The life history, growth, and age structure of Nephelopsis obscura Verrill, 1872 (Hirudinoidea) in Alberta

1977 ◽  
Vol 55 (3) ◽  
pp. 620-627 ◽  
Author(s):  
Ronald W. Davies ◽  
Roger P. Everett
Keyword(s):  
Deep Water ◽  
Late Summer ◽  
Shore Zone ◽  
Cocoon Production ◽  
Summer Generation ◽  
Water Zone ◽  
Nephelopsis Obscura ◽  
Spring Generation ◽  
Two Generations ◽  
First Time

Two generations of Nephelopsis obscura were produced annually in the spring and in the late summer. The spring generation was the progeny of the heavier elements of the previous year's spring generation and of the late-summer generation produced 2 years previously. The late-summer generation was produced by parts of the previous year's spring and late-summer generations. Each generation produced young after either 12 and 15 months or 12 and 19 months although each individual bred once only. Unlike other species of leeches studied N. obscura showed no direct correlation between cocoon production and water temperature, the primary prerequisite being a weight of more than 150 mg. Seasonal movements from the deep-water zone to the shore zone in spring and vice versa in the fall were recorded for the first time. The movements to the deep-water zone were not synchronous throughout the population, the spring generation completing its movements before the other components of the population.

ANALYSIS OF THE FUNCTIONING OF MARINE ECOSYSTEMS ON CHANGING THE PARAMETERS OF THE BIOLUMINESCENCE FIELD ON THE CRIMEAN BLACK SEA SHELF

2017 ◽  
Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  
Keyword(s):  
Black Sea ◽  
Field Intensity ◽  
Deep Water ◽  
Coastal Waters ◽  
Integrated Management ◽  
Abiotic Factors ◽  
Environmental Safety ◽  
The Black Sea ◽  
Intensity Increase ◽  
First Time

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.

From the Madrasah to the Museum: The Social Life of the “Kietaabs” of Cape Town

2011 ◽  
Vol 38 ◽  
pp. 369-399 ◽  
Author(s):  
Saarah Jappie
Keyword(s):  
South Africa ◽  
Social Life ◽  
Living Room ◽  
Family Tree ◽  
Personal Journey ◽  
The Social ◽  
Arabic Script ◽  
Two Generations ◽  
Place Of Origin ◽  
First Time

Ebrahiem Manuel sits opposite me, about to embark upon his story. His living room is filled with material manifestations of his research: boxes overflowing with books and papers cover his entire sofa, newspapers and articles line the floor, and collages of images and texts hang on the walls and sit in the cabinets. It is clear that he is consumed by his passion for heritage, and his personal journey of discovery. He speaks in an animated, almost theatrical tone, raising and lowering his voice, stressing certain syllables, alive as he tells his story of “the ancient kietaabs.”The journey began in 1997, when Ebrahiem returned to South Africa after years at sea, working as a cook on shipping vessels. Upon his return, he began a quest to learn about his personal heritage, inspired by a dream he had had about his grandfather. This search led him to an oldkietaab, given to him by an elderly aunt. This was not the first time he had come across the old book; he remembered seeing it as a child, amongst other kietaabs, stored out of reach of the children, on top of his grandfather's wardrobe. It was inside this book that a possible key to his ancestors was to be found.This significant find was a range of hand-written inscriptions inside the book, in Arabic, English, and an unknown script. The Arabic script and its corresponding English transliteration read “Imaam Abdul Karriem, son of Imaam Abdul Jaliel, son of Imaam Ismail of Sumbawa.” Here was his family tree, starting from his great-grandfather and leading to two generations before him and, it seemed, their place of origin, the island of Sumbawa in eastern Indonesia. Ebrahiem then decided to go to Indonesia to solve what had become the mystery of “the ancient kietaab.”

Deep Water Scientific Drilling in Lake Malawi, Africa

2006 ◽  
Vol 40 (1) ◽  
pp. 29-35
Author(s):  
K. Moran ◽  
M. Paulson ◽  
M. Lengkeek ◽  
P. Jeffery ◽  
A. Frazer
Keyword(s):  
Deep Water ◽  
Lake Malawi ◽  
Design Work ◽  
Scientific Drilling ◽  
Drilling Rig ◽  
Core Recovery ◽  
Lake Floor ◽  
Drilling System ◽  
Rift Valley Lakes ◽  
First Time

A new deep water drilling system was developed and applied to recover deeply buried sediments for scientific analyses in one of the deep rift valley lakes of Africa—Malawi. This approach overcame the difficulty of maintaining position over a drill site in a remotely located, large, deep lake. Environmental conditions in Lake Malawi are similar to deep water marine settings and, as such, a marine approach was adopted for the Lake Malawi Drilling Project (LMDP). In February and March 2005, the modified pontoon, Viphya, successfully completed a scientific drilling expedition in Lake Malawi. This expedition recovered core at depths greater than 380 m below lake-floor in water depths as great as 600 m. The major refit of Viphya included installation of a moonpool, bridge, crew accommodations, mess, washroom, power system, dynamic positioning, and a drilling system. These major modifications required early pontoon surveys and naval architectural analyses and design work prior to their commencement. The expedition also used modified scientific coring tools with a marine geotechnical drilling rig for the first time, resulting in excellent core recovery and quality.

The sequence and correlation of Early Ordovician (Arenig) graptolite faunas in the Richardson Trough and Misty Creek Embayment, Yukon Territory and District of Mackenzie, Canada

2006 ◽  
Vol 43 (12) ◽  
pp. 1791-1820 ◽  
Author(s):  
D E Jackson ◽  
A C Lenz
Keyword(s):  
Northwest Territories ◽  
Deep Water ◽  
Yukon Territory ◽  
Early Ordovician ◽  
The Road ◽  
Bedded Chert ◽  
First Occurrence ◽  
Mackenzie Mountains ◽  
First Time

Four graptolite biozones are recorded from the Arenig portion of the Road River Group in the Richardson and Mackenzie mountains in the Yukon and Northwest Territories. In ascending order, these zones are Tetragraptus approximatus, Pendeograptus fruticosus, Didymograptus bifidus, and Parisograptus caduceus australis (new). The Castlemainian stage may be represented by nongraptolitic massive bedded chert. The Arenig–Llanvirn boundary is drawn below the first occurrence of Undulograptus austrodentatus. Fifty-four graptolite taxa are present, and 16 of these species and subspecies are recorded for the first time in this deep-water biotope, namely, Didymograptus? cf. adamantinus, D. asperus, D. dilatans, D. cf. kurcki, D. validus communis, Holmograptus aff. leptograptoides, H. sp. A, Isograptus? sp. nov. A, I. ? dilemma, Keblograptus geminus, Pseudisograptus manubriatus harrisi, Ps. m. koi, Ps. m. janus, Ps. cf. tau, Xiphograptus lofuensis, and Zygograptus cf. abnormis.

scholarly journals Zeiform mouthbrooding in the deepsea – dispelling a myth

2020 ◽  
Author(s):  
Ralf ◽  
G. David Johnson ◽  
Kevin Conway
Keyword(s):  
Deep Water ◽  
Deep Sea ◽  
Developmental Stages ◽  
Extended Period ◽  
Marine Fishes ◽  
Early Developmental Stages ◽  
Water Fish ◽  
First Time ◽  
Early Developmental ◽  
Deep Sea Fauna

Mouthbrooding or oral incubation, the retention of early developmental stages inside of the mouth for an extended period of time, has evolved multiple times in bony fishes1,2. Though uncommon, this form of parental care has been documented and well-studied in several groups of freshwater fishes but is also known to occur in a small number of marine fishes, all inhabiting coastal waters1,2. A recent paper3, reported for the first time mouthbrooding in a deep-water fish species, the zeiform Parazen pacificus, which according to the authors “fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.”

scholarly journals A biodiversity hotspot for Microgastrinae (Hymenoptera, Braconidae) in North America: annotated species checklist for Ottawa, Canada

ZooKeys ◽  
2016 ◽  
Vol 633 ◽  
pp. 1-93 ◽  
Author(s):  
Jose Fernandez-Triana ◽  
Caroline Boudreault ◽  
Joel Buffam ◽  
Ronald Maclean
Keyword(s):  
North America ◽  
General Pattern ◽  
Late Summer ◽  
The United States ◽  
Early Summer ◽  
Individual Species ◽  
Early Fall ◽  
Two Peaks ◽  
Annotated Checklist ◽  
First Time

Microgastrinae wasps (Hymenoptera, Braconidae) from the city of Ottawa and its surroundings (a 50-km radius circle, ~7,800 km2) were studied based on 1,928 specimens collected between 1894 and 2010, and housed in the Canadian National Collection of Insects. A total of 158 species from 21 genera were identified, which is by far the highest number of species ever recorded for a locality in North America. An annotated checklist of species is provided.Choerasparasitellae(Bouché, 1834) andPholetesornanus(Reinhard, 1880) are recorded for the first time in the Nearctic (previously only known from the Palearctic region),Cotesiadepressa(Viereck, 1912) is recorded for the first time in Canada (previously only known from the United States), andCotesiahemileucae(Riley, 1881) andProtapantelesphlyctaeniae(Muesebeck, 1929) are recorded for the first time in the province of Ontario. In Ottawa the most diverse genera areCotesia,Apanteles,Microplitis,Pholetesor,Microgaster, andDolichogenidea, altogether comprising 77% of the species found in the area. A total of 73 species (46%) were represented by only one or two specimens, suggesting that the inventory for Ottawa is still relatively incomplete. Seasonal distribution showed several peaks of activity, in spring, summer, and early fall. That general pattern varied for individual species, with some showing a single peak of abundance either in the summer or towards the end of the season, others species attaining two peaks, in late spring and late summer, or in early summer and early fall, and yet others attaining up to three different peaks, in spring, summer and fall. At least 72 of the Microgastrinae species from Ottawa have been previously associated with 554 species of Lepidoptera as hosts – but those historical literature records are not always reliable and in many cases are based on data from areas beyond Ottawa. Thus, our knowledge of the associations between the 158 species of microgastrine parasitoids and the caterpillars of the 2,064 species of Lepidoptera recorded from Ottawa is still very incomplete.

Ordovician Formations and Faunas, Southern Mackenzie Mountains

1975 ◽  
Vol 12 (4) ◽  
pp. 663-697 ◽  
Author(s):  
Rolf Ludvigsen
Keyword(s):  
Deep Water ◽  
Carbonate Facies ◽  
Northern Canada ◽  
Northeastern Part ◽  
Early Ordovician ◽  
The Road ◽  
Carbonate Sedimentation ◽  
Skull Formation ◽  
Tectonic Features ◽  
First Time

Ordovician strata of the South Nahanni River area occur as a western fine clastic facies with graptolitic faunas (Road River Formation) and an eastern carbonate facies with shelly faunas (Broken Skull, Sunblood, Esbataottine, and Whittaker Formations). The lithofacies are controlled by major tectonic features. In the early Ordovician the Selwyn Basin received fine clastic sedimentation (Road River) while carbonate sedimentation (Broken Skull, Sunblood, Esbataottine) was confined to the Root Basin and the fringes of the emergent Redstone Arch. Later in the Ordovician a pronounced transgression caused a marked eastwardly shift of facies belts and resulted in the flooding of the Arch and deposition of a widespread carbonate sheet (Whittaker) in the northeastern part of the study area.The carbonate facies of the Root Basin and south of the Redstone Arch contains a complete record of shelly faunas of Canadian to, probably, Maysvillian age. The Broken Skull Formation consists of craggy weathering, variably sandy carbonates and contains, in its highest parts, the Hesperonomia fauna (Canadian). The Sunblood Formation consists of generally resistant, red-orange-buff weathering limestones and minor dolostones and contains two faunas; the Orthidiella-'Goniotelina' fauna (Whiterockian) and the Bathyurus sp. 1 fauna (?Chazyan). The Esbataottine Formation (proposed) comprises moderately recessive, grey-buff weathering limestones and contains two faunas; the Mimella fauna (Chazyan) and the Doleroides fauna (Blackriveran). The lower Whittaker Formation (Trentonian to ?Maysvillian) comprises three lithosomes containing discrete faunas which appear to represent coeval communities: The Strophomena-Ceraurus fauna in thinly bedded, argillaceous limestones; the Bighornia-Thaerodonta fauna in well bedded, nonargillaceous limestones; and the Hesperorthis-Oepikina fauna in well bedded dolostones. A unique fauna of deep water aspect, the Cryptolithus-Anataphrus fauna, occurs in shales and black limestones of the Road River Formation and is, in part, equivalent to the faunas of the lower Whittaker Formation. The Sunblood, Esbataottine, and Whittaker Formations contain abundant and well preserved silicified trilobites; many of which are reported for the first time from western and northern Canada.

Halimeda incrassata (Bryopsidales, Chlorophyta) reaches the Canary Islands: mid- and deep-water meadows in the eastern subtropical Atlantic Ocean

2018 ◽  
Vol 61 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Carlos Sangil ◽  
Laura Martín-García ◽  
Julio Afonso-Carrillo ◽  
Jacinto Barquín ◽  
Marta Sansón
Keyword(s):  
Atlantic Ocean ◽  
Canary Islands ◽  
Deep Water ◽  
Population Coverage ◽  
Isolated Populations ◽  
La Palma ◽  
Soft Bottoms ◽  
The Caribbean ◽  
Marine Flora ◽  
First Time

AbstractExtensive offshore meadows ofHalimeda incrassataare documented for the first time in sandy bottoms of La Palma, Canary Islands.Halimeda incrassataforms dense sublittoral assemblages between 20 and 55 m, but isolated populations occur down to 65 m depth. This species currently spreads over an area of 9.14 ha. Population coverage varies with depth, with the highest values at 35–40 m and an average cover of 62.34%. The calcified segments ofH. incrassataact as a stable substratum in these soft bottoms for the growth of other macroalgae, such as the rhodophytesLophocladia trichocladosandCottoniella filamentosa. Specimens reach lengths of up to 10 cm, shorter than individuals from the Caribbean. Although it is difficult to ascertain whether this species is a recent introduction, there is evidence of a correlation between the increase in population coverage and recent ocean warming, constituting another example of the tropicalization of the marine flora of this region.

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