taxonID	type	description	language	source
03F8375C9D38FF82FF33A329FD30C571.taxon	description	Forbes (1882): 641 – 642, Plate IX, Figs. 12 – 15 Herrick (1884): 22 – 23, Plate N, Fig. 11 Birge (1918): 693, Figs. 1060, 1061 a Brooks (1959): 603, Figs. 27.12 a, b Pennak (1953): 364 – 365, Figs. 227 a, b Pennak (1978): 365 – 366, Figs. 254 a, b Pennak (1989): 386 – 387, Figs. 12 a, b Dodson & Frey (1991): 746 – 747, Fig. 20.7	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D38FF82FF33A329FD30C571.taxon	etymology	Etymology. glacialis refers to the near restriction of this species to regions of North America that were glaciated during the Pleistocene.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D38FF82FF33A329FD30C571.taxon	materials_examined	Type locality. Wren Lake, Ontario (45.183 º N, 78.866 º W). This lake is situated near Carnarvon, Ontario, approximately 3 km past the Leslie M. Frost Natural Resources Centre on Hwy 35 N. Type specimens. Holotype: an ovigerous female in ethanol deposited in the CMN under accession number CMNC 2007 - 0745 (collection date Sept. 29 th 2007). Paratypes: Twenty ovigerous females, also from Wren Lake, Ontario, preserved in ethanol, deposited in the CMN under accession number CMNC 2007 - 0746 (collection date Sept. 29 th 2007). Material examined. Other habitats with H. glacialis are listed in Appendix A. Morphological description. FEMALE. Representative photomicrographs are shown in Figure 7. The jelly coat is of the Z type, in which the anterior jelly curl is relatively straight and ends in a short curve posteriorly toward the carapace, and the lateral lobes are divided (see Montvilo et al. 1987). Adult female carapace lengths range from 0.68 – 1.30 mm (mean 0.98 mm), while carapace heights range from 0.75 – 1.82 mm (mean 1.26 mm). The H / L ratios range from 0.61 – 1.95 (mean 1.30). The ventral carapace margins usually have many, tightly-spaced spinules posteriorly, but are often smooth anteriorly. Anal spine number is less variable than in H. gibberum, ranging from 11 – 20 (mean 15.1). H. glacialis typically possesses at least one basal spine on each postabdominal claw. Each claw has a row of denticles running laterally from the base of the claw to its midpoint.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D38FF82FF33A329FD30C571.taxon	description	MALE. Males were encountered in autumn collections. The jelly coat is present and resembles that of the female of this species. Mature males are often half the size of adult females, with individuals ranging from 0.40 – 0.63 mm in length (CLR, pers. obs.). The ventral carapace margin is spinulated posteriorly, but is smooth anteriorly. The postabdomen is long and terminates posteriorly with two postabdominal claws. A single row of anal spines runs ventro-laterally on each side of the postabdomen (range 13 – 17). There is one basal spine on each postabdominal claw, and each claw invariably has a row of denticles running laterally from the base of the claw to its midpoint. Differential diagnosis. Holopedium glacialis can be distinguished from all members of the H. amazonicum species complex by its possession of at least one basal spine on each postabdominal claw. It is morphologically indistinguishable from H. gibberum, although they have largely allopatric distributions (Fig. 4 a, b). Holopedium glacialis can be biochemically distinguished from North American H. gibberum at the Gpi locus. Holopedium glacialis was never found to possess Gpi 114, while H. gibberum was monomorphic for this allele. COI mtDNA sequence divergence between H. glacialis and H. gibberum averages 13.1 %. Based on current evidence, individuals showing less than 4.3 % divergence from a representative COI mtDNA sequence (GenBank AF 245355) belong to H. glacialis.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D38FF82FF33A329FD30C571.taxon	distribution	Distribution. Holopedium glacialis presumably occurs over most of the formerly glaciated regions of North America (Fig. 4 a), from the Coastal and Rocky Mountain ranges in the west through to the Atlantic coast in the east, excepting the central Great Plains, where habitats with suitable water chemistry are absent (see Rowe 2000 for a discussion of the ecological requirements of Holopedium). It occurs as far south as the Sierra Nevada mountains of California and the Rocky Mountains of Colorado, but in the east there are no confirmed populations south of New York State. It occurs sympatrically with H. atlanticum in New Brunswick and Maine, with no evidence of hybridization. H. glacialis is also present in the Canadian arctic, but not north of 68.5 ° N latitude. The northernmost habitats were a few lakes on the Melville Peninsula, including three in which it was sympatric with H. gibberum, again with no evidence of hybridization. Breeding system. Many populations were invariant, but 43 of 59 polymorphic populations were in H-W equilibrium, suggesting that at least these populations reproduce by cyclical parthenogenesis. Males were discovered in several populations in the spring and in larger numbers in the autumn. The few single-species populations in H-W disequilibrium were due to occasional heterozygote excesses or deficits, patterns that may result from extended bouts of asexual reproduction.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3EFF80FF33A379FB6EC699.taxon	description	Stingelin (1904 a): 54 – 64, Table 1, Figs. 1 – 2 Stingelin (1904 b): 577 – 578, Table 20, Figs. 1 – 2 Thomasson (1955): No figures (paper incorrectly identifies specimens as H. gibberum) Korovchinsky (1992): 77 – 78, Figs. 378 – 381 Paggi (1995): 912, 930 – 931. Figs. 14 – 15 Korovchinsky (2004): 345 – 348, Fig. 141	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3EFF80FF33A379FB6EC699.taxon	etymology	Etymology. amazonicum refers to the distribution of this species in waterbodies throughout the Amazon River basin.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3EFF80FF33A379FB6EC699.taxon	materials_examined	Type locality. Rio Aramá Grande on Marajó Island at the mouth the Amazon River in Brazil (Stingelin 1904 a; approx. 1.02 ° S, 49.24 ° W). Type specimens. Stingelin’s (1904 a) type material is housed in the Naturmuseum Olten (Kirchgasse 10, CH – 4600 Olten, Switzerland; Dr. D. Vallen, curator). The material consists of two mounts, with some adult females and many juveniles from “ Amazonas, 1900 ”. One of the females is designated as the lectotype, and the others as paralectotypes. Voucher specimens. Twenty ovigerous females from Lago Coari, Amazonas, Brazil (collected by P. Mera, INPA, Manaus, Amazonas, on May 24, 1996; 4.08 ° S, 63.14 ° W) were deposited in the CMN under accession number CMNC 2007 - 0740 and an additional 30 ovigerous females from this collection were deposited at INPA, Manaus, Amazonas. Material examined. Other habitats with H. amazonicum are listed in Appendix A. Morphological description. FEMALE. Representative photomicrographs are shown in Fig. 8. In this study, due to specimens’ preservation in formalin, jelly coat sculpturing was not discernable. Females are small, with adult carapace lengths ranging from 0.39 – 1.27 mm (mean 0.74 mm), while carapace heights range from 0.32 – 1.17 mm (mean 0.71 mm). The H / L ratios range from 0.66 – 1.64 (mean 0.99). The ventral carapace margin has many, tightly-spaced spinules posteriorly, but is smooth anteriorly. Anal spine number ranges from 5 – 12 (mean 8.37). Holopedium amazonicum lacks a basal spine on each postabdominal claw. Each claw ordinarily has a row of denticles running laterally from the base of the claw to its midpoint, although individuals were observed lacking claw denticulation.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3EFF80FF33A379FB6EC699.taxon	description	MALE. Two males were discovered by CLR in a collection from Lago Coari, Amazonas, Brazil (4.08 º S, 63.14 º W), which constitutes their first report from South America. The jelly coat was present, but due to its preservation in formalin, sculpturing was not discernable. The specimens were small, with a mean length and height of 0.36 mm and 0.21 mm, respectively. The ventral carapace margin has many, tightly-spaced spinules posteriorly, but is smooth anteriorly. Differential diagnosis. Holopedium amazonicum is morphologically indistinguishable from H. atlanticum, but these species have allopatric distributions (Fig. 4 c, e). H. amazonicum is distinguished from H. acidophilum by its smaller size and smaller number of anal spines. It differs from members of the H. gibberum complex by its absence of a basal spine on either postabdominal claw. COI mtDNA sequence divergence between H. amazonicum and H. atlanticum averages 12.3 %, while the divergence between H. amazonicum and H. acidophilum averages 8.7 %. Levels of genetic variation within this species remain poorly known, but, based on patterns in the other Holopedium species, individuals showing less than 4 % divergence from a representative COI mtDNA sequence (GenBank AF 245351) are likely to belong to H. amazonicum.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3EFF80FF33A379FB6EC699.taxon	distribution	Distribution. H. amazonicum appears restricted to the Amazon River basin (see also Rowe 2000), from which it was described (Stingelin 1904 a) (Fig. 4 e). It has been reported from several ria lakes throughout the Amazon River basin, typically associated with highly humic-stained “ blackwater ”. Records indicate that H. amazonicum is present throughout the year, with highest densities during the semi-annual rising and lowering of the water level (E. R. Hardy, INPA, Manaus, Amazônia, unpubl. data). It has occasionally been collected in low densities from whitewater ria lakes, but it has likely been washed into these habitats from blackwater habitats during periodic flooding. Breeding system. Members of this species were not included in allozyme analyses, and so the breeding system cannot be diagnosed in this fashion. However, males of H. amazonicum were detected by CLR in a collection made by Pedro Mera (INPA, Manaus, Amazônia) from Lago Coari, Brazil (4.077 ° S, 63.140 ° W; May 24, 1996), suggesting that cyclic parthenogenesis may be the mode of reproduction.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3CFFBEFF33A341FBC0C501.taxon	etymology	Etymology. acidophilum refers to the apparent restriction of populations of this species to acidic bogs, ponds, and lakes.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3CFFBEFF33A341FBC0C501.taxon	materials_examined	Type locality. Red Rock Pond, New Brunswick, Canada (45.233 º N, 66.733 º W), which is located near St. George, NB. It is situated north of Lake Utopia. From Hwy 785, turn onto Red Rock Lake Road. This road bifurcates 3.5 km later. Take the right fork. Proceed 2.9 km to Red Rock Pond which is on the right hand side of the gravel road. Type specimens. Holotype: an ovigerous female in ethanol deposited in the CMN under accession number CMNC 2007 - 0738 (collection date June 13, 1992). Paratypes: 10 ovigerous females, preserved in ethanol, deposited in the CMN under accession number CMNC 2007 - 0739 (collection date June 13, 1992). Material examined. Other habitats with H. acidophilum are listed in Appendix A. Morphological description. FEMALE. Representative photomicrographs are shown in Fig. 9. The jelly coat is of the A type, in which the anterior jelly curl arches toward the anterior portion of the jelly coat, and the lateral lobes are undivided (see Montvilo et al. 1987). Adult carapace lengths range from 0.62 – 1.46 mm (mean 1.10 mm), while carapace heights range from 0.24 – 1.48 mm (mean 1.08 mm). The H / L ratios range from 0.40 – 1.29 (mean 0.97). The ventral carapace margin is ordinarily spinulated posteriorly, but smooth anteriorly. Individuals lacking spinulation along the entire ventral valve margin were encountered. Anal spine number ranges from 8 – 21 (mean 14.07). Holopedium acidophilum lacks a basal spine on each postabdominal claw. Each claw invariably has a row of denticles running laterally from the base of the claw to its midpoint.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3CFFBEFF33A341FBC0C501.taxon	description	MALE. Males were found in the type locality (Red Rock Pond, NB) from collections made in June and September over several years. Body lengths range from 0.40 – 0.91 mm. The ventral carapace margin is spinulated posteriorly, but smooth anteriorly. Males possess 9 – 17 anal spines. Holopedium acidophilum lacks a basal spine on each postabdominal claw. Each claw invariably has a row of denticles running laterally from the base of the claw to its midpoint. Differential diagnosis. H. acidophilum can be distinguished from H. amazonicum and H. atlanticum by its larger size and greater number of anal spines. It differs from both members of the H. gibberum species complex by its lack of a basal spine on the postabdominal claw. Holopedium acidophilum can be biochemically distinguished from H. atlanticum at the Pgm locus. Holopedium acidophilum possesses an allele that migrates faster than the allele present in H. atlanticum. COI mtDNA sequence divergence between H. acidophilum and H. amazonicum averages 8.7 %, while the divergence between H. acidophilum and H. atlanticum averages 10.6 %. Based on current evidence, individuals showing less than 6 % divergence from a representative COI mtDNA sequence (GenBank AF 245352) belong to H. acidophilum.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D3CFFBEFF33A341FBC0C501.taxon	distribution	Distribution. Holopedium acidophilum appears to be restricted to a narrow latitudinal range (43 º to 47 º N) spanning North America (Fig. 4 d). This species was not found to co-occur with other species of Holopedium. Despite concentrated sampling within this range, this species was found rarely. It occurred in three lakes and one pond on the west coast of Oregon, a small pond on the upper Michigan peninsula, and two bogs in southeastern New Brunswick. The eastern bog habitats were situated within a few kilometers of lake populations of both H. glacialis and H. atlanticum, but there was no evidence of genetic exchange as indicated by distinctive allozyme and mtDNA profiles. In the west, H. acidophilum was found in coastal lakes and ponds in Oregon, while the nearest populations of H. glacialis were in lakes in the Coastal Mountains. Breeding system. Males were detected in the eastern populations in mid June and late September, indicating that members of these populations are cyclical parthenogens. Males were not detected in western and central populations, but this was likely because they were sampled in the summer. Moreover, genotype frequencies were generally concordant with Hardy-Weinberg expectations.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D02FFBCFF33A3C9FC97C2B1.taxon	description	Birge (1918): 693, Fig. 1061 b Pennak (1953): 364 – 365, Fig. 227 d Brooks (1959): 603, Fig. 27.13 Pennak (1978): 365 – 366, Fig. 254 d Pennak (1989): 386 – 387, Fig. 12 d Korovchinsky (1992): 77 – 78, Figs. 371 – 373, 375, 377	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D02FFBCFF33A3C9FC97C2B1.taxon	etymology	Etymology. atlanticum refers to the distribution of this species in lakes along the eastern Atlantic seaboard of North America.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D02FFBCFF33A3C9FC97C2B1.taxon	materials_examined	Type locality. Moosehead Lake, Maine (45.633 º N, 69.683 º W). On Hwy ME- 6, in close proximity to the town of Moosehead. Type specimens. Holotype: an ovigerous female in ethanol deposited in the CMN under accession number CMNC 2007 - 0741 (collection date September 2, 1993). Paratypes: 10 ovigerous females, preserved in ethanol, deposited in the CMN under accession number CMNC 2007 - 0742 (collection date September 2, 1993). Material examined. Other habitats with H. atlanticum are listed in Appendix A. Morphological description. FEMALE. Representative photomicrographs are shown in Fig. 10. The jelly coat is of the A type, in which the anterior jelly curl arches toward the anterior portion of the jelly coat, and the lateral lobes are undivided (see Montvilo et al. 1987). Adult carapace lengths range from 0.44 – 1.01 mm (mean 0.73 mm), while carapace heights range from 0.30 – 1.06 mm (mean 0.74 mm). The H / L ratios range from 0.68 – 1.37 (mean 1.00). The ventral carapace margin is ordinarily spinulated posteriorly, but smooth anteriorly. Individuals lacking spinulation along the entire ventral valve margin were encountered. Anal spine number ranges from 6 – 11 (mean 8.35). Holopedium atlanticum lacks a basal spine on each postabdominal claw. Each claw ordinarily has a row of denticles running laterally from the base of the claw to its midpoint, although individuals were observed that lacked claw denticulation.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D02FFBCFF33A3C9FC97C2B1.taxon	description	MALE. Males have been found in small numbers in collections from sites in North Carolina in May and June; however, they are typically found in the highest abundance in the autumn (Hegyi 1973). Males of this species were not examined in this study, and thus detailed morphometrics cannot be presented. However, Hegyi (1973) presented a photograph and brief description of a male Holopedium which, based on distributional data, is probably H. atlanticum. Differential diagnosis. Although H. atlanticum is morphologically indistinguishable from H. amazonicum, these two species have allopatric distributions reducing the likelihood of genetic exchange (Fig. 4 c, e). Holopedium atlanticum is distinguished from H. acidophilum by the larger size and greater number of anal spines of the latter species. It differs from members of the H. gibberum complex by the absence of a basal spine on either postabdominal claw. Holopedium atlanticum can be biochemically distinguished from H. acidophilum at the Pgm locus, as H. atlanticum produces an enzyme which migrates slower than that of the latter species. COI mtDNA sequence divergence between H. atlanticum and H. amazonicum averages 12.3 %, while the divergence between H. atlanticum and H. acidophilum averages 10.6 %. Based on current evidence, individuals showing less than 4.8 % divergence from a representative COI mtDNA sequence (GenBank AF 245353) belong to H. atlanticum.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
03F8375C9D02FFBCFF33A3C9FC97C2B1.taxon	distribution	Distribution. H. atlanticum was found along the Atlantic coast of North America from New Brunswick and Maine south to Florida, (Fig. 4 c). Populations of Holopedium reported by other workers from the southeastern United States are likely also H. atlanticum. Its range overlaps that of H. glacialis in the northeastern USA and southern New Brunswick, where these species occur sympatrically without hybridization. The extent of range overlap with H. glacialis is unresolved by this study, but several workers have identified H. atlanticum (formerly H. amazonicum) as far north as New Brunswick and H. glacialis (formerly H. gibberum) as far south as Tennessee and possibly South Carolina (Coker 1938, Bunting 1970, Hebert & Finston 1997). Breeding system. Males were not detected in populations collected throughout the summer in this study. In a life history study spanning two years, males were most abundant in early spring and late autumn (Hegyi 1973). In some southern localities, populations persist throughout the winter. Due to the existence of males, this species likely reproduces by cyclic parthenogenesis, but there is very little allozyme variation, suggesting that either this species engages in sexual reproduction infrequently or that variation has been trimmed due to a population bottleneck. A note regarding H. groenlandicum and H. ramasarmii While individuals from Greenland were not included in the present study, the recently described species H. groenlandicum (Korovchinsky 2005) can purportedly be distinguished from H. gibberum by its “ dorsally low shell and jelly envelope, shorter row of valve marginal spinules which are subdivided in groups, and comparatively longer postabdominal claws. ” However, shell shape is a highly variable feature, which may be environmentally influenced (Røen 1962) and can depend upon the locality and presence / absence of fish (CLR pers. obs). The body lengths (0.74 to 1.09 mm, mean 1.45 mm), carapace heights (0.80 to 1.57 mm, mean 1.19 mm), and H: L ratios (0.641 to 1.000, mean 0.814) found by Korovchinsky (2005) in the Greenland populations fall within the ranges of values found in H. gibberum and H. glacialis populations in the present study (the preceding ranges and means that were not published in Korovchinsky [2005] were provided to CLR by that author). Jelly coat shape may be influenced by preservation (CLR, pers. obs), and therefore this trait may not be a good feature for diagnosing species. Moreover, the degree of carapace margin spinulation is also a highly variable trait within species (present study), although the discontinuous nature of the spinulation in the Greenland populations is noteworthy. Finally, the length of the postabdominal claws reported by Korovchinsky (2005, his Figure 1) is within the range of claw lengths observed for the H. gibberum s. s. populations studied here. Furthermore, the fact that we detected closely related lineages of H. gibberum s. s. in both northern Europe and North America suggests that similar lineages may be found in intervening arctic areas. Individuals from India were also not included in the present study. Consideration of the differences between either of the species in the H. gibberum complex and H. ramasarmii (Rao et al. 1998) is not currently possible due to the poor description of the latter species, lacking in detail. Korovchinsky (2004) labeled this species incertae sedis. We suggest that genetic evidence is required to determine if H. groenlandicum and H. ramasarmii are distinct species or if they are synonymous with described taxa.	en	Rowe, Chad L., Adamowicz, Sarah J., Hebert, Paul D. N. (2007): Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods. Zootaxa 1656: 1-49, DOI: 10.5281/zenodo.179852
