Microgeographic, Genetic and Morphological-Differentiation of Fresh-Water Snails - the Hydrobiidae of Wilson Promontory, Victoria, South-Eastern Australia

1994 ◽  
Vol 42 (5) ◽  
pp. 557 ◽  
Author(s):  
WF Ponder ◽  
DJ Colgan ◽  
GA Clark ◽  
AC Miller ◽  
T Terzis
Keyword(s):  
Morphological Differentiation ◽  
Geographic Area ◽  
Low Flow ◽  
Secondary Contact ◽  
Shell Shape ◽  
Population Subdivision ◽  
Additional Species ◽  
Sea Levels ◽  
Eastern Australia ◽  
Genetic Patterns

Population differentiation and speciation in freshwater snails in a small geographic area were investigated in a study of the morphology and genetics of 75 populations of hydrobiid snails from streams on Wilsons Promontory, Victoria, Australia. At least four genetically definable species occur in sympatry. One (Fluvidona recta sp. nov.) is genetically isolated from the others and the other three (of which only F: turbata sp. nov. is named) appear to be closely related and distinguished by a nearly fixed allozyme (MPI) difference. Heterozygote frequencies for the diagnostic Mpi locus fall well below Hardy-Weinberg expectations in zones of sympatry. There is significant population subdivision within at least two of the genetic species, but as the partitions are allopatric they are not categorised taxonomically. The situation may be explained by the divergence of upland and lowland populations when sea levels fell during the Pleistocene with subsequent secondary contact and low levels of hybridisation in the contact zones. Generally, there is very low gene flow between even closely adjacent populations and extremely low flow between different catchments, F-ST between populations within the same tributary ranging from 0.02 to 0.14 and within adjacent tributaries of the same catchment ranging from 0.03 to 0.59. Some correlations between allozyme data and measured environmental variables were observed but none of these were consistent over all taxa. Size (shell length) appears to be influenced by environment, but shell shape and the length of the opercular smear are more correlated with genetic patterns. A notable lack of correlation between anatomy and genetic groupings was found, although there was some with shell and opercular morphology. Two additional species (F: gippslandica, sp. nov. and F: foris, sp. nov.) from areas adjacent to the Promontory are used as outgroups.

The genus Echinolittorina Habe, 1956 (Gastropoda: Littorinidae) in the Indo-West Pacific Ocean

Zootaxa ◽  
2007 ◽  
Vol 1420 (1) ◽  
pp. 1-161 ◽  
Author(s):  
DAVID G. REID
Keyword(s):  
Mitochondrial Gene ◽  
Morphological Differentiation ◽  
Open Water ◽  
Distribution Patterns ◽  
Morphological Characters ◽  
Molecular Data ◽  
Shell Shape ◽  
Additional Species ◽  
West Pacific ◽  
Distribution Maps

The phylogeny of the genus Echinolittorina, and phylogeography of some of its members, have previously been examined using molecular data, so that species can now be defined by a combination of phylogenetic, morphological and geographical criteria. The 26 species recognized in the Indo-West Pacific biogeographical region form a monophyletic group, here defined as the subgenus Granulilittorina Habe & Kosuge, 1966. Morphological descriptions are provided for these 26 species, including details of shell, pigmentation of headfoot, reproductive anatomy, spermatozoa, egg capsules and radulae. Diagnoses include reference to mitochondrial gene sequences (COI). A key is based on shells, tentacle pigmentation, penial shape and geographical distribution. Seven new species are described: E. marisrubri, E. omanensis, E. austrotrochoides, E. marquesensis, E. wallaceana, E. tricincta, E. philippinensis. Three name changes are proposed: E. malaccana (Philippi, 1847) and E. cecillei (Philippi, 1851) are valid names for two members of the former ‘E. trochoides’ group; E. biangulata (von Martens, 1897) replaces ‘E. quadricincta’. Full synonymies are given for all taxa, and the taxonomic, evolutionary and ecological literature reviewed. Distribution maps are based on examination of 1701 samples and reliable literature records. The contrast between continental and oceanic distribution patterns is emphasized; one clade of five species and two additional species are shown to have an association with upwelling areas. All species are known (or predicted from protoconch size and oviduct anatomy) to have planktotrophic development, and rare extralimital records suggest a maximum open-water dispersal distance of 1000–2100 km. The most useful morphological characters for identification are the shell, penial shape and copulatory bursa in the pallial oviduct. Sister species can be morphologically similar, but are almost always entirely allopatric, so that distributional information is important for identification. Substantial intraspecific variation is present in the shell shape and sculpture of most species; where there is a pronounced geographical pattern this may have a genetic basis, but ecophenotypic effects are also implicated, e.g. by predictable associations in some species of strongly nodulose sculpture with limestone substrates and with dry habitats where growth rate may be slow. Morphological characters are superimposed on a molecular phylogeny to demonstrate the synapomorphies of clades. This is essentially a morphostatic radiation of largely allopatric species with little morphological differentiation; ecological divergence is limited to specialization to oceanic, continental or upwelling areas and to small differences in zonation level.

scholarly journals Variation in palaeo-shorelines explains contemporary population genetic patterns of rocky shore species

2014 ◽  
Vol 10 (6) ◽  
pp. 20140330 ◽  
Author(s):  
Jessica A. Toms ◽  
John S. Compton ◽  
Malcolm Smale ◽  
Sophie von der Heyden
Keyword(s):  
Population Genetic ◽  
Rocky Shore ◽  
Rocky Intertidal ◽  
Secondary Contact ◽  
Intertidal Habitat ◽  
Isolated Populations ◽  
Sea Levels ◽  
Genetic Patterns ◽  
Glacial Periods ◽  
Extant Population

Processes driving and maintaining disjunct genetic populations in marine systems are poorly understood, owing to a lack of evidence of hard barriers that could have shaped patterns of extant population structure. Here, we map two genetically divergent lineages of an obligate rocky shore fish, Clinus cottoides , and model sea-level change during the last 110 000 years to provide the first evidence of a vicariant event along the southern coastline of Africa. Results reveal that lowered sea levels during glacial periods drastically reduced rocky intertidal habitat, which may have isolated populations in two refugia for at least 40 000 years. Contemporary coastal dynamics and oceanography explain secondary contact between lineages. This scenario provides an explanation for the origin of population genetic breaks despite a lack of obvious present-day geographical barriers and highlights the need for including palaeo-oceanography in unravelling extant population patterns.

Acoustic analysis of an intergrade zone between two call races of the Limnodynastes tasmaniensis complex (Anura : Leptodactylidae) in south-eastern Australia

1975 ◽  
Vol 23 (1) ◽  
pp. 113 ◽  
Author(s):  
MJ Littlejohn ◽  
JD Roberts
Keyword(s):  
Acoustic Analysis ◽  
Secondary Contact ◽  
Ecological Gradient ◽  
North Central ◽  
Call Structure ◽  
Central Victoria ◽  
South Eastern ◽  
Eastern Australia ◽  
Mating Calls ◽  
South Eastern Australia

Mating calls of the northern and southern call races of the L. tasmaniensis complex are described. Analysis of call structure along a transect across the main contact between these allopatric forms in north central Victoria indicates that there is a zone of intergradation between 90 and 135 km wide, about 215 km long and with a north-westerly orientation. The interaction is interpreted as a secondary contact in which there is hybrid or recombinant superiority along a subtle ecological gradient.

Mid Pleistocene arid shift in southern Australia, dated by magnetostratigraphy

Soil Research ◽  
2001 ◽  
Vol 39 (1) ◽  
pp. 89 ◽  
Author(s):  
Brad Pillans ◽  
Robert Bourman
Keyword(s):  
Marked Change ◽  
Source Area ◽  
Pronounced Change ◽  
Sea Levels ◽  
Leeuwin Current ◽  
Polarity Transition ◽  
Tasman Sea ◽  
Eastern Australia ◽  
Regional Climates ◽  
Regional Rainfall

In coastal sections at Hallett Cove and Sellicks Beach, south of Adelaide, and at Redbanks section on Kangaroo Island, the Brunhes/Matuyama polarity transition (780 ka) is identified in the strongly oxide-mottled Ochre Cove Formation. At all 3 sections, the Ochre Cove Formation is overlain by a calcareous grey-green aeolian clay, called Ngaltinga Clay, which in turn is overlain by calcareous sediments of the Taringa and Christies Beach Formations. The marked change from an oxide-dominated weathering regime to a carbonate-dominated weathering regime, estimated to have occurred at about 500–600 ka, is interpreted as a major arid shift in regional climates. Similar arid shifts are known from Lake Bungunnia in the Murray Basin and Lake Lefroy in southern Western Australia, where changes from lacustrine clays to evaporites and dune sediments are estimated to have occurred between 400 and 700 ka, and about 500 ka, respectively. An increase in aeolian dust accession in south-eastern Australia, consistent with increased aridity in the interior source area, occurred after 780 ka, and was probably coeval with increased dust input to Tasman Sea sediments since 350 ka. Between 600 and 900 ka, oxygen isotope fluctuations in deep-sea cores showed a pronounced change in frequency, from a 40 ka (obliquity dominated) to a 100 ka (eccentricity dominated) pattern. At the same time, glacial-interglacial amplitudes increased, with a marked enrichment of glacial d18O values consistent with larger continental based ice-sheets. Colder global temperatures, and lower sea levels during glacials, may have played a part in the mid Pleistocene arid shift recorded in southern Australia. Associated variations in the strength of the warm Leeuwin Current may also have affected regional rainfall patterns in southern Australia.

Conservation Genetics of Corroboree Frogs, Pseudophryne-Corroboree Moore (Anura, Myobatrachidae) - Population Subdivision and Genetic-Divergence

1991 ◽  
Vol 39 (3) ◽  
pp. 285 ◽  
Author(s):  
WS Osborne ◽  
JA Norman
Keyword(s):  
Genetic Divergence ◽  
Conservation Management ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Population Subdivision ◽  
Southern Form ◽  
Eastern Australia ◽  
Geographic Populations ◽  
Taxonomic Implications ◽  
Growth Abnormalities

Reproductive compatibility and population genetic structure were examined in the corroboree frog, Pseudophryne corroboree, a species restricted to montane and subalpine environments in south-eastern Australia. The species comprises three geographic populations, represented by two morphological forms. Hybridisation experiments showed that the allopatric populations are interfertile, although crosses between the Snowy Mountains population (southern form) and each of the two northern populations (northern form) resulted in a significantly higher number of tadpoles with growth abnormalities. An electrophoretic examination of metamorphlings indicated that there was considerable genetic divergence between the two forms, with several loci approaching fixation of alternate alleles. The Snowy Mountains population also had substantially reduced levels of genetic variation compared to the two northern populations. Although genetic distances generally correlate with geographic distance, the genetic differences between the northern and southern populations form a pronounced step, not explicable by geographic distance alone. These findings have taxonomic implications which should be taken into account when considering the conservation management of this uncommon species.

Genetic structure of Gahnia radula (Cyperaceae), a key sedge for revegetation

2017 ◽  
Vol 65 (2) ◽  
pp. 128
Author(s):  
Alex Arnold ◽  
Andrea Kodym ◽  
Nancy M. Endersby-Harshman ◽  
John Delpratt ◽  
Ary A. Hoffmann
Keyword(s):  
Genetic Variation ◽  
Adaptive Potential ◽  
Genetic Studies ◽  
Potential Source ◽  
Landscape Processes ◽  
Disturbed Areas ◽  
Eastern Australia ◽  
Genetic Patterns ◽  
Source Populations ◽  
High Level

Genetic studies can help guide effective ecological restoration by identifying potential source populations that contain the genetic variation necessary for adaptive potential, based on past landscape processes. Here we investigate genetic patterns in Gahnia radula (R.Br.) Benth., a sedge from south-eastern Australia that has potential for revegetation of disturbed areas. We developed microsatellite markers for this species and used them to show that it propagates mostly in a clonal manner. Levels of genetic variability differed between populations and the spatial scale of this variability within these populations is identified. A population used in recent restoration efforts and which sets seed has a particularly high level of variability. Recommendations are developed for sourcing material when using this sedge for revegetation.

scholarly journals Impact of Coal Resource Development on Streamflow Characteristics: Influence of Climate Variability and Climate Change

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1161 ◽  
Author(s):  
Francis Chiew ◽  
Guobin Fu ◽  
David Post ◽  
Yongqiang Zhang ◽  
Biao Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Coal Mining ◽  
Resource Development ◽  
Low Flow ◽  
Cumulative Impact ◽  
Eastern Australia ◽  
Hydroclimate Variability ◽  
Coal Resource ◽  
Flow Variables ◽  
The Impact

The potential cumulative impact of coal mining and coal seam gas extraction on water resources and water-dependent assets from proposed developments in eastern Australia have been recently assessed through a Bioregional Assessment Programme. This study investigates the sensitivity of the Bioregional Assessment results to climate change and hydroclimate variability, using the Gloucester sub-region as an example. The results indicate that the impact of climate change on streamflow under medium and high future projections can be greater than the impact from coal mining development, particularly where the proposed development is small. The differences in the modelled impact of coal resource development relative to the baseline under different plausible climate futures are relatively small for the Gloucester sub-region but can be significant in regions with large proposed development. The sequencing of hydroclimate time series, particularly when the mine footprint is large, significantly influences the modelled maximum coal resource development impact. The maximum impact on volumetric and high flow variables will be higher if rainfall is high in the period when the mine footprint is largest, and vice-versa for low flow variables. The results suggest that detailed analysis of coal resource development impact should take into account climate change and hydroclimate variability.

scholarly journals Megadiversity in the Ant Genus Melophorus: The M. rufoniger Heterick, Castalanelli and Shattuck Species Group in the Top End of Australia’s Northern Territory

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 386
Author(s):  
Alan N. Andersen ◽  
Benjamin D. Hoffmann ◽  
Stefanie K. Oberprieler
Keyword(s):  
Morphological Differentiation ◽  
Single Species ◽  
Species Group ◽  
Northern Region ◽  
Northern Territory ◽  
Distributional Analysis ◽  
Additional Species ◽  
Sympatric Distribution ◽  
Total Species ◽  
Eleven Species

This study contributes to an understanding of megadiversity in the arid-adapted ant genus Melophorus by presenting an integrated genetic, morphological and distributional analysis of diversity within the M. rufoniger group in the 400,000 km2 Top End (northern region) of Australia’s Northern Territory. An earlier study of the Top End’s ant fauna lists eleven species from the M. rufoniger group, but a recent revision of Melophorus described the taxon as a single species occurring throughout most of the Australian mainland. CO1 sequences were obtained for 120 Top End specimens of the M. rufoniger group, along with a specimen from just outside the Top End. We recognize a total of 30 species among the sequenced specimens from the Top End, based on marked CO1 divergence (mean > 9%) in association with morphological differentiation and/or sympatric distribution. The sequenced specimen from just outside the Top End represents an additional species. Our unpublished CO1 data from other specimens from elsewhere in monsoonal Australia indicate that all but two of the 30 sequenced Top End species are endemic to the region, and that such diversity and endemism are similar in both the Kimberley region of far northern Western Australia and in North Queensland. The total number of species in the M. rufoniger group is potentially more than the 93 total species of Melophorus recognized in the recent revision. It has previously been estimated that Melophorus contains at least 1000 species, but our findings suggest that this is a conservative estimate.

Revision of leaf-beetles of the genus Cadmus Erichson, subgenus Lachnabothra Saunders (Coleoptera: Chrysomelidae: Cryptocephalinae)

1999 ◽  
Vol 13 (1) ◽  
pp. 1 ◽  
Author(s):  
C. A. M. Reid
Keyword(s):  
Life History ◽  
New Guinea ◽  
Additional Species ◽  
Leaf Beetles ◽  
Nomen Dubium ◽  
Eastern Australia ◽  
Senior Synonym ◽  
New Synonymy

The genus Cadmus Erichson, subgenus Lachnabothra Saunders, is redefined and revised. It includes at least 24 species, of which 7 are redescribed and 13 described as new: bicornutus, burru, clibanarius, gullanae, karina, lawrencei, magnus, malleecola, mokarei, murrungga, storeyi, tasmaniae, walgalu. Four additional species, represented by females or damaged males, are noted but not described. The following new synonymy is recognised (senior synonym first): braccatus (Klug) = saundersi Baly; breweri Baly = duboulai Baly. Cryptocephalus incoctus Lea and Chlamydicadmus adspersatus Chapuis are transferred to Cadmus (Lachnabothra). The latter species name is a nomen dubium. Lectotypes are designated for Lachnabothra distincta Baly, Cryptocephalus incoctus Lea, Lachnabothra waterhousei Baly and Lachnabothra wilsoni Baly. The new definition excludes all Cadmus (Lachnabothra) species previously described from New Guinea. The larvae are described and for 10 species briefly diagnosed, the pupae are described, life-history observations are noted and the phylogeny and biogeography of the species are discussed. The species of Cadmus (Lachnabothra) are found throughout southern and eastern Australia, where they feed on eucalypts.

Description of capillariid nematodes (Trichinelloidea: Capillariidae) parasitic in Australian marsupials and rodents

Zootaxa ◽  
2006 ◽  
Vol 1348 (1) ◽  
pp. 1 ◽  
Author(s):  
DAVID M. SPRATT
Keyword(s):  
Molecular Evidence ◽  
Epithelial Tissue ◽  
Additional Species ◽  
New Host ◽  
Diverse Range ◽  
Nasal Sinus ◽  
Southeastern Australia ◽  
Eastern Australia ◽  
The Family ◽  
Murid Rodents

Capillariid nematodes (Trichinelloidea: Capillariidae) parasitic in Australian dasyurid, peramelid and potoroid marsupials and murid rodents are described. Diagnosis of the genus Eucoleus and a key to species are given. Two species are redescribed: E. gastricus (Baylis) and E. rickardi (Beveridge and Barker), comb. nov. Nine species are described as new: E. breviductus sp. nov., E. buckenbourensis sp. nov., E. fluvidus sp. nov., E. longiductus sp. nov., E. parvulus sp. nov., E. perplexus sp. nov., E. plumosus sp. nov., E. posterus sp. nov. and E. pseudoplumosus sp. nov. Three additional species are recognized but not named. Species of Eucoleus occur in a diverse range of epithelial tissue habitats in Australian hosts throughout eastern Australia; one species is known from peramelids in Western Australia. Members of the genus have not been found in any other families of Australian marsupials. Three species are parasites of dasyurids, eight species are parasites of peramelids, two species occur in both dasyurid and peramelid hosts and two species are parasites of murid rodents. Morphologically, species of Eucoleus appear to be reasonably host specific at the family level. Molecular evidence indicates that sibling species of Eucoleus occur in distinct but closely related host species. Baruscapillaria conspecta sp. nov. is described from murid rodents and the potoroid marsupial rufous rat kangaroo, Aepyprymnus rufescens, primarily in north Queensland. Capillaria ornamentata sp. nov. is described from the distal nasal sinus behind the orbit of the eye of species of dasyurids of the genus Antechinus in southeastern Australia. Aonchotheca praeputialis (Obendorf, 1979) comb. nov. is redescribed and appears to occur exclusively in the native Rattus fuscipes. New host and geographic records, and tissue localities of the trichurid nematode, Anatrichosoma haycocki (Trichinelloidea: Trichuridae, Trichosomoidinae) are given.

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