Thermoacclimatory Variation in the Haemoglobin Systems of Goldfish (Carassius Auratus) and Rainbow Trout (Salmo Gairdneri)

1974 ◽  
Vol 61 (2) ◽  
pp. 455-461
Author(s):  
A. H. HOUSTON ◽  
D. CYR

Significant increases in total haemoglobin concentrations, and microhaematocrit values were associated with acclimation of rainbow trout and goldfish to increased temperature. Goldfish held at 2°C were characterized by two haemoglobin components, whereas those acclimated to 20° and 35°C exhibited three. Nine haemoglobin variants were observed in trout at 2°, 10° and 18°C. The data provide evidence that both species selectively alter the concentrations of specific haemoglobin fractions during the thermoacclimatory process.

1979 ◽  
Vol 36 (10) ◽  
pp. 1174-1179 ◽  
Author(s):  
T. J. Trust ◽  
L. M. Bull ◽  
B. R. Currie ◽  
J. T. Buckley

Grass carp (Ctenopharyngodon idella), bred in Arkansas and maintained in British Columbia under defined culture conditions on pelleted diets and on aquatic weeds, were examined to determine their commensal gastrointestinal bacterial flora. Using anaerobic incubation, the total bacterial numbers cultured ranged from 6 × 104 to 4 × 108 (average 4 × 106) per g of alimentary tract plus contents. Obligately anaerobic bacteria were isolated and identified as species of Actinomyces, Bacteroides, Eubacterium, Fusobacterium, and Peptostreptococcus. This is the first description of the presence of these strictly anaerobic organisms in the gastrointestinal tract of fish. Indeed, many of the anaerobes isolated did not conform to previously described species. Members of the Genus Clostridium were also isolated by enrichment culture and appeared to be associated with a pond weed diet. A wide variety of facultative anaerobic bacteria were also isolated, with Aeromonas hydrophila predominating. The gastrointestinal tracts of goldfish (Carassius auratus) were also found to contain sizable numbers of obligate anaerobes, but the gastrointestinal tracts of hatchery-cultured rainbow trout (Salmo gairdneri) contained insignificant numbers. Key words: grass carp, anaerobic bacteria, gastrointestinal microflora, Aeromonas hydrophila, rainbow trout, goldfish


1976 ◽  
Vol 33 (4) ◽  
pp. 948-958 ◽  
Author(s):  
Fumio Yamazaki

Methyltestosterone, when incorporated in the diet at a concentration of 1 ppm, accelerated the growth of goldfish (Carassius auratus), horai masu, a variant of rainbow trout (Salmo gairdneri), and kokanee (Oncorhynchus nerka). Simultaneous acceleration in the growth of the testes was also observed in some of the horai masu. Administration of 5 ppm methyltestosterone or diethylstilbestrol in the diet combined with injection of salmon gonadotropin was effective in accelerating the sexual maturation of rainbow trout. However, a concentration of 50 ppm methyltestosterone inhibited gonadal development if the treatment was initiated shortly after hatching and continued for a period of 5 mo. The fish thus treated were found to have threadlike gonads even after 3 yr. Courtship behavior and feeding behavior were also influenced by methyltestosterone treatment. The sex ratio of zebra fish (Zebrafario) and rainbow trout was altered when the administration of methyltestosterone was initiated just after hatching. This suggests a strong possibility of introducing sex reversal or mono sex culture in these important commercially raised fish. Results with the cobalt variant of rainbow trout, a fish lacking a complete pituitary and found only with immature gonads, suggest that this animal may be a promising model for future studies in fish endocrinology.


1976 ◽  
Vol 33 (6) ◽  
pp. 1403-1407 ◽  
Author(s):  
A. H. Houston ◽  
J. T. Corlett ◽  
R. J. Woods

The influence of specimen weight upon induction of and recovery from Stage I M.S. 222 (ethyl m-aminobenzoate methanesulphonate) was examined in goldfish (Carassius auratus), brook (Salvelinus fontinalis), and rainbow trout (Salmo gairdneri) exposed to various anesthetic concentration–temperature combinations. Both induction and recovery times varied inversely with weight, the influence of weight being particularly pronounced among smaller specimens. These observations are consistent with the hypothesis that attainment of "critical" internal anesthetic concentration is influenced by weight-specific variation in the relationship between gill area and extracellular phase volume.


1994 ◽  
Vol 72 (3) ◽  
pp. 423-426 ◽  
Author(s):  
Paul W. Webb ◽  
Hongbao Zhang

We measured reaction distance, escape velocity, and the apparent looming threshold (ALT) of heat-shocked goldfish (Carassius auratus) attacked by trout (Oncorhynchus mykiss). We tested fish at the acclimation temperature of 15 °C after heat-shocking prey for 2 min at temperatures ranging from 34 to 39 °C. Escape speeds were unaffected by heat shock. Reaction distance decreased from about 21 cm for fish shocked at 35 °C to about 6 cm for those shocked at 39 °C. ALT increased from 0.2 rad∙s−1 for controls to 0.4 rad∙s−1 for goldfish heat-shocked at 39 °C. The elusiveness of prey, E, was measured as the number of attacks required per prey capture. E was related to ALT as: E = 1.29 (±0.47)∙ALT−0.82(±0.25) (mean (±2 SE)). Factors that decrease responsiveness of prey have large effects on the ability of prey to avoid predators.


1991 ◽  
Vol 69 (1) ◽  
pp. 111-116 ◽  
Author(s):  
A. P. Scott ◽  
A. V. M. Canario ◽  
Nancy M. Sherwood ◽  
Carol M. Warby

In an accompanying paper we report that herring milt contains high concentrations of conjugated cortisol and 17α,20β-dihydroxy-4-pregnen-3-one. We suggest that one source of these steroids was the urine, which could have become mixed with the milt during the hand-stripping procedure. In the present study, samples of hand-stripped milt from several other species, plaice (Pleuronectes platessa), dab (Limanda limanda), flounder (Platichthys flesus), goldfish (Carassius auratus), and rainbow trout (Oncorhynchus mykiss, formerly Salmo gairdneri), were assayed for free and conjugated cortisol. Uncontaminated samples of plasma, seminal fluid, and urine of male herring and plaice were also assayed for free and conjugated cortisol (both species), 17α,20β-dihydroxy-4-pregnen-3-one (herring only), 17α,20α-dihydroxy-4-pregnen-3-one, and 3α,17α,21-trihydroxy-5β-pregnan-20-one (plaice only). The results showed that hand-stripped milt from these other species, excluding rainbow trout (from which it was possible to obtain urine-free milt), also had markedly high levels of conjugated cortisol (200–1000 ng∙mL−1). Urine of herring and plaice had particularly high levels of conjugated cortisol (ca. 5 μg∙mL−1). Uncontaminated seminal fluid from herring, but not from plaice, also had high levels of conjugated cortisol (ca. 2 μg∙mL−1). Urine and plasma, but not seminal fluid, of herring had elevated levels of conjugated 17α,20β-dihydroxy-4-pregnen-3-one. Urine, but not plasma or seminal fluid, of male plaice had elevated levels of 17α,20α -dihydroxy-4-pregnen-3-one and 3α,17α,21-trihydroxy-5β-pregnan-20-one. It would appear that fish urine is a rich source of conjugated steroids and that care must be taken, when collecting milt for pheromone studies, to avoid urine contamination.


1977 ◽  
Vol 34 (4) ◽  
pp. 501-508 ◽  
Author(s):  
Peter V. Hodson ◽  
Beverley R. Blunt ◽  
Douglas J. Spry ◽  
Keith Austen

The activity of erythrocyte δ-amino levulinic acid dehydratase (ALA-D) of fish is easily measured under a variety of experimental conditions. Exposure of rainbow trout (Salmo gairdneri), brook trout (Salvelinus fontinalis), goldfish (Carassius auratus), and pumpkinseeds (Lepomis gibbosus) to lead consistently inhibited ALA-D within 2 wks at concentrations as low as 10, 90, 470, and 90 μg/ℓ, respectively. In rainbow and brook trout these concentrations were closely related to the published minimum effective concentrations causing sublethal harm. There was a significant linear relationship between ALA-D activity and log of blood lead concentration, between ALA-D activity and log of lead in water, and between blood lead and lead in water. Near lethal exposures to cadmium, copper, zinc, and mercury did not significantly inhibit ALA-D activity. Recovery of ALA-D activity of rainbow trout after transfer from 120 μg/ℓ lead to clean water occurred in 8 wk. This enzyme provides fast, consistent, specific, and sensitive estimates of lead concentrations causing sublethal harm to fish and may help to relate sources of lead to degree of exposure of fish populations in the field. Key words: lead, sublethal toxicity, fish, indicator enzyme, δ-amino levulinic acid dehydratase


1986 ◽  
Vol 64 (9) ◽  
pp. 1883-1888 ◽  
Author(s):  
Nini Tun ◽  
A. H. Houston

Blood O2-carrying capacity and hemoglobin system organization were examined in rainbow trout acclimatized to eight combinations of two treatment levels of three variables: temperature (5, 20 °C), O2 availability (≤ 30%, ≥ 75% saturation), and photoperiod (16L:8D, 8L:16D). Increases in hemoglobin, hematocrit, and individual hemoglobin isomorph abundances were associated with hypoxia, shortened day length, and increased temperature. Under nominal "summer" conditions (20 °C, hypoxia, 16L:8D) photoperiod influence was apparently masked by hypoxic and thermal effects, with the converse being true under "winter" circumstances (5 °C, normoxia, 8L: 16D). The complex, 12-membered hemoglobin system provided some evidence of differential isomorph formation during the acclimatization process. Cellular involvements remain unclear.


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