Tomasz Rewicz

Out of the Black Sea: Phylogeography of the Invasive Killer Shrimp Dikerogammarus villosus across Europe

The amphipod Dikerogammarus villosus has colonized most of the European main inland water bodies in less than 20 years, having deteriorating effect on the local benthic communities. Our aim was to reveal the species phylogeography in the native Black Sea area, to define the source populations for the colonization routes in continental Europe and for the newly established UK populations. We tested for the loss of genetic diversity between source and invasive populations as well as along invasion route. We tested also for isolation by distance. Thirty three native and invasive populations were genotyped for mtDNA (COI, 16S) and seven polymorphic nuclear microsatellites to assess cryptic diversity (presence of deeply divergent lineages), historical demography, level of diversity within lineage (e.g., number of alleles), and population structure. A wide range of methods was used, including minimum spanning network, molecular clock, Bayesian clustering and Mantel test. Our results identified that sea level and salinity changes during Pleistocene impacted the species phylogeography in the Black Sea native region with four differentiated populations inhabiting, respectively, the Dnieper, Dniester, Danube deltas and Durungol liman. The invasion of continental Europe is associated with two sources, i.e., the Danube and Dnieper deltas, which gave origin to two independent invasion routes (Western and Eastern) for which no loss of diversity and no isolation by distance were observed. The UK population has originated in the Western Route and, despite very recent colonization, no drastic loss of diversity was observed. The results show that the invasion of the killer shrimp is not associated with the costs of loosing genetic diversity, which may contribute to the success of this invader in the newly colonized areas. Additionally, while it has not yet occurred, it might be expected that future interbreeding between the genetically diversified populations from two independent invasion routes will potentially even enhance this success.

Neogene paleogeography provides context for understanding the origin and spatial distribution of cryptic diversity in a widespread Balkan freshwater amphipod

Background The Balkans are a major worldwide biodiversity and endemism hotspot. Among the freshwater biota, amphipods are known for their high cryptic diversity. However, little is known about the temporal and paleogeographic aspects of their evolutionary history. We used paleogeography as a framework for understanding the onset of diversification in Gammarus roeselii: (1) we hypothesised that, given the high number of isolated waterbodies in the Balkans, the species is characterised by high level of cryptic diversity, even on a local scale; (2) the long geological history of the region might promote pre-Pleistocene divergence between lineages; (3) given that G. roeselii thrives both in lakes and rivers, its evolutionary history could be linked to the Balkan Neogene paleolake system; (4) we inspected whether the Pleistocene decline of hydrological networks could have any impact on the diversification of G. roeselii. Material and Methods DNA was extracted from 177 individuals collected from 26 sites all over Balkans. All individuals were amplified for ca. 650 bp long fragment of the mtDNA cytochrome oxidase subunit I (COI). After defining molecular operational taxonomic units (MOTU) based on COI, 50 individuals were amplified for ca. 900 bp long fragment of the nuclear 28S rDNA. Molecular diversity, divergence, differentiation and historical demography based on COI sequences were estimated for each MOTU. The relative frequency, geographic distribution and molecular divergence between COI haplotypes were presented as a median-joining network. COI was used also to reconstruct time-calibrated phylogeny with Bayesian inference. Probabilities of ancestors’ occurrence in riverine or lacustrine habitats, as well their possible geographic locations, were estimated with the Bayesian method. A Neighbour Joining tree was constructed to illustrate the phylogenetic relationships between 28S rDNA haplotypes. Results We revealed that G. roeselii includes at least 13 cryptic species or molecular operational taxonomic units (MOTUs), mostly of Miocene origin. A substantial Pleistocene diversification within-MOTUs was observed in several cases. We evidenced secondary contacts between very divergent MOTUs and introgression of nDNA. The Miocene ancestors could live in either lacustrine or riverine habitats yet their presumed geographic localisations overlapped with those of the Neogene lakes. Several extant riverine populations had Pleistocene lacustrine ancestors. Discussion Neogene divergence of lineages resulting in substantial cryptic diversity may be a common phenomenon in extant freshwater benthic crustaceans occupying areas that were not glaciated during the Pleistocene. Evolution of G. roeselii could be associated with gradual deterioration of the paleolakes. The within-MOTU diversification might be driven by fragmentation of river systems during the Pleistocene. Extant ancient lakes could serve as local microrefugia during that time.

Tiger Beetles (Coleoptera: Carabidae: Cicindelinae) of Tunisia: Distribution, Phenology, Taxa List and New Records

Based on the literature and new faunistic records, the diversity and distribution of the tiger beetles in Tunisia are summarized and discussed. In total, 15 species (one with two subspecies) are reported from the country. However, the occurrence of Cicindela maroccana maroccana is questionable, and should be confirmed by newer data. Checklists of tiger beetles are also provided for each Tunisian governorate. The highest diversity was recorded in the region adjacent to the Mediterranean Sea coastline. The area is mainly up to 100 m a.s.l. with salt marshes, strands of sandy sea beaches and river banks as main types of habitats occupied by Cicindelinae (14 species or 94 % of tiger beetle fauna). Mountainous and desert regions are characterized by much lower diversity (six species or 38% of fauna and two species or 13% of fauna, respectively). Cicindelinae occurring in these areas inhabit predominantly river banks and oases. In chorotype classification, Tunisian tiger beetles fall into six different groups including West Mediterranean species (50% of fauna), Maghreb endemics (19%), Mediterranean, North-African, Mediterranean-Westturanian and Afrotropico-Indo-Mediterranean species (each of them 6% of fauna). According to their phenology, the Tunisian tiger beetles may be divided into three main groups: 1) spring-active species (Cicindela campestris atlantis and all Neolaphyra taxa), 2) spring-summer-active species (Calomera littoralis littoralis, C. lunulata lunulata, Cassolaia maura cupreothoracica, Lophyra flexuosa flexuosa, Myriochila melancholica melancholica, Grammognatha euphratica euphratica), and 3) summer-active species (Calomera aulica aulica, Cylindera trisignata sciliensis and Cephalota spp.).

Pollinator diversity and reproductive success of Epipactis helleborine (L.) Crantz (Orchidaceae) in anthropogenic and natural habitats

Background Epipactis helleborine is an Eurasian orchid species which prefers woodland environments but it may also spontaneously and successfully colonise human-made artificial and disturbed habitats such as roadsides, town parks and gardens. It is suggested that orchids colonising anthropogenic habitats are characterised by a specific set of features (e.g., large plant size, fast flower production). However, as it is not well known how pollinator diversity and reproductive success of E. helleborine differs in populations in anthropogenic habitats compared to populations from natural habitats, we wanted to compare pollinator diversity and reproductive success of this orchid species between natural and anthropogenic habitat types. Methods Pollination biology, reproductive success and autogamy in populations of E. helleborine from anthropogenic (roadside) and natural (forest) habitats were compared. Eight populations (four natural and four human-disturbed ones) in two seasons were studied according to height of plants, length of inflorescences, as well as numbers of juvenile shoots, flowering shoots, flowers, and fruits. The number and diversity of insect pollinators were studied in one natural and two human-disturbed populations. Results Reproductive success (the ratio of the number of flowers to the number of fruits) in the populations from anthropogenic habitats was significantly higher than in the natural habitats. Moreover, plants from anthropogenic habitats were larger than those from natural ones. In both types of populations, the main insect pollinators were Syrphidae, Culicidae, Vespidae, Apidae and Formicidae. With respect to the type of pollinators’ mouth-parts, chewing (39%), sponging (34%) and chewing-sucking (20%) pollinators prevailed in anthropogenic habitats. In natural habitats, pollinators with sponging (55%) and chewing mouth-parts (32%) dominated, while chewing-sucking and piercing-sucking insects accounted for 9% and 4% respectively. Discussion We suggest that higher reproductive success of E. helleborine in the populations from anthropogenic habitats than in the populations from natural habitats may result from a higher number of visits by pollinators and their greater species diversity, but also from the larger size of plants growing in such habitats. Moreover, our data clearly show that E. helleborine is an opportunistic species with respect to pollinators, with a wide spectrum of pollinating insects. Summarising, E. helleborine is a rare example of orchid species whose current range is not declining. Its ability to make use of anthropogenically altered habitats has allowed its significant spatial range expansion, and even successful colonisation of North America.

Taxonomic etymology - in search of inspiration

Abstract We present a review of the etymology of zoological taxonomic names with emphasis on the most unusual examples. The names were divided into several categories, starting from the most common – given after morphological features – through inspiration from mythology, legends, and classic literature but also from fictional and nonfictional pop-culture characters (e.g., music, movies or cartoons), science, and politics. A separate category includes zoological names created using word-play and figures of speech such as tautonyms, acronyms, anagrams, and palindromes. Our intention was to give an overview of possibilities of how and where taxonomists can find the inspirations that will be consistent with the ICZN rules and generate more detail afterthought about the naming process itself, the meaningful character of naming, as well as the recognition and understanding of names.

Europe-wide reassessment of Dictyocoela (Microsporidia) infecting native and invasive amphipods (Crustacea): molecular versus ultrastructural traits

Microsporidia are common parasites infecting animals and protists. They are specifically common pathogens of amphipods (Crustacea, Malacostraca), with Dictyocoela spp. being particularly frequent and highly prevalent, exhibiting a range of phenotypic and ecological effects. Until now, seven species of Dictyocoela were defined, predominantly based on the genetic distance. However, neither the taxonomic status of this provisionally erected genus (based on eight novel sequences and one micrograph of the spore), nor its internal phylogenetic relationships have been clearly revealed. The formal description of the genus and of most of the putative species are still lacking. Here we aimed to fill this gap and performed both ultrastructural and molecular studies (based on SSU, ITS and partial LSU) using different species delimitation methods. As a consensus of these results and following conservative data interpretation, we propose to distinguish five species infecting gammarid hosts, and to keep the names introduced by the authors of the type sequences: Dictyocoela duebenum, D. muelleri, D. berillonum and D. roeselum. We provide full descriptions of these species. Moreover, thanks to our extensive sampling, we extend the known host and geographic range of these Microsporidia.

Pleistocene phylogeography and cryptic diversity of a tiger beetle, Calomera littoralis, in North-Eastern Mediterranean and Pontic regions inferred from mitochondrial COI gene sequences

Background. Calomera littoralis is a Palearctic species, widely distributed in Europe; inhabiting predominantly its Atlantic, Mediterranean and Black Sea coastlines. Methods. Its phylogeography on the Balkan Peninsula and on the north-western Black Sea coast was inferred using a 697 bp long portion of the mitochondrial COI gene, amplified from 169 individuals collected on 43 localities. Results. The results revealed two genetically divergent groups/lineages, the southern one inhabiting both the Balkan Peninsula and the Pontic Region and the northern one found exclusively in the Pontic Region. Species delimitation based on DNA barcoding gap suggested an interspecific level of divergence between these groups. Multivariate analysis of eight male and female morphometric traits detected no difference between the groups, implying they may represent cryptic species. The Bayesian time-calibrated reconstruction of phylogeny suggested that the lineages diverged ca. 2.3 Ma, in early Pleistocene. Discussion. The presence of the two genetically divergent groups results most likely from contemporary isolation of the Pontic basin from the Mediterranean that broke the continuous strip of coastal habitats inhabited by C. littoralis. Demographic analyses indicated that both lineages have been in demographic and spatial expansion since ca. 0.15 Ma. It coincides with the terminal stage of MIS-6, i.e., Wartanian/Saalian glaciation, and beginning of MIS-5e, i.e., Eemian interglacial, during which, due to eustatic sea level rise, a wide connection between Mediterranean and the Pontic basin was re-established. This, along with re-appearance of coastal habitats could initiate north-east expansion of the southern lineage and its secondary contact with the northern one. The isolation of the Pontic basin from the Mediterranean during the Weichselian glaciation most likely did not have any effect on their phylogeography.

Morphometric traits in the fine-leaved fescues depend on ploidy level: the case of Festuca amethystina L.

Background Polyploid specimens are usually characterized by greater exuberance: they reach larger sizes and/or have a larger number of some organs. Festuca amethystina L. belongs to the section Aulaxyper. Based on morphological features, four subspecies of F. amethystina have been already identified. On the other hand, it has two cytotypes: diploid and tetraploid. The main aim of our study was to distinguish morphological differences between the cytotypes of F. amethystina, assuming that its phenotype differs significantly. Methods The nuclear DNA content was measured by flow cytometry in dry leaves from specimens originating from 13 populations of F. amethystina. Several macrometric and micrometric traits of stems, spikelets and leaf blades were taken into account in the comparative analysis of two cytotypes. Results In the case of cytotypes, specimens of tetraploids were larger than diploids. The conducted morphometric analysis of leaf cross-sections showed significant differences between the cytotypes. Discussion The research has confirmed for the first time that in the case of F. amethystina the principle of greater exuberance of polyploids is true. Differences between the cytotypes are statistically significant, however, they are not enough to make easy the distinction of cytotypes on the basis of the measurements themselves. Our findings favor the rule known in Festuca taxonomy as a whole, i.e. that the ploidy level can be one of the main classification criteria.

Morphological variability of Consolida regalis seeds of south-eastern and central Europe

The aim of the paper was to analyse the morphological variability of Consolida regalis Gray (common name Forking Larkspur) seeds in populations derived from different geographic origins. A review of available literature showed scarcity of data on seed sizes and a complete lack of information describing the morphological variation of C. regalis seeds in the geographic gradient. Therefore, the main aim of the study was to analyse the morphological variability of C. regalis seeds from south-eastern and central Europe. Larkspur seeds, collected during expeditions spanning 2012–2014 from 29 sites located in Bulgaria, Romania, Moldova and Poland, were the study material. Four biometric traits were analysed, that is, the length, the width, the perimeter and the area of the seeds. The pictures of the surface structure and sculpture of the seeds were made using the scanning electron microscope (SEM). The results showed differences in biometric traits and the seed sculpture across the latitudinal transect. There was a trend observed of an increase in the length, the width, the perimeter and the area of the seeds towards the northern border of the geographic species range. Besides the geographic factor, the morphological variation of larkspur seeds was affected by environmental conditions (mainly temperature) in which plants grew and availability of habitat resources.

First African Records of Agabus ramblae Millán & Ribera, 2001 (Coleoptera: Dytiscidae)

The genus Agabus (Dytiscidae) in North Africa is poorly studied. Agabus (Gaurodytes) ramblae was found for the first time in two localities in Tunisia (Sidi Bouzid and Tozeur governorates) and one in Libya (Yafran province). This is the first report of this species from Africa, which increases the number of Agabus species known from North Africa to 13. The known distribution of A. ramblae is discussed. An updated checklist of Agabus species occurring in the North Africa is provided.