The influence of the zona radiata on the toxicity and uptake of cadmium in embryos of Atlantic salmon (Salmo salar)

1983 ◽  
Vol 61 (10) ◽  
pp. 2338-2343 ◽  
Author(s):  
P. J. Rombough ◽  
E. T. Garside
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Metal Content ◽  
Exposure Period ◽  
The Body ◽  
Cadmium Content ◽  
Direct Proportion ◽  
Anterior Portion ◽  
Zona Radiata ◽  
Atlantic Salmon Salmo Salar

Eyed embryos of Atlantic salmon (Salmo salar) were significantly more resistant to cadmium if the zona radiata (capsule) was removed (10-day LC50, 4.80 mg Cd/L) than if the zona radiata was intact (10-day LC50, 3.20 mg Cd/L). Differences in resistance times were attributed to slower absorption of cadmium by decapsulated embryos than by encapsulated embryos. The metal content of naked embryos increased slowly and in direct proportion to the length of exposure. The metal content of encapsulated embryos was proportional to the logarithm of the exposure period and rapidly approached an asymptotic maximum. As a consequence, the cadmium content of naked embryos after a 24-h exposure to 8 mg Cd/L was less than 3% of that of encapsulated embryos. An opaque precipitate formed around the head and anterior portion of the body of encapsulated embryos but not of naked embryos exposed to acutely lethal cadmium concentrations. This material was probably cadmium carbonate and may have facilitated metal absorption by effectively exposing the encapsulated embryos to cadmium concentrations considerably greater than those in the ambient environment.

Cadmium toxicity and accumulation in eggs and alevins of Atlantic salmon Salmo salar

1982 ◽  
Vol 60 (8) ◽  
pp. 2006-2014 ◽  
Author(s):  
P. J. Rombough ◽  
E. T. Garside
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Cadmium Toxicity ◽  
Exposure Period ◽  
Cadmium Content ◽  
Atlantic Salmon Salmo Salar ◽  
Inhibition Of Growth ◽  
Ambient Concentration ◽  
Yolk Absorption ◽  
Dose Dependent

Embryos and alevins of Atlantic salmon (Salmo salar) were exposed to cadmium concentrations of between 0.47 μg Cd/L and 27 mg Cd/L from fertilization to near complete yolk absorption. The most sensitive indicator of cadmium toxicity was the inhibition of growth in alevins, with significant reduction occurring in 0.47 μg Cd/L. The LC50 for the interval from fertilization to viable hatch was estimated to lie between 300 and 800 μg Cd/L. Newly hatched alevins had a 24-day LC50 of between 1.5 and 2.7 mg Cd/L. Sensitivity increased sharply in late alevins and significant mortality was recorded in concentrations as low as 8.2 μg Cd/L. Cadmium uptake by eggs was rapid, with dose-dependent saturation levels reached within 24 h and maintained until hatch. Although the total cadmium content of eggs increased with ambient concentration, the degree of bioaccumulation declined. The cadmium contents of newly hatched alevins were much lower but directly proportional to those of eggs. Uptake by alevins was logarithmic, independent of ambient concentration above about 1 μg Cd/L, and did not reach equilibrium during the exposure period (46 days).

scholarly journals Oogenesis in Atlantic salmon (Salmo salar L.) occurs by zonagenesis preceding vitellogenesis in vivo and in vitro

1998 ◽  
Vol 158 (2) ◽  
pp. 259-266 ◽  
Author(s):  
T Celius ◽  
BT Walther
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Polyclonal Antiserum ◽  
Control Mechanisms ◽  
Zona Radiata ◽  
Atlantic Salmon Salmo Salar ◽  
Molecular Components ◽  
Hepatic Synthesis

Fish oogenesis represents pleiotropic cytodifferentiative programs including hepatic synthesis of the molecular components for both the eggshell and the oocytic energy deposits. Both hepatic processes are directly controlled by plasma levels of estradiol (E2), and injected E2 induces both biogenetic processes in prepubertal fish of both sexes. This work compares the temporal pattern of E2-induced biosynthesis of zona radiata proteins (zr-proteins) and vitellogenin in Atlantic salmon (Salmo salar L.) in vivo and in vitro. We monitored the presence of plasma zr-proteins and vitellogenin, using homologous polyclonal antiserum to zr-proteins and a monoclonal antibody to vitellogenin. Zr-proteins were induced by all E2 concentrations (0.001-1.1 mg/kg body weight (bw)) within one week of exposure while vitellogenin was not induced until two weeks post-injection and then only in plasma from fish injected with high E2 concentrations (0.4 mg or 1.1 mg/kg bw). After E2 treatment, hepatocytes isolated from male fish synthesized zr-proteins and vitellogenin in vitro. However, zr-proteins were secreted into the medium two days before vitellogenin, as measured by ELISA. The data indicate a preferential induction of zr-proteins compared with vitellogenin, both with regard to E2 sensitivity and response time to E2 treatment. These findings suggest an obligate sequence in salmon oogenesis. During sexual maturation low E2 levels at first induce only zonagenesis, while increasing levels of E2 subsequently induce both zonagenesis and vitellogenesis. In nature, the interval between zonagenesis and vitellogenesis may, therefore, be considerable. The data suggest new control mechanisms in fish oogenesis.

Development, survival, and structural alterations of embryos and alevins of Atlantic salmon, Salmo salar L., continuously exposed to alkaline levels of pH, from fertilization

1980 ◽  
Vol 58 (3) ◽  
pp. 369-377 ◽  
Author(s):  
P. G. Daye ◽  
E. T. Garside
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Hydrogen Ions ◽  
Gradual Decline ◽  
Cumulative Mortality ◽  
Zona Radiata ◽  
Atlantic Salmon Salmo Salar ◽  
Branchial Epithelium ◽  
The Brain ◽  
Degree Of Severity

Embryos of the Atlantic salmon, Salmo salar L., were incubated continuously from fertilization at pH 6.8 (control) and pH 9.0 and 9.5, initially at 6.7 °C but with a gradual decline in the first 5 weeks to 5.0 °C for the remaining 10 weeks of exposure. Subsequently, the alevins were maintained in these environments for 50 days after hatching. Developmental processes and hatching were not affected by these levels of pH. Percentage cumulative mortality of treated embryos, 8%, was approximately that in the controls. Alevin mortality in the control lots was 1.2 and 1.3%. At pH 9.0, cumulative mortality was 0.4%, but at pH 9.5 there was an accelerating increase to 18%, at the termination of observation.Sublethal changes in embryos were confined mostly to cell necrosis and sloughed rudimentary epidermis. Some metaplasia of the brain stem occurred at pH 9.5. Sites and intensity of alterations increased in alevins at pH 9.5, following the loss of the zona radiata. In addition to ongoing injury of epidermis, including mucous cells, deleterious alterations occurred in branchial epithelium, erythrocytes, myocardium, blood vessels of the viscera, liver, brain, and optic lenses. In general, sublethal changes caused by hydroxylions are similar to those caused by excessive hydrogen ions but are somewhat less extensive in the structures affected or in their degree of severity.

Increase of heart rate without elevation of cardiac output in adult Atlantic salmon (Salmo salar) exposed to acidic water and aluminium

1999 ◽  
Vol 56 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Julie C Brodeur ◽  
Trine Ytrestøyl ◽  
Bengt Finstad ◽  
R Scott McKinley
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Atlantic Salmon ◽  
Stroke Volume ◽  
River Water ◽  
Salmo Salar ◽  
Exposure Period ◽  
Atlantic Salmon Salmo Salar ◽  
Concomitant Reduction ◽  
Ventral Aorta

Adult Atlantic salmon (Salmo salar) were exposed for 48 h to water from acidified (pH 5.2) Fossbekk River (Norway), with and without 94 µg aluminium (Al)/L added as AlCl3, and to water from circumneutral (pH 6.7) Ims River (Norway) (controls). Cardiac output, heart rate, and stroke volume were monitored throughout the exposure period with Doppler flow probes placed around the ventral aorta of the fish. Fish exposed to Fossbekk River water without added Al showed few physiological disturbances. When 94 µg Al/L was added to Fossbekk River water, most of the fish died before the end of the 48-h exposure period, and a large elevation in heart rate was observed together with a decrease in plasma chloride concentrations and an increase in haematocrit, plasma glucose and plasma cortisol levels. Cardiac output was maintained at basal levels during the first 24 h of exposure because the tachycardia was accompanied by a concomitant reduction of stroke volume. Signs of arrhythmia appeared after 32 h of exposure and were associated with a further decrease in stroke volume that caused cardiac output to decrease below basal levels. The incapacity of the tachycardia to elevate cardiac output and the subsequent death of the fish suggest that this response to low pH and Al is more of a maladaptation reaction than a compensatory or adaptative reaction.

Selection of Microhabitat in Summer by Juvenile Atlantic Salmon (Salmo salar)

1987 ◽  
Vol 44 (1) ◽  
pp. 120-129 ◽  
Author(s):  
D. L. Morantz ◽  
R. K. Sweeney ◽  
C. S. Shirvell ◽  
D. A. Longard
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
The Body ◽  
Flow Conditions ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Salmon Fry ◽  
Study Sites ◽  
Selection Of ◽  
Atlantic Salmon Parr

This study was designed to define the microhabitats selected in summer by juvenile Atlantic salmon (Salmo salar). Curves were developed describing the preference of 880 young salmon for water velocity at the fish's position (nose velocity), mean water column velocity, total water depth, and stream substrate size. Study sites were chosen in six morphologically diverse streams in Nova Scotia and New Brunswick during 1982–84. Of the four variables measured, only nose velocity chosen by both fry and parr was not significantly different among years or rivers. Atlantic salmon fry (< 65 mm) most frequently selected nose velocities between 5 and 15 cm∙s−1, small parr (65–100 mm) between 5 and 25 cm∙s−1 and large parr (> 100 mm) between 5 and 35 cm∙s−1. Apparently, juvenile salmon utilized water depths and stream substrates which varied within tolerable limits according to their availability in conjunction with preferred water velocities. Significant differences in the body shape and size of the pectoral fin of Atlantic salmon parr in different rivers did not influence the selection of nose velocities within the range of flow conditions sampled.

Site specificity of Gyrodactylus salaris Malmberg, 1957 (Monogenea) on Atlantic salmon (Salmo salar L.) in the River Lakselva, northern Norway

1992 ◽  
Vol 70 (2) ◽  
pp. 264-267 ◽  
Author(s):  
Arne Johan Jensen ◽  
Bjørn Ove Johnsen
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Infection Intensity ◽  
The Body ◽  
Site Specificity ◽  
Caudal Fin ◽  
Northern Norway ◽  
Dorsal Fin ◽  
Atlantic Salmon Salmo Salar

Site specificity of Gyrodactylus salaris on 853 Atlantic salmon (Salmo salar) parr infected with 1 – 10 625 parasites was studied in the River Lakselva in northern Norway. At low intensities (< 100), the dorsal fin was the principal site of attachment, followed by the pectoral and anal fins. However, the distribution of parasites on the fish, and their crowding, varied with infection intensity. When the intensity increased to more than 100, more parasites were located on the caudal fin, and when it exceeded 1000, the body of the fish was also heavily infected.

The Uptake and Detoxification of C14-labelled DDT in Atlantic Salmon, Salmo salar

1963 ◽  
Vol 20 (3) ◽  
pp. 827-837 ◽  
Author(s):  
F. H. Premdas ◽  
J. M. Anderson
Keyword(s):  
Spinal Cord ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
The Body ◽  
Mosquito Larvae ◽  
Swim Bladder ◽  
Time To Death ◽  
Atlantic Salmon Salmo Salar ◽  
High Concentrations ◽  
Brain And Spinal Cord

Atlantic salmon underyearlings were exposed to 1 ppm DDT-C14 and the amounts of DDT adsorbed to external surfaces and absorbed internally determined separately on the basis of the C14 activity. Fish killed by the exposure contained on the average 5.87 ppm DDT of which almost two-thirds represented absorbed DDT. After only 5 minutes exposure appreciable quantities of DDT were found throughout the body. At all times, up to and including the time to death, high concentrations of DDT were found in the gills, liver, spleen, heart, kidneys, gonads, and swim bladder. Much smaller concentrations occurred in the stomach, intestines, brain and spinal cord. The muscles, bone, and integument contained the least. It was concluded that DDT entered mainly through the gills from whence it was transported throughout the body via bone circulatory system.Bioassays showed that on the average almost two-thirds of the absorbed DDT was non-toxic, or at least relatively so, to mosquito larvae. The adsorbed DDT showed little, if any, loss of toxicity.

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