Cytogenetic diversity in the Antarctic plunderfishes (Notothenioidei: Artedidraconidae)

2010 ◽  
Vol 22 (6) ◽  
pp. 805-814 ◽  
Author(s):  
Laura Ghigliotti ◽  
Thomas J. Near ◽  
Sara Ferrando ◽  
Marino Vacchi ◽  
Eva Pisano
Keyword(s):  
Biological Diversity ◽  
Genomic Organization ◽  
Diploid Number ◽  
Fish Fauna ◽  
Ribosomal Genes ◽  
Species Relationship ◽  
Victoria Land ◽  
Species Specific ◽  
The Antarctic ◽  
New Evidence

AbstractAntarctic plunderfishes (Notothenioidei, Artedidraconidae) are important components of the Southern Ocean fish fauna. As a contribution to the Victoria Land Transect Project, we performed a cytogenetic analysis of six species from three of the four artedidraconid genera,Artedidraco glareobarbatus,A. orianae,A. skottsbergi,A. shackletoni,Histiodraco velifer, andPogonophrynesp. We investigated the species-specific cytogenetic features and highlighted patterns of chromosomal evolutionary change using a molecular phylogeny based on mitochondrial and nuclear genes. Despite a conserved diploid number, some important karyotypic traits account for major differences among artedidraconid species. Specific cytogenetic features, including the chromosomal organization of ribosomal genes and the occurrence of sex chromosomes, are characteristics ofA. skottsbergi, making this species distinct among those studied. These chromosomal peculiarities are consistent with the phylogenetic hypothesis resolvingA. skottsbergias the sister lineage of all other Artedidraconidae. A karyological similarity was found betweenA. glareobarbatusandA. shackletoniconsistent with their inferred sister species relationship in the phylogeny. The results indicate that artedidraconids are not conservative in their genomic organization at the chromosomal level and provide new evidence for the degree of biological diversity in this notothenioid group.

scholarly journals II.—The Antarctic Fishes of the Scottish National Antarctic Expedition

1913 ◽  
Vol 49 (2) ◽  
pp. 229-292 ◽  
Author(s):  
C. Tate Regan
Keyword(s):  
Fish Fauna ◽  
Antarctic Fish ◽  
The South ◽  
South Georgia ◽  
Antarctic Fishes ◽  
Victoria Land ◽  
Antarctic Expedition ◽  
South Shetlands ◽  
The Antarctic

Our knowledge of the Antarctic fish-fauna has greatly increased during the last ten years. The Belgian expedition to Graham Land (1897–1899) was followed by that of the Southern Cross to Victoria Land (1898–1900), fitted out by Sir George Newnes. Next were the British expedition of the Discovery to Victoria Land and Edward Land (1901–1904), the German voyage of the Gauss to Kerguelen and Willhelm Land (1901–1903), and Nordenskjöld's Swedish expedition to South Georgia, the South Shetlands, and Graham Land. Then came the voyage of the Scotia to the South Orkneys and Coats Land (1902–1904), and Charcot's expeditions to the Palmer Archipelago and Graham Land in the Français. (1904–1905) and the Pourquoi Pas? (1908–1910), and finally Shackleton's expedition (1908–1909).

Phyllolepid placoderm fish remains from the Devonian Aztec Siltstone, southern Victoria Land, Antarctica

2005 ◽  
Vol 17 (3) ◽  
pp. 387-408 ◽  
Author(s):  
GAVIN C. YOUNG ◽  
JOHN A. LONG
Keyword(s):  
Mass Extinction ◽  
Middle Devonian ◽  
Fish Fauna ◽  
Disjunct Distribution ◽  
Late Devonian ◽  
Antarctic Species ◽  
Victoria Land ◽  
Fish Remains ◽  
Dispersal Events ◽  
The Antarctic

Phyllolepid placoderm remains from the Aztec Siltstone fish fauna are described as Austrophyllolepis quiltyi sp. nov., Austrophyllolepis cf. A. youngi, Placolepis tingeyi sp. nov., and phyllolepid indet. The new Antarctic species of two genera previously only known from Australia reinforce evidence from other fish taxa of close biogeographic affinity, as part of the eastern margin of Palaeozoic Gondwana. At least three genera and four species gives the Aztec Siltstone fish fauna the most diverse phyllolepid assemblage known, and probably the oldest documented so far (?late Middle Devonian). Specimens of Austrophyllolepis from the type locality at Mount Howitt, Victoria, are refigured for comparison with the Antarctic species. The order Phyllolepida is a key group for understanding Devonian vertebrate biogeography and palaeogeography, with a unique disjunct distribution in both time and space between the Southern and Northern hemispheres. Phyllolepids document one of the major dispersal events in early vertebrate history, which approximately coincided with the Frasnian–Famennian boundary mass extinction during the Late Devonian.

Antarctic notothenioid fishes as subjects for research in evolutionary biology

2000 ◽  
Vol 12 (3) ◽  
pp. 276-287 ◽  
Author(s):  
Joseph T. Eastman
Keyword(s):  
Evolutionary Biology ◽  
Fish Fauna ◽  
Taxonomic Diversity ◽  
Late Eocene ◽  
Taxonomic Composition ◽  
Species Flock ◽  
Subzero Temperatures ◽  
Key Innovation ◽  
The Antarctic ◽  
Upper Slope

Antarctica is a continental island and the waters of its shelf and upper slope are an insular evolutionary site. The shelf waters resemble a closed basin in the Southern Ocean, separated from other continents by distance, current patterns and subzero temperatures. The benthic fish fauna of the shelf and upper slope of the Antarctic Region includes 213 species with higher taxonomic diversity confined to 18 families. Ninety-six notothenioids, 67 liparids and 23 zoarcids comprise 45%, 32% and 11% of the fauna, a combined total of 88%. In high latitude (71–78°S) shelf areas notothenioids dominate abundance and biomass at levels of 90–95%. Notothenioids are also morphologically and ecologically diverse. Although they lack a swim bladder, the hallmark of the notothenioid radiation has been repeated diversification into water column habitats. There are pelagic, semipelagic, cryopelagic and epibenthic species. Notothenioids exhibit the disproportionate speciosity and high endemism characteristic of fish species flock. Antifreeze glycopeptides originating from a transformed trypsinogen gene are a key innovation. It is not known when the modern Antarctic shelf fauna assumed its current taxonomic composition. A late Eocene fossil fauna was taxonomically diverse and cosmopolitan. There was a subsequent faunal replacement with little carryover of families into the modern fauna. Basal notothenioid clades probably diverged in Gondwanan shelf locations during the early Tertiary. Dates inferred from molecular sequences suggest that phyletically derived Antarctic clades arose 15–5 m.y.a.

scholarly journals Karyotypic diversity among three species of the genus Astyanax (Characiformes: Characidae)

2016 ◽  
Vol 76 (2) ◽  
pp. 360-366 ◽  
Author(s):  
P. B. Nishiyama ◽  
M. M. R. Vieira ◽  
F. E. Porto ◽  
L. A. Borin ◽  
A. L. B. Portela-Castro ◽  
...  
Keyword(s):  
Diploid Number ◽  
Fish Fauna ◽  
Distinct Pattern ◽  
Supernumerary Chromosome ◽  
C Banding ◽  
Incertae Sedis ◽  
Banding Analysis ◽  
Karyotypic Diversity ◽  
Karyotype Formula

Abstract The group Incertae sedis within the Characidae family currently includes 88 genera, previously included in the subfamily Tetragonopterinae. Among them is the genus Astyanax comprising a group of species with similar morphology and widely distributed in the Neotropics. Thus, the present study aimed to analyze the karyotype diversity in Astyanax species from different watersheds by conventional Giemsa staining, C-banding and fluorescence in situ hybridization (FISH rDNA 18S) probe.specimens of Astyanax aff. paranae belonging to the “scabripinnis complex”, Astyanax asunsionensis and Astyanax aff. bimaculatus were analyzed”. Two sympatric karyomorphs were observed in Astyanax.aff paranae, one of them having2n=48andthe other one with 2n=50 chromosomes. Other population of this same species also presented 2n=50 chromosomes, but differing in the karyotype formula and with macro supernumerary chromosome found in 100% of the cells in about 80%of females analyzed. Two population of A. asuncionensis and one population of Astyanax. aff. bimaculatus, also showed a diploid number of 50 chromosomes, but also differing in their karyotype formulas. Therefore, A. asuncionensis was also characterized by intraspecific chromosome diversity. The C-banding analysis was able to demonstrate a distinctable to demonstrate a distinct pattern of heterochromatin differing A. asuncionensis from Astyanax aff. paranae and Astyanax aff. bimaculatus. The supernumerary chromosome of Astyanax aff. paranae proved completely heterochromatic. Only Astyanax.aff. bimaculatus multiple showed multiple sites of nucleolar organizing regions. The other species were characterized by having a simple system of NOR. These data contributes to the know ledge of the existing biodiversity in our fish fauna, here highlighted by the inter- and intraspecific chromosomal diversity in the genus Astyanax.

scholarly journals Wind drives drought responses of green roof vegetation in two substrates

2018 ◽  
Author(s):  
Arkadiusz Przybysz ◽  
Konstantin Sonkin ◽  
Arne Sæbø ◽  
Hans Martin Hanslin ◽  
Keyword(s):  
Biological Diversity ◽  
Green Roof ◽  
Green Roofs ◽  
Plant Performance ◽  
Succulent Plant ◽  
Hieracium Pilosella ◽  
Key Factor ◽  
Substrate Moisture ◽  
Species Specific ◽  
Functional And Phylogenetic Diversity

The multifunctionality and delivery of ecosystem services from green roofs is improved by biological diversity of the roof vegetation. However, the frequency and intensity of drought episodes on extensive green roofs may limit the use of non-succulent species and the potential functional and phylogenetic diversity of the vegetation. Wind accelerates water use by plants and desiccation of the green roof substrate, and may be a key factor in selection of non-succulent plant species for green roofs. In this study, we tested wind interactions with green roof substrate composition and the effects on plant and substrate water balance, overall plant performance, and wilting and survival of three non-succulent species (Plantago maritima L., Hieracium pilosella L., and Festuca rubra L.) under realistic prolonged water deficit conditions. We found that, regardless of species or substrate tested, wind accelerated drought response. Drought-stressed plants exposed to wind wilted and died earlier, mostly due to more rapid desiccation of the growth substrate (critical substrate moisture content was 6-8%). The moderate wind levels applied did not affect plant performance when not combined with drought. Species with contrasting growth forms showed similar responses to treatments, but there were some species-specific responses. This highlights the importance of including wind to increase realism when evaluating drought exposure in non-succulent green roof vegetation.

Palaeomagnetic results from the middle Tertiary Meander Intrusives of northern Victoria Land, East Antarctica

1996 ◽  
Vol 8 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Elena Belluso ◽  
Roberto Lanza
Keyword(s):  
Remanent Magnetization ◽  
Ross Sea ◽  
East Antarctica ◽  
Magnetic Mineralogy ◽  
Tilt Correction ◽  
Palaeomagnetic Data ◽  
Victoria Land ◽  
Geological Models ◽  
Laboratory Investigations ◽  
The Antarctic

The Tertiary stocks (Meander Intrusives) cropping out along the coasts of the Ross Sea were sampled for a palaeomagnetic study during the sixth Italian expedition to northern Victoria Land. Laboratory investigations concerned magnetic mineralogy and remanent magnetization. Minerals of the magnetiteulvöspinel series occur in the rocks from all stocks, with low-Ti titanomagnetite usually prevalent. Haematite and goethite occur in small amounts as alteration products. Large secondary components commonly screen the characteristic remanent magnetization and were removed by thermal or AF demagnetization at temperatures or peak-fields higher than 360°C and 20 mT respectively. A total of 10 VGPs were obtained from radiometrically dated rocks (42–22 Ma); the averaged position (69°S, 334°E; α95=9.9°) is the first middle Tertiary palaeomagnetic pole for East Antarctica, and gives evidence for a reversal in the course of the APW path. This evidence is not substantially altered by a supposed tilt-correction consistent with geophysical and geological models for the uplift of the Transantarctic Mountains. No definite conclusion about relative movements between East Antarctica and the Antarctic Peninsula can be drawn from the existing palaeomagnetic data.

Historical Changes in Large River Fish Assemblages of the Americas

2005 ◽  
Keyword(s):  
Biological Diversity ◽  
Oil And Gas ◽  
Fish Assemblages ◽  
Land Use Changes ◽  
Fish Fauna ◽  
Coal Extraction ◽  
River Drainage ◽  
Local Loss ◽  
Oil And Gas Exploration ◽  
Wabash River

<em>Abstract.</em>—The Patoka River drainage is a lowland-gradient watershed of the Wabash River lowlands in southwestern Indiana. During the late 18th century, the river was part of an extensive riparian floodplain wetland that connected the White River with the lower Wabash River. Through anthropogenic changes as a result of ditching, channelization, levee creation, coal extraction, and oil and gas exploration, the Patoka River drainage has been highly altered. These changes have resulted in a loss of sitespecific biological diversity and integrity, causing drainage-wide biological diversity decline. Extirpations in the watershed have resulted in the local loss of 12.7% of the fish fauna during the last century. The local extirpations of six species included central mudminnow <em>Umbra limi</em>, black redhorse <em>Moxostoma duquesnei</em>, brindled madtom <em>Noturus miurus</em>, bluebreast darter <em>Etheostoma camurum</em>, slenderhead darter <em>Percina phoxocephala</em>, and saddleback darter <em>P. vigil</em>. Black redhorse, bluebreast darter, slenderhead darter, and saddleback darter were only known from pre-1900, while brindled madtom and central mudminnow were known until the early 1940s. These species may have been rare to begin with in the Patoka River drainage, but since they are widespread elsewhere, it seems more probable that they disappeared as a result of the land-use changes. Sensitive species of darters and minnows have declined in abundance, but recent sampling has shown that they remain in the watershed at low abundance. Based on a probability sample, less than 12% of the channels represented reference least-disturbed conditions, while 61% exhibited degraded conditions.

scholarly journals Sub-decadal variations in outlet glacier terminus positions in Victoria Land, Oates Land and George V Land, East Antarctica (1972–2013)

2017 ◽  
Vol 29 (5) ◽  
pp. 468-483 ◽  
Author(s):  
A.M. Lovell ◽  
C.R. Stokes ◽  
S.S.R. Jamieson
Keyword(s):  
Antarctic Peninsula ◽  
East Antarctica ◽  
West Antarctica ◽  
Position Change ◽  
Outlet Glacier ◽  
Glacier Terminus ◽  
Victoria Land ◽  
Decadal Scale ◽  
Decadal Variations ◽  
The Antarctic

AbstractRecent work has highlighted the sensitivity of marine-terminating glaciers to decadal-scale changes in the ocean–climate system in parts of East Antarctica. However, compared to Greenland, West Antarctica and the Antarctic Peninsula, little is known about recent glacier change and potential cause(s), with several regions yet to be studied in detail. In this paper, we map the terminus positions of 135 glaciers along the coastline of Victoria Land, Oates Land and George V Land from 1972–2013 at a higher temporal resolution (sub-decadal intervals) than in previous research. These three regions span a range of climatic and oceanic conditions and contain a variety of glacier types. Overall, from 1972–2013, 36% of glaciers advanced, 25% retreated and the remainder showed no discernible change. On sub-decadal timescales, there were no clear trends in glacier terminus position change. However, marine-terminating glaciers experienced larger terminus position changes compared with terrestrial glaciers, and those with an unconstrained floating tongue exhibited the largest variations. We conclude that, unlike in Greenland, West Antarctica and the Antarctic Peninsula, there is no clear glacier retreat in the study area and that most of the variations are more closely linked to glacier size and terminus type.

scholarly journals Biogeography of terrestrial cyanobacteria from Antarctic ice-free areas

2010 ◽  
Vol 51 (56) ◽  
pp. 171-177 ◽  
Author(s):  
Z. Namsaraev ◽  
M.-J. Mano ◽  
R. Fernandez ◽  
Annick Wilmotte
Keyword(s):  
Rrna Gene ◽  
Distribution Analysis ◽  
Operational Taxonomic Units ◽  
Terrestrial Cyanobacteria ◽  
Victoria Land ◽  
Low Degree ◽  
Range Transport ◽  
Antarctic Continent ◽  
The Antarctic ◽  
Further Development

AbstractCyanobacteria inhabit the Antarctic continent and have even been observed in the most southerly ice-free areas of Antarctica (86–87° S). The highest molecular diversity of cyanobacterial communities was found in the areas located between 70° S and 80° S. Further south and further north from this zone, the diversity abruptly decreased. Seventy-nine per cent (33 of 42 operational taxonomic units) of Antarctic terrestrial cyanobacteria have a cosmopolitan distribution. Analysis of the sampling efforts shows that only three regions (southern Victoria Land, the Sør Rondane Mountains and Alexander Island) have been particularly well studied, while other areas did not receive enough attention. Although cyanobacteria possess a capacity for long-range transport, regional populations in Antarctic ice-free areas seem to exist. The cyanobacterial communities of the three most intensively studied regions, separated from each other by a distance of 3000–3400 km, had a low degree of similarity with each other. Further development of microbial biogeography demands a standardized approach. For this purpose, as a minimal standard, we suggest using the sequence of cyanobacterial 16S rRNA gene between Escherichia coli positions 405 and 780.

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