International Journal of Aquaculture, 2016, Vol.6, No.5, 1
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Mahmoud, 1997; EL-Boray et al., 2012; Hashemi et al., 2013) for the same species but comparatively smaller
than that obtained by (Albieri and Araújo, 2010) which may be due to different ecological conditions. (Javadzadeh,
2004; Hashemi et al., 2013) also recorded high K - value in spring and earlier summer for the same species. K
value in the present study not closely associated with the gonado - somatic index and this result may suggest that
the reproduction does not influence fish condition. The condition factor of fishes has been reported to be
influenced by a number of factors such as the onset of maturity, Spawning (De - Silva and Silva, 1979; Al-Daham
and Wahab, 1991), sex and maturity (Gowda et al., 1987; Doddamani and Shanbouge, 2001) and Pollution
(Bakhoum, 1999; Devi et al., 2008). During the present study also the monthly fluctuations in condition factor
seemed to be influenced by gonadal development, availability of food and gastral activity.
3.5 Maturity stages
Maturity stages, refers to the degree of ripeness of the ovaries and testes of fish. In the present study seven sexual
maturity stages of
L.carinata
was classified according to the macroscopic scale used by (Abou-seedo and Stephen,
2004) with some modification. The maturity scale used in the present study is as follows:
3.5.1 Female maturity stage
Stage I (Immature):
The ovaries are narrow, small, thread like, transparent in color and occupy 1/4 of the body
cavity. In this stage sex cells are not discernible macroscopically and the two sexes are difficult to differentiate.
Stage II (Immature & recovering):
The ovaries become larger in size than the previous stage. In this stage the
ovary is light red or pink in color, translucent and occupies about 1/3 of the body cavity. The eggs become slightly
visible.
Stage III (Developing):
The ovaries undergo a further increase in size and the eggs become more visible by the
naked eyes and occupying about 1/2 of the body cavity. The color of ovary changes to be reddish - yellow and
presence to many blood capillaries around the organ.
Stage IV (Maturing):
In this stage, 2/3 body cavity is occupied by the ovaries. The ovaries are long, broad,
swollen, reddish – yellow in color. Eggs are highly visible and numerous and more blood capillaries are observed.
Stage V (Mature):
The ovary is longer than the previous stages, completely swollen, long and almost filling the
body cavity. Color, is reddish yellow or yellow. Large number of vitellogenic oocytes easily observed beneath a
thin, transparent ovary wall, eggs are easily extruded with slight pressure on the belly of fish.
Stage VI (Spawning):
The ovary after complete swollen starts to enter spawning phase and become partially
spawning - ovary with slightly shrunken and flaccid but not completely hollow. In external appearance partially
spawning ovary is similar to ovaries in stages IV or V and is very difficult to differentiate from external feature.
The ovaries color turn to red or reddish – yellow with few crumpled.
Stage VII (Spent):
Ovaries are flaccid but not fully empty, occupying about 1/2 body cavity deeper in color.
Sometimes contain large opaque-yellow residual eggs. In this stage the ovary wall filled with blood capillaries.
Immature ovary of female
L. carinata
present all the year except in pre-spawning and spawning period, while
stage II (Immature & recovering) found with more dominance than the previous stage .Inactive gonads started to
appear from Febraury (9%) to August (15%). stage III was considered the most abundant stage for female during
the study which recorded almost the year except from February to April with high dominance in October (28%) in
pre - spawning period. Mature ovary with visible egg (stage IV) started to appear in September (30%) increasing
to November (32%) when spawning activity was recorded and continued until January (14%), ovaries in (stage V)
started to appear clearly from October (31%) and continued during most of spawning period. Stage (VI) was
recorded in spawning period with high dominance in December (39%) and January (45%), while spent ovary (VII)
was observed at the end of the spawning period in February (58%) and continued with low percentage in April
(8%), and this result indicated that
L. carinata
in Suez Bay has a prolonged winter spawning season started from
November to March (Figure 7).
