First report of Hirnantian (Upper Ordovician) high-latitude peri-gondwanan macrofossil assemblages from Portugal

2018 ◽  
Vol 93 (3) ◽  
pp. 460-475 ◽  
Author(s):  
Jorge Colmenar ◽  
Sofia Pereira ◽  
Timothy P. Young ◽  
Carlos M. da Silva ◽  
Artur A. Sá
Keyword(s):  
High Latitude ◽  
Cold Water ◽  
First Record ◽  
Late Ordovician ◽  
Upper Ordovician ◽  
First Report ◽  
Central Iberian Zone ◽  
Water Species ◽  
Cold Water Species ◽  
Single Locality

AbstractThe first report of theHirnantiahigh-latitude peri-Gondwanan Fauna from Portugal (Upper Ordovician, Ribeira do Braçal Formation) is presented here. The described macroassemblages are fairly diverse containing fossils of brachiopods, trilobites, echinoderms, machaeridians, and ostracodes. Among the brachiopods, the most abundant isMirorthis mira.Plectothyrellacf.P.libyca,Paromalomenacf.P.polonica,Plectoglossa? sp., and a small indeterminate discinoid are also present. The trilobites are represented by abundant sclerites ofMucronaspiscf.M.mucronata, and an isolated cranidium and pygidium assigned toFlexicalymene. The occurrence ofMucronaspisandFlexicalymenerepresents the first record of these genera in Portugal. Echinoderms are dominant in the basal bed of the formation; the columnal plates tentatively ascribed to morphogenusPentagonocyclicusare the most abundant, followed by the echinosphaeritids. Abundant disarticulated machaeridian plates, of the genusPlumulites, associated with trilobites are present in one of the localities. Ostracodes were found in one single locality and have been assigned tentatively to the genusHerrigia. Ramose and massive bryozoans also occur in the assemblage. This new macrofossil assemblage supports the assignment of an Hirnantian age for the Ribeira do Braçal Formation. Most of the brachiopod species and the dalmanitidMucronaspisare commonly present in Hirnantian deposits globally, but the presence in the assemblage of a brachiopod close toPlectothyrella libyca, a cold-water species, previously reported only from the Hirnantian of Libya and Morocco, is noticeable. This strengthens the case for a high latitudinal setting of the present-day territory of the Portuguese Central Iberian Zone during the Late Ordovician.

scholarly journals Salinity effects on cultured Neogloboquadrina pachyderma (sinistral) from high latitudes: new paleoenvironmental insights

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Jacqueline Bertlich ◽  
Nikolaus Gussone ◽  
Jasper Berndt ◽  
Heinrich F. Arlinghaus ◽  
Gerhard S. Dieckmann
Keyword(s):  
Sea Ice ◽  
Cold Water ◽  
Weddell Sea ◽  
Wall Thickening ◽  
High Latitudes ◽  
Neogloboquadrina Pachyderma ◽  
Antarctic Sea Ice ◽  
The Antarctic ◽  
Water Species ◽  
Cold Water Species

AbstractThis study presents culture experiments of the cold water species Neogloboquadrina pachyderma (sinistral) and provides new insights into the incorporation of elements in foraminiferal calcite of common and newly established proxies for paleoenvironmental applications (shell Mg/Ca, Sr/Ca and Na/Ca). Specimens were collected from sea ice during the austral winter in the Antarctic Weddell Sea and subsequently cultured at different salinities and a constant temperature. Incorporation of the fluorescent dye calcein showed new chamber formation in the culture at salinities of 30, 31, and 69. Cultured foraminifers at salinities of 46 to 83 only revealed chamber wall thickening, indicated by the fluorescence of the whole shell. Signs of reproduction and the associated gametogenic calcite were not observed in any of the culture experiments. Trace element analyses were performed using an electron microprobe, which revealed increased shell Mg/Ca, Sr/Ca, and Na/Ca values at higher salinities, with Mg/Ca showing the lowest sensitivity to salinity changes. This study enhances the knowledge about unusually high element concentrations in foraminifera shells from high latitudes. Neogloboquadrina pachyderma appears to be able to calcify in the Antarctic sea ice within brine channels, which have low temperatures and exceptionally high salinities due to ongoing sea ice formation.

scholarly journals Oxythermal habitat as a primary driver of ecological niche and genetic diversity in cisco (Coregonus artedi)

2021 ◽  
Author(s):  
Ryan C Grow ◽  
Kyle D Zimmer ◽  
Jennifer L Cruise ◽  
Simon K Emms ◽  
Loren M Miller ◽  
...  
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Dissolved Oxygen ◽  
Cold Water ◽  
Global Scale ◽  
Isotopic Niche ◽  
Coregonus Artedi ◽  
Primary Driver ◽  
Water Species ◽  
Cold Water Species

Cisco (Coregonus artedi) are threatened by climate change and lake eutrophication, and their oxythermal habitat can be assessed with TDO3, the water temperature at which dissolved oxygen equals 3 mg L-1. We assessed the influence of TDO3 on cisco habitat use, genetic diversity, diets, and isotopic niche in 32 lakes ranging from oligotrophic to eutrophic. Results showed that as TDO3 increased cisco were captured higher in the water column, in a narrower band, with higher minimum temperatures and lower minimum dissolved oxygen. TDO3 was also negatively related to cisco allelic richness and expected heterozygosity, likely driven by summer kill events. Moreover, TDO3 influenced the isotopic niche of cisco, as fish captured deeper were more depleted in δ13C and more enriched in δ15N compared to epilimnetic baselines. Lastly, cisco in high TDO3 lakes consumed more Daphnia, had fewer empty stomachs, and achieved larger body size. Our work identifies specific characteristics of cisco populations that respond to climate change and eutrophication effects, and provides a framework for understanding responses of other cold-water species at the global scale.

scholarly journals Lipidomic study of the influence of dietary fatty acids on structural lipids of cold-water nudibranch molluscs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrey B. Imbs ◽  
Valeria P. Grigorchuk
Keyword(s):  
Fatty Acids ◽  
Molecular Species ◽  
Cold Water ◽  
High Resolution Mass Spectrometry ◽  
Dietary Fatty Acids ◽  
Alkyl Groups ◽  
Chain Lengths ◽  
Trophic Markers ◽  
Water Species ◽  
Cold Water Species

AbstractNudibranch molluscs occur in marine ecosystems worldwide and prey on numerous invertebrate species. During feeding, dietary fatty acids (FAs) unusual for nudibranchs are transferred to their lipids. Normal biomembrane functions require stable composition of structural polar lipids (PL), but the pathways of dietary FA utilization to PL in nudibranchs still remain unknown. A combination of chromatography and tandem high-resolution mass spectrometry was used to determine total lipid, PL, FA, and PL molecular species composition of two cold-water species of Dendronotus, which then were compared with those of Tritonia tetraquetra. The use of FA trophic markers showed that Dendronotus sp. and T. tetraquetra prey on different soft corals, while D. robustus may consumes hydrocorals and bryozoans. Nudibranch FA profiles were strongly modified by dietary FAs but their PL profilers were similar. Dietary FAs are not included in ceramide aminoethylphosphonate and inositol glycerophospholipids, but directed to ethanolamine, choline, and serine glycerophospholipids and, in some cases, form isobaric molecular species with different FA chain lengths. For such isobaric species, nudibranchs reduce the length of alkyl groups when very-long-chain FAs are obtained with diet. This molecular mechanism may explain the adaptation of nudibranch membrane structure to dietary input of unusual FAs.

A new species of deep-sea Dendronotus Alder & Hancock (Mollusca:Nudibranchia) from California, with an expanded phylogeny of the genus

2011 ◽  
Vol 25 (1) ◽  
pp. 60 ◽  
Author(s):  
Carla C. Stout ◽  
Nerida G. Wilson ◽  
Ángel Valdés
Keyword(s):  
New Species ◽  
Deep Sea ◽  
Cold Water ◽  
Sequence Data ◽  
Sister Group ◽  
Well Differentiated ◽  
Pacific Species ◽  
A New Species ◽  
Water Species ◽  
Cold Water Species

Dendronotus patricki, sp. nov. is a new species collected from a whalefall in the Monterey Canyon, California. This new species is characterised by having a small number of dorsal appendages compared with similarly sized species of Dendronotus Alder & Hancock, 1845. Anatomically, D. patricki, sp. nov. has a small prostate with just a few alveoli, a very small seminal receptacle situated near the distal end of the vagina, and a relatively short and small ampulla. The rachidian radular teeth of D. patricki, sp. nov. are unique among Dendronotus as they have a well differentiated, conical cusp with very small denticles on either side, but most denticles are located on the sides of the teeth, rather than on the sides of the cusp. Dendronotus patricki, sp. nov., is genetically distinct from other species of Dendronotus for which sequence data are available. A phylogenetic analysis of Dendronotus based on COI, 16S, and H3 sequence data reveals that D. patricki, sp. nov. forms a polytomy with Dendronotus orientalis (Baba, 1932) and a clade of the shallow temperate and cold water species. The tropical Indo-Pacific species D. regius Pola & Stout, 2008 is the sister group to all other Dendronotus species.

scholarly journals Late Miocene ostracods from the Fujikotogawa Formation, northern Japan – with reference to cold water species involved with trans-Arctic interchange

1994 ◽  
Vol 13 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Toshiaki Irizuki
Keyword(s):  
Late Miocene ◽  
Cold Water ◽  
The Arctic ◽  
Bering Strait ◽  
The Pacific ◽  
Northern Atlantic ◽  
Water Species ◽  
Cold Water Species ◽  
Ostracod Species ◽  
Northern Japan

Abstract. Seventy-eight ostracod species belonging to 38 genera are recognized from the late Miocene Fujikotogawa Formation (c. 7–8 Ma), 40 km NE of Akita City, northern Japan. Some 30–40% of the ostracod species belong to the cold water groups (circumpolar and cryophilic species) reported from Plio-Pleistocene formations yielding the Omma-Manganji Fauna, the name given by Otuka (1939) to the Pliocene Japanese cold water molluscan fauna. This study demonstrates that most ostracod species distinguished in deposits yielding the Omma-Manganji Fauna had already appeared in the late Miocene. At least 13 of the ostracod species have been reported from both the Arctic and northern Atlantic Oceans, implying migration from the Pacific to the northern Atlantic through the Arctic after the Bering Strait had been breached. The 13 circumpolar, nine cryophilic and four endemic cold water species are illustrated, with brief taxonomic notes.

Chemical and Organoleptic Comparison of Fish Sauce Made from Cold Water Species and Typical Thai Fish Sauce

2007 ◽  
Vol 16 (3) ◽  
pp. 31-42 ◽  
Author(s):  
Asbjørn Gildberg ◽  
Jetsada Wichaphon ◽  
Sittiwat Lertsiri ◽  
Apinya Assavanig ◽  
Nils K. Sørensen ◽  
...  
Keyword(s):  
Cold Water ◽  
Fish Sauce ◽  
Water Species ◽  
Cold Water Species

scholarly journals Contrasting species functional trait structuring of subarctic versus subtropical copepod communities

2020 ◽  
Author(s):  
Carmen García-Comas ◽  
Chih-hao Hsieh ◽  
Sanae Chiba ◽  
Hiroya Sugisaki ◽  
Taketo Hashioka ◽  
...  
Keyword(s):  
Functional Traits ◽  
Cold Water ◽  
Functional Trait ◽  
Relative Fitness ◽  
Niche Theory ◽  
Empirical Tests ◽  
The Tropics ◽  
Water Species ◽  
Cold Water Species ◽  
Rank Abundance

ABSTRACTClassic niche theory assumes that species-level functional traits affect species relative fitness and thus community structuring, but empirical tests of this assumption are scarce. Moreover, recent evidence shows increasing functional over-redundancy towards the tropics, suggesting that the extent to which functional traits confer species’ fitness and thus impact community structuring differs across latitudes. Here, we develop a new method: comparing the frequencies of trait categories in the species-rank abundance distributions of local communities versus their frequencies in the regional average species pool. We contrasted subarctic versus subtropical copepod communities for six important traits. In subarctic communities, medium-sized and cold-water species are selected to dominate, thus traits affect relative fitness as predicted by classic niche theory. In subtropical communities, most species are small and warm-water, but these categories are not selected to dominate, suggesting that greater diversity towards the tropics results from lesser trait-based fitness differences allowing more species to coexist.

scholarly journals Southward range extension of the goldeye rockfish, Sebastes thompsoni (Actinopterygii: Scorpaeniformes: Scorpaenidae), to northern Taiwan

2021 ◽  
Vol 51 (2) ◽  
pp. 153-158
Author(s):  
Tak-Kei Chou ◽  
Chi-Ngai Tang
Keyword(s):  
Northern Hemisphere ◽  
New Record ◽  
Cold Water ◽  
Range Extension ◽  
Reported Study ◽  
Water Species ◽  
Cold Water Species ◽  
Northern Taiwan

The goldeye rockfish, Sebastes thompsoni (Jordan et Hubbs, 1925), is known as a typical cold-water species, occurring from southern Hokkaido to Kagoshima. In the presently reported study, a specimen was collected from the local fishery catch off Keelung, northern Taiwan, which represents the first specimen-based record of the genus in Taiwan. Moreover, the new record of Sebastes thompsoni in Taiwan represented the southernmost distribution of the cold-water genus Sebastes in the Northern Hemisphere.

scholarly journals Biodiversity of Indian Rotifers (Rotifera) with remarks on biogeography and richness in diverse ecosystems

2021 ◽  
Vol 52 (1) ◽  
pp. 69-97
Author(s):  
Bhushan Kumar Sharma ◽  
Sumita Sharma
Keyword(s):  
Cold Water ◽  
Habitat Diversity ◽  
Northeast India ◽  
Valid Species ◽  
Urban Wetlands ◽  
Small Water ◽  
Limited Sampling ◽  
Unidentified Species ◽  
Water Species ◽  
Cold Water Species

We assess biodiversity status of Rotifera known from India to-date based on our studies from various regions of this country and evaluation of other viable records, and highlight notable features of biogeography and richness. The Indian fauna reveals 434 valid species belonging to 68 genera and 25 families and thus indicates the most biodiverse Rotifera vis-àvis south and Southeast Asia, and records ~25% and ~41% species of global and regional biogeographic interest. It depicts the littoral-periphytic nature, broadly tropical character, the limited reports of cold-water species from the sub-Himalayan and Himalayan latitudes, paucity of the endemics and Bdelloids, and cryptic diversity awaits analyses. The richest diversity and distinct biogeographic identity of Rotifera of Northeast India (NEI) is attributed to location of this region in the ‘Himalayan and Indo-Burmese’ biodiversity hot-spots, ‘Assam gateway’ – the biogeographic corridor, and the ‘Rotiferologist effect’. Regional disparity and spatial heterogeneity of biodiversity elsewhere from India are attributed to the limited sampling, inadequate collections from diverse ecosystems, unidentified species, and paucity of attention on smaller species. The biodiverse rotifer assemblages of the floodplain lakes including Deepor Beel and Loktak Lake, the two Ramsar sites and globally megadiverse ecosystems, are hypothesized to habitat diversity of these ecotones, while ‘Rotifera paradox’ depict speciose constellations per sample. The species-rich small floodplain and urban wetlands focus interest on rotifer diversity in small water bodies. We estimate more diverse Indian Rotifera following analyses of collections from underexplored and unexplored regions and ecosystems, and the bdelloid and sessile rotifers using integrative taxonomic approaches.

Blood parasites of fish from the northwestern Atlantic Ocean

1980 ◽  
Vol 58 (5) ◽  
pp. 770-781 ◽  
Author(s):  
R. A. Khan ◽  
M. Barrett ◽  
J. Murphy
Keyword(s):  
Atlantic Ocean ◽  
Marine Fish ◽  
Cold Water ◽  
The Other ◽  
Blood Parasites ◽  
Scotian Shelf ◽  
Blood Smears ◽  
Water Species ◽  
Cold Water Species ◽  
Thin Blood Smears

Examination of thick and thin blood smears from 5013 marine fish from the northwestern Atlantic Ocean revealed 25 of 59 species to be infected with one or more of the following blood parasites: trypanosomes (27% of 3610), trypanoplasms (9% of 588), piroplasms (26% of 2584), and haemogregarines (36% of 1708). Higher prevalences of infection were observed in cold-water, benthic, sedentary fish than in warm-water, littoral, epipelagic, or midwater species. Trypanosome infections were more prevalent among fish taken off the Labrador – east Newfoundland coasts, lower in those from St. Pierre Bank, Grand Bank, and Gulf of St. Lawrence, and lowest in forms from the Scotian Shelf. Seven of nine species of hematophagous leeches harboured asexual stages of haemogregarines, whereas natural infections of trypanosomes occurred in one leech, Johanssonia arctica. Using five species of laboratory-reared leeches and laboratory-initiated infections of trypanosomes in piscine hosts, development of Trypanosoma murmanensis was observed only in J. arctica. It is suggested that the distribution of trypanosomes of marine fish is related to that of J. arctica, a cold-water species, whereas the other haematozoan infections might be attributed to those leech species that are associated with their respective piscine hosts.

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