Apparent Onset of Rigor Mortis in Steelhead Trout (Salmo gairdneri) in the Absence of Loss of Adenosine Triphosphate from the Ordinary Muscle

1964 ◽  
Vol 21 (4) ◽  
pp. 857-859 ◽  
Author(s):  
N. Tomlinson ◽  
S. E. Geiger ◽  
W. W. Kay

not available

1976 ◽  
Vol 54 (9) ◽  
pp. 1530-1534 ◽  
Author(s):  
John R. Smith ◽  
Lavern J. Weber

Elevation in pineal hydroxyindole-O-methyltransferase (HIOMT; EC 2.1.1.4) activity in juvenile steelhead trout was associated with the dark portions of three different photoperiods with a sharp increase in pineal HIOMT activity occurring in the first 4 h of darkness. This pattern of activity could be abolished by bilateral enucleation but not by surgical capping of the pineal region. Surgical exposure of the pineal region in blinded fish did not restore HIOMT responses to changes in lighting.


1986 ◽  
Vol 12 (4) ◽  
pp. 304-313 ◽  
Author(s):  
James M. Haynes ◽  
David C. Nettles ◽  
Kevin M. Parnell ◽  
Michael P. Voiland ◽  
Robert A. Olson ◽  
...  

1985 ◽  
Vol 63 (3) ◽  
pp. 552-566 ◽  
Author(s):  
E. P. Groot ◽  
D. F. Alderdice

Fine structure of the external egg membrane of five species of Pacific salmon (sockeye, Oncorhynchus nerka; pink, O. gorbuscha; chum, O. keta; coho, O. kisutch; and chinook, O. tshawytscha) and the anadromous steelhead trout (Salmo gairdneri), is examined and compared using the scanning electron microscope. Membrane thickness in fixed material varies for the six species as follows (micrometres, [Formula: see text]): sockeye, 34.15 ± 0.15; pink, 61.64 ± 1.53; chum, 53.05 ± 0.33; coho, 27.96 ± 0.48; chinook, 50.82 ± 0.74; steelhead, 30.74 ± 0.11. The membrane consists of a thin outermost layer, the externus, 0.2–0.3 μm thick, and the internus, 24–55 μm thick, which constitutes the remainder of the membrane. In sockeye, pink, and chum salmon and steelhead trout, an additional layer 3–8 μm thick, the "subinternus," occurs beneath the internus. The entire membrane appears fibrous except for the thin and apparently solid externus. Pores in both the inner and outer surfaces are arranged in a hexagonal pattern and are connected by pore canals traversing the membrane. Except in the sockeye, plugs commonly were seen blocking the external openings of the pore canals. Significance of the egg membrane fine structure is considered in relation to several of its roles in the water-activated egg: semipermeability, retention of internal pressure, and mechanical protection. A structural and functional analogy is drawn between the fine structure of the salmonid egg membrane and the mammalian aorta.


1977 ◽  
Vol 34 (7) ◽  
pp. 996-1003 ◽  
Author(s):  
H. Tsuyuki ◽  
S. N. Williscroft

Rainbow trout (Salmo gairdneri) homozygous for liver lactate dehydrogenase alleles ldhHαA and ldhHαB were artificially propagated and their swimming stamina compared. The time required to fatigue 50% of the HαAHαA phenotypes in fixed water velocity tests was 2.3 times greater on the average than that of HαAHαB phenotypes.Likewise, LDH phenotypes HαAHαA, HαAHαB, and HαAHαB of steelhead trout from the Thompson River were artifically propagated and their swimming stamina compared. In contrast to the rainbow trout, significant differences in stamina among the three phenotypes of steelhead were not evident in the stocks from this river nor between phenotypes HαAHαB and HαBHαB from another stream, the Vedder River, which has a very low frequency of the ldhHαA allele. The stamina of young steelhead from the Thompson River was, however, 3.8 times greater than that of those from the Vedder River. Key words: stamina, LDH, rainbow trout, steelhead, phenotype, swimming, fatigue


1988 ◽  
Vol 45 (7) ◽  
pp. 1110-1122 ◽  
Author(s):  
B. R. Ward ◽  
P. A. Slaney

A decade of data on wild steelhead trout (Salmo gairdneri) from a coastal stream in British Columbia demonstrated large fluctuations in smolt number, age structure, size, estimates of adult run sizes, smolt-to-adult survival, and adult age. Adult runs averaged 922 (range 209–2730) with approximately 10% repeat spawning incidence. Females repeat spawned more than males and were more abundant as kelts, but maiden run adults were equally male and female. The proportion of males returning after 1, 2, and 3 yr in the ocean averaged 3, 62, and 35%, respectively; 58 and 42% of females returned after 2 and 3 yr, respectively. Adult age structure, smolt number, and smolt size varied biennially. Adult size decreased with freshwater age, but increased with ocean age of returns. Males were larger at each ocean age. Mean number of smolts (50:50 sex ratio) was 5543 and varied fivefold. Mean smolt length was 173 mm and mean weight was 49 g. Smolts were 2–5 yr old, and freshwater age 3 was most prevalent (average 56%). Mean survival from smolt to adult was 16% (7% from 1978 cohorts to 26% from 1982 cohorts). Survival was positively correlated with smolt length and weight. However, 1982 cohorts had twice the survival of other cohorts, possibly related to El Niño. No clear relationship was found between return age and mean smolt size, but on average, freshwater age was inversely related to ocean age. The relationships suggest that predictive models may be developed over the longer term from this type of study.


Aquaculture ◽  
1985 ◽  
Vol 45 (1-4) ◽  
pp. 133-142 ◽  
Author(s):  
Richard J. Lin ◽  
Rodolfo J. Rivas ◽  
Richard S. Nishioka ◽  
E.Gordon Grau ◽  
Howard A. Bern

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