Discovery of <Emphasis Type="Italic">Dermacentor reticulatus</Emphasis> (Acari: Amblyommidae) populations in the Lubuskie Province (Western Poland)

The distribution of the meadow tick, Dermacentor reticulatus (Fabricius) is divided into two separate areas—Western Europe and Eastern (Russian). The break in distribution of this species falls in Poland, as well as other sites. The populations of D. reticulatus in Poland, which have been confirmed by collecting ticks from vegetation, are located in the north-eastern and western parts of the country, although there are also reports of D. reticulatus occurring on hosts in several parts of Poland which have not been confirmed by collecting ticks from vegetation. Until this research was carried out, the view was that this species does not occur in the western part of Poland in the area between the Vistula and Oder rivers. In the site surveys conducted in the Lubuskie Province (western part of Poland around the city of Zielona Góra, about 55 km from the Polish-German border), during the springtime activity peak for adult stages looking for hosts, seven natural implantations of D. reticulatus were discovered where 208 tick specimens were collected by flagging. These were exclusively adult stages, including 127 females and 81 males. Because of the distance (around 350 km) from the nearest focus in Mazuria in North-eastern Poland, the populations discovered have been named the D. reticulatus “Lubuskie Focus”. The research proves for the first time that D. reticulatus occurs in Western Poland. The research indicates that D. reticulatus is the second most important tick in Poland, after Ixodes ricinus (L.), which is epidemiologically very important, especially as a parasite on dogs and cattle. The proliferation of the meadow tick in Central Europe is inseparably linked with the expansion of canine babesiosis.     

First record of ostracods (Crustacea) in Baltic amber

Ostracods were found in two pieces of Baltic amber for the first time. The animals belong to the freshwater genus Cyclocypris. Since Baltic amber was formed during Eocene times in southern Scandinavia, the age of the specimens is estimated at 42–54 million years. As aquatic organisms, ostracods are seldom trapped in amber; it is considered that one specimen, already dead and dried, was either blown onto sticky resin on a plant stem, or washed there by a high flood level, while the other was probably splashed, alive, in a drop of water against the flowing resin, again probably during a flood. Associated faunal remains, including other crustaceans, suggest a coastal palaeoenvironment with some marine as well as freshwater influence.     

Despite marine traits,the endemic Fucus radicans (Phaeophyceae) is restricted to the brackish Baltic Sea

Many of the marine species that were introduced to the Baltic Sea during the Littorina stage (c. 8500–3000 years BP), e.g. Fucus vesiculosus and F. serratus, have adapted to the present low salinity. These marine species have gone from marine conditions into lower salinity environments. In this paper we ask why the recently discovered endemic brown alga Fucus radicans shows the opposite pattern. Fucus radicans is only present in the northern parts of the Baltic Sea, the low salinity Bothnian Sea (4–6 psu). Potentially, the fitness of F. radicans might be reduced in higher salinities if it is better adapted to brackish conditions. We hypothesize, however, that the southern distribution limit of F. radicans is set by biotic factors, e.g. competition with F. vesiculosus and higher grazing pressure by Idotea balthica and not by salinity. Our results show that the reproductive output of F. radicans is limited by low salinity (4 psu) but increases in higher salinities. However, the southern distribution limit, i.e. the northern Baltic Proper, is regulated by biotic factors, where the additive effects from shading by taller F. vesiculosus thalli and grazing on F. radicans by the isopod I. balthica limit the biomass production of F. radicans. We suggest that F. radicans still maintains marine traits due to its ability to propagate clonally and is restricted to the Bothnian Sea by interactions with F. vesiculosus and I. balthica. We also propose that increased precipitation due to climate change might affect the northern range limit and that the distribution of F. radicans could be expected to shift further south into the Baltic Proper.     

New long-horned caddisflies in Eocene Baltic amber (Insecta,Trichoptera)

We describe two new extinct caddisflies, Electroadicella kuenowi sp. nov. and Triaenodes simoni sp. nov., embedded in Baltic amber. Both species belong to the tribe Triaenodini and enlarge the family Leptoceridae to a remarkable number of 18 extinct Eocene species from Baltic amber. The extinct Electroadicella and the extant Triaenodes are possibly closely related, by a distinct synapomorphy, a recurved process from the basal plate of the inferior appendages of the ninth abdominal segment in the male genitalia.     

Holocene environmental changes and the seal (Phocidae) fauna of the Baltic Sea: coming,going and staying

• 1 The occurrence of different species of seal (Phocidae) during the Holocene in north‐eastern Europe was influenced by a changing geological situation over the last 12 000 years, characterized by alternating freshwater, brackish and marine stages and by spatially and temporally limited opportunities for migration of marine species into the Baltic basin. The patterns of immigration by ringed seal Phoca hispida, harp seal Phoca groenlandica, grey seal Halichoerus grypus and harbour seal Phoca vitulina are reviewed here in order to understand present distributions and population sizes. Furthermore, the future of their populations is analysed.
• 2 Phoca hispida immigrated into the Baltic basin during its brackish Yoldia Stage at the Late Glacial/Early Holocene boundary and has persisted in some disjunct populations until now. A second immigration followed at the beginning of the Littorina Transgression – which resulted in the present stage of the Baltic Sea, obviously caused by the strong cooling event that occurred 6200 calibrated ¹⁴C years BC. Its present status is not threatened, but global warming will restrict suitable habitat.
• 3 Phoca groenlandica had a mid‐Holocene intermezzo in the Baltic Sea. Its later disappearance was probably caused by hunting of subadult animals by humans.
• 4 Halichoerus grypus and Phoca vitulina also immigrated at the beginning of the present stage of the Baltic Sea. Whereas H. grypus has been common from this beginning point until modern times, the population of P. vitulina persisted at a low level for millennia. Only since the 18th century has its population increased and spread over the whole Baltic Sea.

     

Reappearance of Eumarcia fumigata (G.B. Sowerby II, 1853) (Bivalvia: Veneridae) into the Swan River,Western Australia

ABSTRACT

The venerid bivalve Eumarcia fumigata was a common species in Western Australia (WA) during the Pleistocene, where it was distributed as far north as Shark Bay. It became extinct in WA as the climate changed several thousand years ago but remains common in eastern Australia from southern Queensland to South Australia and Tasmania. The species has recently reappeared in the Swan River, probably due to shipping movements. Of the > 60 marine and estuarine species introduced into WA it is only the third confirmed introduction from eastern Australia, and the first that is a reappearance in the Swan River of a species present in the geological past. The present reappearance of E. fumigata, and the introduction of other species, has been made possible by the removal of a rocky bar at the mouth of the estuary and the creation of more marine conditions in the lower Swan estuary.     

Diversity,ecology, and seasonality of hard ticks (Acari: Ixodidae) in eastern Croatia

The diversity of hard tick fauna was studied in different forest communities in 48 localities of eastern Croatia using the dragging‐flagging method and by hand from ten different vertebrate hosts. A total of 2,225 specimens comprising seven species in three genera were identified. Ixodes ricinus, the most abundant species (72.8% of all collected specimens) was recorded in 44 localities, followed by Dermacentor reticulatus in 19 localities, while the other five species (D. marginatus, H. concinna, H. inermis, I. canisuga, and I. hexagonus) were recorded in fewer localities. The highest ratio (67% of collected ticks) was in the adult stage with the predominance of females. The numbers of collected females, males, and nymphs of I. ricinus and H. concinna differed significantly. Ten new tick‐host associations in Croatia were recorded. Fifty‐three animals were infested with one tick species. Single species infestation with I. ricinus was found in 45.8% of animals, followed by D. reticulatus with 25.4%, D. marginatus with 10.2%, H. inermis and I. hexagonus with 3.4%, and I. canisuga with 1.7%. Coinfestation with two species of ticks were recorded in six animals. Ixodes ricinus, H. inermis, and D. reticulatus showed bimodal seasonal activity; for other species unimodal activity patterns were recorded.     

On Pentacoelum hispaniensis,a marine triclad from Spanish freshwater (Platyhelminthes,Tricladida, Maricola)

The marine triclad Pentacoelum hispaniensis is known from a freshwater biotope near Valencia, Spain. Preliminary results suggest a diploid complement of 12 chromosomes for the species. A historical scenario is presented for the occurrence of P. fucoideum in the Caspian Sea and the Baltic Sea, and for the presence of P. hispaniensis in the Mediterranean.     

A molecular phylogeny of the north‐east Atlantic species of the genus Idotea (Isopoda) with focus on the Baltic Sea

Today, the marine isopods of the genus Idotea Fabricius, 1798 consist of 26 accepted species. Most species can be found in the Northern Hemisphere. While some species have a cosmopolitan distribution, others are endemic to a few coastlines. In the Baltic Sea, Idotea species have a key role as important meso‐grazers. Only three species can be found in this brackish environment, I. balthica, I. chelipes and I. granulosa, while nine species are described from the whole European coast. The goal of the present study was to reconstruct the phylogeny of the genus Idotea and to test whether the Baltic low‐salinity tolerant species represent a single lineage within the genus. The phylogeny of north‐east Atlantic Idotea species was investigated based on a fragment of the nuclear gene 28S and the mitochondrial gene COI for eight Idotea species. The phylogenetic reconstructions showed that the genus Idotea might not be monophyletic. Neither I. linearis nor I. urotoma did belong to the separated and well‐supported Idotea clade of I. balthica, I. chelipes, I. emarginata, I. granulosa, I. metallica and I. pelagica. The three Idotea species found in the Baltic belonged to different lineages, with estimated COI‐based divergence time older than 7 Myr. This suggests that the tolerance to low salinity has likely evolved in the genus Idotea more than once.     

On the taxonomic position of <Emphasis Type="Italic">Issus reticulatus</Emphasis> Bervoets, 1910 (Hemiptera: Fulgoroidea: Issidae) from Baltic amber

A new genus Bolbossus gen. n. is erected in the tribe Parahiraciini for Issus bervoetsi Gnezdilov et Bourgoin, nom. n. pro Issus reticulatus Bervoets, 1910 (nom. praeocc., non Issus reticulatus Herrich-Schäffer, 1835) described from the Baltic amber of Kaliningrad Province in Russia. The genus Issites Haupt, 1956 is assigned to the nominotypical subtribe of the tribe Issini Spinola. Bolbossus bervoetsi (Gnezdilov et Bourgoin) is the first species of the Oriental tribe of the family Issidae discovered in Europe. This finding implies the dispersal of taxa from the Oriental Region to the Western Palaearctic during the Eocene. Other fossil Issidae are briefly discussed.     

A new fossil species of the extinct tribe Mimoplatycini Kazantsev, 2013 (Coleoptera Cantharidae)

A new fossil species from the Eocene Baltic amber of the extinct tribe Mimoplatycini Kazantsev, 2013 (Cantharidae Malthininae), is illustrated and described here. Mimoplatycis marchettii sp. nov. is characterized by a transverse but interrupted carina in the middle of pronotum. The tribe is known from Baltic and Rovno amber, and the pronotum with carinae similar to Lycidae could be interpreted as mimicry. The pronotal shape is here indicated as a diagnostic character of the species level.     

Genetic diversity of Saccharina latissima (Phaeophyceae) along a salinity gradient in the North Sea–Baltic Sea transition zone

The North Sea–Baltic Sea transition zone constitutes a boundary area for the kelp species Saccharina latissima due to a strong salinity gradient operating in the area. Furthermore, the existence of S. latissima there, along Danish waters, is fairly patchy as hard bottom is scarce. In this study, patterns of genetic diversity of S. latissima populations were evaluated along the salinity gradient area of Danish waters (here designated brackish) and were compared to reference sites (here designated marine) outside the gradient area, using microsatellite markers. The results showed that the S. latissima populations were structured into two clusters corresponding to brackish versus marine sites, and that gene flow was reduced both between clusters and between populations within clusters. In addition, results provided empirical evidence that marginal populations of S. latissima in the salinity gradient area exhibited a distinct genetic structure when compared to marine ones. Brackish populations were less diverse, more related, and showed increased differentiation over distance compared to marine populations. The isolation of the brackish S. latissima populations within the salinity gradient area of Danish waters in conjunction with their general low genetic diversity makes these populations vulnerable to ongoing environmental and climate change, predicted to result in declining salinity in the Baltic Sea area that may alter the future distribution and performance of S. latissima in the area.     

Mass mortality of an asteriid starfish (Forcipulatida,Asteroidea, Echinodermata) from the late Maastrichtian (Late Cretaceous) of Morocco

Abstract: A mass occurrence, numbering tens of thousands of individuals in a single lens, belonging to a single species of asteroid, is described from the late Maastrichtian (Late Cetaceous) of Morocco. The lens of partially silicified asteroidal limestone is made up largely of fully articulated specimens of similar size and probably represents the mass mortality of a single recruitment. By comparison with mass strandings of the present‐day species Asterias rubens (Linnaeus), it can be inferred that a feeding swarm of individuals was swept into a submarine channel by either a storm or an exceptionally strong tidal current, and permanently buried. The genus and species are herein described as Cretasterias reticulatus gen. et sp. nov. The exceptional preservation of the material enables the identification of wreath organs (clusters of crossed pedicellariae set in a dermal pad around spines) for the first time in the fossil record. Comparison between extant Asteriidae, putative fossil asteriids and C. reticulatus provides ambiguous evidence of its affinities; it appears to display a combination of plesiomorphic and derived characters. It is shown that all Mesozoic forcipulatid asteroids described so far share a very simple arm construction (single row of adradial ossicles) unknown in adult extant Forcipulatida.     

First archaeozoological identification of Atlantic sturgeon (Acipenser oxyrinchus Mitchill 1815) in France

To this day, the only sturgeon to be listed on the French vertebrate inventory is the European sturgeon (Acipenser sturio Linnaeus, 1758). The recent study of sturgeon remains on various French archaeological sites shows the presence of another species: the Atlantic sturgeon (A. oxyrinchus Mitchill 1815). This species already existed in the French Atlantic region at the end of the Neolithic Age 5000 years ago and was still to be found 3000 years later. Thus the A. oxyrinchus determined in several Baltic medieval sites are neither the only nor the first sturgeons to have inhabited European waters. Sturgeon restoration projects in European rivers necessitate a precise determination of the native species. In the case of relict or extinct species, the bone remains found on archaeological sites represent the most reliable source of information. This discovery will also be the starting point of palaeogenetical research (mitochondrial and cellular aDNA) and will give information about the genetic diversity of these threatened or recently extinct populations.     

New information on the invasive to Europe aphid species <Emphasis Type="Italic">Brachycaudus divaricatae</Emphasis> Shaposhnikov, 1956 (Hemiptera: Aphididae)

Brachycaudus divaricatae (Hemiptera: Aphididae), a recent invader to Europe, has already reached Czech Republic. Partial sequences of mitochondrial COI and nuclear EF-1α genes have been analysed across the sixteen Czech samples of B. divaricatae, together with morphometric analysis of the same samples based on eighteen morphological characters of the apterous viviparous females. For comparative studies, thirteen samples from the Eastern Baltic region of Europe (Latvia, Lithuania and Poland) were used. All sampled populations appeared similar in their genetic and morphological characters studied. One haplotype of mitochondrial COI gene was predominant; it was characteristic for all samples from Czech Republic and 8 out of 13 samples from Eastern Baltic region. Two other haplotypes were found in the Eastern Baltic region only. Four different haplotypes of EF-1α gene were detected. Most of the samples (except one sample from the Eastern Baltic region and two samples from Czech Republic) had the same haplotype. Out of remaining three haplotypes, one was unique for the Eastern Baltic region, whilst two were found in Czech Republic only. For the present, Moravia is the southernmost region in Europe, where B. divaricatae has been already reported. Presumably, this invasive aphid species has entered the Czech Republic from the north via the Moravian Gate, a natural pass formed by the depression between the Western Carpathians and Eastern Sudetes.     

FREQUENT CLONALITY IN FUCOIDS (FUCUS RADICANS AND FUCUS VESICULOSUS; FUCALES,PHAEOPHYCEAE) IN THE BALTIC SEA1

Asexual reproduction by cloning may affect the genetic structure of populations, their potential to evolve, and, among foundation species, contributions to ecosystem functions. Macroalgae of the genus Fucus are known to produce attached plants only by sexual recruitment. Recently, however, clones of attached plants recruited by asexual reproduction were observed in a few populations of Fucus radicans Bergström et L. Kautsky and F. vesiculosus L. inside the Baltic Sea. Herein we assess the distribution and prevalence of clonality in Baltic fucoids using nine polymorphic microsatellite loci and samples of F. radicans and F. vesiculosus from 13 Baltic sites. Clonality was more common in F. radicans than in F. vesiculosus, and in both species it tended to be most common in northern Baltic sites, although variation among close populations was sometimes extensive. Individual clonal lineages were mostly restricted to single or nearby locations, but one clonal lineage of F. radicans dominated five of 10 populations and was widely distributed over 550 × 100 km of coast. Populations dominated by a few clonal lineages were common in F. radicans, and these were less genetically variable than in other populations. As thalli recruited by cloning produced gametes, a possible explanation for this reduced genetic variation is that dominance of one or a few clonal lineages biases the gamete pool resulting in a decreased effective population size and thereby loss of genetic variation by genetic drift. Baltic fucoids are important habitat‐forming species, and genetic structure and presence of clonality have implications for conservation strategies.     

A new freshwater halacarid mite, genus Peregrinacarus (Halacaridae, Acari) from the Falklands

Peregrinacarus falklandensis n. sp., a halacarid mite from an East Falkland creek, is described and illustrated. This is the second Peregrinacarus species to date. The other species, P. reticulatus Bartsch, is recorded from Marion Island, Indian Ocean. The two species differ in chaetotaxy of the legs. The presence of halacarids in freshwater of southern polar and adjacent regions is discussed.