Monthly variations in the profile of sex steroids and ovarian development of brook trout (Salvelinus fontinalis Mitchill) during the annual reproductive cycle in Tasmania

2015 ◽  
Vol 63 (3) ◽  
pp. 220 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Reproductive Cycle ◽  
Sex Steroids ◽  
Brook Trout ◽  
Ovarian Development ◽  
Gonadosomatic Index ◽  
Annual Reproductive Cycle ◽  
Total Fecundity ◽  
Mature Fish ◽  
Index Value ◽  
Monthly Variations

Control of maturation in all-female salmonid stock can be achieved by manipulating photoperiod. This initially requires an assessment of the annual reproductive cycle under ambient photoperiod. This study therefore describes the seasonal variations in ovarian development and plasma profiles of oestradiol-17β and testosterone during the second year of a population of female brook trout. It was found that fish recruited for maturation following the summer solstice in December. Shortening of photoperiod likely stimulated the brain–pituitary–gonadal axis for vigorous progress of ovarian development, as indicated by increasing levels of oestradiol-17β and gonadosomatic index values. The highest gonadosomatic index value (18.26 ± 1.1%) was observed in June. During July, eggs were released from mature females by manual stripping. Total fecundity was observed as 4266 ± 341 oocytes per mature fish. Profiles of sex steroids observed here were found to be finely entrained within the succession of seasonal photoperiod. This finding indicates that maturation suppression by photoperiod manipulation should be instigated before initiation of oocyte recruitment that commenced during December.

Monthly variations in the profile of sex steroids and gonadal development of brook trout (Salvelinus fontinalis Mitchill) during puberty in Tasmania

2014 ◽  
Vol 62 (3) ◽  
pp. 200 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Sex Steroids ◽  
Brook Trout ◽  
Ovarian Development ◽  
Salvelinus Fontinalis ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
First Year ◽  
Female Fish ◽  
Oocyte Stage ◽  
Monthly Variations

Puberty is an important reproductive event that has not been studied in brook trout in the Southern Hemisphere. The present study describes the histological development of gonads and variations in the levels of oestradiol-17β (E2), testosterone (T) and 11-ketotestosterone (11-KT) during the first year of male and female brook trout. The study started when the trout were at an age of 8 months (n = 10) and continued until they were 15 months. Of the males, 60% attained puberty at an age of 14 months. The peak of the gonadosomatic index in males was observed at 15 months of age (3.0 ± 0.9%). Female fish did not achieve maturation during their first year and ovarian development did not progress beyond the vesicular oocyte stage within the study period.

Seasonal variation in the profile of sex steroids and histological testicular development of brook trout (Salvelinus fontinalis Mitchill) during the annual reproductive cycle in Tasmania

2017 ◽  
Vol 65 (5) ◽  
pp. 313 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Reproductive Cycle ◽  
Sex Steroids ◽  
Brook Trout ◽  
Gonadosomatic Index ◽  
Mean Value ◽  
Testicular Development ◽  
Ambient Light ◽  
Annual Reproductive Cycle ◽  
Early Maturation ◽  
Second Year

Early maturation in brook trout males has been a constraint for commercial production of this species in Tasmania. However, control of maturation in males can be achieved by manipulating photoperiod (duration of light phase). To design an appropriate light treatment regime, an assessment of the annual reproductive cycle was initially required under ambient photoperiod as the annual reproductive cycle of male brook trout under ambient Tasmanian conditions of light and temperature was unknown. Here we describe the seasonal variations in testicular development and plasma profiles of testosterone (T), 11-ketotestosterone (11-KT) and oestradiol-17β (E2) during the second year in a male brook trout cohort held under ambient light conditions. Brook trout males were recruited for maturation in December when a reduction in daylength presumably stimulated testicular development. Increases in levels of T, 11-KT and gonadosomatic index (GSI) values were observed soon after the summer solstice, corresponding with maturation. The highest GSI mean value (3.44 ± 0.11%) was observed in April when mature males could be manually stripped of milt and such males were present until July. Profiles of sex steroids and histological development observed in this study were finely synchronised with variations in seasonal photoperiod changes. Photoperiod before recruitment during December should be controlled to manipulate maturation in brook trout males during their second year.

scholarly journals Dynamics of ovarian maturation during the reproductive cycle of Metynnis maculatus, a reservoir invasive fish species (Teleostei: Characiformes)

2013 ◽  
Vol 11 (4) ◽  
pp. 821-830 ◽  
Author(s):  
Thiago Scremin Boscolo Pereira ◽  
Renata Guimarães Moreira ◽  
Sergio Ricardo Batlouni
Keyword(s):  
Reproductive Cycle ◽  
Ovarian Development ◽  
Gonadosomatic Index ◽  
Ovarian Maturation ◽  
Invasive Fish ◽  
Multiple Spawning ◽  
Adult Females ◽  
The Mean ◽  
Ovulatory Follicles ◽  
Morphometric Evaluation

In this study, we evaluated the dynamics of ovarian maturation and the spawning processes during the reproductive cycle of Metynnis maculatus. Adult females (n = 36) were collected bimonthly between April 2010 and March 2011. The mean gonadosomatic index (GSI) was determined, ovarian and blood samples were submitted for morphometric evaluation and the steroid plasma concentration was determined by ELISA. This species demonstrated asynchronous ovarian development with multiple spawns. This study revealed that, although defined as a multiple spawning species, the ovaries of M. maculatus have a pattern of development with a predominance of vitellogenesis between April and August and have an intensification in spawning in September; in October, a drop in the mean GSI values occurred, and the highest frequencies of post-ovulatory follicles (POFs) were observed. We observed a positive correlation between the POF and the levels of 17α-hydroxyprogesterone. Metynnis maculatus has the potential to be used as a source of pituitary tissue for the preparation of crude extracts for hormonal induction; the theoretical period for use is from September to December, but specific studies to determine the feasibility of this approach must be conducted.

scholarly journals Mobilization of energetic substrates in the endangered catfish Steindachneridion parahybae (Siluriformes: Pimelodidae): changes in annual reproductive cycle in captivity

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Carlos E. Tolussi ◽  
Aline D. Gomes ◽  
Cristiéle da S. Ribeiro ◽  
Danilo Caneppele ◽  
Renata G. Moreira ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Negative Correlation ◽  
Gonadosomatic Index ◽  
Reproductive Period ◽  
Annual Reproductive Cycle ◽  
Plasma Triglycerides ◽  
Glucose Levels ◽  
Adult Females ◽  
In Captivity ◽  
Continuous Feeding

ABSTRACT This study aimed at analyzing the energetic substrate (ES) in the main storage tissues of Steindachneridion parahybae, throughout the reproductive cycle in captivity. Differently from wild, in captivity, feeding is not interrupted during the reproductive period, the females do not spawn spontaneously, and they are sedentary. Adult females were sampled monthly and based on their histology and gonadosomatic index (GSI), ovaries were classified into: previtellogenic (PRV), vitellogenic (VTG), and regression (REG) stages. Ovaries at the VTG stage showed higher protein and lipids levels than at the PRV stage with a positive correlation between these substrates and the GSI. Muscle was the main source of proteins transferred to the ovaries, according to the negative correlation between these organs. Lipids remained unchanged in the liver, which is an important supplier in vitellogenesis, a pattern that probably occurs due to the continuous feeding. Muscular glycogen levels were higher at the VTG and REG than at the PRV stages. Plasma triglycerides were also higher during REG, while glucose levels were more elevated during the VTG stage. These results suggest that with constant food supply, the pattern of deposition of ES in S. parahybae is different from that described for other wild potamodromous species.

scholarly journals Ovarian Development and Serum Steroid Hormone Profiles in Hatchery-bred Female Catfish Clarias macrocephalus (Gunther) during an Annual Reproductive Cycle

1997 ◽  
Vol 63 (6) ◽  
pp. 867-872 ◽  
Author(s):  
Josefa D. Tan-Fermin ◽  
Shigeho Ijiri ◽  
Hiroshi Ueda ◽  
Shinji Adachi ◽  
Kohei Yamauchi
Keyword(s):  
Reproductive Cycle ◽  
Ovarian Development ◽  
Steroid Hormone ◽  
Annual Reproductive Cycle ◽  
Clarias Macrocephalus

Annual reproductive cycle of the captive female Japanese sardineSardinops melanostictus: Relationship to ovarian development and serum levels of gonadal steroid hormones

1991 ◽  
Vol 108 (1) ◽  
pp. 21-29 ◽  
Author(s):  
M. Matsuyama ◽  
S. Adachi ◽  
Y. Nagahama ◽  
C. Kitajima ◽  
S. Matsuura
Keyword(s):  
Steroid Hormones ◽  
Reproductive Cycle ◽  
Ovarian Development ◽  
Serum Levels ◽  
Gonadal Steroid Hormones ◽  
Gonadal Steroid ◽  
Annual Reproductive Cycle
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