Categories
vol-25POSSIBLE INVOL VEMENT OF SOMA TOLACTIN IN THE
REGULATION OF SEXUAL MATURATION AND SPAWNING OF
MUGIL CEPHALUS
By
MOSTAFA A. MOUSA*, SHAABAN A. MOUSA
*Nationallnstitute ojOceanography and Fisheries, Aif:;xandrta, Egypt.
Key words: Immunocytochemistry – Pituitary gland- SomatolactinMugU cephalus.
ABSTRACT
An antiserum to chum salmon somatolactin (SL) was usedfor ‘ .
immunocytochemical investigation of SL cell activity of Mugil
cephalus, during gonadal cycle in both natural habitat andcaptivity.
The SL-immunoreactive cells showed strong and speCific
immunoreactive
immunoreactivity
cells
to
showed
anti-chum salmon
an increase in
somatolactin.
the secretory
The
and
SLthe
synthetic activity during sexual maturation and spawning in natural
habitat. SL cells were rather small and moderately immunoreactive in
immature fish. They were enlarged andfrequently more granulated
during gonadal development. In addition, in late stages ofmaturation,
comparatively larger and more degranulated cells were noted, also
indicating an active release of SL grarmles. Prespawningfemales
tended to have more enlarged SL cells with strong immunoreactivity
than equivalent males. Degranulation, vacuolization and weak
immunoreactivity of SL cells have occurred during spawning. The SL
cells of Mugil cephalus, reared in captivity, appeared with high
activity. This may be due to the low concentration ofcalcium infresh
water. The gradual stimulation of SL syrithesis and release during
sexual maturation and spawning ofM. cephalus suggest that SL may
be involved in the control of some steps ofreproductive processes,
such as steroidogenesis, calcium metabolism and energy mobilization.
