17α,20β-Dihydroxy-4-pregnen-3-one: a steroidal primer pheromone increasing milt volume in the goldfish, Carassius auratus

1986 ◽  
Vol 64 (11) ◽  
pp. 2412-2417 ◽  
Author(s):  
N. E. Stacey ◽  
P. W. Sorensen
Keyword(s):  
Carassius Auratus ◽  
Primer Pheromone ◽  
Goldfish Carassius Auratus ◽  
Final Maturation ◽  
17Β Estradiol ◽  
Releaser Pheromone

The volume of milt that could be stripped from male goldfish, Carassius auratus, increased dramatically when fish were exposed overnight to water with concentrations of 17α,20β-dihydroxy-4-pregnen-3-one (17,20P) as low as 10−10 M. A variety of free steroids (pregnenolone, androstenedione, testosterone, 11-ketotestosterone, 17β-estradiol) and glucuronated steroids (etiocholanolone glucuronide, testosterone glucuronide, 17β-estradiol glucuronide), suggested by others to function as pheromones in fish, failed to increase milt volume at a concentration of 5 × 10−9 M. The milt response appears to be specific to 17,20P and progesterone precursors (17α-hydroxyprogesterone, progesterone), but is most sensitive to 17.20P. Because bilateral section of the olfactory tracts completely blocked the milt response to 17.20P, it is believed to be a pheromone. Selective sectioning of the lateral and medial subdivisions of the olfactory tracts demonstrated that the milt response to 17,20P is dependent on the medial tract. Increases in milt in response to 17,20P are not affected by interaction with conspecifics; exposure to 17,20P induced equivalent responses in males held in isolation, paired with a male, or paired with a female. It is proposed that 17,20P, which is produced during oocyte final maturation in the female, is a "primer" pheromone released to the water and that it increases milt volume in the male. This effect is discussed in relation to releaser pheromone effects previously demonstrated in goldfish.

Interaction of 17β-estradiol and ketoconazole on endocrine function in goldfish (Carassius auratus)

2013 ◽  
Vol 132-133 ◽  
pp. 19-25 ◽  
Author(s):  
Zhenhua Yan ◽  
Guanghua Lu ◽  
Donghai Wu ◽  
Qiuxia Ye ◽  
Zhengxin Xie
Keyword(s):  
Carassius Auratus ◽  
Endocrine Function ◽  
Goldfish Carassius Auratus ◽  
17Β Estradiol

The effect of 17β-estradiol on spontaneous ovulation in the goldfish, Carassius auratus

1985 ◽  
Vol 63 (12) ◽  
pp. 2979-2981 ◽  
Author(s):  
N. W. Pankhurst ◽  
N. E. Stacey
Keyword(s):  
Body Weight ◽  
Carassius Auratus ◽  
Mature Female ◽  
Goldfish Carassius Auratus ◽  
17Β Estradiol ◽  
Gonadotropin Surge ◽  
Sexually Mature

Sexually mature female goldfish were treated daily with 17β-estradiol in oil (2 μg∙g body weight−1) or given a single silastic pellet containing 17β-estradiol (50 μg∙g−1) and held under conditions which promote spontaneous ovulation. Levels of 17β-estradiol were found to be significantly elevated by the treatments during the period prior to ovulation. However, neither of the 17β-estradiol treatments had any effect on gonadotropin levels or the number of fish ovulating. A decline in the level of serum 17β-estradiol does not appear to be a critical requisite for the occurrence of the preovulatory gonadotropin surge in goldfish.

Changes in plasma concentrations of gonadotropin, 17β-estradiol, testosterone, and 17α-hydroxy-20β-dihydroprogesterone during spontaneous and brain lesion induced ovulation in goldfish

1983 ◽  
Vol 61 (12) ◽  
pp. 2646-2652 ◽  
Author(s):  
N. E. Stacey ◽  
R. E. Peter ◽  
A. F. Cook ◽  
B. Truscott ◽  
J. M. Walsh ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Brain Lesion ◽  
Time Of Day ◽  
Plasma Testosterone ◽  
Anterior Portion ◽  
Potent Inducer ◽  
Induced Ovulation ◽  
Goldfish Carassius Auratus ◽  
Final Maturation ◽  
17Β Estradiol

Female goldfish (Carassius auratus) were held at 20–21 °C and ovulation was triggered by radiofrequency lesion of the anterior portion of the nucleus preopticus periventricularis (NPP) as in previous studies. NPP lesions induced a rapid and dramatic increase in blood gonadotropin (GtH) which reached peak levels between 9 and 15 h postlesioning and persisted for at least 48 h postlesioning. Unlike spontaneous ovulation, which is synchronized with photoperiod, NPP lesion-induced ovulation at 20–21 °C occurs 10–14 h postlesioning regardless of the time of day the operation is performed. 17α-hydroxy-20β-dihydroprogesterone, a potent inducer of oocyte final maturation in goldfish, could be detected in plasma of lesioned fish only at 5 h after the operation, Plasma testosterone levels peaked 2.5 h postlesioning (about 10 h prior to ovulation) and tended to decrease at subsequent sampling times. In contrast, peak levels of estradiol were not seen until 15 h postlesioning (several hours after ovulation). Pre- and post-ovulatory samples from spontaneously ovulating fish demonstrated a similar pattern of decreasing testosterone and increasing estradiol.

SEM of Hepatocytes and Biliary Passages in Goldfish Liver

1977 ◽  
Vol 35 ◽  
pp. 556-557
Author(s):  
Waykin Nopanitaya ◽  
Joe W. Grisham ◽  
Johnny L. Carson
Keyword(s):  
Carassius Auratus ◽  
Cell Layer ◽  
Three Dimensional ◽  
Cell Types ◽  
Biliary System ◽  
Fish Food ◽  
Commercial Fish ◽  
Goldfish Carassius Auratus ◽  
Commercial Fish Food

An interesting feature of the goldfish liver is the morphology of the hepatic plate, which is always formed by a two-cell layer of hepatocytes. Hepatic plates of the goldfish liver contain an infrequently seen second type of cell, in the centers of plates between two hepatocytes. A TEH study by Yamamoto (1) demonstrated ultrastructural differences between hepatocytes and centrally located cells in hepatic plates; the latter were classified as ductule cells of the biliary system. None of the previous studies clearly showed a three-dimensional organization of the two cell types described. In the present investigation we utilize SEM to elucidate the arrangement of hepatocytes and bile ductular cells in intralobular plates of goldfish liver.Livers from young goldfish (Carassius auratus), about 6-10 cm, fed commercial fish food were used for this study. Hepatic samples were fixed in 4% buffered paraformaldehyde, cut into pieces, fractured, osmicated, CPD, mounted Au-Pd coated, and viewed by SEM at 17-20 kV. Our observations were confined to the ultrastructure of biliary passages within intralobular plates, ductule cells, and hepatocytes.

Induction of Gynogenesis and Androgenesis in Goldfish Carassius auratus (var. oranda)

2001 ◽  
Vol 36 (3-4) ◽  
pp. 195-198 ◽  
Author(s):  
I Paschos ◽  
L Natsis ◽  
C Nathanailides ◽  
I Kagalou ◽  
E Kolettas
Keyword(s):  
Carassius Auratus ◽  
Goldfish Carassius Auratus
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