EFFECT OF HORMONAL INJECTION ON CONCENTRATION OF SEX STEROID HORMONES AND FINE STRUCTURE OF OVA IN FEMALE CHRYSICHTHYS RUEPPELLI DURING SPAWNING SEASON

EFFECT OF HORMONAL INJECTION ON CONCENTRATION
OF SEX STEROID HORMONES AND FINE STRUCTURE OF
OVA IN FEMALE CHRYSICHTHYS RUEPPELLI DURING
SPAWNING SEASON
EL-AGAMY, A.E*; EL-GHARABAWY, M.M.**; EBRAHEEM, N.A.*;
ASSEM, S.S** AND FAHMY A.F.**
* Faculty of Science, Zoology Department, Zagazig University.
** National Institute of Oceanography and Fisheries, Kayed Bey, Alexandria, Egypt.

Key words: Chrysichthys rueppelli – gonadotropin hormone – pituitary extracts– steroid
hormone (estradiol and testosterone) – fine structure.
ABSTRACT
During spawning months “from April to July” the average gonadosomatic index (GSI)
of control female Chrysichthys rueppelli varied between 37.8 ± 4.3 maximal in May and
12.4 ± 2.5 minimal in July. Both serum estradiol and testosterone concentration positively
correlated with GSI. The fish injected by gonadotropin hormone and pituitary extracts as
cumulative dose 15500 I.U. + 4 pituitary extracts in first experiment and day by day with
cumulative dose 11500 I.U.+ 3 pituitary extracts in second experiment. As a result of
injection gradual decrease in the GSI value, serum estradiol and testosterone values were
recorded throughout experiment I and II with highly significant correlation at P< 0.05. This decreases continued after the end of these two experiments. During the third experiment where the fish injected day by day dose by gonadotropin hormone only, as a result of injection the GSI value, serum estradiol and testosterone decrease progressively with increasing cumulative dose of hormonal induction from 3500 I.U. to 13500 I.U. through 24 days. The fish were injected day by day with GtH & LHRHa, in fourth experiment as a result of injection the GSI value increased gradually from (10.5 ± 6.6) to maximum value (22.5 ± 7.40) with increasing cumulative dose of hormonal induction from 1500 I.U. +250 µm to 1500 I.U. + 1000 µm respectively. While serum estradiol and testosterone decrease progressively with increasing cumulative dose of hormonal induction. The ultrastructural studies of the oocyte wall revealed that there are five different layers in the control ripe oocyte of Chrysichthys rueppelli at spawning season. As a result of injection in the third experiment, early atretic oocytes were recorded in the wall of the oocyte after final injection with gonadotropin hormone only. While in fourth experiment late atretic oocyte was recorded after final injection with GtH & LHRHa. In early atretic oocyte there were observed enlargement of theca layer separated from the granulose cells by deformed incomplete basement membrane and the nucleus was de-fragmented in some sites, whereas in late atretic oocytes the cell appeared without any nucleus. The zona radiata becomes more compact without any continuation between granulose cells.