Population genetics of two tropical sharks, Carcharhinus tilstoni and C. sorrah, in Northern Australia

1989 ◽  
Vol 40 (5) ◽  
pp. 541 ◽  
Author(s):  
S Lavery ◽  
JB Shaklee
Keyword(s):  
Eastern Coast ◽  
Population Subdivision ◽  
Starch Gel Electrophoresis ◽  
Northern Australia ◽  
Tissue Samples ◽  
North West ◽  
The North ◽  
North Eastern ◽  
Starch Gel ◽  
Sufficient Variation

The genetic structure of the Australian populations of Carcharhinus tilstoni and C. sorrah was investigated by starch gel electrophoresis. Tissue samples were taken from 1580 sharks from throughout the fishery, which extends from the North-West Shelf (off Western Australia) to the north-eastern coast of Queensland. From a total of 47 enzyme loci screened in each species, 13 proved to be polymorphic (P0.99) for at least one species, with only 5 loci for each species showing sufficient variation (P0.95) to be of use in the analysis of population structure. Mean heterozygosity values were relatively low: 0.037 for C. tilstoni and 0.035 for C. sorrah. A low level of population subdivision was found within each species, with FST values of 0.0094 for C. tilstoni and 0.0076 for C. sorrah. There was insufficient evidence to suggest that there is more than one population of either species of shark in Australian waters.

Genetic subdivision of the pearl oyster Pinctata maxima (Jameson, 1901) (Mollusca: Pteriidae) in northern Australia

1993 ◽  
Vol 44 (4) ◽  
pp. 519 ◽  
Author(s):  
MS Johnson ◽  
LM Joll
Keyword(s):  
Western Australia ◽  
Pearl Oyster ◽  
Starch Gel Electrophoresis ◽  
Northern Australia ◽  
Genetic Subdivision ◽  
Two Samples ◽  
North Eastern ◽  
Starch Gel ◽  
Pinctada Maxima ◽  
Polymorphic Enzymes

The genetic structure of the pearl oyster Pinctada maxima in northern Australia was investigated by starch-gel electrophoresis. Six polymorphic enzymes were examined in 220 individuals from five areas which span a distance of 3400 km. Across this range, the average FST is 0.104, with three of the loci showing highly significant variation in allelic frequencies. Most of the geographic variation is clinal between western and eastern populations. Particularly striking is the near substitution of alternate alleles for GOT between Western Australia and north-eastern Queensland. Comparisons between adjacent pairs of samples usually revealed significant genetic differences, including differences between two areas in the Northern Territory separated by 320 km. In contrast, two samples from Western Australia showed little evidence of genetic subdivision over a distance of more than 800 km. These genetic comparisons indicate that stocks of P. maxima are highly subdivided in northern Australia, but they also favour the view that there are substantial connections of Western Australian populations over large distances.

Stanowiska reliktowego gatunku Betula humilis (Betulaceae) w Dolinie Górnego Nurca na Nizinie Północnopodlaskiej

2019 ◽  
pp. 161-168
Author(s):  
Aleksander Kołos
Keyword(s):  
Drainage Ditches ◽  
North West ◽  
Hay Meadows ◽  
The North ◽  
South West ◽  
North Eastern ◽  
New Localities ◽  
Western Border ◽  
Betula Humilis ◽  
Trees And Shrubs

Betula humilis Schrank (shrubby birch) is among the most endangered shrub species in Poland. All localities are in the eastern and northern parts of the country, where the species reaches the western border of its geographical range in Europe. Betula humilis is disappearing in Poland due to wetland melioration and shrub succession. Over 80% of the localities described in Poland have not been confirmed in the last 20 years. Five new localities of B. humilis in the North Podlasie Lowland were recorded from 2008 to 2019 in the Upper Nurzec Valley (Fig. 1): 1–1.5 km south-west of Pawlinowo village (in the ATPOL GC7146 plot) and 1.5–2 km north-west of Żuki village (ATPOL GC7155, GC156 and GC166). The population near Pawlinowo (locality 1) is currently composed of ~80 individuals (101 individuals were noted in 2010) and is one of the largest populations in north-eastern Poland. Betula humilis grows there within patches dominated by Salix rosmarinifolia and megaforbs. The population at locality 5 is composed of 18 individuals. At the remaining localities, only 1–4 individuals were found, scattered along drainage ditches surrounded by hay meadows. At some of these localities the species is threatened with extinction. It is suggested to remove competitive trees and shrubs (mainly Populus tremula, Betula pubescens and Salix cinerea) in order to maintain the local populations.

scholarly journals Geomorphology of the north-eastern coast of Gozo (Malta, Mediterranean Sea)

2018 ◽  
Vol 14 (2) ◽  
pp. 402-410 ◽  
Author(s):  
Mariacristina Prampolini ◽  
Christopher Gauci ◽  
Anton S. Micallef ◽  
Lidia Selmi ◽  
Vittoria Vandelli ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Eastern Coast ◽  
The North ◽  
North Eastern

Baskinta and Bqaatouta: Two new early Barremian fossiliferous amber outcrops from Central Lebanon

2021 ◽  
Vol 4 (4) ◽  
Author(s):  
SIBELLE MAKSOUD ◽  
MOUNIR MAALOUF ◽  
RAMY MAALOUF ◽  
DANY AZAR
Keyword(s):  
Eastern Coast ◽  
The North ◽  
North Eastern

Two new fossiliferous amber outcrops in the heights of Baskinta and Bqaatouta (El-Maten and Kesserouan districts, Central Lebanon) are described. These new discoveries constitute respectively the 27th and 28th amber outcrops with biological inclusions in Lebanon, enrich and improve our knowledge about the palaeobiodiversity and palaeoenvironment of the North-Eastern coast of Gondwana during the early Barremian.

scholarly journals Morphological description of six species of Suberitida (Porifera: Demospongiae) from the unexplored north-eastern coast of Brazil, with emphasis on two new species

2020 ◽  
Vol 100 (3) ◽  
pp. 389-400
Author(s):  
Humberto F. M. Fortunato ◽  
Thierry Pérez ◽  
Gisele Lôbo-Hajdu
Keyword(s):  
Current Knowledge ◽  
Atlantic Coast ◽  
Marine Sponges ◽  
Eastern Coast ◽  
Morphological Description ◽  
Brazilian Coast ◽  
Northern Coast ◽  
Western Atlantic ◽  
The North ◽  
North Eastern

AbstractThe Order Suberitida is defined as a group of marine sponges without an obvious cortex, a skeleton devoid of microscleres, and with a deletion of a small loop of 15 base pairs in the secondary structure of the 28S rDNA as a molecular synapomorphy. Suberitida comprises three families and 26 genera distributed worldwide, but mostly in temperate and polar waters. Twenty species were reported along the entire Brazilian coast, and although the north-eastern coast of Brazil seems to harbour a rich sponge fauna, our current knowledge is concentrated along the south-eastern Atlantic coast. A survey was implemented along the northern coast of Brazil, and the collection allowed the identification of six species belonging to the Order Suberitida. Two of them are considered new to science: Suberites purpura sp. nov., Hymeniacidon upaonassu sp. nov., and four, Halichondria (Halichondria) marianae Santos, Nascimento & Pinheiro, 2018, Halichondria (H.) melanadocia de Laubenfels, 1936, Suberites aurantiacus (Duchassaing & Michelotti, 1864), and Terpios fugax Duchassaing & Michelotti, 1864, are re-described. Taxonomic comparisons are made for Tropical Western Atlantic species and type species of the four genera. Finally, an identification key for the Western Atlantic Suberites species is provided.

A geochemical investigation into the resource potential of the Lawn Hill Platform, northern Australia

2020 ◽  
Vol 60 (2) ◽  
pp. 722
Author(s):  
Amber J. M. Jarrett ◽  
Adam E. H. Bailey ◽  
Christopher J. Boreham ◽  
Tehani Palu ◽  
Lisa Hall ◽  
...  
Keyword(s):  
Organic Geochemistry ◽  
Source Rocks ◽  
Geochemical Data ◽  
Northern Australia ◽  
Hydraulic Stimulation ◽  
Petroleum Potential ◽  
North West ◽  
North Eastern ◽  
Resource Exploration ◽  
Geochemical Investigation

The Lawn Hill Platform (LHP) is a sedimentary province in north-eastern Northern Territory and north-western Queensland that hosts a significant Paleoproterozoic–Mesoproterozoic sequence, often referred to as 'the ‘Isa Superbasin’, and includes the overlying South Nicholson Group. Shale gas resources and base-metals mineralisation are known in north-west Queensland, but the larger basin is underexplored. The Australian Government’s Exploring for the Future (EFTF) 2016−2020 program aims to boost resource exploration in northern Australia. New precompetitive geochemical data obtained in this program includes source rock geochemistry, kerogen kinetics, bitumen reflectance, biomarker and δ13C n-alkanes for understanding the petroleum potential, organic geochemistry of source rocks and fluids, stratigraphic correlations and mineralogy to determine the brittleness of shales. All data and derived reports are accessible on the EFTF portal (www.eftf.ga.gov.au), providing a central location for informed decision making. The results in this study demonstrate fair to excellent source rocks in multiple supersequences that are brittle and favourable to hydraulic stimulation. A comparison to the greater McArthur Basin demonstrates, that although there are many similarities in bulk geochemistry, LHP mudstones are largely heterogeneous, reflecting local variations that may be inherited from variations in contributing biomass, microbial reworking, depositional environment, sediment input and paleoredox conditions.

scholarly journals Evaluation of Soil Moisture Variability in Poland from SMOS Satellite Observations

2019 ◽  
Vol 11 (11) ◽  
pp. 1280 ◽  
Author(s):  
Bogusław Usowicz ◽  
Jerzy Lipiec ◽  
Mateusz Lukowski
Keyword(s):  
Soil Moisture ◽  
North West ◽  
Moisture Contents ◽  
North East ◽  
The North ◽  
Linear Distance ◽  
Classical Statistics ◽  
Ocean Salinity ◽  
North Eastern ◽  
Smos Satellite

Soil moisture (SM) data play an important role in agriculture, hydrology, and climate sciences. In this study, we examined the spatial-temporal variability of soil moisture using Soil Moisture Ocean Salinity (SMOS) satellite measurements for Poland from a five-year period (2010–2014). SMOS L2 v. 551 datasets (latitudinal rectangle 1600 × 840 km, centered in Poland) averaged for quarterly (three months corresponding to winter, spring, summer, and autumn) and yearly values were used. The results were analysed with the use of classical statistics and geostatistics (using semivariograms) to acquire information about the nature of anisotropy and the lengths and directions of spatial dependences. The minimum (close to zero) and maximum soil moisture values covered the 0.5 m3 m−3 range. In particular quarters, average soil moisture did not exceed 0.2 m3 m−3 and did not drop below 0.12 m3 m−3; the corresponding values in the study years were 0.171 m3 m−3 and 0.128 m3 m−3. The highest variability of SM occurred generally in winter (coefficient of variation, CV, up to 40%) and the lowest value was recorded in spring (around 23%). The average CV for all years was 32%. The quarterly maximum (max) soil moisture contents were well positively correlated with the average soil moisture contents (R2 = 0.63). Most of the soil moisture distributions (histograms) were close to normal distribution and asymmetric data were transformed with the square root to facilitate geostatistical analysis. Isotropic and anisotropic empirical semivariograms were constructed and the theoretical exponential models were well fitted (R2 > 0.9). In general, the structural dependence of the semivariance was strong and moderate. The nugget (C0) values slightly deceased with increasing soil moisture while the sills (C0 + C) increased. The effective ranges of spatial dependence (A) were between 1° and 4° (110–440 km of linear distance). Generally, the ranges were greater for drier than moist soils. Anisotropy of the SM distribution exhibited different orientation with predominance from north-west to south-east in winter and spring and changed for from north-east to south-west or from north to south in the other seasons. The fractal dimension values showed that the distribution of the soil moisture pattern was less diverse (smoother) in the winter and spring, compared to that in the summer and autumn. The soil moisture maps showed occurrence of wet areas (soil moisture > 0.25 m3 m−3) in the north-eastern, south-eastern and western parts and dry areas (soil moisture < 0.05 m3 m−3) mainly in the central part (oriented towards the south) of Poland. The spatial distribution of SM was attributed to soil texture patterns and associated with water holding capacity and permeability. The results will help undertake appropriate steps to minimize susceptibility to drought and flooding in different regions of Poland.

scholarly journals The sensitivity of the Arctic sea ice to orbitally induced insolation changes: a study of the mid-Holocene Paleoclimate Modelling Intercomparison Project 2 and 3 simulations

2013 ◽  
Vol 9 (2) ◽  
pp. 969-982 ◽  
Author(s):  
M. Berger ◽  
J. Brandefelt ◽  
J. Nilsson
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Eastern Coast ◽  
Sea Ice Extent ◽  
The North ◽  
Arctic Sea ◽  
North Eastern ◽  
Intercomparison Project ◽  
Insolation Change

Abstract. In the present work the Arctic sea ice in the mid-Holocene and the pre-industrial climates are analysed and compared on the basis of climate-model results from the Paleoclimate Modelling Intercomparison Project phase 2 (PMIP2) and phase 3 (PMIP3). The PMIP3 models generally simulate smaller and thinner sea-ice extents than the PMIP2 models both for the pre-industrial and the mid-Holocene climate. Further, the PMIP2 and PMIP3 models all simulate a smaller and thinner Arctic summer sea-ice cover in the mid-Holocene than in the pre-industrial control climate. The PMIP3 models also simulate thinner winter sea ice than the PMIP2 models. The winter sea-ice extent response, i.e. the difference between the mid-Holocene and the pre-industrial climate, varies among both PMIP2 and PMIP3 models. Approximately one half of the models simulate a decrease in winter sea-ice extent and one half simulates an increase. The model-mean summer sea-ice extent is 11 % (21 %) smaller in the mid-Holocene than in the pre-industrial climate simulations in the PMIP2 (PMIP3). In accordance with the simple model of Thorndike (1992), the sea-ice thickness response to the insolation change from the pre-industrial to the mid-Holocene is stronger in models with thicker ice in the pre-industrial climate simulation. Further, the analyses show that climate models for which the Arctic sea-ice responses to increasing atmospheric CO2 concentrations are similar may simulate rather different sea-ice responses to the change in solar forcing between the mid-Holocene and the pre-industrial. For two specific models, which are analysed in detail, this difference is found to be associated with differences in the simulated cloud fractions in the summer Arctic; in the model with a larger cloud fraction the effect of insolation change is muted. A sub-set of the mid-Holocene simulations in the PMIP ensemble exhibit open water off the north-eastern coast of Greenland in summer, which can provide a fetch for surface waves. This is in broad agreement with recent analyses of sea-ice proxies, indicating that beach-ridges formed on the north-eastern coast of Greenland during the early- to mid-Holocene.

Structure and Affinities of Freshwater Sea Lamprey (Petromyzon marinus) Populations

1981 ◽  
Vol 38 (12) ◽  
pp. 1708-1714 ◽  
Author(s):  
Peter F. Brussard ◽  
Marjorie Collings Hall ◽  
Janet Wright
Keyword(s):  
New York ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Population Subdivision ◽  
Starch Gel Electrophoresis ◽  
Clustering Methods ◽  
Test Procedures ◽  
Simultaneous Test ◽  
Population Structuring ◽  
Starch Gel

We have examined genetic differentiation at 23 loci in 12 populations of sea lamprey, Petromyzon marinus, by means of starch gel electrophoresis. Based on two measures of overall genetic distance and two clustering methods, our analysis shows that there are three genetically distinct groups of lamprey in eastern North America: (1) anadromous populations plus those in Lake Champlain, (2) populations in Lake Erie and the upper Great Lakes, and (3) populations in Lake Ontario and three interior New York Lakes (Cayuga, Seneca, and Oneida). Analysis of population subdivision using contiguity partitions and simultaneous test procedures (STP) confirms the above conclusions and offers additional insight into the genetic structure of lamprey in this area.Key words: sea lamprey, Petromyzon marinus; genetic variation, electrophoresis, population structuring

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