scholarly journals Changes in Plasma and Ovarian Steroid Hormone Level in Wild Female Blue Tang Fish Paracanthurus hepatus during a Reproductive Cycle

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 889
Author(s):  
Huynh Sang ◽  
Ho Lam ◽  
Le Hy ◽  
Pham Ky ◽  
Phan Minh-Thu

This study aimed to document the seasonal cycle of steroid levels in the plasma and ovary, including testosterone (T), estradiol-17β (E2) and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) in relation to ovarian development in wild populations of female blue tang fish. The gonadosomatic index (GSI%) maintained high values from April to July and increased from the II to IV ovarian stages and dropped in the V stage. Levels of plasma, ovary T and E2 and DHP were high from March to July. Plasma T and E2 levels were low in the II stage when most oocytes were previtellogenic, reaching a peak during spawning, and decreased in the V stages when fish were going to late spawning and termination. DHP was detected in all stages of the ovary with a higher level in spawning fish but decreased after spawning. These results revealed that T, E2 and DHP could be involved in ovarian development and DHP may play a significant role as a maturational inducing hormone in blue tang fish.

2011 ◽  
Vol 142 ◽  
pp. 233-237
Author(s):  
Han Wen Yuan ◽  
Fang Chen ◽  
Qiao Qing Xu ◽  
Shi Yuan Gong ◽  
Zhang Jie Chu ◽  
...  

The effects of stocking density on various growth parameters and sex reversal in the rice field eel (Monopterus albus) were investigated by evaluating steroid hormone, the gonadosomatic index (GSI) and sex ratio. Fish (mean initial weight of 9.88 ± 0.70 g) were stocked to densities of 4, 20, 36, 52, 68, 84 or 100 fish/m2 in cages (2 m × 1 m × 1.5 m) in a pond, with five replicate cages for each density. Fish were fed for 420 days on a formulated isocaloric diet containing 40.22% crude protein and 12.86 MJ/kg. Serum E2 and T concentrations were determined by radioimmunoassays. There were no significant differences in final bodyweight (FBW) and daily weight gain (DWG) for fish in the groups containing less than 52 fish/m2, while FBW and DWG were significant lower in groups at 68 fish/m2 or more. Specific growth rate (SGR) differed significantly between the 84 and 100 fish/m2 groups compared with the 4, 20 and 36 fish/m2 groups. There was no significant difference in SGR in groups containing less than 84 fish/m2. There were no significant difference between the 4 and 20 fish/m2 groups in net yield (NY), but these groups did differ significantly from the other groups. The final condition factors of fish stocked at 84 or 100 fish/m2 were significantly lower than fish stocked at the other densities. E2 and T hormone concentrations declined as stocking density increased, while GSI values increased initially but then reduced with increasing stocking density. Female ratio and survival decreased with increasing stocking density. The proportion of male fish was significantly greater in the three highest stocking density groups. Therefore, high stocking density may promote sex change from female to male in M. albus.


Reproduction ◽  
2021 ◽  
Author(s):  
Vasiliki E. Mourikes ◽  
Jodi A Flaws

The ovaries play a critical role in female reproductive health because they are the site of oocyte maturation and sex steroid hormone production. The unique cellular processes that take place within the ovary make it a susceptible target for chemical mixtures. Herein, we review the available data regarding the effects of chemical mixtures on the ovary, focusing on development, folliculogenesis, and steroidogenesis. The chemical mixtures discussed include those to which women are exposed to environmentally, occupationally, and medically. Following a brief introduction to chemical mixture components, we describe the effects of chemical mixtures on ovarian development, folliculogenesis, and steroidogenesis. Further, we discuss the effects of chemical mixtures on corpora lutea and transgenerational outcomes. Identifying the effects of chemical mixtures on the ovaries is paramount to preventing and treating mixture-inducing toxicity of the ovary that has long-term consequences such as infertility and ovarian disease.


2013 ◽  
Vol 11 (4) ◽  
pp. 821-830 ◽  
Author(s):  
Thiago Scremin Boscolo Pereira ◽  
Renata Guimarães Moreira ◽  
Sergio Ricardo Batlouni

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.


2019 ◽  
Vol 39 (4) ◽  
pp. 493-499
Author(s):  
Naoya Osaka ◽  
Akihiro Takemura

Abstract We investigated the reproductive characteristics of a terrestrial hermit crab (Coenobita rugosus H. Milne Edwards, 1837) inhabiting Okinawa-Jima. Monthly changes in the gonadosomatic index and ovarian histology revealed that this species had fully developed oocytes from May to October. Data showing that females with (ovigerous females) and without (non-ovigerous females) embryos on their pleopods appeared simultaneously on the shore from June to September 2014 demonstrates that this species undergoes larval release several times for four months. When non-ovigerous females were reared under a combination of two day lengths and two temperatures, oocyte development was induced in the high-temperature group, suggesting that temperature is a proximate factor in ovarian development. The weekly collection of females during the spawning season revealed that the proportion of fully developed oocytes in an ovary increased toward the time of the new moon and decreased around the first-quarter moon, suggesting that this species is a lunar-spawner with a new-moon preference. Some females releasing larvae around the new or full moon were recaptured at approximately 30 d intervals, suggesting at least two major groups with lunar-synchronized larval release. The ovarian development and larval release of C. rugosus are likely entrained to external factors, which change periodically in their habitats.


2016 ◽  
Vol 2 (3) ◽  
pp. 349
Author(s):  
Tarsim Tarsim ◽  
Muhammad Zairin Junior ◽  
Etty Riani

Studi ini bertujuan untuk mengetahui pengaruh penyuntikan hormon estradiol-17β terhadap perkembangan ovari udang putih (Litopenaeus vannamei). Dosis estradiol17β yang digunakan adalah 0,05 μg/g; 0,10 μg/g; 0,25 μg/g bobot tubuh dan kontrol Hasil penelitian menunjukkan bahwa penyuntikan estradiol-17β berpengaruh terhadap perkembangan gonad. Indeks maturasi pada perlakuan dosis 0,10 μg/g and 0,25 μg/ g bobot tubuh lebih besar (75,00% dan 66,67%) dibanding kontrol. Peningkatan diameter oosit terlihat nyata pada TKG I dan II. Meskipun pada TKG III dan IV peningkatan oosit tidak terlihat nyata, tetapi proporsi oosit matang lebih besar. Hal ini menunjukkan bahwa pemberian estradiol-17β pada induk udang ablasi menghasilkan telur yang lebih cepat berkembang dibandingkan jika hanya menggunakan ablasi. Penyuntikan estradiol-17β sangat berpengaruh pada awal perkembangan gonad. Hal ini menunjukkan bahwa estradiol-17β berperan penting dalam merangsang endogenous vitelogenesis.The present study analyzed the effect of estradiol-17 β injection on ovarian development of white shrimp, Litopenaeus vannamei. Estradiol-17 β dose of 0.05 υ g/g, 0.10 μ g/g, 0.25 μ g/g body weight and the control was used, with 15 females broodstock of each. The result showed that ovarian development affected by estradiol-17 β injection. Maturation index in dose of 0.10 μ g/g and 0.25 μ g/g body weight was 75.00% and 66.67% respectively and higher than that of control. Oocytes diameter increased significantly on stage I and stage II, although oocytes diameter in stage III and IV was no significant different but the proportion of mature oocyte higher than that of control. It suggested that estradiol-17 β gave much more developed conditions in oocytes developmental stages and size, compared to control with unilateral eyestalk ablation only. The dominant effect is in early developmental stage of oocyte. It indicates that estradiol-17 β is important to induction of endogenous vitellogenesis in white shrimp.


1997 ◽  
Vol 48 (8) ◽  
pp. 875 ◽  
Author(s):  
Megumi Minagawa ◽  
Motohiko Sano

Oogenesis and ovarian development in female Panulirus japonicus were examined by light and electron microscopy. Eight substages (oogonium, bouquet, chromatin nucleolus, oil globule, pre-yolk platelet, yolk platelet, pre-maturation and maturation) were distinguished in the typical process of oogenesis (multiplication, pre-vitellogenesis, vitellogenesis and maturation stages). Yolk accumulation started at the late pre-yolk platelet substage, when electron-dense granules appeared. Yolk granules seemed to be accumulated in two ways, being produced endogenously by the abundant rough endoplasmic reticulum during vitellogenesis and exogenously by micropinocytosis from the yolk platelet to pre-maturation substages. Ovulation occurred after oocytes became mature (i.e. after the metaphase of the primary maturation division was reached). The diameter of mature oocytes was 465–477 µm. The seasonal ovarian development cycle was divided into seven stages: inactive, developing, ripe, re- developing, re-ripe, spawned and recovery. The morphological characteristics relating to the gonadosomatic index (GSI) of each stage are described (GSI was calculated by the formula I = W × 105/L3, where I represents GSI, W is the gonad weight in grams, and L is the carapace length in millimetres). Estimated GSI values ranged from 11.3 to 12.4 in individuals with mature oocytes, and the 99% confidence intervals for GSI values of adjacent oogenesis substages did not overlap. GSI values at the developing and ripe stages were significantly larger than those at the re-developing and re-ripe stages, respectively.


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