scholarly journals Delay of gametogenesis and spawning by constant illumination of rainbow trout (Salmo gairdneri) during the first reproductive cycle

1984 ◽  
Vol 62 (11) ◽  
pp. 2183-2187 ◽  
Author(s):  
A. Bourlier ◽  
R. Billard
Keyword(s):  
Rainbow Trout ◽  
Reproductive Cycle ◽  
Gonadosomatic Index ◽  
Continuous Light ◽  
Salmo Gairdneri ◽  
Constant Illumination ◽  
Follicle Diameter ◽  
Paris Area ◽  
Natural Photoperiod

Two-year-old, 500–600 g immature and prepuberal male and female rainbow trout were exposed on June 21 to continuous light (CL group) or, as a control, to the natural photoperiod in the Paris area (C group) and were kept under seasonal variation of temperature. Gametogenesis was studied by periodic sampling of the gonads for quantitative analysis of spermatogenesis and measurement of follicle diameter. Gonadotropin (GTH) profiles were measured in pituitary and plasma by radioimmunoassay. During spawning, the quantity and quality of gametes were measured. Under continuous light, gametogenesis and spawning were delayed by about 2 months as compared with the controls kept under a natural photoperiod. Delayed gametogenesis in the fish under continuous light showed some alterations. In the males, the dynamics of spermatogenesis was modified since the proportion of the germ cells in the testis was changed as compared with the controls; e.g., spermatids were present in the testicular lobules when spermiation started. The yield of spermiation measured in four samplings was lower in males under continuous light as compared with the controls. In the females, follicle diameter and gonadosomatic index tended to remain lower during vitellogenesis in the CL group as compared with the C group, but finally, the diameter of the eggs stripped and the fecundity were not different in both groups. GTH profiles were different only for the plasma in December. The pituitary GTH content was low in December in both groups and sexes, irrespective of the stage of the reproductive cycle and of the light environment. There was no difference in hepatosomatic and viscerosomatic indices between the two groups.

Sex differences in hepatic cytochrome P-450 monooxygenase activities in rainbow trout during an annual reproductive cycle

1990 ◽  
Vol 124 (2) ◽  
pp. 207-213 ◽  
Author(s):  
L. Förlin ◽  
C. Haux
Keyword(s):  
Rainbow Trout ◽  
Reproductive Cycle ◽  
Annual Reproductive Cycle ◽  
Aryl Hydrocarbon Hydroxylase ◽  
Aryl Hydrocarbon ◽  
Natural Photoperiod ◽  
Pyrene Hydroxylase ◽  
Cytochrome P 450 ◽  
Isoenzyme Patterns ◽  
Hepatic Cytochrome

ABSTRACT Hepatic microsomal cytochrome P-450 monooxygenase activities were investigated in rainbow trout during an annual reproductive cycle. The fish were kept in tanks supplied with fresh water at a constant temperature of 10 °C. The daily light and darkness cycle was adjusted to follow the natural photoperiod. Sampling was performed once every month for 1 year. Higher benzo(a)pyrene-hydroxylase (or aryl hydrocarbon hydroxylase; AHH), ethoxycoumarin-O-deethylase (ECOD) and ethylmorphine-N-demethylase (END) activities and cytochrome P-450 content were found during the late stage of sexual development in rainbow trout. When monooxygenase activities were expressed on a per cytochrome P-450 basis, sex-dependent differences were observed only for AHH and ECOD activities. It was thus found that sex-dependent variations of END were closely correlated with the total amount of cytochrome P-450. The results indicate that differences exist in hepatic cytochrome P-450 isoenzyme patterns between the sexes in rainbow trout. The similarity of the annual pattern of plasma levels of oestradiol and testosterone to that of sex-dependent differences in the cytochrome P-450 monooxygenases support the contention that sex steroids play a role in regulating the cytochrome P-450 system. Journal of Endocrinology (1990) 124, 207–213

scholarly journals Gonad Size Measured by Ultrasound to Assign Stage of Maturity in Burbot

2021 ◽  
Author(s):  
Lauren McGarvey ◽  
Jason E. Ilgen ◽  
Christopher S. Guy ◽  
Jason G. McLellan ◽  
Molly A. H. Webb
Keyword(s):  
Reproductive Cycle ◽  
Ovarian Follicle ◽  
Gonadosomatic Index ◽  
Measurement Methods ◽  
Ultrasound Transducer ◽  
Gonad Tissue ◽  
A Value ◽  
Follicle Diameter ◽  
Ultrasound Measurements ◽  
Gonad Size

Gonad size (diameter and circumference) measured by ultrasound was assessed as a metric to assign stage of maturity in Burbot Lota lota from Lake Roosevelt, Washington.  Paired gonad tissue and ultrasound measurements were collected monthly from November 2017 to March 2018.  Gonad tissue was processed for histological analysis to confirm stage of maturity.  Gonad diameter and circumference were measured by ultrasound.  Excised gonad diameter (i.e., true gonad diameter) was measured by digital calipers, and excised gonad circumference (i.e., true gonad circumference) was measured by a measuring tape.  All late vitellogenic (stage 6) ovaries measured by ultrasound had a diameter greater than 3.90 cm, suggesting a value of 3.90 cm or greater may be used to characterize females capable of spawning in the current reproductive cycle.  One mid-spermatogenic (stage 3) and all ripe (stage 4) testes were too large to be measured and assigned diameter of 5.11 cm, the maximum value capable of being measured by our ultrasound transducer.  A value of 5.11 cm or greater may be used to characterize males capable of spawning in the current reproductive cycle.  Testis circumference measured by ultrasound is not reported because some testes were wider than the ultrasound transducer and could not be measured.  Measurements of testis diameter did not differ between measurement methods (ultrasound vs. true), but ultrasound measurements of ovary diameter and circumference were higher than true measurements.  We attributed the difference between measurement methods to flattening of ovary while applying the ultrasound transducer.  Gonad diameter and circumference measured by ultrasound were highly correlated with gonadosomatic index and ovarian follicle diameter indicating gonad size measured by ultrasound is an appropriate index of gonad development in Burbot.

Early stages of the reproductive cycle in virgin female rainbow trout (Salmo gairdneri Richardson)

Aquaculture ◽  
1984 ◽  
Vol 43 (1-3) ◽  
pp. 235-242 ◽  
Author(s):  
J.P. Sumpter ◽  
A.P. Scott ◽  
S.M. Baynes ◽  
P.R. Witthames
Keyword(s):  
Rainbow Trout ◽  
Reproductive Cycle ◽  
Virgin Female ◽  
Salmo Gairdneri ◽  
Early Stages
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