Received: 06 June 2011 / Accepted: 23 January 2012 / Published online: 06 June 2011
Species status and population structure of mussels (Mollusca: Bivalvia: Mytilus spp.) in the Wadden Sea of Lower Saxony (Germany)Download PDFAbstract
Three species of mussel (genus Mytilus) occur in Europe: M. edulis (Linnaeus 1758), M. galloprovincialis (Lamarck 1819) and M. trossulus (Gould, Boston Society of Natural History 3: 343–348, 1850). Although these species are indigenous to the North Sea, the Mediterranean and the Baltic Sea, respectively, they form an extended patchy species complex along the coasts of Europe (“the Mytilus edulis complex”) and are able to hybridize where their distributions overlap. Recent studies examining the taxonomic status and genetic composition of Mytilus populations in the Netherlands and the British Isles have revealed introgressive hybridization processes within this species complex, with hints of an invasion of nonindigenous M. galloprovincialis into the North Sea. Furthermore, an extensive international mussel fishery industry in Europe (i.e., Great Britain, the Netherlands, Denmark, and Germany) is also in discussion for a possibly anthropogenically induced bioinvasion of nonindigenous Mytilus traits into the Wadden Sea area. Although it is assumed that the Wadden Sea of Germany comprises M. edulis only, this has never been confirmed in a molecular genetic study. To assess the situation for the Wadden Sea of Lower Saxony, we conducted the first molecular study of the Mytilus genus in the region. Taxonomic identification of 504 mussels from 13 intertidal mussel banks using the nDNA marker Me15/16 revealed a population composition of 99% M. edulis and 1% M. edulis X M. galloprovincialis hybrids. Hence, the Wadden Sea population is unaffected by range expansion of nonindigenous Mytilus traits. The genetic structure of the M. edulis populations was investigated using the phylogenetic and population genetics analyses of the mitochondrial DNA cytochrome-c-oxidase subunit I (COI) and the first variable domain of the control region (VD1), which were sequenced for >120 female individuals. These results showed a heterogeneous, panmictic population due to unrestricted gene flow. This can be attributed to extensive larval dispersal linked to the tidal circulation system in the back barrier basins of the Wadden Sea.
Received: 28 February 2011 / Accepted: 27 August 2012 / Published online: 28 February 2011
Who am I — and if so, how many? Species diversity of calcareous dinophytes (Thoracosphaeraceae, Peridiniales) in the Mediterranean SeaDownload PDFAbstract
The diversity of extant calcareous dinophytes (Thoracosphaeraceae, Dinophyceae) is not fully recorded at present. The establishment of algal strains collected at multiple localities is necessary for a rigorous study of taxonomy, morphology and evolution in these unicellular organisms. We collected sediment and water tow samples from more than 60 localities in coastal areas of the eastern Mediterranean Sea and documented 15 morphospecies of calcareous dinophytes. Internal transcribed spacer (ITS) barcoding identified numerous species of the Scrippsiella trochoidea species complex that were genetically distinct, but indistinguishable in gross morphology (i.e. with the same tabulation patterns of the motile theca and similar spiny coccoid stages). We assessed a possible minimal number of cryptic species using ITS ribotype networks that indicated the existence of at least 21 species within the Scrippsiella trochoidea species complex. Species diversity of calcareous dinophytes appears higher in the Mediterranean Sea than in other parts of the world’s oceans such as the North Sea. Our data underline the importance of field work to record the diversity of calcareous dinophytes and other unicellular life forms.
Received: 27 April 2011 / Accepted: 28 November 2011 / Published online: 27 April 2011
Invading a refugium: post glacial replacement of the ancestral lineage of a Nymphalid butterfly in the West MediterraneanDownload PDFAbstract
The power of a fixed scenario was compared to that of a dynamic scenario, in order to explain the distribution pattern of two well established subspecies (morphotypes) of the model butterfly species Maniola jurtina in the central Mediterranean. Samples were collected from a transect of 21 sites along the western side of the Italian Peninsula as well as in Sicily, North Africa and some Italian islets in the Tyrrhenian sea. Samples from the Balkans Peninsula have been added for comparison. Geometric morphometrics, suggested as a reliable marker to identify hybrid individuals, were applied to 150 male genitalia. Their shape was analysed by the means of the partial least square (PLS) discriminant analysis and then modelled through geographic information system (GIS) spatial analyses. The timing of invasion was reconstructed by comparing sea-level changes with the recent isobaths both on the mainland and on islands. The occurrence of the eastern morphotype on the Italian Peninsula and of the western morphotype in North Africa and Sicily was confirmed. However, we found intermediate populations at the tip of the Italian Peninsula and on the islands of Ischia and Capri. No intermediate populations were found in Sicily. The fixed scenario is unlikely, since a dispersal of the western morphotype from Sicily to the distant islands of Ischia and Capri might be hypothesized. A more parsimonious hypothesis minimises dispersal across the sea barriers. It assumes the ancestral presence over the entire study area of the western morphotype, which was later replaced on the Italian mainland but maintained on the islands. These rapid movements could drastically modify European biogeographic patterns.
Received: 29 March 2011 / Accepted: 22 August 2011 / Published online: 29 March 2011
raxmlGUI: a graphical front-end for RAxMLDownload PDFAbstract
With the increasing availability of molecular data, maximum likelihood approaches have gained a new central role in phylogenetic reconstructions. Extremely fast tree-search algorithms have been developed to handle data sets of ample size in reasonable time. In the past few years, RAxML has achieved great relevance in this field and obtained wide distribution among evolutionary biologists and taxonomists because of its high computational performance and accuracy. However, there are certain drawbacks with regard to its usability, since the program is exclusively command-line based. To overcome this problem, we developed raxmlGUI, a graphical user interface that makes the use of RAxML easier and highly intuitive, enabling the user to perform phylogenetic analyses of varying complexity. The GUI includes all main options of RAxML, and a number of functions are automated or simplified. In addition, some features extend the standard use of RAxML, like assembling concatenated alignments with automatic partitioning. RaxmlGUI is an open source Python program, available in a cross-platform package that incorporates RAxML executables for the main operating systems. It can be downloaded from
Received: 28 October 2011 / Accepted: 20 February 2012 / Published online: 28 October 2011
Phylogeny, classification and taxonomy of European dragonflies and damselflies (Odonata): a reviewDownload PDFAbstract
Although Europe is the cradle of dragonfly systematics and despite great progress in the last 2 decades, many issues in naming its species and understanding their evolutionary history remain unresolved. Given the public interest, conservation importance and scientific relevance of Odonata, it is time that remaining questions on the species’ status, names and affinities are settled. We review the extensive but fragmentary literature on the phylogeny, classification and taxonomy of European Odonata, providing summary phylogenies for well-studied groups and an ecological, biogeographic and evolutionary context where possible. Priorities for further taxonomic, phylogenetic and biogeographic research are listed and discussed. We predict that within a decade the phylogeny of all European species will be known.
Received: 21 January 2011 / Accepted: 22 January 2012 / Published online: 21 January 2011
The enigmatic Alpine opilionid Saccarella schilleri gen. n., sp. n. (Arachnida: Nemastomatidae)—isolated systematic placement inferred from comparative genital morphologyDownload PDFAbstract
In Opiliones, male genital morphology plays a key role in systematics and understanding the evolution of the group because functional modifications often outline higher taxonomic levels. In Nemastomatidae, different lateral stabilizing structures on the penial truncus cane developed independently. These wing-like protuberances serve as anchor points for two muscular tendons and are interpreted traditionally as generic characters. A newly discovered species from Monte Saccarello in the Ligurian Alps of North-western Italy is unique in providing anchor points as stabilizing parts of the distal truncus cane below the glans by short and narrow lateral folds. To place this unusual species within the Nemastomatidae one must re-evaluate the usefulness of male genital morphological and other characters used in the systematics of the family. The resulting phylogenetic framework is supplemented with available molecular genetic data. Based on both datasets, the creation of a new genus seems justified. Saccarella schilleri gen. n. sp. n. is subsequently described and further defined. The endemism and biogeography of the harvestmen fauna in the South-western Alps are discussed with respect to this enigmatic genus.
Received: 22 November 2010 / Accepted: 28 November 2011 / Published online: 22 November 2010
Molecular and phytochemical systematics of the subtribe Hypochaeridinae (Asteraceae, Cichorieae)Download PDFAbstract
The systematics of the Hypochaeridinae subtribe was re-evaluated based on a combination of published and new molecular data. Newly found clades were additionally characterized using published and new phytochemical data. In addition to flavonoids and sesquiterpene lactones, which had been reviewed recently as chemosystematic markers in the Cichorieae, we analysed the reported occurrences of caffeic acid derivatives and their potential as chemosystematic markers. Our molecular results required further changes in the systematics of the genus Leontodon. Based on previous molecular data, Leontodon s.l.—i.e. including sections Asterothrix, Leontodon, Thrincia, Kalbfussia, and Oporinia (Widder 1975)—had been split into the genera Leontodon s.str. (sections Asterothrix, Leontodon, and Thrincia) and Scorzoneroides (sections Kalbfussia and Oporinia). Instead of splitting Leontodon into even a higher number of segregate genera we propose to include Hedypnois into Leontodon s.str. and here into section Leontodon. Moreover, sections Asterothrix and Leontodon should be merged into a single section Leontodon. The newly defined genus Leontodon is characterised by the unique occurrence of hydroxyhypocretenolides. The monophyly of the genus Hypochaeris is neither supported nor contradicted and potentially comprises two separate molecular clades. The clade Hypochaeris I comprises the majority of the European and Mediterranean as well as all South American taxa of Hypochaeris s.l. while the clade Hypochaeris II encompasses only H. achyrophorus L., H. glabra L., H. laevigata Benth. & Hook.f., and H. radicata L.
Received: 31 March 2011 / Accepted: 22 January 2012 / Published online: 31 March 2011
Inflorescence morphology and flower development in Pinguicula alpina and P. vulgaris (Lentibulariaceae: Lamiales): monosymmetric flowers are always lateral and occurrence of early sympetalyDownload PDFAbstract
Earlier interpretations of shoot morphology and flower position in Pinguicula are controversial, and data on flower development in Lentibulariaceae are scarce. We present scanning electron microscopy about the vegetative shoot, inflorescence and flower development in Pinguicula alpina and P. vulgaris. Analysis of original data and the available literature leads to the conclusion that the general pattern of shoot branching and inflorescence structure is uniform in all the Pinguicula species studied so far. The inflorescence is a sessile terminal umbel that is sometimes reduced to a solitary pseudoterminal flower. Flower-subtending bracts are either cryptic or present as tiny scales. A next order lateral shoot develops in the axil of the uppermost leaf, below the umbel. It is usually though not always homodromous, i.e., the direction of the phyllotaxy spiral is the same as in the main shoot. Among Pinguicula species that overwinter as a hibernaculum, the initiation of floral organs takes place in the same year as flowering in P. vulgaris, and 1 year earlier in P. alpina. Early congenital petal fusion (‘early’ sympetaly) is documented in Pinguicula, though most other members of Lamiales exhibit ‘late’ sympetaly. Sporadic occurrence of rudiments of two posterior stamens in Pinguicula is confirmed. A speculation is made that, in angiosperms, monosymmetric flowers cannot be terminal on shoots bearing more than two (or three) phyllomes.
Received: 20 October 2011 / Accepted: 14 March 2012 / Published online: 20 October 2011
Africa’s smallest damselfly—a new Agriocnemis from Namibia (Odonata: Coenagrionidae)Download PDFAbstract
Agriocnemis bumhilli sp. n., a new damselfly from the Kwando River in northeastern Namibia is described. The new species is similar to Agriocnemis angolensis but characterized by unique male appendages, swollen abdominal segments 9 and 10, the complete absence of antehumeral stripes, and smaller size. The species is illustrated and a photograph is provided. For comparison, an illustrated key to the other members of Agriocnemis within south-central Africa is provided.
Received: 20 October 2011 / Accepted: 16 February 2012 / Published online: 20 October 2011
Argia mayi, a new species from México (Zygoptera: Coenagrionidae)Download PDFAbstract
A new species of Argia is illustrated and described from material collected in the states of Colima, Guerrero, Jalisco, Michoacán, Morelos and Oaxaca, México. Argia mayi n. sp. is morphologically similar to Argia pocomana Calvert. It differs from the latter by the morphology of the abdominal appendages in the males and by having four postquadrangular cells in FW in both sexes, blue on the dorsum of males restricted to S8-9 and an erect hind margin of the mesostigmal plate in females.
Received: 30 October 2011 / Accepted: 16 February 2012 / Published online: 30 October 2011
Using dragonflies to monitor and prioritize lotic systems: a South African perspectiveDownload PDFAbstract
The ever-worsening condition of streams due to local, regional, and global demands on water has resulted in the development of increasingly streamlined, rapid assessment methods using macroinvertebrates. Biotic indices in particular are versatile and robust, although not always easy to use. For example, the family-level South African Scoring System is an effective water quality measure, but is time-consuming and requires high-level expert training. The index could be used alongside the species-level Dragonfly Biotic Index (DBI), originally developed for monitoring habitat integrity, with which it is significantly and strongly correlated. We review here the relevant biotic indices in stream biomonitoring and their advantages and disadvantages, and present a new extension of the DBI, the Habitat Condition Scale (HCS). The HCS enables comparison and ranking of sites in terms of their habitat condition. Indeed, the DBI is a very flexible index, having been used in site selection and prioritization for conservation, as well as the measurement of habitat recovery. The theoretical framework behind the index demonstrates the potential of the index to track biotic changes due to climate change. The index could also be easily adapted for use in other biogeographical regions, given that species distributions, threat levels and sensitivities are well-known, and that there is an adequate number of endemic species. However, like all benthic macroinvertebrate indices, the DBI cannot always identify exactly which in-water impacts have an effect and to what extent. The real power of the DBI lies in being able to quantify community response to known physical changes on the riverscape and across the region.
Received: 06 April 2011 / Accepted: 22 March 2012 / Published online: 06 April 2011
A general definition of the term “plastron“ in terrestrial and aquatic arthropodsDownload PDFAbstract
The term “plastron”, as it applies to terrestrial and aquatic arthropods, has been used in a variety of ways. A generalised and simple definition of this term is provided based on a classification of its structural and functional aspects.
Received: 31 January 2011 / Accepted: 13 December 2011 / Published online: 31 January 2011
Outdated but established?! Conchologically driven species delineations in microgastropods (Carychiidae, Carychium)Download PDFAbstract
Valid taxonomic descriptions are paramount in evolutionary biology. Many date back centuries and are based on ambiguous morphological data. Microgastropods, in particular the taxon Carychiidae (Eupulmonata, Ellobioidea), demonstrate a paucity of informative conchological features. However, as exemplified by Carychium mariae Paulucci, 1878, their taxonomic classification is based almost entirely on these few features. Here we investigated the questionable taxonomic status of Carychium mariae combining DNA barcoding, field-emission scanning electron microscopy and conchological data. This taxon occurs in the Southern Alps, where it shows a sympatric distribution with two widely distributed members of Carychium—C. minimum Müller, 1774 and C. tridentatum (Risso, 1826). Our analyses do not support the species status of C. mariae. In contrast, DNA barcoding reveals a monophyletic grouping of C. minimum and C. mariae specimens with averaged intraspecific variability less than 3.2% (barcoding gap for Carychiidae). Hence, C. mariae is treated and should be regarded as a synonym of C. minimum, just representing a different morphotype. The differentiation and monophyletic status of C. tridentatum can be validated by showing an averaged interspecific variability of 5.9% to C. minimum. In general, we are critical of the sole use of conchological characters for microgastropod taxonomy and strongly recommend the implementation of molecular data (e.g., DNA barcoding) to reevaluate established species designations.
Received: 29 March 2011 / Accepted: 07 June 2012 / Published online: 29 March 2011
Historical biogeography of tits (Aves: Paridae, Remizidae)Download PDFAbstract
Tits (Aves: Paroidea) are distributed all over the northern hemisphere and tropical Africa, with highest species numbers in China and the Afrotropic. In order to find out if these areas are also the centers of origin, ancestral areas were reconstructed based on a molecular phylogeny. The Bayesian phylogenetic reconstruction was based on sequences for three mitochondrial genes and one nuclear gene. This phylogeny confirmed most of the results of previous studies, but also indicated that the Remizidae are not monophyletic and that, in particular, Cephalopyrus flammiceps is sister to the Paridae. Four approaches, parsimony- and likelihood-based ones, were applied to derive the areas occupied by ancestors of 75 % of the extant species for which sequence data were available. The common ancestor of the Paridae and the Remizidae inhabited tropical Africa and China. The Paridae, as well as most of its (sub)genera, originated in China, but Baeolophus originated in the Nearctic and Cyanistes in the Western Palearctic. Almost all biogeographic reconstruction methods produced similar results, but those which consider the likelihood of the transition from one area to another should be preferred.
Received: 06 October 2011 / Accepted: 15 August 2012 / Published online: 06 October 2011
Are there pitfalls to pitfalls? Dung beetle sampling in French GuianaDownload PDFAbstract
Dung beetles have widely been accepted as cost-effective indicator taxa for biodiversity assessment; thus, standard protocols have been created to examine their species richness and diversity in many habitats. However, the vast majority of studies adopt short-term sampling protocols; few studies have quantified sampling efficiency at longer time scales or tested the efficacy of species richness estimates. Here we present long- and short-term sampling data from two regions of French Guiana: the Nouragues Tropical Forest Research Station and Kaw Mountain. We examine species richness and diversity, and use these data to make suggestions for future biodiversity assessments of dung beetles using dung baited pitfall transects. Species richness estimates based on short-term samples strongly underestimate the actual species richness by approximately 40 %. Duration of trapping was found to be more important than the number of traps and length of transects; by setting a second transect (4-day sample period) in the same habitat of Nouragues, thereby increasing the sample duration, the number of species increased by 14 %.
Received: 19 October 2011 / Accepted: 27 February 2012 / Published online: 19 October 2011
Phylogeny of the dragonfly genus Sympetrum (Odonata: Libellulidae)Download PDFAbstract
The libellulid dragonfly genus Sympetrum has been recognized since 1833, but lacks any morphological synapomorphies to unite the taxon. Previous researchers have disagreed over which species belong in Sympetrum, bringing the monophyly of the genus into question. We use DNA sequence data from 6 genetic loci (16S, tRNA-valine, 12S, elongation factor 1 alpha, cytochrome oxidase subunit I, and the second internal transcribed spacer region) and 25 morphological characters (mainly genitalic) to test the monophyly of Sympetrum with Bayesian inference and maximum likelihood analyses. Under Bayesian inference, all Sympetrum species included in this study form a clade, which also contains the Hawaiian monotypic genus Nesogonia, often considered a close relative of Sympetrum. Phylogenetic analyses also reveal at least six strongly supported clades (treated as species groups) within Sympetrum, but relationships between these species groups remain unresolved or unsupported. Although the relationships between Sympetrum species groups remain unresolved, several species groups include taxa from multiple biogeographic regions/continents, and the species group sister to the rest of Sympetrum contains migratory species from the New World and Africa. This pattern suggests a complex biogeographic history in Sympetrum shaped by vicariance and dispersal. Preliminary estimates of the divergence dates of Sympetrum species groups outline a rapid radiation of the groups approximately 32-38 million years ago, possibly influenced by cooling and drying climates of the late Eocene and early Oligocene.
Received: 13 April 2011 / Accepted: 10 September 2012 / Published online: 13 April 2011
Systematics and phylogenetic species delimitation within Polinices s.l. (Caenogastropoda: Naticidae) based on molecular data and shell morphologyDownload PDFAbstract
Here, we present the first phylogenetic analysis of a group of species taxonomically assigned to Polinices sensu latu (Naticidae, Gastropoda) based on molecular data sets. Polinices s.l. represents a speciose group of the infaunal gastropod family Naticidae, including species that have often been assigned to subgenera of Polinices [e.g. P. (Neverita), P. (Euspira), P. (Conuber) and P. (Mammilla)] based on conchological data. The results of our molecular phylogenetic analysis confirm the validity of five genera, Conuber, Polinices, Mammilla, Euspira and Neverita, including four that have been used previously mainly as subgenera of Polinices s.l. Our results furthermore indicate a close relationship of members of the Polinicinae to Sinum—a genus traditionally placed in the naticid subfamily Sininae. We furthermore present conchological analyses to determine the validity of shell characters used traditionally in species designation in the genus Polinices. Our data reveal several characters (e.g. protoconch, operculum colour, parietal callus) to be informative, while many characters show a high degree of homoplasy (e.g. umbilicus, shell form). Among the species arranged in the genus Polinices s.s., four conchologically very similar taxa often subsumed under the common Indo-Pacific species P. mammilla are separated distinctly in phylogenetic analyses. Despite their striking conchological similarities, none of these four taxa are related directly to each other. Additional conchological analyses of available name-bearing type specimens and type figures reveal the four “mammilla”-like white Polinices species to include true P. mammilla and three additional species, which could be assigned to P. constanti (replacement name for P. dubius), P. jukesii and possibly P. tawhitirahia, based on protoconch and operculum characteristics.
Received: 01 December 2011 / Accepted: 14 March 2012 / Published online: 01 December 2011
The symbiotic hesionid Parasyllidea humesi Pettibone, 1961 (Annelida: Polychaeta) hosted by Scrobicularia plana (da Costa, 1778) (Mollusca: Bivalvia: Semelidade) in European watersDownload PDFAbstract
Heretofore, the hesionid polychaete Parasyllidea humesi was only known from its original description, living in association with the bivalve Tellina nymphalis in mangrove swamps north of Pointe-Noire (Republic of Congo, West Africa). The discovery of a stable population in Río San Pedro (Gulf of Cádiz, southern Atlantic coast of Iberian Peninsula) thus represents the second report for this species worldwide, and the first for European waters. Furthermore, the new population is associated with another bivalve, Scrobicularia plana. The host-symbiont relationship is characterized by a high host-specificity (the symbiont was absent from Ruditapes decussatus and Cerastoderma glaucum collected in the same habitat and location), regular distribution (one, exceptionally two symbionts per host and then being male and female), and prevalence ranging from 0.22 % (in Caño Sancti Petri) to 4.74 % (Río San Pedro). The symbionts seem to affect the metabolism of their hosts and, thus, their normal growth, so this association may tentatively be considered as close to parasitism. Parasyllidea humesi seems to be restricted to salt marsh areas with stable marine salinities all over the year. As there is no evidence that the presence of P. humesi in the Gulf of Cádiz results from an introduction, we strongly suggest that it may be better considered as native to the region, with our finding representing the northernmost known geographical limit of its distribution.
Received: 02 September 2011 / Accepted: 16 January 2012 / Published online: 02 September 2011
Import and export of biological samples from tropical countries–considerations and guidelines for research teamsDownload PDFAbstract
‘Biodiversity’ is increasingly perceived as an important resource for research and conservation, but also for economy. Conservation, access and sustainable use of biodiversity (genetic resources, species, samples) are negotiated on different political levels, resulting in an internationally binding legal framework. Resulting legislation is binding for all parties involved in biological sampling, i.e. researches and (and in italics) countries, and especially applies for tissue or DNA samples and dervied products thereof. Understanding and awareness of export and import permits for biological samples is increasingly important for biologists to perform research projects legally and timely. Nevertheless, some biologists are still exporting and importing biological samples ignoring or non-compliant with national and international legislation, conventions, and regulations. Resulting difficulties may not only cause serious problems during field work, but may also delay the export, import or exchange of samples. Comprehensive a
priori information regarding legal requirements helps to avoid or at least diminish potential problems. We identified four major factors facilitating export/import permits: (1) good personal (mutually trusted) contacts in the country of origin, (2) understanding and compliance with all relevant laws and regulations; (3) access to information regarding knowledge on permits, regulations and laws including their circulation within the researcher communities; and (4) access to consistent and up to date regulations
Received: 16 June 2011 / Accepted: 28 November 2011 / Published online: 16 June 2011
The phylogeny of halichondrid demosponges: past and present re-visited with DNA-barcoding dataDownload PDFAbstract
Halichondrid sponges play a pivotal role in the classification of demosponges as changes in their classification has had direct consequences for the classification of Demospongiae. Historically, the systematics of halichondrids has been unstable. During the 1950s, the order was divided into two subclasses, which were based on empirical and assumed reproductive data. Subsequent morphological and biochemical analyses postulated the re-merging of halichondrid families, but recent molecular data indicate their polyphyly. Here we review the classification history of halichondrid taxa, compare it with the current and predominantly ribosomal molecular data, and support the new phylogenetic hypotheses with mitochondrial data from DNA barcoding.
The Young Systematists special issue—promoting the scientific work of early career scientists in taxonomy and systematicsDownload PDF
Received: 18 July 2011 / Accepted: 22 March 2012 / Published online: 18 July 2011
Refugia and geographic barriers of populations of the desert poppy, Hunnemannia fumariifolia (Papaveraceae)Download PDFAbstract
Phylogeographic data and divergence estimation times as well as current and past ecological niche modeling for the Mexican tulip poppy, Hunnemannia fumariifolia Sweet, were combined in order to understand its biogeographic history. Divergence times were estimated to determine if divergence occurred during the Pleistocene. Ecological niche modelling was used to determine if the last glacial maximum (LGM) was responsible for the southward movement of poppy populations into the Tehuacán-Cuicatlán Valley. Analyses were performed to detect any geographical barriers that might have caused genetic discontinuities among populations across the entire range of distribution. Current and Pleistocene ecological niche models were created for H. fumariifolia using eight environmental variables derived from temperature and precipitation. The evidence shows that divergence of the three main clades in H. fumariifolia occurred from the Early Pleistocene to Mid-Miocene. It was also found that gene flow between the populations of H. fumariifolia could have been limited by the LGM, by climate change during the Quaternary, and by the complex topography of the Sierra Madre Oriental and the Trans-Mexican Volcanic Belt. Furthermore, all of these processes may have resulted in the patchy distribution of suitable microhabitats for H. fumariifolia in its geographical range. Ecological niche models constructed using the MIROC3 model indicated that populations did not move to the north but rather that they had suitable ecological habitats in the Chihuahuan Desert, which harbored Pinus-Juniperus forests during that period.
Received: 30 September 2011 / Accepted: 20 February 2012 / Published online: 30 September 2011
A dragonfly in the desert: genetic pathways of the widespread Trithemis arteriosa (Odonata: Libellulidae) suggest male-biased dispersalDownload PDFAbstract
Water-dependent species inhabiting desert regions seem to be a contradiction in terms. Nevertheless, many species have evolved survival strategies for arid conditions. In Odonates (dragonflies and damselflies), both larvae and adults require very different and complex water-associated habitat conditions. The present study investigates the genetic diversity, population structure and dispersal patterns of a desert inhabiting odonate species, the Red-veined Dropwing dragonfly, Trithemis arteriosa. Eight populations from the arid Namibia and four population sites in the more tropical Kenya were compared by using nine microsatellite loci, one non-coding nuclear fragment and the mtDNA fragment ND1. Microsatellite analyses as well as the nuclear fragment reveal a high allelic diversity in all populations with almost no genetic sub-structuring. In contrast, ND1 sequence analyses show sub-structuring and—with two exceptions—only private haplotypes. The conflicting patterns of nuclear versus mitochondrial markers suggest a male-biased dispersal in this species. Results indicate that male dispersal is dependent on the environmental stability of the habitat, while females are philopatric. This life history adaptation would allow females to save energy for mating and oviposition in the demanding environment of a desert region. The results give direct insights into the dispersal pathways of a desert-inhabiting, strongly water dependent flying insect.
Received: 20 October 2011 / Accepted: 14 March 2012 / Published online: 20 October 2011
The nymph of Anisagrion Selys 1876, based on the discovery of A. inornatum (Selys, 1876) in Ecuador (Odonata: Coenagrionidae)Download PDFAbstract
The final instar nymph of Anisagrion inornatum is described and illustrated based on five specimens (one reared) from southern Ecuador. It is the first to be discovered for the genus. The nymph of Anisagrion inornatum differs from its closest relative, Apanisagrion lais, by: (1) antenna shorter in relation to head length (ratio 1.35 in An. inornatum vs 1.55 in Ap. lais); (2) fewer palpal and premental setae (5 palpal and 4 or 5 premental setae in An. inornatum vs 6–8 palpal and 5–8 premental setae in Ap. lais); (3) venter of S3–S8 with medial dark stripe. The nymphs were found in a slow shallow seep overgrown with emergent wetland plants.
Received: 08 February 2012 / Accepted: 22 April 2012 / Published online: 08 February 2012
Phylogenetic relationships of Dysaphis pyri (Boyer de Fonscolombe) and Dysaphis reaumuri (Mordvilko) (Hemiptera, Sternorrhyncha: Aphididae): COI and EF-1α evidenceDownload PDFAbstract
Dysaphis (Pomaphis) pyri (Boyer de Fonscolombe, 1841) and Dysaphis (Pomaphis) reaumuri (Mordvilko, 1928) are two holocyclic aphid species alternating between Pyrus (Rosaceae) and Galium (Rubiaceae). Comparative phylogenetic analysis was performed using partial mitochondrial cytochrome oxidase subunit I (COI) and nuclear elongation factor 1 alpha (EF-1α) sequences. Partial COI data indicate the possibility of the early divergence in the D. pyri–D. reaumuri stem, which might have occurred even before the splitting of the common ancestral species of the D. reaumuri–D. plantaginea complex. Such a conclusion seems to be compatible with the available data on host specificity, life cycles and distribution of both species. This introductory phylogenetic analysis based on partial COI and EF-1α sequences indicates the need for reconsideration of the subgeneric structure in the genus Dysaphis.
Received: 23 January 2012 / Accepted: 30 April 2012 / Published online: 23 January 2012
Geographical versus ecological isolation of closely related black flies (Diptera: Simuliidae) inferred from phylogeny, geography, and ecologyDownload PDFAbstract
To investigate patterns of geographical and ecological separation among morphologically similar, closely related species of black flies, we integrated ecological, geographical, and phylogenetic information, based on multiple gene sequences, for 12 species in the subgenus Gomphostilbia in Thailand. Molecular characters supported the monophyly of the Simulium ceylonicum species group, but not of the Simulium batoense species group, suggesting that revisionary work is needed for the latter. Both ecological and geographical isolation of similar taxa were revealed. Stream velocity and altitude were among the principal ecological factors differing between closely related species. Most closely related species in the subgenus Gomphostilbia overlap geographically, suggesting the possibility of sympatric speciation driven by ecological divergence. Geographical isolation via dispersal also might have contributed to species divergence, while Pleistocene climate changes possibly influenced population genetic structure, demographic history, and speciation of some members of the subgenus.
Received: 16 December 2011 / Accepted: 29 May 2012 / Published online: 16 December 2011
Evolution of reproductive strategies in libellulid dragonflies (Odonata: Anisoptera)Download PDFAbstract
In Libellulidae, oocyte production has been assumed to be continuous, with periods of egg-laying interspersed with periods of resting/eating; however, recent work suggests that two types of oocyte production are common: either (a) continuous or (b) step-wise. These are mirrored in the arrangement of the ovarioles in the ovaries. Likewise, two types of mate-guarding behavior have been observed in Libellulidae: (1) non–contact guarding and (2) tandem guarding in which the male either hovers above the female or is physically attached to her during oviposition. Using molecular (mitochondrial and nuclear) data we explored the evolution of female reproductive traits, focusing on ovariole morphology, as well as guarding behavior, in Libellulidae. Continuous egg production appears to have evolved more than once, as have tandem and non-contact guarding. We discuss how the evolution of different ovariole types and guarding behavior may have been influenced by habitat instability, dispersal and crowded oviposition sites; thus, migratory behavior or habitat availability may have been the driving force of ovariole evolution.
Received: 30 March 2011 / Accepted: 15 December 2011 / Published online: 30 March 2011
Contribution to the molecular phylogenetic analysis of extant holocephalan fishes (Holocephali, Chimaeriformes)Download PDFAbstract
Much attention has been paid to the molecular phylogeny of holocephalan fishes during recent years, but sampling was very low and not all genera were examined. This study offers an extended sampling of species from all known genera to clarify their phylogeny and to provide an estimate of the time of origin of extant holocephalan taxa. Three mitochondrial genes (cytochrome b, 12S rRNA, and 16S rRNA) were sequenced and analysed using a variety of phylogenetic methods (Bayes, maximum likelihood, and maximum parsimony). Callorhinchidae diverged from Rhinochimaeridae and Chimaeridae about 187 Ma ago. Chimaeridae and Rhinochimaeridae diverged from each other about 159 Ma ago. Within Rhinochimaeridae, Neoharriotta is the sister genus to the closely related Harriotta and Rhinochimaera. Eight species of the family Chimaeridae, belonging to the genera Hydrolagus and Chimaera, were examined. They probably had a common ancestor about 107 Ma ago and appear paraphyletic. These results indicate that the traditional morphological generic definition of the families Rhinochimaeridae and Chimaeridae has to be reinvestigated.
Received: 19 October 2011 / Accepted: 14 March 2012 / Published online: 19 October 2011
Non-ecological speciation, niche conservatism and thermal adaptation: how are they connected?Download PDFAbstract
During the last decade, the ecological theory of adaptive radiation, and its corollary “ecological speciation”, has been a major research theme in evolutionary biology. Briefly, this theory states that speciation is mainly or largely the result of divergent selection, arising from niche differences between populations or incipient species. Reproductive isolation evolves either as a result of direct selection on mate preferences (e.g. reinforcement), or as a correlated response to divergent selection (“by-product speciation”). Although there are now many tentative examples of ecological speciation, I argue that ecology’s role in speciation might have been overemphasised and that non-ecological and non-adaptive alternatives should be considered more seriously. Specifically, populations and species of many organisms often show strong evidence of niche conservatism, yet are often highly reproductively isolated from each other. This challenges niche-based ecological speciation and reveals partial decoupling between ecology and reproductive isolation. Furthermore, reproductive isolation might often evolve in allopatry before ecological differentiation between taxa or possibly through learning and antagonistic sexual interactions, either in allopatry or sympatry. Here I discuss recent theoretical and empirical work in this area, with some emphasis on odonates (dragonflies and damselflies) and suggest some future avenues of research. A main message from this paper is that the ecology of species differences is not the same as ecological speciation, just like the genetics of species differences does not equate to the genetics of speciation.
Received: 29 July 2011 / Accepted: 28 November 2011 / Published online: 29 July 2011
Mitochondrial DNA sequences suggest unexpected phylogenetic position of Corso-Sardinian grass snakes (Natrix cetti) and do not support their species status, with notes on phylogeography and subspecies delineation of grass snakesDownload PDFAbstract
We supplement a previously published mitochondrial DNA data set of grass snake sequences (ND1, ND2, ND4, cyt b, in total 3,806 bp) with sequences of Corso-Sardinian and Tuscan specimens and infer their phylogeny using Bayesian, maximum likelihood and maximum parsimony methods. In addition, we estimate divergence times of grass snake clades using a relaxed molecular clock calibrated with fossil evidence, and, in a second approach, the post-Messinian reopening of the Strait of Gibraltar. Recently it was suggested that Corso-Sardinian grass snakes represent a distinct species: Natrix cetti. All tree-building methods revealed well-supported branching patterns and deep divergences among grass snakes. However, sequences of N. natrix were consistently paraphyletic with respect to Corso-Sardinian sequences. The sister group of Corso-Sardinian grass snakes is a clade embracing N. n. helvetica and N. n. lanzai. Extensive gene flow between N. n. helvetica and a more distantly related subspecies (N. n. natrix) is well known, which is why we conclude that the status of Corso-Sardinian grass snakes as subspecies of N. natrix should be reinstated. Many currently recognized grass snake subspecies conflict with mitochondrial clades, suggestive of inappropriate morphological taxon delineation and mitochondrial introgression. Divergences among grass snakes are old, and the results of the two independent dating approaches are largely congruent. Accordingly, the Alpine orogenesis seems to have caused the origin of the oldest clade, corresponding to Iberian N. n. astreptophora. The formation of Corso-Sardinian grass snakes was dated to the Early Pliocene and could result from post-Messinian flooding of the Mediterranean Basin. Another deeply divergent clade of approximately the same age, endemic in central and northern Europe, suggests the Pleistocene survival of grass snakes north of the Alps. At least one glacial refuge in which old lineages survived Pleistocene cold periods was located on each of the three major southern European peninsulas and in Anatolia. Due to pronounced sequence divergences among Italian and southern Swiss grass snakes, we hypothesize multiple refugia south of the Alps and in the Apennine Peninsula, and there is evidence for two refuges on the Balkan Peninsula.
Received: 24 June 2011 / Accepted: 13 February 2012 / Published online: 24 June 2011
Polyphyly of the grass tribe Hainardieae (Poaceae: Pooideae): identification of its different lineages based on molecular phylogenetics, including morphological and cytogenetic characteristicsDownload PDFAbstract
The small pooid grass tribe Hainardieae comprises six genera with approximately ten species; however, this tribe was not accepted by all previous taxonomic treatments. To study the relationships among these genera and to infer the phylogeny and evolutionary patterns, we used sequence variation of the internal transcribed spacers (ITS) of nuclear ribosomal and chloroplast (cp) matK DNA and morphology. Many genera of the Aveneae/Poeae tribe complex additionally were included. Both molecular datasets showed Hainardieae to be highly polyphyletic, and its genera to branch with different groups of the Aveneae/Poeae. Parapholis and Hainardia are corroborated as being closely related, and belonging to a firmly supported Eurasian clade together with Catapodium incl. Scleropoa, Cutandia, Desmazeria, Sphenopus, Vulpiella (subtribe Parapholiinae) and with Cynosurus as sister to this assemblage. The other genera of traditionally recognised Hainardieae are positioned phylogenetically distant: Mediterranean Narduroides is verified as more or less related to Festuca and relatives (subtribe Loliinae), whereas the west Eurasian Pholiurus is close to the lineage of Poa and relatives (subtribe Poinae). North American Scribneria is sister to Deschampsia and both genera should be unified under a common subtribe (Aristaveninae or Holcinae). The phylogenetic position of the Algerian genus Agropyropsis (close to Narduroides and within the Loliinae) is suggested on morphology only, because no molecular data was obtained for it. Considering classification, we support the abandonment of tribe Hainardieae and argue to abandon Poeae subtribe Scribneriinae. Poeae subtribe Parapholiinae is redefined with a novel genus content, due to the exclusion of Agropyropsis and Pholiurus and the inclusion of Vulpiella.
Received: 20 December 2011 / Accepted: 23 April 2012 / Published online: 20 December 2011
Age and body size of Salamandrella keyserlingii (Caudata: Hynobiidae): a difference in altitudes, latitudes, and temperaturesDownload PDFAbstract
The debate surrounding Bergmann’s rule, in which the body size of animals is predicted to be larger in cooler environments, is still open concerning ectotherms. Our goal was to test this rule in the broadest ranging amphibian species Salamandrella keyserlingii. We determined age and body size in a cooler region (Darhadyn, Mongolia: mean yearly air temperature = –8.31 °C) using skeletochronology, and compared their differences in altitude, latitude, and temperature with those of a warmer area (Kushiro, Japan: 7.98 °C). In Darhadyn, both sexes reached sexual maturity at 5–6 years of age (growth coefficient: male = 0.585, female = 0.266), 2–3 years later than those in Kushiro (male = 1.341, female = 1.129). Mean body size was smaller in Darhadyn (53.08 mm) than in Kushiro (57.63 mm) for males despite their constant metamorphic size around 30 mm. We also analyzed data available from published studies for 27 populations within the geographic range of this species from 43 to 69°N across a 2,900-km long latitudinal gradient. The analysis indicated an intraspecific tendency to decrease body size with increased latitude from 43 to 57°N, to increase size from 57 to 69°N, and to decrease body size with decreased temperature from 8 to –7 °C and increase size from –7 to –15 °C. This pattern does not follow the intraspecific extension of Bergmann’s rule and may follow the converse of Terentjev’s optimum rule—a rule formulated to be an inverted-U shaped curve between increased latitude (or decreased temperature) and increased body size.
Received: 21 October 2011 / Accepted: 14 March 2012 / Published online: 21 October 2011
The larva of Libellula foliata (Kirby, 1889) (Odonata: Libellulidae)Download PDFAbstract
The larva of Libellula foliata (Kirby) is described based upon mature larvae from the Biosphere Reserve of “El Triunfo” in the state of Chiapas. It belongs to the small group of species without dorsal protuberances, L. composita (Hagen), L. comanche Calvert and L. saturata Uhler. The following combination of characters permits the separation of L. foliata larva from the other aforementioned larvae: tergites 6–10 uniformly colored, no lateral spines on segments 8–9, 5–6 palpal setae and 3 long premental setae. After this finding, only the larvae of Libellula gaigei Gloyd and L. nodisticta Hagen remain undiscovered for the Mexican species of Libellula.
Received: 05 June 2011 / Accepted: 28 November 2011 / Published online: 05 June 2011
Using haplotype networks, estimation of gene flow and phenotypic characters to understand species delimitation in fungi of a predominantly Antarctic Usnea group (Ascomycota, Parmeliaceae)Download PDFAbstract
Species delimitations in the predominantly Antarctic and South American group of neuropogonoid species of the lichen-forming fungal genus Usnea are poorly understood. Morphological variability has been interpreted as a result of harsh ecological conditions, but preliminary molecular data have led to doubts about the current species delimitations in these lichenized fungi. We examined species boundaries using a phylogenetic approach and a cohesion species recognition method generating haplotype networks and looking at associations of phenotypic characters with clades found in the networks. In addition, we estimated gene flow among detected clades and currently circumscribed species. We identified several clades that were significantly associated with phenotypic characters, but did not necessarily agree with current species circumscriptions. In one case (U. aurantiaco-atra/U. antarctica), network analysis and the estimation of gene flow provided no evidence of distinct species. The distinctness of another species pair (U. subantarctica/U. trachycarpa) remains dubious, showing evidence for gene flow among currently accepted species.
Received: 10 June 2011 / Accepted: 28 November 2011 / Published online: 10 June 2011
An exquisitely preserved harvestman (Arthropoda, Arachnida, Opiliones) from the Middle Jurassic of ChinaDownload PDFAbstract
Sclerosomatids constitute the largest family of the arachnid order Opiliones, and one of the two families commonly found in the temperate regions of the northern Hemisphere. Harvestmen have a sparse fossil record in the Mesozoic, with only two species known from the Jurassic, one of them poorly preserved and none with precise phylogenetic placement. Here we report a new fossil, Mesobunus dunlopi sp. nov., from the Middle Jurassic (approx. 165 Mya) of Daohugou, Inner Mongolia, China. The new species is related to another genus of the same formation, but the preservation quality and details of the penis and pedipalps allow us to place them in the extant sclerosomatid subfamilies Gagrellinae or Leiobuninae. The first recognisable fossil in this subfamily highlights morphological stasis over ca. 165 Mya and the finding of this species along with lacustrine insects suggests a life mode similar to that of some modern sclerosomatids, and a possible connection between morphological and ecological stasis.
Received: 25 November 2011 / Accepted: 23 April 2012 / Published online: 25 November 2011
All the better to see you with: a review of odonate color vision with transcriptomic insight into the odonate eyeDownload PDFAbstract
Although dragonflies and damselflies (Insecta: Odonata) represent some of the most advanced visual systems among insects, odonate visual systems are not as well understood as those of model or more economically important insects. Yet, with their large and complex eyes, aquatic and terrestrial life stages, entirely carnivorous lifestyle, exceptional mating behaviors, diversity in coloration, occupancy of diverse light environments, and adult success that is completely dependent on vision, it would seem studying the visual system of Odonata at the molecular level would yield highly rewarding scientific findings related to predator/prey interactions, the physiological and molecular shifts associated with ecological shifts in light environments, and the role of vision on behavioral ecology. Here, we provide a review of odonate color vision. The first odonate opsin sequences are published using a degenerate PCR approach for both dragonfly and damselfly lineages as well as a transcriptome approach for a single species of damselfly. These genetic data are combined with electrophysiology data from odonates to examine genotype/phenotype relationships in this visual system. Using these data, we present the first insights into the evolution and distribution of the visual pigments (opsins) among odonates. The integration of molecular and behavioral studies of odonate vision will help answer long-standing questions about how sensory systems and coloration may coevolve.
Received: 13 March 2012 / Accepted: 20 March 2012 / Published online: 13 March 2012
Phylogeny of Cidaroida (Echinodermata: Echinoidea) based on mitochondrial and nuclear markersDownload PDFAbstract
We present the first molecular phylogeny of Cidaroida, one of the most problematic groups within the echinoids. Two genes—the nuclear ribosomal gene 28 S rRNA and the mitochondrial protein-encoding gene COI—were obtained from 21 specimens representing 17 genera and 20 species, among which 13 species belong to Cidaroida. Phylogenetic analyses of the combined molecular data using parsimony and maximum likelihood optimality criteria resulted in a well-resolved phylogeny. Our results are broadly compatible (with the notable exception of Cidaris cidaris) with previous results obtained from morphological data. We find that Cidaroida represent a monophyletic group sister to the non-cidaroid Echinoidea. The family Cidaridae sensu Mortensen (1928) and Fell (1966) is paraphyletic because of the placement of Psychocidaris ohshimai as sister-group to Histocidaris elegans. Inside the Stylocidarina, we show that the two Atlantic species Stylocidaris affinis and Stylocidaris lineata constitute a well-supported clade. However, these two taxa could also represent two morphotypes within a single species showing high morphological variation.