The osmotic and ionic regulation of Branchinecta gaini Daday

1967 ◽  
Vol 252 (777) ◽  
pp. 339-341 ◽  
Keyword(s):  
South America ◽  
Salt Spray ◽  
Ionic Regulation ◽  
Freshwater Lakes ◽  
Deep Lakes ◽  
Large Lakes ◽  
Chemical Changes ◽  
Signy Island ◽  
Different Types ◽  
The Antarctic

The anostracan crustacean, Branchinecta gaini , has been recorded from freshwater lakes and pools in many places in the Antarctic and from the southern tip of South America. On Signy Island, in the South Orkneys group, the animal occurs in two rather different types of habitat. It is found in large, relatively deep lakes and also in small, shallow pools on a rocky headland. The latter are occasionally influenced by salt spray from the sea. The seasonal chemical changes in one of the large lakes and the ecology of Branchinecta and other crustaceans in it have been studied in detail by Heywood (1967). A similar study on the smaller pools has been made by Goodman (unpublished).

Distinctive aspects of the zooplankton of large lakes in Australasia, Antarctica and South America

1995 ◽  
Vol 46 (8) ◽  
pp. 1109 ◽  
Author(s):  
IAE Bayly
Keyword(s):  
New Zealand ◽  
South America ◽  
Species Level ◽  
Salt Lakes ◽  
Freshwater Lakes ◽  
Large Lakes ◽  
Numerous Species ◽  
Andean Altiplano ◽  
Biogeographic Regions ◽  
Wilson’S Phalarope

Not only has the degree of species-level cosmopolitanism amongst zooplanktonic organisms been considerably overestimated, but differences between the different classical biogeographic regions (established from terrestrial studies) occur at supra-specific levels as high as family or even suborder. The Centropagidae, and particularly the genus Boeckella, are found in New Zealand, most of Australia, southern and high altitude regions of South America, and around the periphery of Antarctica. The biogeography and ecology of this family is discussed in detail. Most predaceous families of Cladocera are entirely absent from the Australian and Neotropical regions. The genus Daphniopsis occurs in salt lakes in Australia and South America and in freshwater lakes in Antarctica. In southern Australia numerous species of ostracod have colonized the limnetic region of salt lakes, and the largest of these prey on species of Calamoecia, Daphniopsis and small ostracods. Chaoboridae are absent from New Zealand as, too, are obligate planktivorous fish. The Chilean flamingo, Phoenicopterus chilensis, and Wilson's phalarope, Phalaropus tricolor, are significant predators on Boeckella poopoensis in salt lakes on the Andean Altiplano and elsewhere in South America.

Antarctic Ecosystems The freshwater lakes of Signy Island and their fauna

1967 ◽  
Vol 252 (777) ◽  
pp. 347-362 ◽  
Keyword(s):  
Summer Season ◽  
Falkland Islands ◽  
Freshwater Lakes ◽  
Orkney Islands ◽  
Signy Island ◽  
Antarctic Expedition ◽  
South Orkney Islands ◽  
The Antarctic ◽  
Taxonomic Evaluation ◽  
British Sector

Prior to 1962 work on freshwater within the British Sector of the Antarctic had been confined to the collection of specimens and their subsequent taxonomic evaluation. Collections were made by such expeditions as the Scottish National Antarctic Expedition 1902- 04, the various Discover y Investigations in this region 1925-37, the British Graham Land Expedition 1934-37 and the Falkland Islands Dependencies Survey 1945-62. During the 1961/1962 summer season an ecological investigation of the freshwater lakes of Signy Island, South Orkney Islands, was started. This paper is an interim report on that work.

scholarly journals Taxonomy, ecology and zoogeography of two East Antarctic freshwater calanoid copepod species: Boeckella poppei and Gladioferens antarcticus

2003 ◽  
Vol 15 (4) ◽  
pp. 439-448 ◽  
Author(s):  
I.A.E. BAYLY ◽  
J.A.E. GIBSON ◽  
B. WAGNER ◽  
K.M. SWADLING
Keyword(s):  
South America ◽  
Antarctic Peninsula ◽  
Endemic Species ◽  
Calanoid Copepod ◽  
East Antarctica ◽  
Copepod Species ◽  
Calanoid Copepods ◽  
Freshwater Lakes ◽  
Isolated Populations ◽  
The Antarctic

New populations of the two species of calanoid copepods known to inhabit freshwater lakes in East Antarctica, Boeckella poppei (Mrázek, 1901) and Gladioferens antarcticus Bayly, 1994, have recently been discovered. The morphology of the populations of B. poppei showed significant differences, notably a reduction in the armature of the male fifth leg, when compared with typical specimens from the Antarctic Peninsula and South America. Gladioferens antarcticus had previously been recorded from a single lake in the Bunger Hills, but has now been recorded from three further lakes in this region. A recent review of Antarctic terrestrial and limnetic zooplankton suggested that neither of these species can be considered an East Antarctic endemic, with B. poppei being listed as a recent anthropogenic introduction and G. antarcticus a ‘marine interloper’. We conclude differently: B. poppei has been present in isolated populations in East Antarctica for significant lengths of time, possibly predating the current interglacial, while G. antarcticus is a true Antarctic endemic species whose ancestors have been present in the region since before Australia separated from Antarctica.

Holocene glacier history of northeastern Cordillera Darwin, southernmost South America (55°S)

2021 ◽  
pp. 1-16
Author(s):  
Scott A. Reynhout ◽  
Michael R. Kaplan ◽  
Esteban A. Sagredo ◽  
Juan Carlos Aravena ◽  
Rodrigo L. Soteres ◽  
...  
Keyword(s):  
South America ◽  
Last Millennium ◽  
Glacial History ◽  
Dry Period ◽  
The North ◽  
Southward Shift ◽  
History Of ◽  
Glacial Expansion ◽  
The Antarctic ◽  
Glacial Advance

Abstract In the Cordillera Darwin, southernmost South America, we used 10Be and 14C dating, dendrochronology, and historical observations to reconstruct the glacial history of the Dalla Vedova valley from deglacial time to the present. After deglacial recession into northeastern Darwin and Dalla Vedova, by ~16 ka, evidence indicates a glacial advance at ~13 ka coeval with the Antarctic Cold Reversal. The next robustly dated glacial expansion occurred at 870 ± 60 calendar yr ago (approximately AD 1150), followed by less-extensive dendrochronologically constrained advances from shortly before AD 1836 to the mid-twentieth century. Our record is consistent with most studies within the Cordillera Darwin that show that the Holocene glacial maximum occurred during the last millennium. This pattern contrasts with the extensive early- and mid-Holocene glacier expansions farther north in Patagonia; furthermore, an advance at 870 ± 60 yr ago may suggest out-of-phase glacial advances occurred within the Cordillera Darwin relative to Patagonia. We speculate that a southward shift of westerlies and associated climate regimes toward the southernmost tip of the continent, about 900–800 yr ago, provides a mechanism by which some glaciers advanced in the Cordillera Darwin during what is generally considered a warm and dry period to the north in Patagonia.

scholarly journals A description and summary of the Antarctic Humpback Whale Catalogue

2020 ◽  
pp. 95-99
Author(s):  
Judith Allen ◽  
Carole Carlson ◽  
Peter T. Stevick
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Western Coast ◽  
Long Distance ◽  
Dorsal Fin ◽  
Feeding Area ◽  
The Antarctic

The Antarctic Humpback Whale Catalogue (AHWC) is an international collaborative project investigating movement patterns of humpback whales in the Southern Ocean and corresponding lower latitude waters. The collection contains records contributed by 261 researchers and opportunistic sources. Photographs come from all of the Antarctic management areas, the feeding grounds in southern Chile and also most of the known or suspected low-latitude breeding areas and span more than two decades. This allows comparisons to be made over all of the major regions used by  Southern Hemisphere humpback whales. The fluke, left dorsal fin/flank and right dorsal fin/flank collections represent 3,655, 413 and 407 individual whales respectively. There were 194 individuals resighted in more than one year, and 82 individuals resighted in more than one region. Resightings document movement along the western coast of South America and movement between the Antarctic Peninsula and western coast of South America and Central America. A single individual from Brazil was resighted off South Georgia, representing the first documented link between the Brazilian breeding ground and any feeding area. A second individual from Brazil was resighted off Madagascar, documenting long distance movement of a female between non-adjacent breeding areas. Resightings also include two matches between American Samoa and the Antarctic Peninsula, documenting the first known feeding site for American Somoa and setting a new long distance seasonal migration record. Three matches between Sector V and eastern Australia support earlier evidence provided by Discovery tags. Multiple resightings of individuals in the Antarctic Peninsula during more than one season indicate that humpback whales in this area show some degree of regional feeding area fidelity. The AHWC provides a powerful non-lethal and non-invasive tool for investigating the movements and population structure of the whales utilising the Southern Ocean Sanctuary. Through this methodical, coordinated comparison and maintenance of collections from across the hemisphere, large-scale movement patterns may be examined, both within the Antarctic, and from the Antarctic to breeding grounds at low latitudes.

New Neogene taxa of the tribe Chlamydini Teppner, 1922 (Pectinidae, Bivalvia) of southern South America

2019 ◽  
Vol 93 (06) ◽  
pp. 1088-1104
Author(s):  
María B. Santelli ◽  
Claudia J. del Río
Keyword(s):  
South America ◽  
Antarctic Circumpolar Current ◽  
Middle Miocene ◽  
South American ◽  
Southern South America ◽  
Southeastern Pacific ◽  
Previous Proposal ◽  
Circumpolar Current ◽  
The Antarctic ◽  
Middle Pliocene

AbstractThe Chilean species traditionally assigned to the genera Chlamys Röding, 1798 or Zygochlamys Ihering, 1907 are now placed in two new endemic South American taxa: Dietotenhosen n. gen. (middle Miocene–early middle Pliocene), to include the southeastern Pacific Ocean species D. hupeanus (Philippi, 1887) n. comb. and D. remondi (Philippi, 1887) n. comb., and Ckaraosippur n. gen. (earliest middle Miocene–Pliocene), for C. calderensis (Möricke, 1896) n. comb. (Chile) and C. camachoi n. sp. (Argentina). Both genera are the youngest survivors of the tribe Chlamydini in southern South America. None of them is related to the circumpolar genus Psychrochlamys Jonkers, 2003, and the previous proposal of the dispersal through the Antarctic Circumpolar Current for the species included herein in Dietotenhosen is rejected.UUID: http://zoobank.org/61b4bb50-321f-4b78-9069-609178ef0817

The effectiveness of Virkon® S disinfectant against an invasive insect and implications for Antarctic biosecurity practices

2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jesamine C. Bartlett ◽  
Richard James Radcliffe ◽  
Pete Convey ◽  
Kevin A. Hughes ◽  
Scott A.L. Hayward
Keyword(s):  
Salt Water ◽  
Hot Water ◽  
Antarctic Region ◽  
Invasive Insect ◽  
Signy Island ◽  
Antarctic Treaty ◽  
Biosecurity Practices ◽  
Water Treatments ◽  
The Antarctic ◽  
Maximum Threshold

Abstract The flightless midge Eretmoptera murphyi is thought to be continuing its invasion of Signy Island via the treads of personnel boots. Current boot-wash biosecurity protocols in the Antarctic region rely on microbial biocides, primarily Virkon® S. As pesticides have limited approval for use in the Antarctic Treaty area, we investigated the efficacy of Virkon® S in controlling the spread of E. murphyi using boot-wash simulations and maximum threshold exposures. We found that E. murphyi tolerates over 8 h of submergence in 1% Virkon® S. Higher concentrations increased effectiveness, but larvae still exhibited > 50% survival after 5 h in 10% Virkon® S. Salt and hot water treatments (without Virkon® S) were explored as possible alternatives. Salt water proved ineffective, with mortality only in first-instar larvae across multi-day exposures. Larvae experienced 100% mortality when exposed for 10 s to 50°C water, but they showed complete survival at 45°C. Given that current boot-wash protocols alone are an ineffective control of this invasive insect, we advocate hot water (> 50°C) to remove soil, followed by Virkon® S as a microbial biocide on ‘clean’ boots. Implications for the spread of invasive invertebrates as a result of increased human activity in the Antarctic region are discussed.

Sign in / Sign up

Export Citation Format

Share Document