Zonation of demersal fishes off Anvers Island, western Antarctic Peninsula

2015 ◽  
Vol 28 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Margaret O. Amsler ◽  
Joseph T. Eastman ◽  
Kathryn E. Smith ◽  
James B. Mcclintock ◽  
Hanumant Singh ◽  
...  
Keyword(s):  
Fish Fauna ◽  
Antarctic Fish ◽  
Abundant Species ◽  
Outer Shelf ◽  
Outer Continental Shelf ◽  
Absolute Abundance ◽  
Inner Shelf ◽  
Photographic Survey ◽  
Upper Slope ◽  
Demersal Fishes

AbstractThe Antarctic fish fauna from outer continental shelf/upper slope depths is under-sampled compared to that of the inner shelf, and there are limited quantitative data available on absolute abundance and taxonomic change with depth. A photographic survey of demersal fishes was conducted along a depth-gradient of 400–2099 m on the outer shelf and upper slope west of Anvers Island, Palmer Archipelago. A total of 1490 fishes were identified at least to the family level. Notothenioids composed 52.7% of absolute abundance and non-notothenioids 47.3%. The most abundant families were Nototheniidae (39.4%), followed by Macrouridae (28.9%), Zoarcidae (16.9%), and Channichthyidae (12.1%). The most abundant species were the notothenioidsLepidonotothen squamifrons(30.5%) andChionobathyscus dewitti(11.7%), and the non-notothenioidMacrourusspp. (29.5%). The absolute abundance of all fishes peaked at 400–599 m. Depths of maximum abundance were 400–599 m forL. squamifrons, 700–1499 m forMacrourusspp., and 900–1499 forC. dewitti. At 700–999 m the abundance shifted from primarily notothenioids to the non-notothenioidsMacrourusspp. and zoarcids. Fishes of the outer shelf and upper slope are not provincialized like those of the inner shelf and are circum-Antarctic.

Photographic survey of benthos provides insights into the Antarctic fish fauna from the Marguerite Bay slope and the Amundsen Sea

2012 ◽  
Vol 25 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Joseph T. Eastman ◽  
Margaret O. Amsler ◽  
Richard B. Aronson ◽  
Sven Thatje ◽  
James B. McClintock ◽  
...  
Keyword(s):  
Water Column ◽  
Fish Fauna ◽  
Antarctic Fish ◽  
Amundsen Sea ◽  
Dissostichus Mawsoni ◽  
West Antarctic ◽  
Marguerite Bay ◽  
Macrourus Whitsoni ◽  
Photographic Survey ◽  
Neutrally Buoyant

AbstractWe reviewed photographic images of fishes from depths of 381–2282 m in Marguerite Bay and 405–2007 m in the Amundsen Sea. Marguerite Bay fishes were 33% notothenioids and 67% non-notothenioids. Channichthyids (47%) and nototheniids (44%) were the most abundant notothenioids. The deep-living channichthyidChionobathyscus dewitti(74%) and the nototheniid genusTrematomus(66%) were the most abundant taxa within these two families. The most abundant non-notothenioids were the macrouridMacrourus whitsoni(72%) and zoarcids (18%). Amundsen Sea fishes were 87% notothenioids and 13% non-notothenioids, the latter exclusivelyMacrourus whitsoni. Bathydraconids (38%) and artedidraconids (30%) were the most abundant notothenioids. We observed thatMacrourus whitsoniwas benthopelagic and benthic and infested by large ectoparasitic copepods. Juvenile (42 cm)Dissostichus mawsoniwas not neutrally buoyant and resided on the substrate at 1277 m.Lepidonotothen squamifronswas seen near and on nests of eggs in early December. APogonophrynesp. from 2127 m was not a member of the deep-living unspottedP. albipinnagroup.Chionobathyscus dewittiinhabited the water column as well as the substrate. The pelagic zoarcidMelanostigma gelatinosumwas documented in the water column a few metres above the substrate. The zoogeographic character of the Marguerite Bay fauna was West Antarctic or low-Antarctic and the Amundsen Sea was East Antarctic or high-Antarctic.

Echinoidea of Oregon

1967 ◽  
Vol 24 (6) ◽  
pp. 1385-1401 ◽  
Author(s):  
James E. McCauley ◽  
Andrew G. Carey Jr.
Keyword(s):  
Continental Shelf ◽  
Deep Water ◽  
Strongylocentrotus Purpuratus ◽  
Outer Shelf ◽  
Shallow Waters ◽  
Outer Continental Shelf ◽  
Geographic Ranges ◽  
Dendraster Excentricus ◽  
Upper Slope

Ten species of echinoids are known to occur off Oregon. Three distinct bathymetric groups are recognized: Strongylocentrotus purpuratus, S. franciscanus, and Dendraster excentricus occur in shallow waters from intertidal down to about 65 m; S. echinoides occurs on the outer continental shelf, and Brisaster latifrons and Allocentrotus fragilis occur on the outer shelf and upper slope at depths of about 70–840 m; and Aëropsis fulva, Sperosoma giganteum, Urechinus loveni, and Ceratophysa rosea are found in deep water from depths of 2090 to 3000 m. Bathymetric ranges are extended for six species and geographic ranges are extended for five species.

scholarly journals Inventory of the fish fauna from Laranjinha River, Paranapanema River system, Brazil

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Bruno Ambrozio Galindo ◽  
Renata Rúbia Ota ◽  
Thiago Deruza Garcia ◽  
Raul Henrique Cardoso Nascimento ◽  
Willian Massaharu Ohara ◽  
...  
Keyword(s):  
Native Species ◽  
Fish Fauna ◽  
River System ◽  
Abundant Species ◽  
Iucn Red List ◽  
Fish Diversity ◽  
Migratory Species ◽  
Absolute Abundance ◽  
Average Abundance ◽  
Comprehensive Survey

Abstract: This work is the most comprehensive survey of the Laranjinha River´s fishes, a tributary of the Cinzas River, Paranapanema River basin. Throughout its course, there is only a low-height dam, including a transposition system located 98 km from its mouth. The sampling was carried out in nine locations, from the source to the mouth, with six field incursions in each location, using different fishing gear. A total of 11,924 fish were collected, distributed in seven orders, 27 families, and 100 species. The most representative order in the number of species was Siluriformes, followed by Characiformes. As for the families, Loricariidae comprised 21% and Characidae 14% of species richness. Phalloceros harpagos was the species with the highest absolute abundance, representing 11.3% of the total, followed by Hypostomus ancistroides with 9.8%. However, considering the average abundance and frequency of occurrence, Hypostomus ancistroides was the most abundant species, followed by Hypostomus cf. paulinus, Psalidodon aff. paranae and Phalloceros harpagos. Among the collected species, the Apteronotus acidops, Brycon orbygnianus, Brycon nattereri, Crenicichla jupiaensis, and Rhinelepis aspera were classified as endangered on the most recent IUCN Red List. Also, from the total sampled fish, 9.8% are considered non-native species. Among the native species recorded, 10 species are large migratory species, which indicates that the Laranjinha River is a route for spawning and maintenance of species diversity in the middle Paranapanema River. Therefore, the Laranjinha River is a heritage of fish diversity and deserves special attention in its preservation.

scholarly journals The Depositional Environments in the Cilento Offshore (Southern Tyrrhenian Sea, Italy) Based on Marine Geological Data

2021 ◽  
Vol 9 (10) ◽  
pp. 1083
Author(s):  
Gemma Aiello ◽  
Mauro Caccavale
Keyword(s):  
Continental Shelf ◽  
Late Quaternary ◽  
Depositional Environments ◽  
Geological Mapping ◽  
Outer Shelf ◽  
Tyrrhenian Sea ◽  
Outer Continental Shelf ◽  
Inner Shelf ◽  
Depositional Sequence ◽  
System Tract

The depositional environments offshore of the Cilento Promontory have been reconstructed based on the geological studies performed in the frame of the marine geological mapping of the geological sheet n. 502 “Agropoli”. The littoral environment (toe-of-coastal cliff deposits and submerged beach deposits), the inner continental shelf environment (inner shelf deposits and bioclastic deposits), the outer continental shelf environment (outer shelf deposits and bioclastic deposits), the lowstand system tract and the Pleistocene relict marine units have been singled out. The littoral, inner shelf and outer shelf environments have been interpreted as the highstand system tract of the Late Quaternary depositional sequence. This sequence overlies the Cenozoic substratum (ssi unit), composed of Cenozoic siliciclastic rocks, genetically related with the Cilento Flysch. On the inner shelf four main seismo-stratigraphic units, overlying the undifferentiated acoustic basement have been recognized based on the geological interpretation of seismic profiles. On the outer shelf, palimpsest deposits of emerged to submerged beach and forming elongated dunes have been recognized on sub-bottom profiles and calibrated with gravity core data collected in previous papers. The sedimentological analysis of sea bottom samples has shown the occurrence of several grain sizes occurring in this portion of the Cilento offshore.

Antarctic notothenioid fishes as subjects for research in evolutionary biology

2000 ◽  
Vol 12 (3) ◽  
pp. 276-287 ◽  
Author(s):  
Joseph T. Eastman
Keyword(s):  
Evolutionary Biology ◽  
Fish Fauna ◽  
Taxonomic Diversity ◽  
Late Eocene ◽  
Taxonomic Composition ◽  
Species Flock ◽  
Subzero Temperatures ◽  
Key Innovation ◽  
The Antarctic ◽  
Upper Slope

Antarctica is a continental island and the waters of its shelf and upper slope are an insular evolutionary site. The shelf waters resemble a closed basin in the Southern Ocean, separated from other continents by distance, current patterns and subzero temperatures. The benthic fish fauna of the shelf and upper slope of the Antarctic Region includes 213 species with higher taxonomic diversity confined to 18 families. Ninety-six notothenioids, 67 liparids and 23 zoarcids comprise 45%, 32% and 11% of the fauna, a combined total of 88%. In high latitude (71–78°S) shelf areas notothenioids dominate abundance and biomass at levels of 90–95%. Notothenioids are also morphologically and ecologically diverse. Although they lack a swim bladder, the hallmark of the notothenioid radiation has been repeated diversification into water column habitats. There are pelagic, semipelagic, cryopelagic and epibenthic species. Notothenioids exhibit the disproportionate speciosity and high endemism characteristic of fish species flock. Antifreeze glycopeptides originating from a transformed trypsinogen gene are a key innovation. It is not known when the modern Antarctic shelf fauna assumed its current taxonomic composition. A late Eocene fossil fauna was taxonomically diverse and cosmopolitan. There was a subsequent faunal replacement with little carryover of families into the modern fauna. Basal notothenioid clades probably diverged in Gondwanan shelf locations during the early Tertiary. Dates inferred from molecular sequences suggest that phyletically derived Antarctic clades arose 15–5 m.y.a.

scholarly journals FORAMINIFERA CHECK LIST AND THE MAIN SPECIES DISTRIBUTION IN THE AVEIRO LAGOON AND ADJACENT CONTINENTAL SHELF (PORTUGAL)

2019 ◽  
Vol 4 (1) ◽  
pp. 1-52 ◽  
Author(s):  
Maria Virgínia Alves Martins ◽  
Johann Hohenegger ◽  
Fabrizio Frontalini ◽  
Cristina Sequeira ◽  
Paulo Miranda ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Distribution Patterns ◽  
Check List ◽  
Outer Continental Shelf ◽  
Depth Functions ◽  
Main Species ◽  
Components Analysis ◽  
Foraminíferos Bentónicos ◽  
Aveiro Lagoon ◽  
Upper Slope

This work is based on a compilation of benthic foraminiferal data collected in the Aveiro Lagoon and in the adjacent continental shelf and upper slope (center of Portugal). It intends to provide an overall analysis from transitional to the outer continental shelf of the occurrence and distribution of species in living and to present updated taxonomic data and illustrations of most of the species found in the in the Aveiro Lagoon and in the adjacent continental shelf including in total assemblages. Cluster analysis (CA) and Principal Components Analysis (PCA) interpreted as depth functions allow us to identify the main species in different ecoenvironments and sectors of the study area. The most unusual living assemblage was documented in the lagoon inlet under very strong tidal currents activity, composed mostly by the following species (both in living and total assemblages): Rotaliammina concava, Lepidodeuterammina ochracea, Quinqueloculina seminula, Gavelinopsis praegeri, Paratrochammina haynesi, Remaneica helgolandica and Remaneicella gonzalezi. The distribution patterns of some Trochamminidae and Remaneicidae species whose ecology and distribution pattern are poorly known, have proved to be a marker of more or less hydrodynamic and stable/unstable environments in coastal and transitional marine environments. OCORRÊNCIA DE FORAMINÍFEROS E DISTRIBUIÇÃO DAS PRINCIPAIS ESPÉCIES NA LAGOA DE AVEIRO E NA PLATAFORMA CONTINENTAL ADJACENTE (PORTUGAL)ResumoEste trabalho baseia-se numa compilação de dados foraminíferos bentónicos recolhidos na Laguna de Aveiro e na plataforma continental adjacente (centro de Portugal). Pretende efetuar uma análise geral da distribuição de espécies nas associações vivas e totais (vivas e mortas) na área de estudo, em função da profundidade. Pretende ainda apresentar dados taxonómicos e ilustrações da maioria das espécies encontradas na Laguna de Aveiro e na plataforma continental adjacente. A análise de agrupamento (CA) e a análise de componentes principais (PCA), em função da profundidade, permitem identificar as principais espécies em diferentes ecossistemas e setores da área de estudo. A associação viva mais invulgar foi encontrada na embocadura da Laguna de Aveiro, um ambiente sujeito a forte corrente de maré. Essa associação era composta principalmente pelas seguintes espécies (na associação viva e total): Rotaliammina concava, Lepidodeuterammina ochracea, Quinqueloculina seminula, Gavelinopsis praegeri, Paratrochammina haynesi, Remaneica helgolandica and Remaneicella gonzalezi. Os padrões de distribuição de algumas espécies de Trochamminidae e Remaneicidae, cuja ecologia e padrão de distribuição são pouco conhecidos, mostraram ser um marcador de ambientes mais ou menos hidrodinâmicos e de estabilidade/instabilidade do substrato em ambientes marinhos costeiros e de transição. Palavras-chave: Ecologia. Taxonomia. Imagens digitais. Análise Estatística. Ambientes Transicionais e Costeiros Marinhos.

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