Anne Bedos

Challenging species delimitation in Collembola: cryptic diversity among common springtails unveiled by DNA barcoding

Abstract. Collembola is one of the major functional groups in soil as well as a model taxon in numerous disciplines. Therefore the accurate identification of specimens is critical, but could be jeopardised by cases of cryptic diversity. Several populations of six well characterised species of springtails were sequenced using the COI barcode fragment as a contribution to the global Collembola barcoding campaign. Each species showed high intraspecific divergence, comparable to interspecific sequence divergence values observed in previous studies and in 10 congeneric species barcoded here as a reference. The nuclear marker, 28S, confirmed all the intraspecific lineages found with COI, supporting the potential specific status of these entities. The implications of this finding for taxonomy and for disciplines relying on species names, such as evolution and ecology, are discussed.

Cryptic Diversity in the Ubiquist Species Parisotoma notabilis (Collembola, Isotomidae): A Long-Used Chimeric Species?

Parisotoma notabilis is the most common species of Collembola in Europe and is currently designated as ubiquist. This species has been extensively used in numerous studies and is considered as well characterized on a morphological ground. Despite the homogeneity of its morphology, the sequencing of the barcoding fragment (5′ end of COI) for several populations throughout Europe and North America revealed four distinct genetic lineages. The divergence found between these lineages was similar to the genetic distance among other species of the genus Parisotoma included in the analysis. All four lineages have been confirmed by the nuclear gene 28S. This congruence between mitochondrial and nuclear signals, as well as the geographical distribution pattern of lineages observed in Europe, supports the potential specific status of these lineages. Based on specimens from the type locality (Hamburg), the species name was successfully assigned to one of these lineages. This finding raises several problems as Parisotoma notabilis has been widely used in many ecological studies. Accumulation of new data for the different lineages detected, especially ecological information and life history traits, is needed to help resolve this situation.

Diversity Patterns in the Tropics

Subterranean habitats in the tropics host a high diversity of species that has been long overlooked.Specieshave beendiscovered at a fast pace over the last few decades. The patterns of habitat diversity differ from those of temperate regions in several respects. In the tropics, a significant contribution to overall subterranean diversity comes from anchihaline/marine and guano habitats. Troglobionts are moderately troglomorphic in the lowland tropics, whereas highly troglomorphic stygobionts are frequent. Troglomorphy levels and proportion of troglobiotic taxa increase with altitude and latitude, in parallel with a decrease in bats and guanobionts. Several taxa are unique to tropics and shared by all tropical regions, but there arealso great differences between regions. A major interest of subterranean fauna of temperate regions is its richness in relictual taxa: this is retrieved in the tropics, but to a lesser extent. On the whole, global diversity of obligate cave fauna in the tropics appears lower than that of the richest temperate regions. This may change however when biodiversity surveys of tropical caves begin totake into account microcrustacea and guanobionts.

Global diversity of springtails (Collembola; Hexapoda) in freshwater

Water-dependency appeared independently in several clades of the class Collembola, which is basically of terrestrial origin according to recent phylogenetic analyses. Though moderately diversified (less than 8,000 species), Collembola are among the most numerous terrestrial arthropods in wetland communities, with a small number of species living on the surface of water. Many species are dependent on water-saturated atmosphere of caves, and on snow or ice in high mountains. A total of 525 water-dependent species have been recognized, of which 103 are linked to free freshwaters and 109 to anchialine or marine waters. Many interstitial species are also dependent to an unknown extent on water saturation in the deep layers of the soil. The numbers provided here are underestimates, as Collembola are extremely poorly known outside the Holarctis, and the ecology of described species usually not documented. However, a general biogeographical pattern is emerging from available data. The most remarkable feature is that about 15% of the fauna is water-dependent in the holarctic region, compared to 4% in the tropics and southern hemisphere.

Organization, usefulness and limitations of an ATBI (All Taxa Biodiversity Inventory): the inventory of terrestrial invertebrates in the Mercantour National Park

ABSTRACT We present here the objectives, organization and preliminary results of the invertebrate inventory of the Mercantour National Park (“Terrestrial Invertebrates Module” of the ATBI Mercantour/Alpi Marittime), carried out by 68 scientists and field-collectors from 2009 to 2012. The conceptual framework of an ATBI and the interactions between inventorying and frequently associated research aims are discussed. The sampling strategy adopted combined standardized multi-taxon sampling (continuous and occasional) with individual taxon-centred sampling. The successive tasks of field sampling, specimen coding, sorting and identification, molecular analysis and data management are briefly described. A coherent system of sample coding ensured the traceability of specimens. The project results in terms of sampling effort, abundance of collected invertebrate fauna and biological diversity are presented globally, by techniques, by sites and by higher taxonomic groups: 259,412 specimens were obtained from 761 sorted samples (out of 1243 samples collected), belonging to 1725 identified species and subspecies, in addition to which 37 species new to science have been recognized. These data are progressively being integrated into the CardObs database of the INPN and are partly accessible through the EDIT and GBIF websites. Molecular analyses (barcoding) have provided 2800 sequences (mostly for the COI gene in Gastropoda, Collembola and Hymenoptera). Analysis of these sequences indicates a significant amount of cryptic diversity in the material. From a macro-ecological perspective, endemicity in the park decreases globally from south to north and species richness decreases at higher elevations, but the data are uneven and patterns vary according to group. Based on this four-year experience, it appears that a smaller survey area with lower habitat diversity would be better suited to the aims of an ATBI when the available resources are limited, and would enhance the efficiency of collective work in the field.

Disjunct distribution of Szeptyckiella gen. nov. from New Caledonia and South China undermines the monophyly of Willowsiini (Collembola: Entomobryidae)

Morphology of scales is an important taxonomical character at all levels of Entomobryidae taxonomy. A new scaled genus of Collembola, Szeptyckiella gen. nov., and three new species are described: Szeptyckiella boulouparica sp. nov. and Szeptyckiella sinelloides sp. nov. from New Caledonia, and Szeptyckiella lii sp. nov. from South China. The genus, assigned to Willowsiini, is characterized by pointed scales on the body, eyes and pigment absent, antennal apical bulb absent, dens lacking spines and scales, and bidentate mucro with a short basal spine. It is closest to Hawinella from Hawaii but the latter possesses a falcate mucro. However, its morphological characteristics and its disjunct distribution raise a number of problems. Its widely disjunct distribution is difficult to explain in terms of palaeobiogeographical or more recent dispersal events. The new genus is similar to Sinella without consideration of scales, although both genera are placed in different tribes following the current supra-generic classification of Entomobryidae. We discuss other cases of paired genera differing only by the presence or absence of scales, and placed in either Willowsiini or Entomobryini. On this basis, we assume that scale presence could independently occur in the former tribe, questioning the monophyly of the tribe Willowsiini.

Updated list of Collembola species currently recorded from South Africa

Abstract Understanding the abundance and richness of species is one of the most fundamental steps in effecting their conservation. Despite global recognition of the significance of the below-ground component of diversity for ecosystem functioning, the soil remains a poorly studied terrestrial ecosystem. In South Africa, knowledge is increasing for a variety of soil faunal groups, but many still remain poorly understood. We have started to address this gap in the knowledge of South African soil biodiversity by focusing on the Collembola in an integrated project that encompasses systematics, barcoding and ecological assessments. Here we provide an updated list of the Collembola species from South Africa. A total of 124 species from 61 genera and 17 families has been recorded, of which 75 are considered endemic, 24 widespread, and 25 introduced. This total number of species excludes the 36 species we consider to be dubious. From the published data, Collembola species richness is high compared to other African countries, but low compared to European countries. This is largely a consequence of poor sampling in the African region, as our discovery of many new species in South Africa demonstrates. Our analyses also show that much ongoing work will be required before a reasonably comprehensive and spatially explicit picture of South Africa’s springtail fauna can be provided, which may well exceed 1000 species. Such work will be necessary to help South Africa meet its commitments to biodiversity conservation, especially in the context of the 2020 Aichi targets of the Convention on Biological Diversity.

Species of the genus Friesea (Collembola, Neanuridae) from New Caledonia and Vanuatu

Weiner W. M., Bedos A. & Deharveng L. 2009. — Species of the genus Friesea (Collembola, Neanuridae) from New Caledonia and Vanuatu. Zoosystema 31 (3): 507-518. ABSTRACT Four species of the genus Friesea Dalla Torre, 1895 (Collembola, Neanuridae) are described from New Caledonia (Grande-Terre and Loyalty Islands) and Vanuatu (Santo Island). Friesea hnaeu n. sp. from Lifou Island in the Loyalties is characterized by two anal spines and the absence of eyes. Friesea wabao n. sp. from two islands of the Loyalties and Grande-Terre has a unique combination of characters: 1+1 or less eyes, a reduced furca, 3 anal spines and 7 s-chaetae on the fourth antennal segment. Friesea santo n. sp. from Santo Island in Vanuatu has 3 anal spines, no eyes and 6 s-chaetae on the fourth antennal segment. Friesea septem n. sp. from Santo Island is characterized by a reduced number of eyes (5–7+5–7 eyes), well-developed muero, and 7 s-chaetae on the fourth antennal segment. The genus Friesea has the same number of species (3) on Grande-Terre, New Caledonia and on Loyalty Islands, with only one species shared. Two species of the mirabilis group, one in Vanuatu and one in New Caledonia, have 7 s-chaetae on the fourth antennal segment, a character unique in this group, suggesting biogeographical affinities between these two regions.

Cylindropygus ferox gen. n., sp. n.: A new member of the Cryptopygus complex (Collembola, Isotomidae) from central France

Cylindropygus, a new genus of isotomid Collembola, is described. It differs from all other genera of Isotomidae by a unique combination of characters (abdominal segments V and VI fused, eyes absent, postantennal organ present and elongate, S‐chaetotaxy, and absence of foil chaetae) and two remarkable features: a modified labium, with papillae A, B, D bearing strong spines; and a swollen, globular accp3 chaeta on Abd.V. Cylindropygus ferox sp. n. is common in forest soils of central France.

The genus Ectonura Cassagnau, 1980 in South Africa (Collembola, Neanuridae, Neanurinae), with a key to South African Neanurinae

Abstract Two new species of Neanurinae (Collembola) are described from the Western Cape, South Africa: Ectonura monochaeta sp. n. and Ectonura barrai sp. n. Ectonura monochaeta sp. n. differs from other species in the genus by its strongly reduced chaetotaxy, and the lateral shift of dorso-internal chaetae on Abd. V and their integration in the tubercles (De+DL). Ectonura barrai sp. n. is similar to Ectonura natalensis (Womersley, 1934), but differs in chaetotaxic details and chaetal group arrangement. A key to the seven species of Neanurinae recorded from South Africa is given.