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Camarda D, Massa E, Guidetti R, Lisi O. A new, simplified, drying protocol to prepare tardigrades for scanning electron microscopy. Microsc Res Tech 2024; 87:716-726. [PMID: 37983688 DOI: 10.1002/jemt.24460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/20/2023] [Accepted: 11/08/2023] [Indexed: 11/22/2023]
Abstract
A new protocol for preparation of tardigrades for scanning electron microscope (SEM) analysis is proposed. The more conventional protocols require various steps and a long time to obtain good drying of water bears, together with specific and uncommon instruments (i.e., critical point dryer) or highly volatile toxic compounds (i.e., hexametildisilazane). The new protocol can be performed using few and simple instruments and materials, all easily accessible, and produces a high yield in terms of dried animals in excellent condition for the observation of external morphological structures with SEM. The acquired data exhibit considerable promise, and the proposed methodology shows potential for application to other meiofaunal groups, including small arthropods, nematodes, and rotifers. RESEARCH HIGHLIGHTS: Cheap, safe, and fast new method for Tardigrada preparation for SEM. With the new protocol, the number of animals required for SEM studies is minimized. New protocol is potentially applicable to the study of other meiofaunal soft-bodied taxa.
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Affiliation(s)
- Daniele Camarda
- Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, Italy
| | - Edoardo Massa
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Roberto Guidetti
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Oscar Lisi
- Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, Italy
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Bertolani R, Cesari M, Giovannini I, Rebecchi L, Guidetti R, Kaczmarek Ł, Pilato G. The Macrobiotus persimilis-polonicus complex (Eutardigrada, Macrobiotidae), another example of problematic species identification, with the description of four new species. ORG DIVERS EVOL 2022. [DOI: 10.1007/s13127-022-00599-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Cesari M, Giovannini I, Altiero T, Guidetti R, Cornette R, Kikawada T, Rebecchi L. Resistance to Extreme Stresses by a Newly Discovered Japanese Tardigrade Species, Macrobiotus kyoukenus (Eutardigrada, Macrobiotidae). INSECTS 2022; 13:insects13070634. [PMID: 35886811 PMCID: PMC9315711 DOI: 10.3390/insects13070634] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Tardigrades are small micrometazoans able to resist several environmental stresses in any stage of their life cycle. The integrated molecular and morphological analysis of tardigrade specimens collected in Tsukuba (Japan) revealed that this population represents a new species, Macrobiotus kyoukenus sp. nov., belonging to the genus Macrobiotus, one of the most speciose and widespread water bear taxon. The stress resistance capabilities of M. kyoukenus sp. nov. have been tested by submitting animals to extreme desiccation, rapid freezing, and high levels of ultraviolet radiations (UVB and UVC). Animals were able to survive desiccation and freezing, and both hydrated and desiccated animals showed a high tolerance to increasing UV radiations. Overall, our findings contribute to the discovery of a larger tardigrade biodiversity in Japan, and the tolerance capabilities of M. kyoukenus sp. nov. show that this new species could become an emerging model for stress resistance studies. Abstract Tardigrades are small micrometazoans able to resist several environmental stresses in any stage of their life cycle. An integrated analysis of tardigrade specimens collected in Tsukuba (Japan) revealed a peculiar morphology and a new sensory field in the cloaca. Molecular taxonomy and phylogenetic analysis on different genes (COI, ITS2, 18S and 28S) confirmed that this population is a new species, Macrobiotus kyoukenus sp. nov., belonging to the widespread Macrobiotus hufelandi group. The stress resistance capabilities of M. kyoukenus sp. nov. have been tested by submitting animals to extreme desiccation, rapid freezing, and high levels of ultraviolet radiations (UVB and UVC). Animals were able to survive desiccation (survivorship 95.71 ± 7.07%) and freezing up to −80 °C (82.33 ± 17.11%). Both hydrated and desiccated animals showed a high tolerance to increasing UV radiations: hydrated animals survived to doses up to 152.22 kJ m−2 (UVB) and up to 15.00 kJ m−2 (UVC), while desiccated specimens persisted to radiations up to 165.12 kJ m−2 (UVB) and up to 35.00 kJ m−2 (UVC). Present data contribute to the discovery of a larger tardigrade biodiversity in Japan, and the tolerance capabilities of M. kyoukenus sp. nov. show that it could become a new emerging model for stress resistance studies.
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Affiliation(s)
- Michele Cesari
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 213/d, 41125 Modena, Italy; (M.C.); (R.G.); (L.R.)
| | - Ilaria Giovannini
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 213/d, 41125 Modena, Italy; (M.C.); (R.G.); (L.R.)
- Department of Education and Humanities, University of Modena and Reggio Emilia, Viale Timavo, 93, 42121 Reggio Emilia, Italy;
- Correspondence:
| | - Tiziana Altiero
- Department of Education and Humanities, University of Modena and Reggio Emilia, Viale Timavo, 93, 42121 Reggio Emilia, Italy;
| | - Roberto Guidetti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 213/d, 41125 Modena, Italy; (M.C.); (R.G.); (L.R.)
| | - Richard Cornette
- Division of Biomaterial Sciences, National Institute of Agrobiological Sciences, NARO, 1-2 Owashi, Tsukuba 305-0851, Ibaraki, Japan; (R.C.); (T.K.)
| | - Takahiro Kikawada
- Division of Biomaterial Sciences, National Institute of Agrobiological Sciences, NARO, 1-2 Owashi, Tsukuba 305-0851, Ibaraki, Japan; (R.C.); (T.K.)
| | - Lorena Rebecchi
- Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 213/d, 41125 Modena, Italy; (M.C.); (R.G.); (L.R.)
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Macrobiotus naginae sp. nov., a New Xerophilous Tardigrade Species from Rokua Sand Dunes (Finland). Zool Stud 2022; 61:e22. [PMID: 36330020 PMCID: PMC9579948 DOI: 10.6620/zs.2022.61-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/11/2022] [Indexed: 02/08/2023]
Abstract
Animals that colonize soil show specific adaptations to soil. Compared to closely related species living on the surface, the limbs of soil-dwelling animals are often shortened, reduced, or absent to allow a less restricted passage through cavities between soil particles. This pattern of limb reduction has also been observed in tardigrades, where multiple lineages that colonized the below-ground habitat show independent reduction and/or loss of legs and claws. In the tardigrade superfamily Macrobiotoidea, leg and claw reductions are a common trait found in the Macrobiotus pseudohufelandi complex. This rarely found species complex currently contains four nominal taxa. Here we describe, with the use of integrative taxonomy, Macrobiotus naginae sp. nov., a new species in the Macrobiotus pseudohufelandi complex from inland sand dunes in Finland. We also provide a dichotomous key to the Macrobiotus pseudohufelandi complex to assist with their identification in future studies.
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Guidetti R, Cesari M, Giovannini I, Ebel C, Förschler MI, Rebecchi L, Schill RO. Morphology and taxonomy of the genus Ramazzottius (Eutardigrada; Ramazzottiidae) with the integrative description of Ramazzottius kretschmanni sp. nov. THE EUROPEAN ZOOLOGICAL JOURNAL 2022. [DOI: 10.1080/24750263.2022.2043468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- R. Guidetti
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - M. Cesari
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - I. Giovannini
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - C. Ebel
- Department Visitor Information, Black Forest National Park, Seebach, Germany
| | - M. I. Förschler
- Department of Ecosystem Monitoring, Research and Conservation. Black Forest National Park, Freudenstadt, Germany
| | - L. Rebecchi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - R. O. Schill
- Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
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Stec D, Vončina K, Møbjerg Kristensen R, Michalczyk Ł. The Macrobiotus ariekammensis species complex provides evidence for parallel evolution of claw elongation in macrobiotid tardigrades. Zool J Linn Soc 2022. [DOI: 10.1093/zoolinnean/zlab101] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Abstract
The recent integrative revision of the family Macrobiotidae demonstrated monophyly of the genus Macrobiotus and its complex, mosaic morphological evolution. Here, we analyse three Macrobiotus populations that exhibit extraordinary claw morphology characterized by elongated primary branches. Two of these populations, from the Arctic, were initially classified as Macrobiotus ariekammensis, but detailed integrative analyses resulted in splitting them into two subspecies: Macrobiotus ariekammensis ariekammensis and Macrobiotus ariekammensis groenlandicus subsp. nov.. The third population was Macrobiotus kirghizicus from Kyrgyzstan. Given the unusual phenotype of the above-mentioned taxa, we tested whether they constitute a distinct lineage in the family Macrobiotidae and could be delineated as a new genus. Although the phylogenetic investigation showed that the three taxa form a monophyletic group, the clade is nested in the genus Macrobiotus. Therefore, despite their morphological distinctiveness, a new genus cannot be established and we group these taxa in the Macrobiotus ariekammensis species complex instead. The complex includes the three above-mentioned taxa and Macrobiotus ramoli, which is included based on morphological characters. Moreover, our results provide evidence for rapid parallel evolution of long claws in macrobiotid tardigrades inhabiting cold and icy environments. Finally, we discuss the validity of the recent suppression of the genus Xerobiotus, which gathers macrobiotids with reduced claws.
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Affiliation(s)
- Daniel Stec
- Department of Invertebrate Evolution, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
- Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016 Kraków, Poland
| | - Katarzyna Vončina
- Department of Invertebrate Evolution, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | | | - Łukasz Michalczyk
- Department of Invertebrate Evolution, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
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