scholarly journals Biologie et situation de la Lamproie du Nord, Ichthyomyzon fossor, au Québec

2007 ◽  
Vol 121 (4) ◽  
pp. 402 ◽  
Author(s):  
Christian Fortin ◽  
Martin Ouellet ◽  
Isabelle Cartier ◽  
Daniel Banville ◽  
Claude B. Renaud

La Lamproie du Nord est une espèce propre à l’Amérique du Nord et elle ne se rencontre, au Québec, que dans l’extrême sud de la province. Cette lamproie a été observée dans le fleuve Saint-Laurent ainsi que dans 11 de ses tributaires. Elle aurait disparu de la rivière Yamaska où elle avait été recensée entre 1946 et 1959. Poisson non parasite, sa taille au stade adulte ne dépasse habituellement pas 160 mm. Les larves, appelées ammocètes, et les adultes ne se retrouvent qu’en eau douce. Les cours d’eau utilisés sont généralement des ruisseaux et des rivières à fond graveleux ou sablonneux. La Lamproie du Nord requiert deux habitats distincts, soit un pour les adultes reproducteurs et un autre, le long du même cours d’eau, pour le développement des ammocètes. La détérioration de l’habitat et la pollution des eaux représentent les principales menaces à la survie des lamproies. La faible fécondité et la mobilité réduite de la Lamproie du Nord font en sorte que cette espèce est peu adaptable aux modifications de son environnement.The Northern Brook Lamprey is endemic to North America. In Quebec, it is restricted to the southernmost part of the province. This lamprey is known from the St. Lawrence River as well as in 11 of its tributaries. It appears to have been extirpated from the Yamaska River where it was collected between 1946 and 1959. It is a nonparasitic fish and its adult size does not usually exceed 160 mm. Larvae, called ammocoetes, and adults are found only in fresh water. Watercourses where it occurs are generally streams and rivers with gravel or sandy bottoms. The Northern Brook Lamprey requires two types of habitats during its life cycle, one for spawning adults and one, along the same watercourse, for the developing ammocoete. Habitat degradation and water pollution are the major threats to the survival of lampreys. The low fecundity and low dispersal abilities of the Northern Brook Lamprey make this species poorly adapted to withstand changes in its environment.

1981 ◽  
Vol 59 (7) ◽  
pp. 1237-1250 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt ◽  
M. Harvey

The life cycle of Bythinia tentaculata has been studied over a period of 2 years in five localities of the freshwater estuary of the St. Lawrence River. Sexual maturity is attained after 2 years and the species is iteroparous; this might prove to be a particularly advantageous reproductive strategy in this river. The main phases of individual growth are related to age and thermal variations of the water and they occur during the months of May, June, and July of the first 2 years. Eggs are laid once a year and growth stops during winter for about 6 months. These results on the life cycle and growth of B. tentaculata, particularly in the fluvial section of the St. Lawrence River, are more similar to those obtained in Europe than to those obtained elsewhere in North America. Numbers, biomass, and production are markedly higher here than the values found by other investigators on the same species.[Journal translation]


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
R.R. DANDAWATE

Present paper deals with study of cestode parasites of genus Circumoncobothrium from fresh water fish Clarius batracus at Savitri river, (Dapoli) for the percentages of infection occurance during summer season,minimum during winter and tolarate during rainy season.The parasite mainly infected the intestine of host and fed on nutrients from digested food. It completed its life cycle in the intestine of host. By camparing different characters of it to identify that the species is new


2021 ◽  
Vol 86 (2) ◽  
pp. 425-427
Author(s):  
John P. Hart ◽  
William A. Lovis ◽  
M. Anne Katzenberg

Emerson and colleagues (2020) provide new isotopic evidence on directly dated human bone from the Greater Cahokia region. They conclude that maize was not adopted in the region prior to AD 900. Placing this result within the larger context of maize histories in northeastern North America, they suggest that evidence from the lower Great Lakes and St. Lawrence River valley for earlier maize is “enigmatic” and “perplexing.” Here, we review that evidence, accumulated over the course of several decades, and question why Emerson and colleagues felt the need to offer opinions on that evidence without providing any new contradictory empirical evidence for the region.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1212
Author(s):  
Ao Liu ◽  
Aixi Han ◽  
Li Chai

Apparel manufacturing involves high water consumption and heavy water pollution in its supply chain, e.g., planting cotton, producing chemical fibers, and dyeing. This study employs a multi-regional input–output (MRIO) model to (1) assess the life cycle of blue and grey water (chemical oxygen demand (COD) specific) of China’s apparel manufacturing; (2) reveal the hidden linkage among sectors and regions in the whole supply chain; and (3) identify the key regions and upstream sectors with the most water consumption and heaviest water pollution. We found that the agricultural sector (i.e., planting fiber crops) is responsible for primary water consumption and water pollution. In addition, different provinces assume different production roles. Guangdong is a major output province in apparel manufacturing. However, its economic output is contributed to by other regions, such as blue water from Xinjiang and Jiangsu and grey water from Hebei and Shandong. Our research reveals the significance of taking an inter-regional perspective on water resource issues throughout the supply chain in apparel manufacturing. The sustainable development of China’s apparel manufacturing relies on improving water-use efficiency and reasonable industrial layout. The results are of significance and informative for policymakers to build a water-sustainable apparel industry.


1967 ◽  
Vol 45 (12) ◽  
pp. 2267-2327 ◽  
Author(s):  
J. A. Parmelee

Sixty-two taxa are recognized in this study of the species of Puccinia completing their life cycle on Heliantheae. Six new species are described: Puccinia guatemalensis Parmelee on Zexmenia spp. and Wedelia spp., P. ghiesbreghtii Parmelee on Wedelia ghiesbreghtii, P. abramsii Parmelee on Geraea viscida (= Encelia viscida), P. chloracae Parmelee on Viguiera spp., P. calanticariae Parmelee on Viguiera spp., and P. praetermissa Parmelee on Lagascea spp. Six new varieties are recognized: Puccinia electrae var. robusta Parmelee and P. electrae var. depressiporosa Parmelee on Zexmenia brevifolia, P. caleae var. cuernavacae Parmelee on Calea spp., P. cognata var. echinulata Parmelee on Verbesina spp., P. cognata var. fraseri Parmelee on Viguiera fraseri, and P. affinis var. triporosa Parmelee on Viguiera spp. Three taxa have been restored from synonomy under P. abrupta, viz. P. subglobosa, P. ximenesiae, and P. affinis, the last two parasitic on Verbesina spp., the first on Rhysolepis (= Viguiera). P. tithoniae, P. nanomitra, and P. ordinata, are reduced to synonomy with P. enceliae var. enceliae, P. iostephanes, and P. melampodii respectively. New combinations include: P. enceliae var. aemulans (Syd.) Parmelee and P. abrupta var. partheniicola (Jacks.) Parmelee. A key based on uredinial and telial characters, others based initially on the hosts, and a host index are provided. Each taxon is illustrated by a photomicrograph from type material. Distribution and host extensions, supplementary to those given in Arthur's Manual of the Rusts, are indicated.


2021 ◽  
Author(s):  
Jeremy Richardson ◽  
◽  
Eric Dixon ◽  
Ted Boettner ◽  

Although coal has powered the nation for generations and today offers well-paying jobs—often the best opportunities in more rural areas—coal negatively affects human health and the environment at every point in its life cycle: when it is mined, processed, transported, burned, and discarded (Freese, Clemmer, and Nogee 2008). Local communities— often low-income communities and/or communities of color—have for decades borne the brunt of these negative impacts, including air pollution, water pollution, and work- place injuries, illnesses, and fatalities.


2021 ◽  
Author(s):  

Abstract C. abietis is a microcyclic rust fungus; an obligate parasite completing its life cycle on species of Picea (spruce). Only the current year's needles of Picea are infected and those needles are shed early. Reported from northern Europe and Asia, the fungus is a Regulated Pest for the USA. It is absent from North America, where susceptible species are native, and Australia and New Zealand, where they are introduced. Although usually not a significant problem in its native range, because conditions are not favourable for heavy infections every year (Smith et al., 1988; Hansen, 1997), this rust could be more damaging as an invasive in other temperate areas. Due to the fact that small amounts of infection may be overlooked, accidental introduction could occur through importation of infected seedlings or young trees.


Sign in / Sign up

Export Citation Format

Share Document