Ammothea tibialis, a new pycnogonid from Drake Passage, Antarctica

2002 ◽  
Vol 14 (2) ◽  
pp. 171-173 ◽  
Author(s):  
Tomás Munilla León

The most recent reports about the family Ammotheidae of pycnogonids from Southern Ocean waters are those of Munilla (2000, 2001, Scotia Sea), Pushkin (1993, various zones), Bamber (1995, Falkland Islands and South Shetland Islands) and Child (1994, various zones) who also provide historical background. Some species from Livingston Island and surrounding waters (South Shetland Islands, Drake Passage, Bransfield Strait) have been documented previously, mainly by Gordon (1932), Fry & Hedgpeth (1969), Pushkin (1993) and the papers of Child and Bamber mentioned above. Keys to this genus are given in Clark (1977) and Child (1994).

2000 ◽  
Vol 12 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Tomás Munilla León

Specimens of 22 species of pycnogonids belonging to twelve genera and seven families were collected during a cruise near Livingston Island, South Shetland Islands. Twenty two of the 94 stations yielded pycnogonids: the new species Ammothea hesperidensis is described fully, illustrated, and compared with similar species. The family Nymphonidae provided both the greatest diversity of species (seven) and number of specimens (35). The most abundant species were Achelia hoekii and Nymphon australe.


Polar Biology ◽  
2007 ◽  
Vol 30 (4) ◽  
pp. 477-486 ◽  
Author(s):  
C. San Vicente ◽  
J. Castelló ◽  
J. Corbera ◽  
A. Jimeno ◽  
T. Munilla ◽  
...  

2001 ◽  
Vol 13 (2) ◽  
pp. 144-149 ◽  
Author(s):  
Tomás Munilla León

Fifty-nine species of pycnogonids belonging to sixteen genera and eight families were collected during a cruise near Livingston Island and surrounding waters, from depths between 0 and 1019 m. The new species Ammothea bentartica is described fully, illustrated and compared with similar species. The family Nymphonidae had both the greatest number of species (20) and number of specimens (67% of 1201). The most abundant species were Nymphon charcoti and N. australe. Nymphon paucidens and Pallenopsis buphtalmus were collected for a second time. The collections increased the geographical distribution of five species and the depth range of seven species. This collection appears typical of the West Antarctic zone.


Author(s):  
O. García-Alvarez ◽  
V. Urgorri ◽  
L. von Salvini-Plawen

This paper describes two new species from the genus Dorymenia (Mollusca: Solenogastres: Proneomeniidae): D. hesperidesi sp. nov. and D. menchuescribanae sp. nov., collected during the Spanish oceanographic expeditions for the study of Antarctic benthos, BENTART'94 and BENTART'95, carried out in the area of the Livingston Island (South Shetland Islands, Antarctica). A comparative study of main specific characteristics of species belonging to the genus Dorymenia found off the South Shetland Islands and in the Bransfield Strait (Antarctica), is also included.


1977 ◽  
Vol 7 (2) ◽  
pp. 268-282 ◽  
Author(s):  
D.E. Sugden ◽  
C.M. Clapperton

Evidence is presented for a more extensive ice cover over South Georgia, the South Orkney Islands, the South Shetland Islands, and the tip of the Antarctic Peninsula. Ice extended across the adjacent submarine shelves to a depth of 200 m below present sea level. Troughs cut into the submarine shelves by ice streams or outlet glaciers and ice-scoured features on the shelf areas suggest that the ice caps were warm-based. The South Shetland Islands appear not to have been overrun by continental ice. Geomorphological evidence in two island groups suggests that the maximum ice cover, which was responsible for the bulk of glacial erosion, predates at least one full glaciation. Subsequently there was a marine interval and then a glaciation which overran all of the lowlying peninsulas. The Falkland Islands, only 2° of latitude north of South Georgia, were never covered by an ice cap and supported only a few slightly enlarged cirque glaciers. This suggests that the major oceanographic and atmospheric boundary represented by the Antarctic Convergence, which is presently situated between the Falkland Islands and South Georgia, has remained in a similar position throughout the glacial age. Its position is probably bathymetrically controlled.


2014 ◽  
Vol 46 (3) ◽  
pp. 389-412 ◽  
Author(s):  
Alan M. FRYDAY ◽  
Hannes HERTEL

AbstractEight new species of Lecideaceae are described from the southern subpolar region: Bryobilimbia coppinsiana Fryday, a saxicolous species with one septate ascospores (Campbell Island, New Zealand); Immersaria fuliginosa Fryday, with a thallus composed of thalloconidia (Falkland Islands); Lecidea aurantia Fryday, with an orange thallus (Auckland Islands, New Zealand); L. campbellensis Fryday, with an endolithic thallus and apothecia resembling those of a species of Porpidia (Campbell Island); Poeltiaria ochyrae Hertel, which is similar to P. subincongua but with a thick areolate thallus (South Orkney and South Shetland Islands); P. tasmanica Fryday, which is similar to P. urbanskyana but with smaller ascopores (Tasmania); Poeltidea inspersa Fryday with an enolithic thallus and a hymenium with large oil globules (Falkland Islands); and Porpidia vulcanoides Hertel & Fryday with immersed apothecia with a thick margin and large ascospores (SW Chile). Lecidea kalbii Hertel is resurrected from the synonymy of L. mannii Tuck. and treated as a distinct species. The circumscription of genera within the Lecideaceae is also discussed: Poeltiaria is shown to be heterogeneous, and the genera Labyrintha and Notolecidea are reduced to synonymy with Poeltidea and Poeltiaria respectively, and the new combinations Poeltidia implexa (Malcolm et al.) Hertel & Fryday and Poeltiaria subcontinua (Hertel) Hertel & Fryday made. A key to the genera of Lecideaceae s. lat. is provided.


2010 ◽  
Vol 7 (1) ◽  
pp. 11-25 ◽  
Author(s):  
M. V. Ardelan ◽  
O. Holm-Hansen ◽  
C. D. Hewes ◽  
C. S. Reiss ◽  
N. S. Silva ◽  
...  

Abstract. As part of the US-AMLR program in January-February of 2006, 99 stations in the South Shetland Islands-Antarctic Peninsula region were sampled to understand the variability in hydrographic and biological properties related to the abundance and distribution of krill in this area. Concentrations of dissolved iron (DFe) and total acid-leachable iron (TaLFe) were measured in the upper 150 m at 16 of these stations (both coastal and pelagic waters) to better resolve the factors limiting primary production in this area and in downstream waters of the Scotia Sea. The concentrations of DFe and TaLFe in the upper mixed layer (UML) were relatively high in Weddell Sea Shelf Waters (~0.6 nM and 15 nM, respectively) and low in Drake Passage waters (~0.2 nM and 0.9 nM, respectively). In the Bransfield Strait, representing a mixture of waters from the Weddell Sea and the Antarctic Circumpolar Current (ACC), concentrations of DFe were ~0.4 nM and of TaLFe ~1.7 nM. The highest concentrations of DFe and TaLFe in the UML were found at shallow coastal stations close to Livingston Island (~1.6 nM and 100 nM, respectively). The ratio of TaLFe:DFe varied with the distance to land: ~45 at the shallow coastal stations, ~15 in the high-salinity waters of Bransfield Strait, and ~4 in ACC waters. Concentrations of DFe increased slightly with depth in the water column, while that of TaLFe did not show any consistent trend with depth. Our Fe data are discussed in regard to the hydrography and water circulation patterns in the study area, and with the hypothesis that the relatively high rates of primary production in the central regions of the Scotia Sea are partially sustained by natural iron enrichment resulting from a northeasterly flow of iron-rich coastal waters originating in the South Shetland Islands-Antarctic Peninsula region.


1995 ◽  
Vol 7 (1) ◽  
pp. 99-113 ◽  
Author(s):  
J.L. Smellie ◽  
M. Liesa ◽  
J.A. Muñoz ◽  
F. Sàbat ◽  
R. Pallàs ◽  
...  

Livingston Island contains several, distinctive sedimentary and volcanic sequences, which document the history and evolution of an important part of the South Shetland Islands magmatic arc. The turbiditic, late Palaeozoic–early Mesozoic Miers Bluff Formation (MBF) is divided into the Johnsons Dock and Napier Peak members, which may represent sedimentation in upper and lower mid-fan settings, respectively, prior to pre-late Jurassic polyphase deformation (dominated by open folding). The Moores Peak breccias are formed largely of coarse clasts reworked from the MBF. The breccias may be part of the MBF, a separate unit, or part of the Mount Bowles Formation. The structural position is similar to the terrigenous Lower Jurassic Botany Bay Group in the northern Antarctic Peninsula, but the precise stratigraphical relationships and age are unknown. The (?) Cretaceous Mount Bowles Formation is largely volcanic. Detritus in the volcaniclastic rocks was formed mainly during phreatomagmatic eruptions and redeposited by debris flows (lahars), whereas rare sandstone interbeds are arkosic and reflect a local provenance rooted in the MBF. The Pleistocene–Recent Inott Point Formation is dominated by multiple, basaltic tuff cone relicts in which distinctive vent and flank sequences are recognized. The geographical distribution of the Edinburgh Hill Formation is closely associated with faults, which may have been reactivated as dip-slip structures during Late Cenozoic extension (arc splitting).


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