Amino acid cues emanating from Pacific salmon eggs and ovarian fluid

2020 ◽  
Vol 97 (5) ◽  
pp. 1408-1414
Author(s):  
Andrew H. Dittman ◽  
Thomas P. Quinn
2005 ◽  
Vol 119 (2) ◽  
pp. 202 ◽  
Author(s):  
K. S. Christie ◽  
T. E. Reimchen

On the Pacific coast of North America, the most abundant vertebrate visitors to estuaries and rivers during salmon migration are gulls, yet the utilization of salmon nutrients by these scavengers, and subsequent ecological impacts are not well documented. On two forested watersheds on the central coast of British Columbia, we tracked gull abundance during the spawning period for two consecutive years, and estimated consumption of post-reproductive salmon carcasses and eggs, as well as guano production. At Clatse River, gulls (Larus glaucescens, L. argentatus, L. thayerii, L. californicus, L. canus, L. philadelphia) consumed 13-26% of total salmon carcass biomass and 29-36% of all salmon eggs deposited in the system. At Neekas River, gulls consumed 11-19% of salmon carcass biomass and 7-18% of total salmon eggs. Local guano production over the 60-day period ranged from 600 kg to 1190 kg at Clatse and from 1200 kg to 2100 kg at Neekas River, and was distributed to marine, estuarine, freshwater and riparian habitats. The large aggregations of gulls and subsequent nutrient cycling observed on our study watersheds may represent a once widespread phenomenon that is now largely reduced due to recent declines in salmon populations.


2010 ◽  
Vol 67 (12) ◽  
pp. 2052-2054 ◽  
Author(s):  
Jonathan B. Armstrong

In their recent article, “Egg consumption in mature Pacific salmon ( Oncorhynchus spp.)” (Can. J. Fish. Aquat. Sci. 66(9): 1546–1553), Garner et al. observed salmon eggs in the stomach contents of mature Chinook, coho, and chum salmon. Through experimentation and simulation of salmon energetics, the authors conclude that the observed feeding represents an important gain in energy, challenging the accepted paradigm that assumes salmon energy budgets contain no gains once adults return to freshwater. Here, I argue that Garner et al. have overestimated the energetic consequence of egg consumption and that the observed consumption rates do not represent biologically significant gains in energy.


1998 ◽  
Vol 76 (3) ◽  
pp. 405-413 ◽  
Author(s):  
Andrew H Dittman ◽  
Gayle S Brown ◽  
Chris J Foote

Egg predation by coastrange sculpins (Cottus aleuticus) and slimy sculpins (C. cognatus) may be a major factor affecting sockeye salmon (Oncorhynchus nerka) production in Iliamna Lake, Alaska. In this study, we examined the potential roles of visual and chemosensory cues in egg predation by sculpins. A field study tested whether sculpins were differentially attracted to minnow traps baited with eggs that were (i) visible with no odours present, (ii) visible with odours present, or (iii) not visible with odours present. Our results indicated that sculpins do not require visual cues for detecting salmon eggs. However, attraction to sockeye eggs did require chemical cues emanating from the eggs. To characterize the chemical attractants that emanate from salmon eggs, we tested whether sculpins were attracted to test odours in a two-choice maze. Test odours were prepared by soaking eggs in lake water. Sculpins preferred egg wash to lake water but demonstrated no attraction to ovarian fluid versus lake water, suggesting that the attractive substances are derived directly from egg material. These results are discussed in relation to the known sensory mechanisms involved in feeding by sculpins as well as to the ecological relationship between spawning sockeye salmon and sculpins.


2009 ◽  
Vol 35 (4) ◽  
pp. 630-633 ◽  
Author(s):  
James H. Johnson ◽  
Christopher C. Nack ◽  
Marc A. Chalupnicki

2018 ◽  
Vol 75 (4) ◽  
pp. 538-548 ◽  
Author(s):  
Brandon S. Gerig ◽  
David N. Weber ◽  
Dominic T. Chaloner ◽  
Lillian M. McGill ◽  
Gary A. Lamberti

Pacific salmon (Oncoryhnchus spp.) and brown trout (Salmo trutta) are introduced species stocked in the Laurentian Great Lakes. In their native range, salmon deliver material that enhances growth, alters isotopic ratios, and increases contaminant burdens of resident fish. However, whether salmon subsidies mediate interactions between competing species is unknown. Here, we employed a mesocosm experiment and a simulation model to determine if salmon tissue consumption influences brook trout (Salvelinus fontinalis) growth, isotopic ratios, and mercury concentrations and whether these were modified by brown trout. Our results indicate that brook trout growth did not increase with provision of salmon tissue and was not reduced by brown trout. However, brook trout exhibited isotopic enrichment and increased mercury concentrations, suggesting dietary intake of salmon tissue. Because salmon eggs have a higher energy density and lower mercury concentration compared with salmon tissue, our simulation model suggests that consumption of salmon eggs rather than tissue can increase growth while reducing mercury accumulation. Overall, our results suggest that the role of introduced Pacific salmon is dependent on both food quantity and quality along with diet contaminant concentrations.


1954 ◽  
Vol 53 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Harry L. Seagran ◽  
David E. Morey ◽  
John A. Dassow

Author(s):  
M.K. Lamvik ◽  
L.L. Klatt

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.


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