Survival of Steelhead Trout (Salmo gairdneri) Eggs, Embryos, and Fry in Air-Supersaturated Water

Egg, embryo, fry, and swim-up stages of steelhead trout (Salmo gairdneri) were exposed to water at total gas saturation levels ranging from 130 to 115%. Eggs, embryos, and newly hatched fry were not affected at 126.7%, but at about day 16 posthatch when the fish began swimming up deaths occurred rapidly, and at the end of the test post button-up mortality ranged from 99% at 126.7% saturation to 45% at 115.3% saturation. Bubbles in the mouth, gill cavity, and yolk sac caused flotation and severe respiratory difficulties. Rupture of yolk-sac membranes also caused death. No differences were noted in survival between fish exposed from egg to fry, and those exposed only from swim-up to fry stage. In summary, there were differences in susceptibility among steelhead life stages to air-supersaturated water; eggs, embryos, and pre-swim-up larvae were more resistant than swim-up and later fry stages. Key words: trout, steelhead, supersaturation, gas-bubble disease, Salmo gairdneri, temperature, fish culture

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Swimming Stamina Differences Between Genotypically Distinct Forms of Rainbow (Salmo gairdneri) and Steelhead Trout

Journal of the Fisheries Research Board of Canada ◽

10.1139/f77-152 ◽

1977 ◽

Vol 34 (7) ◽

pp. 996-1003 ◽

Cited By ~ 28

Author(s):

H. Tsuyuki ◽

S. N. Williscroft

Keyword(s):

Rainbow Trout ◽

Lactate Dehydrogenase ◽

Key Words ◽

Low Frequency ◽

Water Velocity ◽

Salmo Gairdneri ◽

Steelhead Trout ◽

Very Low Frequency ◽

Time Required

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

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Precocious Sexual Development in Hatchery-Reared and Laboratory-Maintained Male Steelhead Trout (Salmo gairdneri)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f79-014 ◽

1979 ◽

Vol 36 (1) ◽

pp. 90-93 ◽

Cited By ~ 22

Author(s):

Steven P. Schmidt ◽

Edwin W. House

Keyword(s):

Water Temperature ◽

Key Words ◽

Sexual Maturation ◽

Sexual Development ◽

Salmo Gairdneri ◽

Steelhead Trout ◽

Juvenile Male ◽

Precocious Males ◽

Sexually Mature ◽

Maturation Age

The incidence of precocious steelhead trout (Salmo gairdneri) was determined in several Idaho hatchery steelhead populations. The range of incidence of precocious males was 0–64% of the sampled populations. This variation appeared to be related to age of the trout, water temperature, and photoperiod. The incidence of precocious males greatly exceeded the incidence (0.1% of the population when encountered) of precocious females. Precocious male steelhead trout are apparently lost from the migrating smolt population and display mating behavior similar to sea-run adult male steelhead. Precocious males maintained in laboratory conditions remained sexually mature for at least 6 mo of observation. This was reflected by mean gonadal weights and mean gonadosomatic indices from precocious male steelhead which differed significantly from nonprecocious juvenile male steelhead maintained under similar conditions. No consistent pattern of growth was observed among laboratory-maintained trout. Key words: steelhead trout, reproduction, precocious sexual maturation, age, photoperiod, temperature

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Morphology and function of the lateral line of juvenile steelhead trout in relation to gas-bubble disease*

Journal of Fish Biology ◽

10.1111/j.1095-8649.1976.tb04675.x ◽

1976 ◽

Vol 9 (3) ◽

pp. 217-233 ◽

Cited By ~ 15

Author(s):

Douglas D. Weber ◽

Michael H. Schiewe

Keyword(s):

Lateral Line ◽

Gas Bubble ◽

Steelhead Trout ◽

Gas Bubble Disease ◽

And Function

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Effect of Carbon Monoxide Exposure on Gas Bubble Disease in Rainbow Trout (Salmo gairdneri)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f89-011 ◽

1989 ◽

Vol 46 (1) ◽

pp. 74-80 ◽

Cited By ~ 3

Author(s):

J. P. Machado ◽

T. G. Bell ◽

A. L. Trapp ◽

D. L. Garling Jr. ◽

N. R. Kevern

Keyword(s):

Carbon Monoxide ◽

Rainbow Trout ◽

Survival Time ◽

Prolonged Survival ◽

Salmo Gairdneri ◽

Gas Bubble ◽

Dissolved Gas ◽

Gas Bubble Disease ◽

Gill Filaments ◽

Afferent Arterioles

Cumulative mortalities of 100, 50, 20, and 0% due to gas bubble disease (GBD) occurred on exposure of rainbow trout (Salmo gairdneri) for 180 min to supersaturated water at 136, 130, 124, and 116% total dissolved gas saturation (TDGS), respectively. At 130% TDGS, a prior exposure to carbon monoxide (CO), which converted 80% of the hemoglobin to carboxyhemoglobin (COHb), significantly prolonged survival time, but cumulative mortality was insignificantly reduced in the same group. Histologically, all supersaturation mortalities had branchial lesions for GBD (characterized by gas displacement of blood from the afferent arterioles of the gill filaments), while 70% had gas emboli in the retinal choroid gland. At a TDGS of 100%, these histological lesions were not observed and the CO 80% COHb conversion did not induce mortality within 120 min. Breathing movements of both control and CO-exposed fish slowed greatly when a TDGS of 130% was imposed; however, the COHb conversion initiated tachypnea and the CO-treated fish maintained a relatively higher respiratory rate when exposed to supersaturation conditions for a period which was proportional to their prolonged survival time. We concluded that the initial formation of gas emboli preceding fatal GBD was delayed as a result of a CO-inhibited function of hemoglobin.

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Histopathoiogy and the Pathogenesis of Embolism (Gas Bubble Disease) in Rainbow Trout (Salmo gairdneri)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f87-243 ◽

1987 ◽

Vol 44 (11) ◽

pp. 1985-1994 ◽

Cited By ~ 12

Author(s):

J. P. Machado ◽

D. L. Garling Jr. ◽

N. R. Kevern ◽

A. L. Trapp ◽

T. G. Bell

Keyword(s):

Rainbow Trout ◽

Fixation Method ◽

Salmo Gairdneri ◽

Gas Bubble ◽

Atmospheric Gases ◽

Progressive Development ◽

Rapid Fixation ◽

Gas Bubble Disease ◽

Gill Filaments ◽

Acid Secreting

Rainbow trout (Salmo gairdneri) affected with gas bubble disease (GBD) were examined histologically to determine the pathogenesis of the early stages of gas emboli formation. Lesions preserved by a rapid fixation method were located in tissues associated with acid-secreting glands or with high metabolic requirements. Following the development of small gas emboli formed in the retinal chorio-capillaries, a progressive development of unilateral exophthalmia was detected. A lesion found in every treated moribund fish but never in controls was gas displacement of the blood from the afferent arteriole within the gill filaments. The exposure of fish to well water containing graded levels of atmospheric gases from 114 to 118% nitrogen and 103 to 110% oxygen saturation resulted in high mortality. However, fish held in nitrogen varying between 103 and 117% and oxygen from 50 to 94% saturation experienced insignificant mortality. We suggest that hatchery oxygen levels should be maintained below 100% if nitrogen supersaturation is present to reduce mortality from GBD.

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The Effects of Temperature and Salinity on the Endocrinology in Two Life Stages of Juvenile Rainbow/Steelhead Trout ( Oncorhynchus mykiss )

Journal of Fish Biology ◽

10.1111/jfb.14741 ◽

2021 ◽

Author(s):

Marissa Giroux ◽

Daniel Schlenk

Keyword(s):

Oncorhynchus Mykiss ◽

Life Stages ◽

Steelhead Trout ◽

Effects Of Temperature

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The regulation of day–night changes in hydroxyindole-O-methyltransferase activity in the pineal gland of steelhead trout (Salmo gairdneri)

Canadian Journal of Zoology ◽

10.1139/z76-175 ◽

1976 ◽

Vol 54 (9) ◽

pp. 1530-1534 ◽

Cited By ~ 30

Author(s):

John R. Smith ◽

Lavern J. Weber

Keyword(s):

Pineal Gland ◽

Sharp Increase ◽

Pineal Region ◽

Salmo Gairdneri ◽

Steelhead Trout ◽

Methyltransferase Activity ◽

Surgical Exposure

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.

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