Evidence for Attacks by the Bathypelagic Fish Anotopterus pharao (Myctophiformes) on Pacific Salmon (Oncorhynchus spp.)

1991 ◽  
Vol 48 (12) ◽  
pp. 2403-2407 ◽  
Author(s):  
D. W. Welch ◽  
L. Margolis ◽  
M. A. Henderson ◽  
S. McKinnell

Adult Pacific salmon (Oncorhynchus spp.) returning from offshore waters to spawn frequently bear a wide range of wounds and scars. One of the most common wounds is a single slash mark on the posterior third of one side of the body, running posteroventrally from near the dorsal fin at a roughly 45° angle. The evidence is reviewed for the occurrence of slash-marked salmon around the Pacific Rim over the past 30 yr. A jaw fragment removed from the wound of a slash-marked sockeye salmon (O. nerka) and identified as belonging to a daggertooth (Anotopterus pharao: order Myctophiformes), a highly modified bathypelagic fish, provides the first direct evidence for the cause of these wounds. Given the frequency of slash-marked adult salmon in coastal fisheries, A. pharao may be a significant cause of mortality in Pacific salmon that has previously gone unrecognized.

1962 ◽  
Vol 40 (7) ◽  
pp. 919-927 ◽  
Author(s):  
H. Tsuyuki ◽  
E. Roberts ◽  
R. E. A. Gadd

The muscle myogens and other components of the spring salmon (O. tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), and sockeye salmon (O. nerka), as well as the lingcod (Ophiodon elongatus), were separated by the use of diethylaminoethyl (DEAE) cellulose columns. Significant amounts of slowly dialyzable inosine and inosinic acid which may lead to spurious peaks in moving-boundary electrophoretic separations have been shown to be present in the muscle myogen preparations. The basic differences in the muscle myogen components of the Pacific salmon and the lingcod are compared.


1963 ◽  
Vol 41 (4) ◽  
pp. 875-887 ◽  
Author(s):  
D. R. Idler ◽  
B. Truscott ◽  
H. C. Freeman ◽  
V. Chang ◽  
P. J. Schmidt ◽  
...  

Intra-arterially injected cortisone-4-C14 and cortisol-4-C14 were cleared from the plasma of sexually mature and spawned sockeye salmon (O. nerka) at a much slower rate than from the plasma of immature sockeye and spawned Atlantic salmon (S. salar). The results explain the elevated hormone levels found in the blood of mature and spawned sockeye salmon. The normal clearance rate found with Atlantic salmon, which frequently survive spawning, would indicate that the impaired hormone metabolism was associated with the imminent death of the Pacific salmon rather than with the act of spawning.Testosterone and 17α-hydroxyprogesterone were found to be precursors of 11-ketotestosterone, a sex hormone found in high concentrations in the blood of mature sockeye salmon. Testosterone was also formed in vivo from 17α-hydroxyprogesterone. The results suggest more than one pathway for the synthesis of 11-ketotestosterone in salmon. Cortisol was converted to cortisone but no conversion of the former to 11-ketotestosterone could be demonstrated.


1963 ◽  
Vol 41 (1) ◽  
pp. 875-887
Author(s):  
D. R. Idler ◽  
B. Truscott ◽  
H. C. Freeman ◽  
V. Chang ◽  
P. J. Schmidt ◽  
...  

Intra-arterially injected cortisone-4-C14 and cortisol-4-C14 were cleared from the plasma of sexually mature and spawned sockeye salmon (O. nerka) at a much slower rate than from the plasma of immature sockeye and spawned Atlantic salmon (S. salar). The results explain the elevated hormone levels found in the blood of mature and spawned sockeye salmon. The normal clearance rate found with Atlantic salmon, which frequently survive spawning, would indicate that the impaired hormone metabolism was associated with the imminent death of the Pacific salmon rather than with the act of spawning.Testosterone and 17α-hydroxyprogesterone were found to be precursors of 11-ketotestosterone, a sex hormone found in high concentrations in the blood of mature sockeye salmon. Testosterone was also formed in vivo from 17α-hydroxyprogesterone. The results suggest more than one pathway for the synthesis of 11-ketotestosterone in salmon. Cortisol was converted to cortisone but no conversion of the former to 11-ketotestosterone could be demonstrated.


2020 ◽  
Vol 32 (2) ◽  
pp. 213-221 ◽  
Author(s):  
J. Scott Weese

Clostridium ( Clostridioides) difficile is a gram-positive, spore-forming bacterium that is an important cause of disease in people, a variably important cause of disease in some animal species, and an apparently harmless commensal in others. Regardless of whether it is a known pathogen in a particular species, it can also be found in healthy individuals, sometimes at high prevalences and typically with higher rates of carriage in young individuals. As it is investigated in more animal species, it is apparent that this bacterium is widely disseminated in a diverse range of domestic and wild animal species. Although it can be found in most species in which investigations have been performed, there are pronounced intra- and inter-species differences in prevalence and clinical relevance. A wide range of strains can be identified, some that appear to be animal associated and others that are found in humans and animals. A large percentage of strains that cause disease in people can at least sporadically be found in animals. It is a potentially important zoonotic pathogen, but there is limited direct evidence of animal–human transmission. Although C. difficile has been studied extensively over the past few decades, it remains an enigmatic organism in many ways.


Author(s):  
HyeJoo Ro ◽  
Jennifer H. Stern ◽  
Aaron J. Wirsing ◽  
Thomas P. Quinn

Brown bears Ursus arctos consume a wide range of organisms, including ungulates and plants, but Pacific salmon Oncorhynchus spp. are especially important to their diet where their ranges overlap. Although some bears minimize antagonistic encounters with other bears or infanticide by avoiding streams where salmon spawn, studies generally assume that bears with ready access to salmon feed heavily on them. To test this assumption, and the hypothesis that male bears would feed more heavily on salmon than females (owing to their sexual size dimorphism), we collected hair samples from brown bears using barbed wire on six small tributaries of Lake Aleknagik, Alaska where adult sockeye salmon O. nerka are readily accessible and frequently consumed by bears. Analysis of DNA distinguished among the different bears leaving the hair samples, some of which were sampled multiple times within and among years. We assessed the contribution of salmon to the diet of individual bears using carbon and nitrogen stable isotope signatures. The 77 samples analyzed, from 31 different bears over four years, showed isotopic ratios consistent with reliance on salmon, but the wide range of isotopic signatures included values suggesting variable, and in one case considerable, use of terrestrial resources. Stable isotope signatures did not differ between male and female bears, nor did they differ between two sides of the lake, despite marked differences in sockeye salmon density. The hair samples were collected when salmon were present, so there was some uncertainty regarding whether they reflected feeding during the current or previous season. Notwithstanding this caveat, the results are consistent with the hypothesis that salmon were sufficiently available to provide food for the bears, and that the considerable isotopic variation among bears with access to salmon reflected their age, status, and behavior.


2020 ◽  
Vol 200 (2) ◽  
pp. 270-291
Author(s):  
E. A. Shevlyakov ◽  
S. V. Shubkin

Aerial survey of the pacific salmon spawning grounds was conducted in the water bodies of Chukotka belonged to the Bering Sea basin (the Anadyr, Velikaya, Tumanskaya Rivers and Meinypilgyno lake-river system) in 2019, for the first time since 1992. Total flight time was 35 hours, approximate length of the transects was 3,800 km. Number of the spawners was estimated as 660.7 . 103 ind. for chum salmon, 112.2 . 103 ind. for sockeye salmon, and 3678.0 . 103 ind. for pink salmon, features of their distribution are described.


1936 ◽  
Vol 32 (10) ◽  
pp. 1240-1250
Author(s):  
V. K. Trutnev

Over the past decades, the problem of nasal breathing has attracted the attention of a wide range of researchers.


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