Details:

Journal Title:
Integrative And Comparative Biology
Personal Author:
Ward, Russell H ; Quinn, Thomas P ; Dittman, Andrew H ; Yopak, Kara E
Ward, Russell H ; Quinn, Thomas P ; Dittman, Andrew H ; Yopak, Kara E Less -
NOAA Program & Office:
NMFS (National Marine Fisheries Service) ; NWFSC (Northwest Fisheries Science Center)
NMFS (National Marine Fisheries Service) ; NWFSC (Northwest Fisheries Science Center) Less -
Description:
Pacific salmon (Oncorhynchus spp.) hatch and feed in freshwater habitats, migrate to sea to mature, and return to spawn at natal sites. The final, riverine stages of the return migrations are mediated by chemical properties of the natal stream that they learned as juveniles. Like some other fish, salmon growth is asymptotic; they grow continuously throughout life toward a maximum size. The continued growth of the nervous system may be plastic in response to environmental variables. Due to the ecological, cultural, and economic importance of Pacific salmon, individuals are often reared in hatcheries and released into the wild as juveniles to supplement natural populations. However, hatchery-reared individuals display lower survivorship and may also stray (i.e., spawn in a non-natal stream) at higher rates than their wild counterparts. Hatchery environments may lack stimuli needed to promote normal development of the nervous system, thus leading to behavioral deficits and a higher incidence of straying. This study compared the peripheral olfactory system and brain organization of hatchery-reared and wild-origin sockeye salmon fry (Oncorhynchus nerka). Surface area of the olfactory rosette, diameter of the olfactory nerve, total brain size, and size of major brain regions were measured from histological sections and compared between wild and hatchery-origin individuals. Hatchery-origin fish had significantly larger optic tecta, and marginally insignificant, yet noteworthy trends, existed in the valvula cerebelli (hatchery > wild) and olfactory bulbs (hatchery < wild). We also found a putative difference in olfactory nerve diameter (dmin) (hatchery > wild), but the validity of this finding needs further analyses with higher resolution methods. Overall, these results provide insight into the potential effects of hatchery rearing on nervous system development in salmonids, and may explain behavioral deficits displayed by hatchery-origin individuals post-release.
Keywords:
[+]
Animal Science And Zoology Plant Science
Source:
Integrative And Comparative Biology (2024)
DOI:
https://doi.org/10.1093/icb/icae002
ISSN:
1540-7063;1557-7023;
Format:
PDF
Publisher:
Oxford University Press (OUP)
Document Type:
Journal Article
Rights Information:
Other
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:12295e9a56c526b4a2d34e56257d875cdad2749b6848b83ce714d82890fd1db0
Download URL:
https://repository.library.noaa.gov/view/noaa/60775/noaa_60775_DS1.pdf
File Type:

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