Łukasz Kaczmarek

Adam Mickiewicz University, Poznan · Department of Animal Taxonomy and Ecology

The study of tardigrades in urban environments, particularly in natural areas within cities, has been significantly overlooked. A recent discovery of a new species of tardigrade in lichens collected from Mong Há Hill Municipal Park in Macau provides new insights into the population of tardigrades within the city. Echiniscus gemmatus sp. nov. was id...

Interactions between a host organism and its associated microbiota, including symbiotic bacteria, play a crucial role in host adaptation to changing environmental conditions. Antarctica provides a unique environment for the establishment and maintenance of symbiotic relationships. One of the most extensively studied symbiotic bacteria in invertebra...

Arctic terrestrial invertebrate biodiversity is generally poorly known, but the archipelago of Svalbard has one of the most up-to-date inventories of its terrestrial and freshwater faunas of any Arctic region, offering a baseline for long term monitoring of invertebrate communities in space and time. Since the most recent review of the Svalbard inv...

The discovery of perchlorate in martian regolith, ubiquitously distributed at levels far exceeding those noted on Earth, raises challenges for in situ resource utilization and life-supporting systems. However, this challenge can be overcome by organisms with extreme tolerance to various stressors, characterization of the mechanisms supporting such...

This is the first survey of marine tardigrades from the British Virgin Islands, though two species were previously reported from St. Croix, U.S. Virgin Islands. In June 2016, we collected subtidal and intertidal sand samples from various locations throughout the British Virgin Islands. We found 602 tardigrades in 18 of 21 samples, and these include...

In this paper we provide integrative description (morphological and genetic) of the new eutardigrade species Mesobiotus mandalori sp. nov. from central Poland, found during research on the vertical distribution of Tardigrada in the Czerniejewskie Forests. Mesobiotus mandalori sp. nov. belongs to the harmsworthi group, but it differs from the member...

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In this paper, samples of mosses, lichens and cryptogams (mosses mixed with lichens) collected from Słowiński National Park (northern Poland) were studied for water bears (Tardigrada). In total, 27 tardigrade taxa were identified: 21 to the species level, one identified as „cf.” and three to the genus level, with six species (Eremobiotus ginevrae,...

Perchlorate salts, including magnesium perchlorate, are highly toxic compounds that occur on Mars at levels far surpassing those on Earth and pose a significant challenge to the survival of life on this planet. Tardigrades are commonly known for their extraordinary resistance to extreme environmental conditions and are considered model organisms fo...

Increasing temperature influences the habitats of various organisms, including microscopic invertebrates. To gain insight into temperature-dependent changes in tardigrades, we isolated storage cells exposed to various temperatures and conducted biochemical and ultrastructural analysis in active and tun-state Paramacrobiotus experimentalis Kaczmarek...

Desiccation-tolerant organisms can survive dehydration in a state of anhydrobiosis. Tardigrades can recover from anhydrobiosis at any life stage and are considered among the toughest animals on Earth. However, the factors that influence recovery from anhydrobiosis are not well understood. The study aimed to evaluate the effect of sex, age, the pres...

Professor dr hab. Barbara Węglarska (Figs 1–3) was born on 20 February 1922 in Łazy (southern Poland), where her father, originally from Wieliczka (a salt mine town in the vicinity of Kraków), was sent by the government to work at a local post office. Two years later he came down with pneumonia, which made the family return to their hometown. Soon...

Recently it was purported that autofluorescence (AF) in Paramacrobiotus n. sp. provided protection from UV radiation. If true, this would be the first documentation of an adaptive function for AF in any microscopic animal. We review what is currently known about AF in tardigrades, and we provide the first true colour images of tardigrade fluorescen...

Tardigrades are common in many terrestrial environments and habitats. Although little is known on their ecological preferences, previous studies found diversity and community composition significantly affected by various variables. This study associated tardigrade species’ records with climatic variables, forest type, and substrate categories explo...

Paramacrobiotus fairbanksi was described from Alaska (USA) based on integrative taxonomy and later reported from various geographical localities making it a true cosmopolitan species. The ‘Everything is Everywhere’ (EiE) hypothesis assumes that the geographic distribution of microscopic organisms is not limited by dispersal but by local environment...

The genera Xerobiotus and Pseudohexapodibius are xerophilic and characterized by reduced appendages and claws as adaptations to move between small interstices. To increase the knowledge of their biodiversity, biogeography and phylogeny, several specimens from European countries and Australia were analysed using an integrative approach, i.e. morphol...

Even for tardigrades, often called the toughest animals on Earth, a hypomagnetic field (HMF) is an extreme environment. However, studies on the effect of HMF on tardigrades and other invertebrates are scarce. Mitochondria play an important role in an organism’s response to extreme conditions. The effect of HMF on the mitochondrial inner membrane po...

Paramacrobiotus species have been described in almost every corner of the world. To date, 45 species have been reported from this genus. Among which, 13 belong to the areolatus group (without a microplacoid) and 32 belong to the richtersi group (with a microplacoid). The species' presence in different climatic conditions and habitats provides evide...

Many vertebrates, both homeo-and poikilothermic, show a significant relationship between body size and environmental temperature. Whether such an association may exist in microscopic invertebrates has been less explored. Therefore, we decided to analyse terrestrial Tardigrada from various habitats worldwide to examine whether these animals reveal a...

Increasing temperature influences the habitats of various organisms, including microscopic invertebrates. To gain insight into temperature-dependent changes in tardigrades, we isolated storage cells exposed to various temperatures and conducted biochemical and ultrastructural analysis in active and tun-state Paramacrobiotus experimentalis Kaczmarek...

Perchlorates are present at high concentrations in Martian regolith and pose an additional challenge to the survival of terrestrial life on Mars. Some microinvertebrates can resist extreme conditions (e.g. low temperatures, lack of oxygen and radiation), making them suitable model species for space experiments. Clarification of whether they can tol...

Tardigrada (water bears) are a group of small invertebrates known for their ability to survive extreme desiccation by entering an anhydrobiotic state. This state is characterized by the loss of ≤ 98% of body water, resulting in body shrinkage and almost complete cessation of metabolism. In anhydrobiosis, multiple mechanical and biochemical stress e...

Paramacrobiotus species has been described from almost every corner of the world. To date 45 species have been reported from this genus. The species’ presence in different climatic conditions and habitat provides evidence of their adaptation to various harsh environments. In this review, we provide a concise summary of changes observed due to vario...

The infamous "master manipulators"-intracellular bacteria of the genus Wolbachia-infect a broad range of phylogenetically diverse invertebrate hosts in terrestrial ecosystems. Wolbachia has an important impact on the ecology and evolution of their host with documented effects including induced parthenogenesis, male killing, feminization, and cytopl...

Desiccation-tolerant organisms can survive dehydration in a state of anhydrobiosis. Tardigrades can recover from anhydrobiosis at any life stage and are considered among the toughest animals on Earth. However, the factors that influence recovery from anhydrobiosis are not well understood. The study aimed to evaluate the effect of sex, age, occurren...

Tardigrades are microscopic ecdysozoans that can withstand extreme environmental conditions. Several tardigrade species undergo reversible morphological transformations and enter into cryptobiosis, which helps them to survive periods of unfavorable environmental conditions. However, the underlying molecular mechanisms of cryptobiosis are mostly unk...

Antarctic is an area with extreme conditions for the survival of living organisms, as well as a specific region for conducting research. For this reason, studies of Antarctic tardigrades are rather fragmentary. Since 1904, when the first tardigrade was described in the Antarctic, up to the present, 76 species of tardigrades have been reported from...

Paramacrobiotus fairbanksi was described from Alaska (USA) based on integrative taxonomy and later reported from various geographical locations making it a true cosmopolitan species. Hypothesis ‘Everything is Everywhere’ (EiE) assumes that microscopic organisms have unique features which help them to inhabit many different environments and they can...

Paramacrobiotus fairbanksi was described from Alaska (USA) based on integrative taxonomy and later reported from various geographical locations making it a true cosmopolitan species. The ‘Everything is Everywhere’ (EiE) hypothesis assumes that microscopic organisms have unique features that help them to inhabit many different environments, meaning...

In a moss sample from Cameroon a few specimens and eggs of a new species of tardigrade were found. Macrobiotus stanislausi sp. nov. belongs to the Macrobiotus nelsonae morpho-group and is most similar to Mac. ragonesei. However, it differs from Mac. ragonesei mainly by the shape of the egg processes and the absence of annulations on process endings...

In a moss sample collected in Ribeiro Frio, Madeira, Paramacrobiotus gadabouti sp. nov. was found and described using the integrative taxonomy approach. The new species is described based on morphological and morphometric data from both phase-contrast light microscopy (PCM), as well as scanning electron microscopy (SEM). Moreover, four DNA markers,...

Using integrative taxonomy, we describe Macrobiotus kosmali sp. nov. from Ribeira Brava, Madeira (Portugal). Based on morphological and morphometric data from both phase contrast light microscopy (PCM), as well as, from scanning electron microscopy (SEM), description of the new species is provided. Additionally, four DNA markers, three nuclear (18S...

Anhydrobiosis is a desiccation tolerance that denotes the ability to survive almost complete dehydration without sustaining damage. The knowledge on the survival capacity of various tardigrade species in anhydrobiosis is still very limited. Our research compares anhydrobiotic capacities of four tardigrade species from different genera, i.e. Echinis...

In the phylum Tardigrada, as in other meiofauna taxa, the small size of the animals and the paucity of morphological characters useful for taxonomy present a challenge for systematic studies. For this reason, an integrated approach is increasingly desirable, including at least morphology, morphometry and molecular investigations, and possibly repro...

Tardigrades are ubiquitous microinvertebrates exhibiting extreme tolerance to various environmental stressors like low and high temperatures, lack of water, or high radiation. Although exact pathways behind the tardigrade extremotolerance are yet to be elucidated, some molecules involved have been identified. Their evidenced properties may lead to...

Tardigrades are considered as one of the toughest animals on Earth due to their survivability under extreme conditions. Under these conditions, the animals display several forms of cryptobiosis including the most studied one termed anhydrobiosis. However, tardigrades’ survival of repeated anhydrobiosis has rarely been studied. The same applies to r...

Background: Madeira Island has total of 741 km2 and goes up to highest elevation of 1,861 metres. It has mild to warm year-round temperatures and has few different bioclimatic zones. Up to now, 33 species i.e. 22 Eutardigrada and 11 Heterotardigrada have been reported from this island. The aim of this study was to determine tardigrade diversity of...

Background: Faunistic study in this area of Czerniejewskie Forests was the first stage of a larger project "Micro- and macrofactors affecting vertical distribution of Tardigrada in temperate forest", which aims to identify the mechanisms which determine the vertical distribution of tardigrades inhabiting epiphytic mosses growing on trees. Which was...

Background: Tardigrades show significant resistance to a number of environmental stressors, including exposure to the space vacuum. But even though, studies on the influence of hypomagnetic conditions or even geomagnetic field in general, on tardigrades were rare, until recently. We present the current state of knowledge on the influence of hypomag...

Background: Tardigrada (water bears) of the Słowiński National Park (SPN) are almost unknown, with only two species, Mesocrista spitzbergensis (Richters, 1903) and Hypsibius pallidus Thulin, 1911, reported from this area. Taking into consideration intensive changes in tardigrade taxonomy in recent years, large number newly described tardigrades and...

Background: Tenerife Island is a part of the Canary Islands Archipelago and it is characterized by varied geological structures which forms a great variability of the potential ecological niches. The relief of the island influences also the weather conditions, leading to a great variety of microclimates which are conducive to the occurrence of many...

Background: Anhydrobiosis is one of the most prevalent adaptations to water deficiency. The phenomenon occurs in different organisms but among animals the best known example are tardigrades, indicated lately as an emerging source of knowledge of importance for medical sciences. Tardigrade anhydrobiosis includes entry, dormant and exit stages, that...

Background: Active and cryptobiotic tardigrades reveal various adaptations to survive extreme environmental conditions. This, in turn, makes them and their chemical constituents promising candidates for different biomedical applications. Methods: Literature search of PubMed database using a combination of keyword “tardigrade” with “health”, “medic...

Background: Tardigrades are common in most habitats, however few studies have focused on large faunistic survey, specifically on tardigrade diversity in forests. Up to now, only 61 species have been recorded in different types of forest in Norway with an additional 25 found in limnic environments in forests. Although little is known about the ecolo...

Anhydrobiosis is induced by loss of water and indicates dehydration tolerance. Survival of dehydration is possible through changes at different levels of organism organization, including a remarkable reduction in metabolic activity at the cellular level. Thus, anhydrobiosis may be regarded as an anti-aging strategy. Accordingly, two hypotheses name...

In the present study, we used an integrative taxonomy approach to redescribe a population of Echiniscus quadrispinosus quadrispinosus Richters, 1902 from the neotype locality in the Taunus Mountain Range (Germany). We found clear differences in the chaetotaxy formula between the life stages of E. q. quadrispinosus. The body appendages B are, in gen...

Anhydrobiosis is a desiccation tolerance that denotes the ability to survive almost complete dehydration without sustaining damage. However, knowledge on the survival capacity of anhydrobiosis in various species of tardigrades is still very limited. Our research has compared anhydrobiotic capacities of four tardigrade species: Echiniscus testudo, P...

In the present study, we used the integrative taxonomy approach to redescribe Minibiotus intermedius based on the newly found topotypic population in Marburg (Germany). As the original type material is not available, we designate a neotype to stabilize the taxonomy of the genus Minibiotus. Obtained mitochondrial COI barcode sequence and nuclear mar...

The infamous “master manipulators” – intracellular bacteria from the genus Wolbachia – infect a broad range of phylogenetically diverse hosts in terrestrial ecosystems. Wolbachia have important impacts on the ecology and evolution of their hosts with documented effects including induced parthenogenesis, male killing, feminization, and cytoplasmic i...

In this paper, samples of mosses and lichens collected from Ivohibory Forest (south-central Madagascar) were studied in search for tardigrades. In total, 39 tardigrade taxa were identified, 21 of which are new records for Madagascar. Moreover, one of these is a new species for science. Bryodelphax beniowskii sp. nov., described here based on morpho...

Anhydrobiosis is considered to be an adaptation of important applicative implications because it enables resistance to the lack of water. The phenomenon is still not well understood at molecular level. Thus, a good model invertebrate species for the research is required. The best known anhydrobiotic invertebrates are tardigrades (Tardigrada), consi...

This paper is the fifth monograph of the series that describes the global records of limno-terrestrial water bears (Tardigrada). Here, we provide a comprehensive list of non-marine tardigrades recorded from Australasia, providing an updated and revised taxonomy accompanied by geographic co-ordinates, habitat, and biogeographic comments. It is hoped...

Cyanobacteria are good candidates for various martian applications as a potential source of food, fertilizer, oxygen, and biofuels. However, the increased levels of highly toxic perchlorates may be a significant obstacle to their growth on Mars. Therefore, in the present study, 17 cyanobacteria strains that belong to Chroococcales, Chroococcidiopsi...

Water availability is one of the most important factors for terrestrial life. Terrestrial habitats may periodically become dry, which can be overcome by an organism's capability to undergo anhydrobiosis. In animals, this phenomenon has been reported for invertebrates, with tardigrades being the best-known. However, different tardigrade species appe...

Anhydrobiosis is considered to be an adaptation of important applicative implications because it enables resistance to the lack of water. The phenomenon is still not well understood at molecular level. Thus, a good model invertebrate species for the research is required. The best known anhydrobiotic invertebrates are tardigrades (Tardigrada), consi...

Abstract. A new heterotardigrade genus, Zealandiscus gen. nov., is erected for the species Echiniscus palmai. Dorsal plates' sculpturing with sparsely distributed large hemispherical protuberances and very tiny granules distinguish this genus from all known members of the genus Echiniscus. The new genus is most similar to the genus Kristenseniscus...

Earth is one of the inner planets of the Solar System, but – unlike the others – it has an oxidising atmosphere, relatively stable temperature, and a constant geomagnetic field (GMF). The GMF does not only protect life on Earth against the solar wind and cosmic rays, but it also shields the atmosphere itself, thus creating relatively stable environ...

The diversity, distribution and ecology of aquatic Tardigrada in Poland remain poorly known. We reviewed the literature focused on tardigrades in Poland and recognized only 15 aquatic taxa which were reported from various freshwater and marine habitats. Among them, 12 are freshwater and three are marine taxa. Hypsibius dujardini is Poland’s most wi...

Mitochondrial alternative oxidase (AOX) is predicted to be present in mitochondria of several invertebrate taxa including tardigrades. Independently of the reason concerning the enzyme occurrence in animal mitochondria, expression of AOX in human mitochondria is regarded as a potential therapeutic strategy. Till now, relevant data were obtained due...

Two new tardigrade species from a moss sample collected in Canada, one representing Macrobiotus hufelandi complex and the second one belonging to the genus Bryodelphax, are described. Integrative analysis was undertaken based on morphological and morphometric data (using both light and scanning electron microscopy (SEM)) combined with multilocus mo...

Since we proposed the standardization of a three-letter abbreviation for the genera of the phylum Tardigrada (Perry et al. 2019) there have been 17 new genera and sub-genera described. In addition, we have been informed by colleagues using the three-letter abbreviations that some editors and reviewers have challenged the abbreviations as not meetin...

One of the largest inventories of tardigrades ever conducted occurred from 2000-2010 in the Great Smoky Mountains National Park, USA. Over 16,000 specimens were catalogued, 85 species were identified, 11 species new to science were described, and 16 other possible new species await further study. More than 20 papers have resulted from the GSMNP tar...

Tardigrada (also known as “water bears”) are hydrophilous microinvertebrates with a bilaterally symmetrical body and four pairs of legs usually terminating with claws. Water bears are quite complex animals and range from 50 to 1200 μm in length. Their body is divided into a head segment and four trunk segments, each bearing a pair of legs. They inh...

We used high-throughput sequencing of 16S rRNA to test whether tardigrade species are infected with Wolbachia parasites. We applied SILVA and Greengenes databases that allowed taxonomic classification of bacterial sequences to OTUs. The results obtained from both databases differed considerably in the number of OTUs, and only the Greengenes databas...

The Central American Isthmus has had profound effects on the evolution and distribution of larger marine organisms, but the impacts on meiobenthic animals have received little attention. Tardigrades are microscopic metazoan lobopodians that are ubiquitous in benthic communities worldwide, but little is known about marine tardigrades in Central Amer...

In the present study, we used integrative taxonomy to describe a population of Diploechiniscus oihonnae (Richters, 1903) from the neotype locality in Merok (Norway). We found no differences in the chaetotaxy formula between the life stages and sex of Dpl. oihonnae. The presence of filaments at B d in some specimens of Dpl. oihonnae appears to be ra...

Anhydrobiosis can be described as an adaptation to lack of water that enables some organisms, including tardigrades, to survive extreme conditions, even some that do not exist on Earth. The cellular mechanisms underlying anhydrobiosis are still not completely explained including the putative contribution of mitochondrial proteins. Since mitochondri...

Abstract: In this paper we applied an integrative taxonomy approach to describe a new tardigrade species from Madagascar. The description is based on morphological and morphometric data (using both light and scanning electron microscopy), combined with genetic data (nuclear sequences, i.e., 18S rRNA, 28S rRNA and mitochondrial COI sequences). Based...