Natal pterylosis of the northwestern crow, Corvus caurinus

1991 ◽  
Vol 69 (6) ◽  
pp. 1534-1537 ◽  
Author(s):  
Nicolaas A. M. Verbeek
Keyword(s):  
British Columbia ◽  
The Body ◽  
Strait Of Georgia ◽  
Corvus Caurinus ◽  
Northwestern Crow

The number of natal down feathers (neossoptiles) and their arrangement in specific feather tracts of the body (pterylosis) are given for 19 nestlings of the northwestern crow, Corvus caurinus, from the Strait of Georgia, British Columbia. The natal pterylosis of the northwestern crow is compared with that of other members of the genus Corvus in the Nearctic and Palearctic regions. This comparison points out several differences in the capital, abdominal, and caudal tracts within the genus.

A Quantitative Study of Economically Important Parasites of Walleye Pollock (Theragra chalcogramma) from British Columbian Waters and Effects of Postmortem Handling on Their Abundance in the Musculature

1982 ◽  
Vol 39 (5) ◽  
pp. 710-726 ◽  
Author(s):  
J. R. Arthur ◽  
L. Margolis ◽  
D. J. Whitaker ◽  
T. E. McDonald
Keyword(s):  
British Columbia ◽  
Body Cavity ◽  
Walleye Pollock ◽  
The Body ◽  
Anisakis Simplex ◽  
Theragra Chalcogramma ◽  
Strait Of Georgia ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Type Larva ◽  
Hysterothylacium Aduncum

The identity of parasites infecting the musculature and body cavity (including external surfaces of viscera) of walleye pollock (Theragra chalcogramma) collected from two British Columbian localities, their distribution within the host's musculature, and the influence of host sex, length, and method of postmortem handling on parasite prevalence and abundance were determined. Three parasite species were found only in the musculature (Pleistophora sp., pseudophyllidean plerocercoids, and Phocanema decipiens (Krabbe, 1878) larva), two species only in the body cavity (Contracaecum-type larva and Hysterothylacium aduncum (Rudolphi, 1802) larva), and two species in both sites (Anisakis simplex (Rudolphi, 1809) larva and Nybelinia surmenicola Okada in Dollfus, 1929 plerocercoid). In the musculature most A. simplex and N. surmenicola infected the region surrounding the body cavity, with A. simplex being distributed more anteriorly, while most pseudophyllidean plerocercoids occurred in the caudal region. No preferred site of infection was observed for P. decipiens larvae. No statistically significant differences in infection with any of these helminths occurred between right and left body musculature. For pollock of similar lengths, males were more heavily infected than females with larvae of A. simplex and plerocercoids of N. surmenicola. Three species (A. simplex, N. surmenicola, and Pleistophora sp.) occurred with greater prevalence or abundance in larger fish. Storage of eviscerated and round pollock from the Strait of Georgia on ice at 3 °C for periods of up to 7 d did not result in any significant change in the prevalence of infection or abundance of parasites in the musculature. The abundance of these parasites in pollock from Queen Charlotte Sound, northern British Columbia, appears similar to that previously reported for some other areas of the North Pacific Ocean (although not as high as the most heavily infected stocks of the northwest Pacific) while their abundance in fish from the Strait of Georgia, southern British Columbia, appears to be the lowest for any pollock stock examined.Key words: walleye pollock, Theragra chalcogramma; economically important parasites, Pleistophora sp., pseudophyllidean plerocercoids, Nybelinia surmenicola plerocercoid, Phocanema decipiens larva, Contracaecum-type larva, Hysterothylacium aduncum larva, Anisakis simplex larva, British Columbia

COOPERATIVE BREEDING OF THE NORTHWESTERN CROW CORVUS CAURINUS IN BRITISH COLUMBIA

Ibis ◽  
2008 ◽  
Vol 123 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Nicolaas A. M. Verbeek ◽  
Robert W. Butler
Keyword(s):  
British Columbia ◽  
Cooperative Breeding ◽  
Corvus Caurinus ◽  
Northwestern Crow

Clam storage in a Northwestern Crow (Corvus caurinus): dispersion and sequencing

1985 ◽  
Vol 63 (4) ◽  
pp. 857-860 ◽  
Author(s):  
Paul C. James ◽  
Nicolaas A. M. Verbeek
Keyword(s):  
Experimental Study ◽  
British Columbia ◽  
Nearest Neighbour ◽  
Recovery Sequence ◽  
Neighbour Distance ◽  
Corvus Caurinus ◽  
Northwestern Crow ◽  
Very High ◽  
Sequence Position ◽  
Made In

An experimental study of clam storage by a Northwestern Crow (Corvus caurinus) was carried out on Mitlenatch Island, British Columbia, Canada. The crow was trained to take clams from a feeding table. His dispersion of the clams was studied using nearest-neighbour distance (NND). The distance clams were carried and the sequence of storage and recovery was also quantified. Median NND was significantly correlated with storage sequence position, as was NND with distance carried. The crow tended to recover the clams in the same order as he stored them, as storage sequence position was significantly correlated with recovery sequence position. The results were compared with other spatiotemporal studies of avian food hoarding. Recovery success of the crow was very high, he appeared to use memory to relocate his caches, as the majority of them were made in new sites, and he never revisited those already emptied.

scholarly journals Upper-crustal structure beneath the Strait of Georgia, Southwest British Columbia

2007 ◽  
Vol 170 (2) ◽  
pp. 800-812 ◽  
Author(s):  
R. K. Dash ◽  
G. D. Spence ◽  
M. Riedel ◽  
R. D. Hyndman ◽  
T. M. Brocher
Keyword(s):  
British Columbia ◽  
Crustal Structure ◽  
Strait Of Georgia

Characterizing spatial structures of larval fish assemblages at multiple scales in relation to environmental heterogeneity in the Strait of Georgia (British Columbia, Canada)

2018 ◽  
Vol 75 (11) ◽  
pp. 1902-1914 ◽  
Author(s):  
Lu Guan ◽  
John F. Dower ◽  
Pierre Pepin
Keyword(s):  
British Columbia ◽  
Environmental Heterogeneity ◽  
Multiple Scales ◽  
Larval Fish ◽  
Critical Role ◽  
Multiscale Approach ◽  
Spatial Structures ◽  
Strait Of Georgia ◽  
Medium Scale

Spatial structures of larval fish in the Strait of Georgia (British Columbia, Canada) were quantified in the springs of 2009 and 2010 to investigate linkages to environmental heterogeneity at multiple scales. By applying a multiscale approach, principal coordinate neighborhood matrices, spatial variability was decomposed into three predefined scale categories: broad scale (>40 km), medium scale (20∼40 km), and fine scale (<20 km). Spatial variations in larval density of the three dominant fish taxa with different early life histories (Pacific herring (Clupea pallasii), Pacific hake (Merluccius productus), and northern smoothtongue (Leuroglossus schmidti)) were mainly structured at broad and medium scales, with scale-dependent associations with environmental descriptors varying interannually and among species. Larval distributions in the central-southern Strait were mainly associated with salinity, temperature, and vertical stability of the top 50 m of the water column on the medium scale. Our results emphasize the critical role of local estuarine circulation, especially at medium spatial scale, in structuring hierarchical spatial distributions of fish larvae in the Strait of Georgia and suggest the role of fundamental differences in life-history traits in influencing the formation and maintenance of larval spatial structures.

Factors influencing the distribution of Egregia menziesii (Phaeophyta, Laminariales) in British Columbia, Canada

1978 ◽  
Vol 56 (9) ◽  
pp. 1198-1205 ◽  
Author(s):  
D. K. Gordon ◽  
R. E. DE Wreede
Keyword(s):  
British Columbia ◽  
High Temperature ◽  
Laboratory Experiments ◽  
Algal Flora ◽  
The West ◽  
Common Component ◽  
Strait Of Georgia ◽  
Low Salinity ◽  
Factors Influencing ◽  
Juan De Fuca

Egregia menziesii (Turner) Areschoug is a common component of the algal flora along the west coast of Vancouver Island, Queen Charlotte Strait, and the Strait of Juan de Fuca but is absent from the Strait of Georgia in British Columbia, Canada. This distribution pattern was found to be correlated with temperature and salinity in that E. menziesii is not present in areas where there are seasonal periods of low salinity and high temperature. To test this correlation, field transplants of sporophytes and laboratory experiments with sporophytes and culture work were carried out. The results suggest that the distribution of E. menziesii is limited by specific combinations of salinity and temperature; it requires high salinities and temperatures less than 15 °C for its survival.

Some Morphological Differences Between the Subspecies of Cutthroat Trout, Salmo clarkii clarkii and Salmo clarkii lewisi, in British Columbia

1959 ◽  
Vol 16 (6) ◽  
pp. 903-922 ◽  
Author(s):  
S. U. Qadri
Keyword(s):  
British Columbia ◽  
Lateral Line ◽  
Cutthroat Trout ◽  
Complete Separation ◽  
The Body ◽  
Natural Distribution ◽  
Spot Number ◽  
Coastal Cutthroat Trout ◽  
Morphological Differences ◽  
Coastal British Columbia

Coastal cutthroat trout, S. c. clarkii Richardson, occupy most lakes and streams of coastal British Columbia, including the adjacent islands. Yellowstone cutthroat, S. c. lewisi (Girard), occupy southeastern British Columbia; their range is separated from that of the coastal subspecies by a zone lacking cutthroat trout. A map showing all natural distribution records in the province is presented. From 60 to 146 specimens were examined for distinguishing characters. Spots below the lateral line are more numerous towards the anterior end in S. c. clarkii, but more numerous towards the posterior end in S. c. lewisi. A plot of spot number in selected areas of the body provides almost complete separation of individuals of the two subspecies. Significant differences also occur in certain scale counts and in body and peduncle depth, although these characters overlap considerably between the subspecies. No difference was found in vertebral count.

Sign in / Sign up

Export Citation Format

Share Document