Ovulation induction in northern pike Esox lucius L. using
different GnRH analogues, Ovaprim,
Dagin and carp pituitary
T.
Szabó-2003
Aquaculture
Research, 34(6): 479-486
Abstract:
The
traditional GnRH analogue treatments applying the chemicals in pure form
proved to be ineffective in inducing ovulation in northern pike (Esox
lucius L). Neither mGnRHa ([D-Ala6, Pro9NEt]-mGnRH)
nor sGnRHa ([D-Arg6, Pro9-Net]-sGnRH) administered
alone or together with pimozide (mGnRHa), metoclopramide (mGnRHa) or
domperidone (sGnRHa) induced ovulation in females, whereas in groups
receiving a carp pituitary injection most females ovulated.
Spawning-inducing agent Dagin did not induce ovulation, whereas all but one
female ovulated in the carp pituitary-treated group. Treatment with another
preparation, Ovaprim, resulted in similar or lower ovulation ratio than
treatment with carp pituitary. After the Ovaprim treatment, time to
ovulation was not as predictable as after the carp pituitary injection. The
mean fertilization rate was relatively low and similar in the groups treated
with Ovaprim (54.7 ± 12.3% and 58.7 ± 19.1% for the
first and second experiment respectively) and with carp pituitary (53.7 ± 10.5%
and 58.9 ± 14.9%). The mean pseudogonadosomatic index (PGSI) was
also similar between the Ovaprim-treated group (14.5 ± 6.1%) and
the carp pituitary-treated one (17.9 ± 4.1%). In the present
experiments, treatment with Ovaprim was less effective than that with carp
pituitary.
(Department of Fish Culture, Faculty of
Agricultural and Environmental Sciences, Szent István University, 2103 Gödöllö,
Hungary. E-mail: tszabo@fau.gau.hu)