Caribbean Naturalist 1 H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 22001177 CARIBBEAN NATURALIST No. 39N:1o–. 1339 Water Bears from the Caribbean Island of Antigua, with the Description of a New Macrobiotus Species (Tardigrada: Eutardigrada: Macrobiotidae) Harry A. Meyer1,*, Juliana G. Hinton1, W. Logan Gladney1, and Mary C. Klumpp1 Abstract - Tardigrada is a phylum of microscopic animals commonly found in mosses, lichens, leaf litter, and freshwater. The tardigrades of many of the islands of the Caribbean and countries bordering the region are virtually or entirely unknown. The tardigrade fauna of Antigua, an island in the West Indies, has not been studied. We collected leaf litter and moss from 2 sites and extracted tardigrades from the samples. Six species were found: Milnesium katarzynae, Hypsibius cf. convergens, Mesobiotus harmsworthi, Minibiotus sp. from the Minibiotus intermedius species complex, Paramacrobiotus sp. from the Paramacrobiotus areolatus species complex, Paramacrobiotus sp. from the P. richtersi species complex, and a new species of Macrobiotus. This is the first record of Milnesium katarzynae from the Caribbean. The new species, Macrobiotus deceptor n. sp., is most similar to Macrobiotus nelsonae and M. pallarii. Adults differ from both in lacking eyes or cuticular pores, and from M. nelsonae in having a more anterior insertion of the stylet supports and proportionally larger claws. Eggs of the new species differ from those of both M. nelsonae and M. pallarii in the structure of processes, and from those of M. pallarii in having 2 instead of 1 row of areoles surrounding each egg process. Introduction Tardigrades (Phylum Tardigrada), commonly known as water bears, are microscopic animals found in marine, freshwater, and terrestrial habitats. The first investigations of water bears in the West Indies were made in the mid-20th Century, when du Bois-Reymond Marcus (1960) found 4 species in the Netherlands Antilles. Since then, tardigrade collections have been published from Puerto Rico, the Dominican Republic, Saint Martin, United States Virgin Islands, Cuba, Grand Cayman, Curaçao, Los Testigos, Saint Lucia, Barbados, and Dominica (Kaczmarek et al. 2014a; Meyer 2011, 2013a, 2013b). There are no published records of tardigrades from Antigua or its coastal waters (Kaczmarek et al. 2014a, 2015a; Meyer 2013b; Miller and Perry 2016). In this paper, we report tardigrades found in terrestrial moss and leaf-litter samples from Antigua and describe a new species of Macrobiotus C.A.S. Schultze, 1834. Field-site Description The nation of Antigua and Barbuda consists of 3 main islands (Antigua, Barbuda, and Redonda), in the Leeward Islands of the Lesser Antilles in the Caribbean 1Department of Biology, McNeese State University, Lake Charles, LA 70609. *Corresponding author - hmeyer@mcneese.edu. Manuscript Editor: Rüdiger Bieler Caribbean Naturalist H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 2 Sea. The island of Antigua has an area of 108 km2; the highest point is Mount Obama (formerly Boggy Peak; maximum elevation of 402 m). The climate is tropical. Average monthly maximum temperatures range from 27.9 to 30.5 °C (Edwards 2008). Rainfall averages 1050 mm per year; the driest months are January through April, and the wettest are September through November (Prosper et al. 2009). Most of the soil is sandy, supporting scrub vegetation. As is true of many Caribbean Islands much of the original habitat was replaced by cane sugar agriculture; currently 11% of the island is forested (Edwards 2008). On 28 May 2014, we collected 12 samples of moss and leaf litter at 2 sites in Saint Mary Parish, Antigua: (1) Christian Valley—moss and leaf litter from a dry seasonal gully, 17°03'17"N, 61°51'25"W, at elevation of 48 m; and (2) Body Bond Nature Park—moss from trees and moss from a concrete weir, 17°03'42"N, 61°49'12"W, at elevation of 38 m. Methods Samples were stored in paper envelopes. In the laboratory, cryptogams and leaf litter were soaked overnight in water and inspected for tardigrades with a dissecting microscope (Nikon SMZ-U Zoom 1:10). Animals and eggs were mounted in polyvinyl lactophenol and examined under 100x oil immersion using phase microscopy (Nikon Eclipse 50i). We measured body length from the mouth to the posterior end, excluding legs IV, of specimens of a new species of Macrobiotus using imaging software (NIS-Elements D 2.30, SPI). Macroplacoid length sequence is given according to Kaczmarek et al. (2014b). The pt index is the ratio of the length of a given structure to that of the buccal tube expressed as a percentage (Pilato 1981). We handled morphometric using the Macrobiotoidea ver. 1.1 template available from the Tardigrada Register, www.tardigrada.net/register (Michalczyk and Kaczmarek 2013). Bartels et al. (2011) demonstrated that morphometric traits in Tardigrada are often allometric (i.e., disproportionate growth rates in different structures) rather than isometric. They recommended that a normalization technique be used to eliminate body-size effects and that 2 metrics be included in species descriptions: b, the allometric exponent, and a*, the Y-intercept of the regression line of the Thorpe normalized trait versus body size (i.e., a* is the theoretical value of a given trait when adjusted to the mean body size of the population). Using the techniques described in Bartels et al. (2011), we calculated b and a* for the new species of Macrobiotus, using buccal tube length as an indicator of body size. Tardigrade taxonomy and nomenclature in this paper follow Bertolani et al. (2014), Degma and Guidetti (2007), Degma et al. (2009–2016), and Guidetti and Bertolani (2005). Comments on species distribution are based on Caicedo et al. (2014), Kaczmarek et al. (2014a), Kaczmarek et al. (2015b), McInnes (1994), and Meyer (2011, 2013a, 2013b). We identified species using diagnostic keys provided by Ramazzotti and Maucci (1983) and Morek et al. (2016), and original descriptions by Kaczmarek et al. (2004), Murray (1907), and Urbanowicz (1925). The new species was compared with literature descriptions and illustrations of similar species Caribbean Naturalist 3 H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 (Guidetti 1998, Bertolani and Rebecchi 1993, Maucci 1954), and to eggs of Macrobiotus pallarii Maucci, 1953. Species complexes are considered to be cosmopolitan if they meet the criterion of Pilato and Binda (2001), namely that they have been reported from 5 or more ecozones. All specimens are deposited in the W.A.K. Seale Museum, Department of Biology, McNeese State University, Lake Charles, LA, USA. Results Six samples had no tardigrades. We found 87 adult specimens and 32 eggs, representing 6 genera and 7 species of tardigrade: Milnesium katarzynae Kaczmarek, Michalczyk and Beasley, 2004 Body Pond Nature Park, moss. Nine specimens, slide SMLA 16044. Milnesium katarzynae has been reported from Costa Rica and Colombia. This is the first record from a West Indian island. Hypsibius cf. convergens (Urbanowicz, 1925) Christian Valley, leaf litter. Four specimens, slide SMLA 16040. Specimen condition and orientation precluded identification to species. Hypsibius convergens is currently considered a cosmopolitan complex of species, and has been reported from Dominica and Saint Lucia in the West Indies (Kaczmarek et al. 2014a). Macrobiotus deceptor n. sp. (Figs. 1–5; Tables 1–2) Diagnosis. Smooth cuticle without pores or eyespots. Wide buccal tube. Oral cavity armature consisting of narrow anterior and broad posterior bands of teeth, and dorsal and ventral transverse crests. Two long macroplacoids and a long microplacoid. Robust claws of the “hufelandi” type, with lunules and pronounced accessory points. Eggs laid freely, with long tapering processes, reticulated except for the medial region, surrounded by double rows of areoles. Material examined. Holotype, 14 paratypes, and 15 eggs collected from leaf litter in Christian Valley, Saint Mary Parish, Antigua (17°03'17"N, 61°51'25"W; elevation = 48 m) were used for morphometric analysis. Three additional specimens and 13 additional eggs were found in the same sample; poor condition and/or unsuitable orientation made them unsuitable for inclusion in morphometric analysis or designation as paratypes. Type depository. The holotype (slide SMLA16039), paratypes (slides SMLA16032–16033, 16034, 16036–16038), and eggs (SMLA 16031, 16032, 16035, 16038, 16039) are deposited in the W.A.K. Seale Museum, Department of Biology, McNeese State University, Lake Charles, LA 70609, USA. Etymology. The specific epithet is a Latin noun in apposition meaning “deceiver”. The name was given because after superficial examination of the eggs, we had for several months mistaken them for those of a different species. Description of the holotype. Morphometric measurements in Table 1. Sex indeterminate. Body white or transparent, cuticle smooth without pores (Fig. 1A). Eyes not visible in live specimens. No granulation visible on legs. Caribbean Naturalist H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 4 Table 1. Morphometric data and pt values of selected structures of the holotype and 14 paratypes of Macrobiotus deceptor n. sp. Range refers to the smallest and largest structure found among all measured specimens. Abbreviations: n = number of specimens measured, SD =standard deviation, n.a. = not applicable, n.m.= not measureable, pt = pt index, b = allometric exponent, and a* = Y-intercept of the regression of the Thorpe normalized trait versus buccal tube length. Values of b with an asterisk indicate that the trait was significantly allo metric. Range Mean SD Holotype a* Character n μm pt μm pt μm pt μm pt b (μm ) Body length 13 360–647 952 –1382 475 1147 73 123 486 1154 2.20* 477 Buccal tube Length 15 37.8–46.8 n.a. 41.3 n.a. 2.4 n.a. 42.1 n.a. n.a. n.a. Stylet support insertion point 14 29.7–36.7 76.4–79.6 32.1 78.1 1.8 1.0 32.6 77.4 0.96 32.1 External width 15 6.5–9.4 17.2–22.8 8.1 19.5 0.8 1.5 7.4 17.6 1.03 8.2 Internal width 14 5.3–7.8 14.0–19.5 6.6 16.1 0.8 1.6 6.4 15.2 1.10 6.9 Placoid lengths Macroplacoid 1 14 9.7–15.4 25.7–32.9 11.8 28.7 1.5 2.3 12.2 29.0 1.75* 11.9 Macroplacoid 2 14 6.7–10.9 16.0–23.3 7.9 19.1 1.1 1.9 7.4 17.6 1.51 7.4 Microplacoid 14 3.7–7.0 7.2–15.0 4.4 10.6 1.2 2.3 5.5 13.1 2.86 4.1 Macroplacoid row 14 17.6–27.6 46.6–59.0 21.0 50.8 2.5 3.7 20.9 49.6 1.69* 20.7 Placoid row 14 22.0–34.9 58.1–74.6 26.3 63.7 3.4 5.4 26.8 63.7 1.75* 26.1 Claws I lengths External primary branch 7 11.3–14.1 26.6–31.0 12.5 29.4 1.0 1.8 12.8 30.4 0.95 12.0 External secondary branch 7 9.1–11.7 21.7–26.0 9.9 23.2 1.0 1.7 9.2 21.9 1.20 9.5 Internal primary branch 8 9.6–13.6 25.4–29.4 11.6 27.9 1.2 1.3 11.4 27.1 1.51 11.6 Internal secondary branch 7 8.3–10.3 21.7–24.0 9.5 22.9 0.7 1.0 10.0 23.8 0.83 9.6 Caribbean Naturalist 5 H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 Table 1, continued. Range Mean SD Holotype a* Character n μm pt μm pt μm pt μm pt b (μm ) Claws II lengths External primary branch 9 11.1–14.7 27.9–34.3 12.3 30.0 1.0 2.0 12.4 29.5 1.27 11.9 External secondary branch 9 9.1–12.0 21.5–28.0 10.0 24.3 0.9 2.3 10.6 25.2 0.51 9.1 Internal primary branch 6 10.3–13.3 27.2–30.3 11.9 28.1 1.1 1.1 11.5 27.3 1.33 11.5 Internal secondary branch 6 8.5–11.3 20.6–24.1 9.5 22.6 1.1 1.5 10.1 24.0 1.28 9.4 Claws III lengths External primary branch 8 12.0–14.0 29.2–32.3 12.7 30.6 0.7 1.1 12.4 29.5 0.81 12.4 External secondary branch 8 9.2–10.6 21.9–26.5 9.9 23.9 0.5 1.3 10.3 24.5 0.45 10.0 Internal primary branch 7 10.3–13.4 25.2–30.1 11.9 28.1 1.1 1.7 11.2 26.6 1.29 11.7 Internal secondary branch 5 8.9–12.3 21.2–26.3 10.1 23.6 1.4 2.2 n.m. n.m. 1.80 9.4 Claws 1V lengths Anterior primary branch 8 11.4–13.5 27.5–31.2 12.2 29.0 0.7 1.3 11.7 27.8 0.63 12.1 Anterior secondary branch 7 9.0–10.8 21.5–25.0 9.8 23.5 0.8 1.4 10.3 24.5 1.23 9.5 Posterior primary branch 8 11.6–14.7 28.2–33.9 12.7 30.6 0.9 2.1 12.0 28.5 1.25 12.4 Posterior secondary branch 7 8.7–10.9 20.1–26.2 10.0 24.3 0.8 2.1 10.2 24.2 0.24 9.5 Caribbean Naturalist H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 6 Mouth antero-ventral. Ten peribuccal lamellae (Fig. 1B). Oral cavity armature: narrow anterior band of small teeth; wide posterior band of larger teeth, increasing in size from anterior to posterior (Fig. 2A). Three transverse crests: dorsal crests longer than ventral (Fig. 2A–D). Oval pharyngeal bulb (length = 48.2 μm, width = 48.5 μm; Fig. 1B). Pharyngeal tube wide; length of ventral lamina approximately half that of buccal tube (Fig. 2D). Two rod-shaped macroplacoids and a large microplacoid; macroplacoid sequence 2 < 1 (Fig. 1B). First macroplacoid long, with medial constriction (Fig. 1C). Second macroplacoid shorter (length is 61% of first) with subterminal constriction (Fig. 1C). Massive claws, of “hufelandi” type (Fig. 3). Claws on all legs approximately the same size, with external primary branches slightly longer than inner primary branches. Primary branches with pronounced accessory points. Lunules present at base of all claws; lunules I–III small (width = 3.1–3.8 μm), with no evident teeth (Fig. 3A); lunules IV larger (anterior: 3.3 μm, posterior :5.8 μm), with teeth of irregular size (Fig. 3B). Description of eggs. Morphometric measurements given in Table 2. Eggs white or transparent, laid freely (Fig. 4A). Long, conical processes with tapering distal end. Processes separated from one another by 2 rows of 10 to 12 polygonal areoles in which no sculpture is visible (Fig. 4A, B). Basal region of processes with reticular pattern of meshes of variable size and shape; medial region appears smooth, with no annulation visible using light microscopy; apical region with small bubblelike cells similar to those of Mesobiotus reinhardti (Michalczyk and Kaczmarek, 2003) (Fig. 4B). Most processes terminate in a single point (Fig. 4C); some process Figure 1. Macrobiotus deceptor n. sp. from Antigua. (A) Habitus of holotype; scale bar = 100 μm. (B) Buccopharyngeal apparatus of holotype; scale bar = 20 μm. (C) Placoids; upper arrow indicates medial constriction of first macroplacoid, lower arrow indicates subterminal constriction of second macroplacoid; scale bar = 5 μm. Caribbean Naturalist 7 H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 tips bifurcated (Fig. 4D). One egg was mounted in the process of hatching, making the assignment of these eggs to Macrobiotus deceptor definitive. Figure 2. Macrobiotus deceptor n. sp. from Antigua. Scale bar = 10 μm. (A) Oral cavity armature of paratype, dorsal view; horizontal arrow indicates posterior band of teeth, vertical arrow indicates dorsal transverse crest. (B) Oral cavity armature of holotype, dorsal view; horizontal arrow indicates anterior band of teeth. (C) Oral cavity armature and buccal tube of paratype, ventral view. (D) Oral cavity armature of paratype, ventral view; arrow indicates subdivided median ventral crest. Caribbean Naturalist H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 8 Remarks. In some specimens, the median ventral crest is subdivided into 2 small segments (Fig. 2D). In large specimens (>600 μm long), the lunules of the claws on the fourth pair of legs are more strongly dentate (Fig. 3C) than in smaller specimens. Differential diagnosis. Macrobiotus deceptor most closely resembles M. nelsonae Guidetti, 1998, and M. pallarii. Adults of M. deceptor are more similar to M. pallarii than to M. nelsonae, with considerable overlap in morphometry. Figure 3. Macrobiotus deceptor n. sp. from Antigua. Scale bars = 10 μm. (A) Claws of first pair of legs of paratype. (B) Claws of fourth pair of legs of 509 μm long paratype. (C) Claws of fourth pair of legs of 657 μm long paratype; arrow indicates strongly dentate lunule of anterior claw. Caribbean Naturalist 9 H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 Adults (i.e., specimens >360 μm long) of the new species differ from those of M. nelsonae in lacking eyes or cuticular pores, in their smaller size (maximum length of M. deceptor 647 μm; maximum length of M. nelsonae 925 μm), in having a more anterior insertion of the stylet supports (pt 76.4–79.6 in M. deceptor; 80.9–84.5 in M. nelsonae), and in having proportionally larger claws (e.g., pt Table 2. Morphometric data of selected structures in eggs of Macrobiotus deceptor sp.n. Range refers to the smallest and largest structure found among all measured specimens. n = number of specimens measured, SD =standard deviation. Character n Range (μm) Mean (μm) SD (μm) Diameter of egg without processes 15 62.2–98.1 78.1 12.7 Diameter of egg with processes 13 109.1–157.5 125.3 13.7 Height of process 13 21.2–30.3 25.7 3.0 Process base width 15 14.6–23.6 19.8 2.4 Process base/height ratio 13 63%–102% 79% Distance between processes 13 2.1–8.2 4.5 1.9 Number of processes on egg circumference 13 10–14 12.3 1.0 Number of processes per egg hemisphere 6 12–15 12.8 1.2 Figure 4. Macrobiotus deceptor n. sp. from Antigua. (A) Egg; scale bar = 20 μm. (B) Detail of egg surface; scale bar = 5 μm. (C). Typical egg processes with pointed tips; scale bar = 5 μm. (C) Egg processes with bifurcated tips; scale bar = 5 μm. Caribbean Naturalist H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 10 of the exterior primary branch of claw I 26.6–31.0 in M. deceptor; 21.0–25.7 in M. nelsonae). The eggs of M. deceptor and M. nelsonae are similar in habitus (e.g., conical processes with reticulation, and processes surrounded by double rows of 10–12 areoles). They can be distinguished by details of the structure of the processes: those of M. nelsonae have rounded, annulated apices without reticulation, while in M. deceptor the apices are longer, tapering, and reticulated, with a medial zone devoid of reticulation. Adults of M. deceptor differ from M. pallarii in lacking eyes or cuticular pores, both of which are present in M. pallarii (R. Guidetti, University of Modena and Reggio Emilia, Modena, Italy, pers. comm.). The eggs of the new species differ from those of M. pallarii in having 2 rows of 10–12 areoles surrounding each process rather than 8 or 9 in a single row (Fig. 5A). Compared to those of M. deceptor, the processes of M. pallarii eggs are more rounded and have uniform reticulation (Fig. 5B). Mesobiotus harmsworthi (Murray, 1907) Body Pond Nature Park and Christian Valley, leaf litter and moss. Five specimens and 3 eggs, slides SMLA 16034, 16035, 16037–16039, 16041, 16043. Mesobiotus harmsworthi is considered a cosmopolitan species complex, and has been reported from Barbados and Saint Thomas; members of the species complex have also been reported from Dominica and Los Testigos (Kaczmarek et al. 2014a). Minibiotus sp. Body Pond Nature Park, moss. Nine specimens, slide 16044. These animals belong to the cosmopolitan Minibiotus intermedius (Plate, 1889) species complex. Absence of eggs precluded further identification. Minibiotus intermedius has been reported from Barbados, Cayman Islands, and the Dominican Republic in the West Indies; members of the species complex have also been reported from Dominica and Saint Martin (Kaczmarek et al. 2014a, Meyer 2011). Figure 5. Macrobiotus pallarii. Paratype eggs of the Maucci collection of the Natural History Museum of Verona, Italy. Photomicrographs by Roberto Guidetti. Scale bars = 10 μm. (A) Egg CT732a. (B) Processes of egg CT732b. Caribbean Naturalist 11 H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 Paramacrobiotus sp. 1 Christian Valley, leaf litter. 26 specimens, slides 16030, 16032–16038. These animals belong to the Paramacrobiotus areolatus (Murray, 1907) species complex. Absence of eggs precluded further identification. Paramacrobiotus areolatus has been reported from Cayman Islands and the Dominican Republic in the West Indies; members of the species complex have also been reported from Dominica and Saint Thomas (Kaczmarek et al. 2014a). Paramacrobiotus sp. 2 Christian Valley, leaf litter. Three specimens, slides 16033, 16040. These animals belong to the Paramacrobiotus richtersi (Murray, 1911) species complex. Absence of eggs precluded further identification. Paramacrobiotus richtersi has been reported from Barbados, Cayman Islands, Dominica, the Dominican Republic and Saint Lucia in the West Indies; members of the species complex have also been reported from Saint Martin and Saint Thomas (Kaczmarek et al. 2014a). Discussion Five of the 7 tardigrade species collected from the island of Antigua belong to cosmopolitan species groups. All 5 have previously been reported from Caribbean islands. Milnesium katarzynae is also known from Colombia and Costa Rica and is probably widespread throughout the Caribbean region (Kaczmarek et al. 2014a). The new species, Macrobiotus deceptor, appears to be most closely related to Macrobiotus nelsonae, a species hitherto reported only from Tennessee, USA (Meyer 2013b). It is also very similar to M. pallarii, a species which is widely distributed in Europe and has been collected in the Western Hemisphere from the USA (Alaska, Tennessee, and North Carolina) and Costa Rica (McInnes 1994, Meyer 2013b). Although recent years have seen an increase in tardigrade research in the islands of the Caribbean and countries bordering it, many gaps in our knowledge remain. Only Costa Rica in Central America has been extensively surveyed; the remaining countries of Central America have received virtually no attention (e.g., Nicaragua) or none at all (Kaczmarek et al. 2014a, Meyer 2013b). The tardigrade fauna of many Caribbean islands is either virtually (e.g., Cuba and Saint Lucia) or entirely (e.g., the Bahamas, Grenada, Guadeloupe, Jamaica, Martinique, Saint Kitts and Nevis, and Saint Vincent and the Grenadines) unknown. Acknowledgments The Government of Antigua and Barbuda is gratefully acknowledged for granting us permission to conduct this survey. In particular, we thank Adriel Thibou and Algernon Grant of the Antiguan Forestry Unit, Ministry of Agriculture, Forestry and Fisheries for transportation and help in locating suitable sampling sites. Roberto Guidetti provided us with valuable advice and unpublished photographs of eggs from the Maucci collection in the Natural History Museum of Verona, Italy. This research was funded by the award of a McNeese State University Endowed Professorship to Harry A. Meyer. Caribbean Naturalist H.A. Meyer, J.G. Hinton, W.L. Gladney, and M.C. Klumpp 2017 No. 39 12 Publisher’s Note The electronic version of this article in Portable Document Format (PDF) will represent a published work according to the International Commission on Zoological Nomenclature (ICZN), and hence the new names contained in the electronic version are effectively published under that Code from the electronic edition alone. This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the ICZN. The ZooBank LSIDs (Life Science Identifiers) can be resolved and the associated information viewed through any standard web browser by appending the LSID to the prefix http://zoobank.org/. The LSID for this publication is: urn:lsid:zoobank.org:pub:841C18DD-CC8C-4F1A-8030-10DC6F17C517. The LSID for the new species (Macrobiotus deceptor) is: urn:lsid:zoobank.org:act:906B1429-5442- 40A9-947F-9AFE687188F3. The online version of this work is archived and available from the following digital repositories: Zenodo. Literature Cited Bartels, P.J., D.R. Nelson, and R.P. Exline. 2011. Allometry and the removal of body size effects in the morphometric analysis of tardigrades. Journal of Zoological Systematics and Evolutionary Research 49 (Supplement 1):17–25. Bertolani, R., and L. Rebecchi. 1993. A revision of the Macrobiotus hufelandi group (Tardigrada, Macrobiotidae), with some observations of the taxonomic characters of eutardigrades. Zoologica Scripta 22:127–152. Bertolani, R., R. 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