scholarly journals An introgression breakthrough left by an anthropogenic contact between two ascidians

2021 ◽  
Author(s):  
Alan Le Moan ◽  
Charlotte Roby ◽  
Christelle Fraisse ◽  
Claire Daguin-Thiebaut ◽  
Nicolas Bierne ◽  
...  
Keyword(s):  
Regional Scale ◽  
Indigenous Species ◽  
North East ◽  
The North ◽  
Allopatric Divergence ◽  
In The Wild ◽  
Speciation Continuum ◽  
Non Indigenous Species ◽  
Evolutionary Consequences ◽  
First And Second Generation

Human-driven translocations of species have diverse evolutionary consequences such as promoting hybridization between previously geographically isolated taxa. This is well-illustrated by the solitary tunicate, Ciona robusta, native to the North East Pacific and introduced in the North East Atlantic. It is now co-occurring with its congener C. intestinalis in the English Channel, and C. roulei in the Mediterranean Sea. Despite their long allopatric divergence, first and second generation crosses showed a high hybridization success between the introduced and native taxa in the laboratory. However, previous genetic studies failed to provide evidence of recent hybridization between C. robusta and C. intestinalis in the wild. Using SNPs obtained from ddRAD-sequencing of 397 individuals from 26 populations, we further explored the genome-wide population structure of the native Ciona taxa. We first confirmed results documented in previous studies, notably i) a chaotic genetic structure at regional scale, and ii) a high genetic similarity between C. roulei and C. intestinalis, which is calling for further taxonomic investigation. More importantly, and unexpectedly, we also observed a genomic hotspot of long introgressed C. robusta tracts into C. intestinalis genomes at several locations of their contact zone. Both the genomic architecture of introgression, restricted to a 1.5 Mb region of chromosome 5, and its absence in allopatric populations suggest introgression is recent and occurred after the introduction of the non-indigenous species. Overall, our study shows that anthropogenic hybridization can be effective in promoting introgression breakthroughs between species at a late stage of the speciation continuum.

Seawater warming at the northern reach for southern species: Gulf of Genoa, NW Mediterranean

2017 ◽  
Vol 98 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Carlo Nike Bianchi ◽  
Francesco Caroli ◽  
Paolo Guidetti ◽  
Carla Morri
Keyword(s):  
Mediterranean Sea ◽  
Native Species ◽  
Indigenous Species ◽  
Ligurian Sea ◽  
The North ◽  
Nw Mediterranean ◽  
The Mediterranean ◽  
Non Indigenous Species ◽  
Southern Species ◽  
North Western

Global warming is facilitating the poleward range expansion of plant and animal species. In the Mediterranean Sea, the concurrent temperature increase and abundance of (sub)tropical non-indigenous species (NIS) is leading to the so-called ‘tropicalization’ of the Mediterranean Sea, which is dramatically evident in the south-eastern sectors of the basin. At the same time, the colder north-western sectors of the basin have been said to undergo a process of ‘meridionalization’, that is the establishment of warm-water native species (WWN) previously restricted to the southern sectors. The Gulf of Genoa (Ligurian Sea) is the north-western reach for southern species of whatever origin in the Mediterranean. Recent (up to 2015) observations of NIS and WWN by diving have been collated to update previous similar inventories. In addition, the relative occurrences of both groups of southern species have been monitored by snorkelling between 2009 and 2015 in shallow rocky reefs at Genoa, and compared with the trend in air and sea surface temperatures. A total of 20 southern species (11 NIS and 9 WWN) was found. Two WWN (the zebra seabream Diplodus cervinus and the parrotfish Sparisoma cretense) and three NIS (the SW Atlantic sponge Paraleucilla magna, the Red Sea polychaete Branchiomma luctuosum, and the amphi-American and amphi-Atlantic crab Percnon gibbesi) are new records for the Ligurian Sea, whereas juveniles of the Indo-Pacific bluespotted cornetfish Fistularia commersonii have been found for the first time. While temperature has kept on increasing for the whole period, with 2014 and 2015 being the warmest years since at least 1950, the number of WWN increased linearly, that of NIS increased exponentially, contradicting the idea of meridionalization and supporting that of tropicalization even in the northern sectors of the Mediterranean basin.

scholarly journals Has Dreissena polymorpha, an older immigrant in a coastal Baltic lagoon, responded to appearance of a new non-indigenous dreissenid?

2018 ◽  
Author(s):  
Brygida Wawrzyniak-Wydrowska ◽  
Anna Skrzypacz ◽  
Adam Wozniczka ◽  
Teresa Radziejewska
Keyword(s):  
Population Structure ◽  
Size Distribution ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Indigenous Species ◽  
Large Share ◽  
Szczecin Lagoon ◽  
The North ◽  
Clear Peak ◽  
Non Indigenous Species

Although a non-indigenous species, Dreissena polymorpha (zebra mussel) has constituted a constant and abundant component of the Szczecin Lagoon biota. A congeneric dreissenid, D. rostriformis bugensis (quagga), was first recorded in the north of the Lagoon in 2014, already in abundance. In summer 2015, the quagga dominated over the zebra mussel in abundance and biomass. Quagga individuals there were much larger than those of D. polymorpha, while elsewhere in the Lagoon the zebra mussel still dominated the dreissenid assemblages. In summer 2016, the population structure of D. r. bugensis was substantially modified and its abundance was greatly reduced. D. polymorpha became the dominant again. In terms of biomass, after the initial domination, D. r. bugensis biomass declined substantially. The zebra mussel, although represented mostly by small individuals, has become a biomass dominant too on account of its high abundance. As of mid-2016, there has been no clear peak (evidencing the appearance of juveniles) in the quagga size distribution. The recent dreissenid samples show a large share of empty quagga shells, an effect not observed earlier. Therefore, it is plausible that the older immigrant, so far at least, has outcompeted the newcomer.

scholarly journals Genome-wide analysis clarifies the population genetic structure of wild Gilthead Sea Bream (Sparus aurata)

2020 ◽  
Author(s):  
Francesco Maroso ◽  
Konstantinos Gkagkavouzis ◽  
Sabina De Innocentiis ◽  
Jasmien Hillen ◽  
Fernanda do Prado ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Sparus Aurata ◽  
Snp Markers ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Commercial Fishing ◽  
North East ◽  
The North ◽  
In The Wild ◽  
The Mediterranean

AbstractGilthead sea bream is an important target for both recreational and commercial fishing in Europe, where it is also one of the most important cultured fish. Its distribution range goes from the Mediterranean to the African and European coasts of the North-East Atlantic. So far, the genetic structure of this species in the wild has been studied with microsatellite DNA, but the pattern of differentiation could not be fully clarified. In this study, almost 1000 wild sea bream from 23 locations in the Mediterranean Sea and Atlantic ocean where genotyped at 1159 SNP markers, of which 18 potentially under selection. Neutral markers suggested the presence of a weak subdivision into three genetic clusters: Atlantic, West and East Mediterranean. This last group could be further subdivided into an Ionian/Adriatic and an Aegean group using outlier markers. Seascape analysis suggested that this differentiation was mainly due to difference in salinity, and this was also supported by preliminary genomic functional analysis. These results are of fundamental importance for the development of proper management of this species in the wild and are a first step toward the study of the potential genetic impact of the sea bream aquaculture industry.

scholarly journals Transversely isotropic lower crust of Variscan central Europe imaged by ambient noise tomography of the Bohemian Massif

Solid Earth ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 1051-1074
Author(s):  
Jiří Kvapil ◽  
Jaroslava Plomerová ◽  
Hana Kampfová Exnerová ◽  
Vladislav Babuška ◽  
György Hetényi ◽  
...  
Keyword(s):  
Bohemian Massif ◽  
Lower Crust ◽  
Ambient Noise ◽  
Regional Scale ◽  
Crustal Thickening ◽  
Scale Model ◽  
Significant Feature ◽  
Ambient Noise Tomography ◽  
North East ◽  
The North

Abstract. The recent development of ambient noise tomography, in combination with the increasing number of permanent seismic stations and dense networks of temporary stations operated during passive seismic experiments, provides a unique opportunity to build the first high-resolution 3-D shear wave velocity (vS) model of the entire crust of the Bohemian Massif (BM). This paper provides a regional-scale model of velocity distribution in the BM crust. The velocity model with a cell size of 22 km is built using a conventional two-step inversion approach from Rayleigh wave group velocity dispersion curves measured at more than 400 stations. The shear velocities within the upper crust of the BM are ∼0.2 km s−1 higher than those in its surroundings. The highest crustal velocities appear in its southern part, the Moldanubian unit. The Cadomian part of the region has a thinner crust, whereas the crust assembled, or tectonically transformed in the Variscan period, is thicker. The sharp Moho discontinuity preserves traces of its dynamic development expressed in remnants of Variscan subductions imprinted in bands of crustal thickening. A significant feature of the presented model is the velocity-drop interface (VDI) modelled in the lower part of the crust. We explain this feature by the anisotropic fabric of the lower crust, which is characterised as vertical transverse isotropy with the low velocity being the symmetry axis. The VDI is often interrupted around the boundaries of the crustal units, usually above locally increased velocities in the lowermost crust. Due to the north-west–south-east shortening of the crust and the late-Variscan strike-slip movements along the north-east–south-west oriented sutures preserved in the BM lithosphere, the anisotropic fabric of the lower crust was partly or fully erased along the boundaries of original microplates. These weakened zones accompanied by a velocity increase above the Moho (which indicate an emplacement of mantle rocks into the lower crust) can represent channels through which portions of subducted and later molten rocks have percolated upwards providing magma to subsequently form granitoid plutons.

scholarly journals Marine hitchhikers: a preliminary study on invertebrates unintentionally transported via the international pet trade

NeoBiota ◽  
2020 ◽  
Vol 61 ◽  
pp. 33-46
Author(s):  
Jiří Patoka ◽  
Romanus E. Prabowo ◽  
Miloslav Petrtýl ◽  
Julian D. Reynolds ◽  
Pavlína Kuříková ◽  
...  
Keyword(s):  
Marine Invertebrates ◽  
Aquatic Organisms ◽  
Indigenous Species ◽  
Pet Trade ◽  
The Czech Republic ◽  
Detection And Identification ◽  
In The Wild ◽  
Preliminary Study ◽  
Non Indigenous Species ◽  
Ornamental Species

The pet trade in aquatic organisms is a significant source of non-indigenous species introductions. In comparison with ornamental animals, unintentionally transported invertebrate assemblages are easily overlooked by traders and keepers. Moreover, hitchhiking species detection and identification is difficult even for experts. The densities of “hitchhikers” in aquaria may be relatively higher than those in the wild. These phenomena are known in freshwater aquaria but poorly studied in marine ones. We found 17 species of non-ornamental marine invertebrates in one of the leading importers of aquarium species in the Czech Republic in November 2017. The set comprised six gastropods, two bivalves, three cnidarians, two echinoderms, two crustaceans, and two polychaete worms. In one case, a symbiont was also detected, associated with the host “hitchhiker”. No “live rocks” are traded by the surveyed wholesaler. Thus, the found animals were not imported together with this item as larvae or eggs. Contrary to the transport of targeted ornamental species, it is clear that transport of “hitchhikers” is occurring despite standard legislative regulations and should be brought to the attention of conservationists, wildlife managers, policymakers and other stakeholders.

scholarly journals Erythristic leopards Panthera pardus in South Africa

Bothalia ◽  
2016 ◽  
Vol 46 (1) ◽  
Author(s):  
Tara J. Pirie ◽  
Rebecca L. Thomas ◽  
Mark D.E. Fellowes
Keyword(s):  
South Africa ◽  
South African ◽  
Camera Traps ◽  
Colour Morph ◽  
Panthera Pardus ◽  
North West ◽  
North East ◽  
The North ◽  
In The Wild ◽  
Genetically Determined

Background: Leopards (Panthera pardus) show genetically determined colour variation. Erythristic (strawberry) morphs, where individuals are paler and black pigment in the coat is replaced by a red-brown colour, are exceptionally rare in the wild. Historically, few records exist, with only five putative records known from India.Objectives: To record the presence of erythristic leopards in our study site (Thaba Tholo Wilderness Reserve, Mpumalanga) and to collate records from across South Africa. Method: A network of camera traps was used to record individual leopards at Thaba Tholo. We also surveyed local experts, searched the popular South African press, and used social media to request observations.Results: Two out of 28 individual leopards (7.1%) recorded in our study site over 3 years were of this colour morph. We obtained records of five other erythristic leopards in the North West and Mpumalanga regions, with no reports outside of this population.Conclusions: Erythristic leopards are widely dispersed across north-east South Africa, predominantly in the Lydenburg region, Mpumalanga. The presence of this rare colour morph may reflect the consequences of population fragmentation.

scholarly journals Has Dreissena polymorpha, an older immigrant in a coastal Baltic lagoon, responded to appearance of a new non-indigenous dreissenid?

2018 ◽  
Author(s):  
Brygida Wawrzyniak-Wydrowska ◽  
Anna Skrzypacz ◽  
Adam Wozniczka ◽  
Teresa Radziejewska
Keyword(s):  
Population Structure ◽  
Size Distribution ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Indigenous Species ◽  
Large Share ◽  
Szczecin Lagoon ◽  
The North ◽  
Clear Peak ◽  
Non Indigenous Species

Although a non-indigenous species, Dreissena polymorpha (zebra mussel) has constituted a constant and abundant component of the Szczecin Lagoon biota. A congeneric dreissenid, D. rostriformis bugensis (quagga), was first recorded in the north of the Lagoon in 2014, already in abundance. In summer 2015, the quagga dominated over the zebra mussel in abundance and biomass. Quagga individuals there were much larger than those of D. polymorpha, while elsewhere in the Lagoon the zebra mussel still dominated the dreissenid assemblages. In summer 2016, the population structure of D. r. bugensis was substantially modified and its abundance was greatly reduced. D. polymorpha became the dominant again. In terms of biomass, after the initial domination, D. r. bugensis biomass declined substantially. The zebra mussel, although represented mostly by small individuals, has become a biomass dominant too on account of its high abundance. As of mid-2016, there has been no clear peak (evidencing the appearance of juveniles) in the quagga size distribution. The recent dreissenid samples show a large share of empty quagga shells, an effect not observed earlier. Therefore, it is plausible that the older immigrant, so far at least, has outcompeted the newcomer.

scholarly journals Sampling native and non-native mobile epifauna with baited traps and habitat collectors – Port of Gdynia case study (southern Baltic Sea, Poland)

2020 ◽  
Vol 49 (3) ◽  
pp. 319-327
Author(s):  
Monika Normant-Saremba ◽  
Joanna Hegele-Drywa ◽  
Lena Marszewska
Keyword(s):  
Baltic Sea ◽  
Growing Season ◽  
Indigenous Species ◽  
Artificial Habitat ◽  
Southern Baltic Sea ◽  
North East ◽  
The North ◽  
Baited Traps ◽  
Southern Baltic ◽  
Mobile Epifauna

AbstractThe effectiveness of two artificial habitat collectors, crab condo (HC1) and habitat crate (HC2), providing a refuge for small mobile fauna, was tested along with two commercial baited traps, Chinese box trap (BT1) and Gee’s Minnow trap (BT2) recommended for only single deployments under a harmonized survey of the Baltic and the North-East Atlantic. Our objective was also to determine whether a multi-deployment of baited traps in the growing season increases the diversity and abundance of collected mobile epifauna. Nineteen species of benthic mobile epifauna, including six non-indigenous species (NIS), were collected between May and October 2014 using all tested types of traps in the Port of Gdynia (southern Baltic Sea). Crustaceans, represented by 16 taxa, constituted the group with the highest diversity and abundance. Our study showed that HC1 and HC2 are more effective gear than BT1 and BT2, as both species richness (including NIS) and abundance were higher. Furthermore, the double deployment of BT1 and BT2 increased the diversity and abundance of the captured fauna. The use of artificial habitat collectors as an additional method to the already recommended baited traps for mobile epifauna monitoring in ports should be considered and the number of baited trap deployments should be increased during the growing season.

scholarly journals Euro-Atlantic winter storminess and precipitation extremes under 1.5 °C versus 2 °C warming scenarios

2017 ◽  
Author(s):  
Monika J. Barcikowska ◽  
Scott J. Weaver ◽  
Frauke Feser ◽  
Simone Russo ◽  
Frederik Schenk ◽  
...  
Keyword(s):  
Global Warming ◽  
Regional Scale ◽  
Storm Track ◽  
Precipitation Extremes ◽  
Storm Tracks ◽  
Atlantic Region ◽  
Storm Activity ◽  
Wind Speeds ◽  
North East ◽  
The North

Abstract. Severe winter storms in combination with precipitation extremes pose a serious threat to Europe. Located at the south-east exit of the North Atlantic's storm track, European coastlines are directly exposed to impacts by high wind speeds, storm floods and coastal erosion. In this study we analyze potential changes in simulated winter storminess and extreme precipitation which may occur under 1.5 °C or 2 °C warming scenarios. Here we focus on a first simulation suite of the atmospheric model CAM5 performed within the HAPPI project and evaluate how changes of the horizontal model resolution impact the results regarding atmospheric pressure, storm tracks, wind speed and precipitation extremes. The comparison of CAM5 simulations with different resolution indicates that an increased horizontal resolution to 0.25° is not only refining regional-scale information, but also improves large-scale atmospheric circulation features over the Euro-Atlantic region. The zonal bias in SLP and wind fields, which is typically found in low-resolution models, is considerably reduced. This allows us to analyze potential changes in regional- to local-scale extreme wind speeds and precipitation in a more realistic way. Our analysis of the future response for the 2 °C warming scenario generally confirms previous model simulations suggesting a poleward shift and intensification of the meridional circulation the Euro-Atlantic region. Additional analysis suggests that this shift occurs mainly after exceeding the 1.5 °C global warming level, when the midltatitude jetstream manifests a strengthening north-eastward. At the same time, this north-east shift of the storm tracks allows an intensification and north-east expansion of the Azores high leading to a tendency of less precipitation across the Bay of Biscay and North Sea. Regions impacted by the strengthening of the midlatitude jet, such as the northwest coasts of British Isles, Scandinavia and the Norwegian Sea, and over the North Atlantic east from Newfoundland experience an increase in the mean as well as daily and sub daily precipitation and wind extremes and storminess suggesting an important influence of increasing storm activity in these regions in response to global warming.

scholarly journals Local Drivers of Change in Southern Ocean Ecosystems: Human Activities and Policy Implications

2021 ◽  
Vol 9 ◽  
Author(s):  
Susie M. Grant ◽  
Cath L. Waller ◽  
Simon A. Morley ◽  
David K. A. Barnes ◽  
Madeleine J. Brasier ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Human Activities ◽  
Marine Mammals ◽  
Regional Scale ◽  
Policy Implications ◽  
Ecological Change ◽  
Indigenous Species ◽  
Ocean Ecosystems ◽  
Projected Changes ◽  
Non Indigenous Species

Local drivers are human activities or processes that occur in specific locations, and cause physical or ecological change at the local or regional scale. Here, we consider marine and land-derived pollution, non-indigenous species, tourism and other human visits, exploitation of marine resources, recovery of marine mammals, and coastal change as a result of ice loss, in terms of their historic and current extent, and their interactions with the Southern Ocean environment. We summarise projected increases or decreases in the influence of local drivers, and projected changes to their geographic range, concluding that the influence of non-indigenous species, fishing, and the recovery of marine mammals are predicted to increase in the future across the Southern Ocean. Local drivers can be managed regionally, and we identify existing governance frameworks as part of the Antarctic Treaty System and other instruments which may be employed to mitigate or limit their impacts on Southern Ocean ecosystems.

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