PHOTOPERIOD REGULATION OF PLASMA GROWTH-HORMONE LEVELS DURING PARR-SMOLT TRANSFORMATION OF ATLANTIC SALMON - IMPLICATIONS FOR HYPOOSMOREGULATORY ABILITY AND GROWTH

被引:63
作者
BJORNSSON, BT
STEFANSSON, SO
HANSEN, T
机构
[1] UNIV BERGEN,CTR HIGH TECHNOL,DEPT FISHERIES & MARINE BIOL,N-5020 BERGEN,NORWAY
[2] INST MARINE RES,DEPT AQUACULTURE,MATRE AQUACULTURE RES STN,N-5198 MATREDAL,NORWAY
关键词
D O I
10.1006/gcen.1995.1135
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
The influence of photoperiod on plasma growth hormone (GH) levels during parr-smelt transformation was studied in Atlantic salmon, using a specific salmon GH radioimmunoassay; in addition, the impact of endogenous changes in GH levels on hypoosmoregulatory ability and growth was assessed using seawater challenge tests and measurements of growth rates. Groups of fish were kept on simulated natural photoperiod or continuous light, and subgroups were subjected to reciprocal transfers between these two light regimes at different times. For Atlantic salmon on simulated natural photoperiod, GH levels increased during the parr-smelt transformation, from 0.6 ng ml(-1) in January-March to 6.6 ng ml(-1) in June, while the corresponding change in fish on continuous light was from 0.4 to 1.0 ng ml(-1). The study demonstrates that photoperiod is a major zeitgeber for the increased GH levels during the parr-smelt transformation of Atlantic salmon. The data further support the view that exposure to continuous light into fall and winter causes a ''free running'' of an endogenous rhythm governing smelting and a subsequent phase-delay of the parr-smelt transformation-related increase in plasma GH levels. A strong positive nonlinear correlation was found between specific growth rate and GH levels, with growth rate increasing rapidly with increasing GH levels up to 2-3 ng ml(-1) at which point near-maximal growth rate is reached, revealing that relatively small increases in GH levels may be of great importance for an increased specific growth rate. A positive nonlinear correlation was also found between GH and hypoosmoregulatory ability, leading to the conclusion that a regime of continuous light has adverse effects on seawater tolerance and that a period of short daylength is necessary for the normal smelt-related physiological improvement in seawater adaptability. (C) 1995 Academic Press, Inc.
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页码:73 / 82
页数:10
相关论文
共 33 条
[1]   PROMOTION OF RAPID GROWTH OF RAINBOW-TROUT (SALMO-GAIRDNERI) BY A RECOMBINANT FISH GROWTH-HORMONE [J].
AGELLON, LB ;
EMERY, CJ ;
JONES, JM ;
DAVIES, SL ;
DINGLE, AD ;
CHEN, TT .
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES, 1988, 45 (01) :146-151
[2]  
AUSTRENG E, 1987, AQUACULTURE, V60, P57
[3]   SUSTAINED EXERCISE AUGMENTS LONG-TERM STARVATION INCREASES IN PLASMA GROWTH-HORMONE IN THE STEELHEAD TROUT, SALMO-GAIRDNERI [J].
BARRETT, BA ;
MCKEOWN, BA .
CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE, 1988, 66 (04) :853-855
[4]   ENDOCRINE CONTROL OF SMOLTIFICATION IN ANADROMOUS SALMONIDS [J].
BARRON, MG .
JOURNAL OF ENDOCRINOLOGY, 1986, 108 (02) :313-319
[5]   THE INTERRELATION BETWEEN PHOTOPERIOD, GROWTH-HORMONE, AND SEXUAL-MATURATION OF ADULT ATLANTIC SALMON (SALMO-SALAR) [J].
BJORNSSON, BT ;
TARANGER, GL ;
HANSEN, T ;
STEFANSSON, SO ;
HAUX, C .
GENERAL AND COMPARATIVE ENDOCRINOLOGY, 1994, 93 (01) :70-81
[6]   PHOTOPERIOD AND TEMPERATURE AFFECT PLASMA GROWTH-HORMONE LEVELS, GROWTH, CONDITION FACTOR AND HYPOOSMOREGULATORY ABILITY OF JUVENILE ATLANTIC SALMON (SALMO-SALAR) DURING PARR SMOLT TRANSFORMATION [J].
BJORNSSON, BT ;
THORARENSEN, H ;
HIRANO, T ;
OGASAWARA, T ;
KRISTINSSON, JB .
AQUACULTURE, 1989, 82 (1-4) :77-91
[7]   EFFECTS OF HYPOPHYSECTOMY AND SUBSEQUENT HORMONAL REPLACEMENT THERAPY ON HORMONAL AND OSMOREGULATORY STATUS OF COHO SALMON, ONCORHYNCHUS-KISUTCH [J].
BJORNSSON, BT ;
YAMAUCHI, K ;
NISHIOKA, RS ;
DEFTOS, LJ ;
BERN, HA .
GENERAL AND COMPARATIVE ENDOCRINOLOGY, 1987, 68 (03) :421-430
[8]  
BJORNSSON BT, 1989, AQUACULTURE, V73, P275
[9]   PLASMA GROWTH-HORMONE LEVELS IN NORMAL AND STUNTED YEARLING COHO SALMON, ONCORHYNCHUS-KISUTCH [J].
BOLTON, JP ;
YOUNG, G ;
NISHIOKA, RS ;
HIRANO, T ;
BERN, HA .
JOURNAL OF EXPERIMENTAL ZOOLOGY, 1987, 242 (03) :379-382
[10]   DEVELOPMENT AND VALIDATION OF A SALMON GROWTH-HORMONE RADIOIMMUNOASSAY [J].
BOLTON, JP ;
TAKAHASHI, A ;
KAWAUCHI, H ;
KUBOTA, J ;
HIRANO, T .
GENERAL AND COMPARATIVE ENDOCRINOLOGY, 1986, 62 (02) :230-238