scholarly journals Comparison of Oogenesis and Sex Steroid Profiles between Twice and Once Annually Spawning of Rainbow Trout Females (Oncorhynchus mykiss)

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Francisco Estay ◽  
Nelson Colihueque ◽  
Cristian Araneda
Keyword(s):  
Rainbow Trout ◽  
Significant Variation ◽  
Gonadosomatic Index ◽  
General Pattern ◽  
Sex Steroid ◽  
Maximum Diameter ◽  
Oocyte Growth ◽  
Maximum Value ◽  
Gonadal Histology ◽  
Steroid Profiles

This study compares the gonadosomatic index (GSI), oocyte growth (OG), gonadal histology, and plasma level concentrations of sex hormones (estradiol-17β(E2) and vitellogenin (V)) of twice-spawning (T-SP) and once-spawning (O-SP) females of rainbow trout throughout the additional and the normal reproductive cycle, respectively. In T-SP, the GSI values rapidly increase from May to November, in contrast to O-SP, which showed low and constant GSI values (1.19 to 14.5 and 1.19 to 0.63, resp.). T-SP exhibited a marked increase of OG in the same period, reaching a maximum diameter of 4,900 ± 141.42 μm, in contrast to O-SP, which presented a slow OG. The gonadal histology of T-SP agreed with the general pattern of ovogenesis observed for O-SP (vitellogenesis, ovulation, and recrudescence); however, this process was nonsynchronous between the two breeder groups. Plasma steroid levels showed significant variation during oogenesis, which agreed with the GSI, OG, and gonadal histology patterns. The level of E2 increased to a maximum value of 26.2 ng/mL and 36.0 ng/mL in O-SP and T-SP, respectively, one or two months before the spawning event where vitellogenesis was fully active. The V concentrations followed a pattern similar to those of E2.

Steroid Profiles of Wild Terror Green (Andinoacara rivulatus) Associated with Gonadal Histology in the Baba River, Ecuador

2021 ◽  
Vol 11 (4) ◽  
pp. 1612
Author(s):  
Juan Ortiz Tirado ◽  
Manjunatha Bangeppagari ◽  
Alfonso Benavides ◽  
Daysi Muñoz ◽  
Pedro Romero ◽  
...  
Keyword(s):  
Gonadal Histology ◽  
Steroid Profiles

Relationship between hepatic deiodination of thyroxine and early oocyte development in rainbow trout, Oncorhynchus mykiss

1999 ◽  
Vol 77 (3) ◽  
pp. 509-513 ◽  
Author(s):  
Sylvia M Ruby ◽  
J Geoffrey Eales
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Gonadosomatic Index ◽  
Stage Iv ◽  
Biologically Active ◽  
Stage Ii ◽  
Oocyte Development ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Yolk Globule ◽  
Thyroidal Status

We examined the relationship between five stages of ovarian growth and development and hepatic microsomal thyroxine (T4) deiodinating activity in rainbow trout, Oncorhynchus mykiss, held in the laboratory at 11.5°C. Thyroxine outer-ring deiodination (T4ORD) activity, which forms biologically active 3,5,3'-triiodothyronine (T3), was low when the gonadosomatic index (GSI = (ovary mass X 100) / body mass) was below 0.2 (stage I, previtellogenesis), but rose sharply between GSI values of 0.2 and 0.3 (stage II), when oocyte Balbiani activity, RNA synthesis, and endogenous vitellogenesis were maximal. Hepatic T4ORD activity was again low during exogenous vitellogenesis at GSI values of 0.3-12, which correspond to stages III-V. Hepatic T4 inner-ring deiodination (T4IRD), which forms biologically inactive 3,3',5'-triiodothyronine, was detected only at stage II. Plasma T3 concentrations were significantly higher at stage II than at stage IV (primary yolk globule formation). Our data indicate changes in systemic thyroidal status at stage II and are consistent with a role for T3 in early oogenesis in trout. Enhanced hepatic T3 production at the late Balbiani stage may be required for oocyte development.

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.

scholarly journals International Real Estate Review

2014 ◽  
Vol 17 (2) ◽  
pp. 241-274
Author(s):  
Frank Packer ◽  
◽  
Timothy Riddiough ◽  
Jimmy Shek ◽  
◽  
...  
Keyword(s):  
Significant Variation ◽  
General Pattern ◽  
Market Development ◽  
Institutional Characteristics ◽  
Economic Data ◽  
Commercial Property ◽  
The Past ◽  
Construction Activity ◽  
New Construction ◽  
Different Sources

Securitized equity interests in commercial property (the so-called listed REIT market) across a number of countries are analyzed. In so doing, we have pulled together financial as well as real economic data from a large number of different sources. On the real side, we focus particularly on office property construction, as data are fairly available in that sector. The comparison of REIT markets across countries reveals significant variation in terms of institutional characteristics, but many similarities in terms of financial performance. Office construction activity also displays some synchronicity across countries, with a general pattern of reduced levels and volatility in construction activity over the past two decades. Linkages between REIT market development and the dynamics of new construction activity are explored.

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