"The Success of Captive Broodstock Programs Depends on High In-Culture Survival, ..." [from the Abstract], 2006-2007 Progress Report.
- National Marine Fisheries Service
The success of captive broodstock programs depends on high in-culture survival, appropriate development of the reproductive system, and the behavior and survival of cultured salmon after release, either as adults or juveniles. Continuing captive broodstock research designed to improve technology is being conducted to cover all major life history stages of Pacific salmon. Accomplishments detailed in this report are listed below by major objective. Objective 1: This study documented that captively reared Chinook exhibited spawn timing similar to their founder anadromous population. An analysis of spawn timing data of captively reared Chinook salmon that had received different levels of antibiotic treatment did not suggest that antibiotic treatments during the freshwater or seawater phase of the life cycle affects final maturation timing. No effect of rearing density was found with respect to spawn timing or other reproductive behaviors. Objective 2: This study investigated the critical period(s) for imprinting for sockeye salmon by exposing juvenile salmon to known odorants at key developmental stages. Molecular assessments of imprinting-induced changes in odorant receptor gene expression indicated that regulation of odorant expression differs between coho and sockeye salmon. While temporal patterns differ between these species, exposure to arginine elicited increases in odorant receptor mRNA expression in sockeye salmon. Objective 3: This study: (i) identified the critical period when maturation is initiated in male spring Chinook salmon and when body growth affects onset of puberty, (ii) described changes in the reproductive endocrine system during onset of puberty and throughout spermatogenesis in male spring Chinook salmon, (iii) found that the rate of oocyte development prior to vitellogenesis is related to body growth in female spring Chinook, and (iv) demonstrated that growth regimes which reduce early (age 2) male maturation slow the rate of primary and early secondary oocyte growth, but do not alter number of oocytes at these stages of development. Objective 4 : This study, (1) determined that infected fish treated with oxytetracycline-medicated feed (as fry or as presmolts) had improved survival compared to nonmedicated fish, (2) determined that a single 14-day course of oral azithromycin at first feeding or at the start of smoltification is sufficient for significant azithromycin retention in internal tissues for at least a year, and (3) established that Renibacterium salmoninarum with an azithromycin-resistant phenotype can be isolated from Chinook salmon receiving macrolide antibiotic treatment. Objective 5: This study determined that for Chinook salmon rearing in similar, 'common environment' regimes in seawater, control fish have survived at a higher rate since seawater transfer than have experimentally inbred fish. However, in all groups, the variation among families in survival has been substantial, ranging from 0% to 100% over the entire year and from 0% to 40% since seawater transfer. The highly significant effect of variation among families within both stocks indicates that substantial genetic variation for size remains in these populations.
- Research Organization:
- Bonneville Power Administration (BPA), Portland, OR (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- 32125
- OSTI ID:
- 962401
- Report Number(s):
- P111275; R&D Project: 1993-056-00; TRN: US200916%%239
- Resource Relation:
- Related Information: document dated June 26, 2007 ; document title: Project 1993-056-00 Progress Report (Performance Period: 1 June 2006 through 31 May 2007)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Research on Captive Broodstock Programs for Pacific Salmon, 2002-2003 Annual Report.
Research on Captive Broodstock Programs for Pacific Salmon; Assessment of Captive Broodstock Technologies, Annual Report 2002-2003.