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Induction of ovulation in endemic
Chalcarburnus
chalcoides,
living in the Caspian Sea, using LRH-Aa combined with
metoclopramide
Mehdi Yousefian*,
Halat Goli Gezel and Hedayati Fard Masoud
Islamic Azad University of Gaemshahre, Iran.
*Corresponding author. E-mail:
Yousefianeco@yahoo.com.
Accepted 9 September, 2008 |
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The study was performed in order to try to provoke the
gonadotropin wave and ovulation in Chalcarburnus
chacoides using GnRH analogue, pituitary extract and
dopamine antagonist. Different doses and injection protocols
were applied using a combination of LRH-Aa, metoclopramide
and carp pituitary extract.
C. chalcoides
show wide individual variation and
much slower response to different hormonal stimulation.
Saline (0.9% Nacl) injected fish were used as a control
group and no ovulation occurred in this group. Based on the
spawning ratio, fertilization rate and hatching rate, the
combination of LRH-Aa 5 µg/kg, carp pituitary
extraction 2.7 mg/kg and metoclopramide 2 mg/kg bw
doses were found to be more efficient than carp pituitary (4
mg/kg). Following
the above procedure it was possible to obtain 80 ± 2%
ovulated females in laboratory condition. Fertilization rate
was 83 ± 5% and hatching rate 90 ± 3% of fertilized eggs.
The survival rate of larvae was 81%. No females ovulated in
the treatment group receiving metoclopramide at 10 mg/kg and
LRH-Aa alone at 100 μg/kg.
Key words:
Chalcarburnus chalcoides,
spawning, LRH-Aa, metoclopramide, carp pituitary extract. |
