Mesostigmata, Prostigmata, in total 9 species) from Signy Island (South Orkney Islands), Byers Peninsula (Livingston Island, South Shetland Islands), and islands within Ryder Bay (south-east Adelaide Island) (Bokhorst and Convey 2016;Bokhorst et al 2019a, b).…”

“…Twelve of the articles from the Arctic related to springtails, including one collectively with mites Petz (1997) (Zmudczyńska-Skarbek et al 2017) and three also considering mites, spiders, rove beetles, dipteran larvae, nematodes and enchytraeids (Bengtson et al 1974;Byzova et al 1995;Lebedeva et al 2020). Of the remaining seven, six focused solely on tardigrades (Zawierucha et al 2015a(Zawierucha et al , b, 2016(Zawierucha et al , 2017(Zawierucha et al , 2018(Zawierucha et al , 2019 and one on testate amoebae (Mazei et al 2018).…”