Grazing Rates and Food Selection in Diaptomus oregonensis (Copepoda) from Marion Lake, British Columbia

1970 ◽  
Vol 27 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Donald J. McQueen
Keyword(s):  
British Columbia ◽  
Cell Volume ◽  
Food Source ◽  
Size Range ◽  
Cell Concentration ◽  
Food Selection ◽  
Ingestion Rates ◽  
Diaptomus Oregonensis ◽  
Natural Phytoplankton

The filtration and ingestion rates of Diaptomus oregonensis females and stage V copepodids were examined in three experimental situations. When unialgal cultures of 20,000 cells per milliliter were offered to D. oregonensis the filtration rates remained constant for cells ranging from 120 to 10,000 µ3. When a mixture of diatoms was offered the animals did not filter cells ranging from 1 to 60 µ3 despite the fact that the cells in this size range were concentrated at about 20,000 per milliliter. When natural phytoplankton from Marion Lake was used as a food source, the filtration rates were low for cells smaller than 100 µ3, increased to a maximum of 12.9 ml per animal per day for cells ranging from 102 to 333 µ3, and remained constant with increased cell volume and decreased cell concentration. Several species of Cyclotella and Merismopedia were not removed from the Marion Lake plankton by D. oregonensis.

scholarly journals Bald Eagles, Haliaeetus leucocephalus, Feeding on Spawning Plainfin Midshipman, Porichthys notatus, at Crescent Beach, British Columbia

2003 ◽  
Vol 117 (4) ◽  
pp. 601 ◽  
Author(s):  
Kyle Hamish Elliott ◽  
Christina L. Struik ◽  
John E. Elliott
Keyword(s):  
British Columbia ◽  
Nous Avons ◽  
Food Source ◽  
Haliaeetus Leucocephalus ◽  
Potential Importance ◽  
Bald Eagles ◽  
Porichthys Notatus ◽  
Tide Height ◽  
Consumption Rates ◽  
Plainfin Midshipman

We observed Bald Eagles feeding on Plainfin Midshipman near Crescent Beach, British Columbia, in May and June 2001 and 2002. We quantified consumption rates and eagle numbers during this period, illustrating the potential importance of this food source to breeding eagles. Tide height was the only significant factor influencing consumption rates, likely because this variable reflected the availability of midshipman prey.Nous avons observé les Pygargues à tête blanche alimenter sur les Crapauds à nageoire unie près de Crescent Beach, Colombie-Britannique, en maie et juin 2001 et 2002. Nous avons mesuré les cadences de consommation et les nombres de pygargues pendant cette période, illustrant l’importance potentielle de cette source de nourriture pour les aigles. La taille de marée était le seul facteur significatif influençant les cadences de consommation et les nombres de pygargues pendant la période d’étude, probablement parce que cette variable a reflété la disponibilité des crapauds.

The Effect of cell concentration on colony growth and feeding in the bryozoanCelleporella hyalina

1993 ◽  
Vol 73 (2) ◽  
pp. 321-331 ◽  
Author(s):  
E. Hunter ◽  
R. N. Hughes
Keyword(s):  
Food Supply ◽  
Cell Concentration ◽  
Colony Growth ◽  
High Cell ◽  
Ingestion Rates ◽  
Male Investment ◽  
Specific Behaviour ◽  
Food Particles ◽  
Cell Concentrations ◽  
Female Investment

The effects of cell concentration on colony growth and feeding behaviour were investigated in the polymorphic marine bryozoanCelleporella hyalina(Bryozoa: Cheilostomata) under controlled, laboratory conditions. We compared the relative zooidal composition of colonies cultured onRhodomonas baltica(Karsten) for seven weeks at 18°C. We observed the pharynx of active lophophores on sudden exposure to high cell concentrations, and recorded the length of feeding episodes and ingestion rates.Colonies grew, reproduced and produced viable larvae at all levels of food supply, but performed optimally at 50–100 cells µl-1. Cell concentration influenced somatic parameters more than sexual, the latter being more closely associated with genotype. Relative somatic investment was greatest at 10 cells µl-1and least at 50 cells µl-1. The frequency of ovicells containing larvae remained at about 74% irrespective of food supply. Basal male investment was greatest at 10 cell µl-1, frontal male investment at 50 cells µl-1, and female investment at 100 cells µl-1.Cell ingestion rates of previously starved zooids increased as a function of cell concentration, with an inverse relationship between length of feeding episode and concentration. Food particles were drawn from below the lophophore by lateral cilia, ciliary reversal brought them over the mouth, and ingestion then resulted from a pharyngeal current. These results suggest that, on exposure to high cell concentrations, bryozoans may exhibit specific behaviour.

The cottonwood mushroom (Tricholoma populinum): a food resource of the Interior Salish Indian peoples of British Columbia

1987 ◽  
Vol 65 (5) ◽  
pp. 921-927 ◽  
Author(s):  
Nancy J. Turner ◽  
Harriet V. Kuhnlein ◽  
Keith N. Egger
Keyword(s):  
British Columbia ◽  
Food Source ◽  
Food Resource ◽  
Edible Mushroom ◽  
Native People ◽  
Important Food ◽  
Mushroom Species ◽  
Important Food Source ◽  
Interior Salish ◽  
First Time

Tricholoma populinum Lange is identified for the first time as one of the edible mushroom species traditionally eaten by Interior Salish Indian peoples of British Columbia. A description of this species is given, and harvesting and preparation information is provided based on its use by contemporary Native people. Nutrient composition data are also reported. This mushroom continues to be an important food source for some Native people in British Columbia.

Predation by the naticid gastropod Polinices lewisii (Gould) on littleneck clams Protothaca staminea (Conrad) in British Columbia

1994 ◽  
Vol 72 (2) ◽  
pp. 319-325 ◽  
Author(s):  
Eija Peitso ◽  
Elizabeth Hui ◽  
Brian Hartwick ◽  
Neil Bourne
Keyword(s):  
British Columbia ◽  
Field Experiments ◽  
Size Range ◽  
Prey Size ◽  
Dry Mass ◽  
Feeding Rates ◽  
Close Proximity ◽  
Protothaca Staminea ◽  
A Minor ◽  
Selection Of

Feeding rates and prey-size selection of the predatory naticid snail Polinices lewisii (Gould) on the littleneck clam Protothaca staminea (Conrad) were studied on the west coast of British Columbia. Caging experiments indicated that few clams of the smallest size class (10–35 mm shell length) were drilled by Polinices lewisii; predation was heaviest on clams in the size range 35–50 mm. Feeding rates of P. lewisii did not vary significantly over the range of densities provided in field experiments, nor were they influenced by the close proximity of other moon snails. Feeding rates were relatively low. Summer feeding rates of P. lewisii indicated a correlation with respect to snail size, and results from the annual study indicated a seasonal trend towards reduced consumption during the winter months. Polinices lewisii, feeding on P. staminea, was estimated to eat 0.1% of its own dry mass per day. Information from recovered shells of drilled clams showed that the diameter of boreholes was correlated with snail length but only poorly correlated with shell thickness. Boreholes on valves of P. staminea were found mainly in the umbo region. No strong preference for either left or right valve was observed. Random sampling of field populations indicated that prédation by P. lewisii was a minor source of mortality in P. staminea populations at Ladysmith Harbour, British Columbia, Canada.

scholarly journals Impact of the rust Puccinia linkii on Highbush Cranberry, Viburnum edule, near Smithers, British Columbia

2013 ◽  
Vol 127 (3) ◽  
pp. 270 ◽  
Author(s):  
Kiri Daust
Keyword(s):  
British Columbia ◽  
Rural Areas ◽  
Food Source ◽  
Leaf Tissue ◽  
Dead Leaf ◽  
Important Food ◽  
Important Food Source ◽  
Ecological Importance ◽  
The Impact

The berries of Highbush Cranberry (Viburnum edule) are an important food source for wildlife and for people in rural areas. In 2012 and 2013, many Highbush Cranberry plants in northwestern British Columbia were unusually severely infected by the rust Puccinia linkii, with telia covering up to half of each leaf. Given the ecological importance of the overwintering berries, I studied the impact of the infection on the production and quality of berries in mixed forests near Smithers, British Columbia. Sites where Highbush Cranberry bushes were infected with the rust had significantly more undeveloped berries. Plants from sites with higher levels of infection produced berries with significantly less sugar. Dead leaf tissue was also significantly more prevalent in infected plants. This study provides evidence that Puccinia linkii may stress plants, leading to reduced quality and quantity of berries, especially if the severity of the infection increases with the increasingly moist springs that are projected for the region.

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