Distribution of FMRFamide-like immunoreactivity in the brain, retina and nervus terminalis of the sockeye salmon parr, Oncorhynchus nerka

1990 ◽  
Vol 261 (3) ◽  
pp. 403-418 ◽  
Author(s):  
Thomas �stholm ◽  
Peter Ekstr�m ◽  
Sven O. E. Ebbesson
1993 ◽  
Vol 71 (6) ◽  
pp. 1207-1211 ◽  
Author(s):  
M. L. Kent ◽  
D. J. Whitaker ◽  
L. Margolis

Laboratory transmission studies were conducted on Myxobolus arcticus, a myxosporean that infects the brain of Pacific salmon (Oncorhynchus spp.). Attempts at transmission from fish to fish with spores of M. arcticus from sockeye salmon (Oncorhynchus nerka), including experiments with spores aged for up to 9 months in sterilized mud, were unsuccessful. Transmission was achieved when hatchery-reared (in well water) sockeye salmon fry were exposed to the oligochaete Stylodrilus heringianus collected from a lake where M. arcticus infections are common in this fish. All experimental fish exhibited the infection when examined 3 –4 months after exposure. Of 23 sockeye salmon fry exposed to triactinomyxon spores collected from naturally infected S. heringianus, 21 were found to be infected with M. arcticus spores when examined after 3 months. Thus, the life cycle of M. arcticus involves transformation into a triactinomyxon stage in S. heringianus. Alternate development of myxosporeans in aquatic oligochaetes has been established or implicated for nine other species of myxosporeans belonging to three families, but this is the first report of alternate development in a lumbriculid worm.


1998 ◽  
Vol 292 (2) ◽  
pp. 267-273 ◽  
Author(s):  
M. Amano ◽  
Moto-oki Ashihara ◽  
Yasutoshi Yoshiura ◽  
Shoji Kitamura ◽  
Kazumasa Ikuta ◽  
...  

1955 ◽  
Vol 12 (1) ◽  
pp. 178-185 ◽  
Author(s):  
William S. Hoar

Light sensitivity of the sockeye salmon smolt (Oncorhynchus nerka) is dependent upon the pineal organ as well as the eyes. Destruction of the pineal area of the brain affects the distribution of pigment in the chromatophores and the phototactic response of the fish.


Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  

1967 ◽  
Vol 45 (1) ◽  
pp. 117-126 ◽  
Author(s):  
M. A. Hafeez ◽  
P. Ford

The morphohistology and some histochemical aspects of the pineal organ in the sockeye salmon were studied. The distal part of the organ lies in a pineal fossa in the cranial roof. Photosensory cells and two kinds of ependymal supporting cells are present throughout its epithelium, which is entirely devoid of either melanin or lipofuchsin. Besides sensory nerve fibers, efferent end-loops are present on the photosensory as well as the supporting cells. The dorsal pineal nerve tract probably contains both sensory and efferent fibers. The apocrine secretion of sensory as well as some supporting cells is probably associated with either the maintenance of a constant chemical composition of the cerebrospinal fluid or with supply of certain chemical substances to the brain tissue. The secretion in the pineal and the subcommissural organ consists of glycogen, mucopolysaccharides, mucoproteins, and aldehyde fuchsin positive granules.It is proposed that the pineal organ is photosensory as well as secretory and that its photosensitivity might be of some significance in the light-dependent behavior of this species in terms of intensity detection.


1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.


2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds

2015 ◽  
Vol 87 (1) ◽  
pp. 169-178 ◽  
Author(s):  
C. Freshwater ◽  
M. Trudel ◽  
T. D. Beacham ◽  
C.-E. Neville ◽  
S. Tucker ◽  
...  

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