scholarly journals Jurassic planktic foraminifera from the Polish Basin

2021 ◽  
Vol 40 (1) ◽  
pp. 1-13
Author(s):  
Maria Gajewska ◽  
Zofia Dubicka ◽  
Malcolm B. Hart
Keyword(s):  
Distribution Pattern ◽  
Depth Distribution ◽  
Open Water ◽  
Clear Relationship ◽  
Shallow Waters ◽  
Planktic Foraminifera ◽  
Complex Forms

Abstract. Jurassic (Bathonian–Oxfordian) planktic foraminifera from the epicontinental strata of the Polish Basin have been investigated. The palaeoecology, palaeobiogeography, and biostratigraphical potential of the recorded taxa are discussed. Four species are recorded: Conoglobigerina helvetojurassica (Haeusler, 1881), Globuligerina balakhmatovae (Morozova, 1961), G. bathoniana (Pazdrowa, 1969), and G. oxfordiana (Grigelis, 1958). This assemblage is probably the most diverse of those described to date from the epicontinental areas of Europe. The recorded taxa are thought to represent three different ecological morphotypes. The clear relationship between transgressive–regressive facies and the palaeobiogeography of the recorded planktic foraminifera indicates a morphotype-related depth–distribution pattern in which small, simple, globular-chambered morphotypes occupied shallow waters whereas slightly larger, more complex forms, or those with hemispherical chambers, inhabited deeper and more open-water environments.

scholarly journals GEOGRAPHIC AND DEPTH DISTRIBUTION OF Bathybembix (bathybembix) bairdii (DALL, 1889) (MOLLUSCA, GASTROPODA, TROCHIDAE) IN THE EAST PACIFIC

2006 ◽  
Vol 21 (1-2) ◽  
pp. 93
Author(s):  
M. E. Hendrickx ◽  
J. López
Keyword(s):  
El Salvador ◽  
Distribution Pattern ◽  
Deep Water ◽  
Gulf Of California ◽  
Depth Distribution ◽  
East Pacific ◽  
The Family

Bathybembix (bathybembix) bairdii, a deep water mollusc of the Family Trochidae, was collected in the Southeast Gulf of California, Mexico and off the coast of El Salvador during exploratory cruises depths of 778 m - 2140 m and was very abundant in El Salvador. Information on B. (b.) bairdii, distribution pattern from the Gulf of California indicate that this species is well adapted to severe hypoxic (

Recent Arborescent Dendrophryid Foraminifera Found On Upper Pleistocene Cold-water Corals from the Inner Sea of the Maldives

2018 ◽  
Vol 48 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Matías Reolid ◽  
Jesús Reolid ◽  
Dorothea Bunzel ◽  
Michael A. Kaminski ◽  
Christian Betzler
Keyword(s):  
Cold Water ◽  
Test Construction ◽  
Shallow Waters ◽  
Calcareous Nannoplankton ◽  
Planktic Foraminifera ◽  
Sea Floor ◽  
The Indian Ocean ◽  
The Caribbean ◽  
Wall Growth ◽  
Sponge Spicules

Abstract Recent specimens of Spiculidendron were found on Late Pleistocene (21,400–22,500 BP) cold-water corals from the sea floor at 457 m depth of the inter-atoll Kardiva Channel of the eastern row of the Maldives archipelago. Spiculidendron and other dendrophryid foraminifera (Rhizammina-like forms) exclusively colonized specimens of the genus Enallopsammia, which was characterized by a phosphatic-stain surface. The Spiculidendron wall was composed of sponge spicules, elongated diatom frustules, tests of juvenile benthic and planktic foraminifera, and calcareous nannoplankton, among other materials. Sponge spicules and elongated diatom frustules were arranged longitudinally, with foraminiferal tests and other bioclasts packed in between, indicating that the agglutination process of Spiculidendron is selective with respect to the manner of growth. In the most distal parts of the branches, only sponge spicules and elongated diatom frustules were present, working as guides for the test construction, prior to the agglutination of juvenile foraminiferal tests and other bioclasts. Moreover, in the sediment associated with the coral fragments, 94 species of benthic foraminifera were identified, an assemblage distinct from the taxa incorporated into the agglutinated Spiculidendron tests. The process of wall growth is complex and ordered. This foraminifer, as well as the Rhizammina-like specimens, tolerates dysoxic conditions (0.896 ml/l) and low temperature (12°C). This observation represents a new record of Spiculidendron from the Indian Ocean and from deeper (aphotic) environments than previously reported from the shallow waters of the Caribbean. A cryptobiontic habitat is interpreted for Spiculidendron.

scholarly journals Biostratigraphy and paleoenvironment of Maastrichtian foraminiferal assemblages from a succession located NW of Tuxtla Gutiérrez, Chiapas (SE Mexico)

2021 ◽  
Vol 38 (1) ◽  
pp. 65-81
Author(s):  
Lourdes Omaña ◽  
Jose Maria Pons ◽  
Ruben Cruz
Keyword(s):  
Shallow Water ◽  
Open Water ◽  
High Energy ◽  
Foraminiferal Assemblage ◽  
Planktic Foraminifera ◽  
Lithostratigraphic Units ◽  
Assemblage Zone ◽  
Siliciclastic Rocks ◽  
The City ◽  
Early Late

During the Maastrichtian, two lithostratigraphic units were deposited in the central Chiapas region; the Ocozocoautla and Angostura formations. The first unit crops out northwest of the city of Tuxtla Gutiérrez in central Chiapas. It is a complex lithological unit mainly composed of siliciclastic rocks interbedded with limestone. Overlying it, the Angostura limestone is recognized. This study focuses on a taxonomic study of the larger benthic and planktic foraminifera from both formations in order to assign age and to infer the paleoenviroment. The Ocozocoautla Formation includes an association of benthic as well as significant planktic foraminifera. Based on the microfossils stratigraphic distribution, two biozones were defined: the Pseudorbitoides rutteni–Ayalaina rutteni Assemblage Zone of earliest Maastrichtian and the upper part of the Gansserina gansseri Interval Zone of early Maastrichtian. The Angostura Formation contains dasycladacean algae and larger foraminifera considered as important age markers in shallow-water environments. Two foraminiferal interval zones were defined, Praechubbina breviclaustra Interval Zone of early late Maastrichtian and Chubbina jamaicensis Total Range Zone of late to latest Maastrichian age. The microfacies (grainstone, wackestone–packstone, wackestone) as well as the foraminiferal assemblage enable the paleoenvironment to be reconstructed, suggesting a deposit that developed in an open-water marine setting with moderate to high energy, characterized by benthic and planktic foraminifera in the Ocozocoautla Formation, while in the Angostura Formation a shallow-water marine protected environment is inferred. The paleobiogeographical distribution of the assemblage from both the Ocozocoautla and Angostura formations mostly contains endemic benthic foraminifera of the Caribbean Province and other few Tethysian forms of the Angostura Formation.

Distribution pattern and habitat shifts during ontogeny of the blue swimming crab, Portunus pelagicus (Linnaeus, 1758) (Brachyura, Portunidae)

Crustaceana ◽  
2020 ◽  
Vol 93 (1) ◽  
pp. 17-32 ◽  
Author(s):  
Fazrul Hisam ◽  
Sukree Hajisamae ◽  
Mohammed Ikhwanuddin ◽  
Siriporn Pradit
Keyword(s):  
Distribution Pattern ◽  
Shallow Waters ◽  
Swimming Crab ◽  
Habitat Shift ◽  
Coastal Habitats ◽  
Portunus Pelagicus ◽  
Offshore Area ◽  
Gill Nets ◽  
Study Sites ◽  
Ontogenetic Habitat Shifts

Abstract This study determined the distribution and ontogenetic habitat shifts of Portunus pelagicus in coastal habitats in Thailand. Samples were collected by gill nets and traps, at six study sites during May 2013 and September 2014. It was found that, in the bay, the catches from both gears were significantly influenced by depth ( and ) but not by season (). For offshore, the catch was significantly influenced by season () but not by depth (). The catches of berried females in the bay and in the offshore area were not influenced either by depth, or by season (). In addition, it is proven by this study that a habitat shift during ontogeny occurs as young crabs or small-sized crabs inhabit shallow waters, and migrate to deeper water when they grow larger.

Holocene Palaeosalinity in a Maya Wetland, Belize, Inferred from the Microfaunal Assemblage

1994 ◽  
Vol 41 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Javier A. Alcala-Herrera ◽  
John S. Jacob ◽  
Maria Luisa Machain Castillo ◽  
Raymond W. Neck
Keyword(s):  
Sea Level ◽  
Open Water ◽  
Shallow Waters ◽  
Freshwater Input ◽  
The Past ◽  
Salinity Changes ◽  
M Sequence ◽  
Freshwater Ostracods ◽  
Rising Sea Level ◽  
Mangrove Peat

AbstractA 5.4-m sequence of peat and marl overlying a basal clay in a northern Belize wetland was studied to assess salinity changes over the past 7000 yr. The distribution of ostracods, gastropods, and foraminifers revealed initially freshwater conditions in a terrestrial wetland, changing to at least mesohaline conditions by about 5600 yr B.P. The mesohaline conditions corresponded to the formation of an open-water lagoon (and precipitation of a lacustrine marl) that was contemporaneous with rapidly rising sea level in the area. A mangrove peat filled the lagoon by 4800 yr B.P. probably as a result of increasingly shallow waters as sea level rise slowed and marl precipitation continued. A new lagoon began to form sometime after 3400 yr B.P. Freshwater ostracods and gastropods found in the marl of this lagoon suggest that it formed under near-limnetic conditions. Freshwater input likely resulted from massive deforestation by the Maya that began by 4400 yr B.P. Subsidence of the mangrove peat likely permitted the formation of a lagoon. A peat has filled the lagoon since at least 500 yr B.P.

Depth distribution and seasonal movements of Chionoecetes opilio (Brachyura: Majidae) in Baie Sainte-Marguerite, Gulf of Saint Lawrence

1995 ◽  
Vol 73 (9) ◽  
pp. 1712-1726 ◽  
Author(s):  
Gustavo A. Lovrich ◽  
Bernard Sainte-Marie ◽  
Barry D. Smith
Keyword(s):  
Large Scale ◽  
Depth Distribution ◽  
Carapace Width ◽  
Shallow Waters ◽  
Adult Males ◽  
Chionoecetes Opilio ◽  
Seasonal Movements ◽  
Class Strength ◽  
Gulf Of Saint Lawrence ◽  
Snow Crabs

Bimonthly beam-trawling from April 1991 to May 1992 and diver observations were used to assess distribution and large-scale movement of snow crabs, Chionoecetes opilio, over depths of 4–140 m in a bay of the northern Gulf of Saint Lawrence. Megalopae settled during October 1991. Immature crabs of instars I–IV (i.e., 3.3–9.7 mm mean carapace width, CW) were found predominantly on bottoms ≈50–80 m deep and were cryptic and sedentary. Most immature crabs of instars V–VIII (i.e., 14.1–34.5 mm mean CW) and adolescent males (i.e., producing sperm but not terminally moulted) migrated in winter to subtidal grounds, where they moulted. Movement to shallow waters was massive and resulted in a mean density of 860 crabs per 1000 m2 at ≈15 m in December 1991. Adult males (i.e., producing sperm and terminally moulted) of <70 mm mean CW also moved to the shallow grounds from October to December 1991, where some mated with pubescent–primiparous females (i.e., adult, first brood) from January to April 1992. Adult males of >90 mm mean CW were mainly found at depths >80 m over most of the year, but from March to May 1992 an increase in mean CW of adult males at <80 m indicated some upslope movement, probably to mate with multiparous females (i.e., adult, second or ulterior brood). Adult females were more gregarious and sedentary than adult males. We expand on the hypothesis that interannual variability in recruitment to adulthood tends to reflect differences in year-class strength, and that year-class strength varies in accordance with megalopal supply and (or) survivorship of cryptic instars.

scholarly journals Identifying important habitats for waterbird conservation at a Greek Regional Nature Park

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Vasilios Liordos ◽  
Vasileios J. Kontsiotis
Keyword(s):  
Habitat Use ◽  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Management Strategies ◽  
Open Water ◽  
Niche Overlap ◽  
Null Models ◽  
Shallow Waters ◽  
Rocky Substrate ◽  
Waterbird Species

Abstract Background Small coastal wetlands are vital sites for wintering waterbirds. Identifying important habitats is critical for managing waterbirds effectively. The Vourkari inlet is a small coastal wetland located near the capital Athens, within the most urbanized and industrialized area of Greece. We aimed at identifying the most important habitats for waterbirds at the Vourkari inlet during winter. Methods Data about habitat use and availability were collected for 14 waterbird species and for seven habitat classes. Habitat selection (Manly’s selection ratio), overlap indices (Pianka’s niche overlap index) and null models were calculated. Results All the studied waterbird species selected available habitats nonrandomly. Shallow waters (0–2 m), were used by 13 waterbirds and selected by five waterbirds. Pools and channels were used and selected by 10 species. Mud was used by nine species and selected by six species. Mud with rocky substrate was used by nine species and selected by eight species. Medium (2–4 m) and deep (4–6 m) open water habitats were used by seven species and selected by four species. Halophytic vegetation was used by six species and selected by two species. Several habitats were selected by nationally important populations: mudflat habitats (i.e., mud, mud with rocky substrate and pools and channels) by Common Redshanks (Tringa totanus), halophytic vegetation by Little Egrets (Egretta garzetta), shallow waters by Common Shelducks (Tadorna tadorna) and medium and deep waters by Sandwich Terns (Thalasseus sandvicencis), whilst shallow waters and mudflat habitats were preferred by a possibly internationally important population of Mediterranean Gulls (Ichthyaetus melanocephalus). Although overlap in habitat use between species was generally low, null models indicated habitat sharing and a lack of competition. Conclusions Waterbirds coexisted in the absence of competition for habitats at Vourkari, where they mostly used and preferred shallow water and mudflats. Small coastal wetlands are numerous, both in Greece and worldwide, therefore our findings would be useful as a basis for comparisons, both temporal at the inlet and spatial with other sites, that would help assess the importance of habitats and improve management strategies to benefit waterbirds, especially in areas with similar Mediterranean-type habitats and climate.

Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations

Zootaxa ◽  
2019 ◽  
Vol 4550 (2) ◽  
pp. 185 ◽  
Author(s):  
FABRIZIO SCARABINO ◽  
RUDÁ AMORIM LUCENA ◽  
TOMÁS MUNILLA ◽  
ANNA SOLER-MEMBRIVES ◽  
LEONARDO ORTEGA ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Deep Water ◽  
Deep Sea ◽  
Future Research ◽  
Shallow Waters ◽  
Southwest Atlantic ◽  
Western Atlantic ◽  
La Plata ◽  
Annotated Checklist ◽  
Lower Slope

Records of pycnogonids from Uruguayan waters (south-western Atlantic) include 26 species cited from precise locations, and at least five other species based on unconfirmed records. Nearly half of the species in that fauna belong to the genus Nymphon (12 spp.). Most species (22) come from deep-water and were recorded and described by C. A. Child. Of these, at least twelve species have an extended Antarctic and Subantarctic distribution, showing the influence of these cold waters in the area; three others have a wide deep-sea distribution pattern. Five species are known only from the lower slope and abyssal basin off La plata river: Mimipallene Atlantis and four species of Nymphon. Records from coastal and shelf areas (four species) are poorly documented and should be the focus of future research. Of these, Colossendeis geoffroyi is considered endemic in the Southwest Atlantic between 34ºS and 40ºS, but presents clear Antarctic affinities. A small-sized species living in shallow waters, Pycnogonum cessaci, is here considered as cryptogenic. 

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