Biology Reference
In-Depth Information
O
O
O
T
O
B
T
T
Male
T
O
C
O
O
O
A
T
T
T
D
O
O
O
O
T
T
T
T
Age
(year)
2
3
4
5
6
T = Testicular tissue
O = Ovarian tissue
O
O
O
O
T
O
T
T
T
T
12
18
7
Age
5
9
(spawning season)
(non spawning season)
(month)
Fig. 52.
Schematic representation of ontogenetic pathways of sex changes in hermaphroditic
fi shes. Upper panel: pathways of (A) egg (B) direct transformation to male through juvenile
hermaphroditism, (C) indirect transformation to male through functional female and (D)
retention of functional female status throughout the life span of protogynic (compiled from
Kokokiris et al., 1999)
.
Lower panel: Ontogenic pathway of transformation to a functional
female in protandric ( compiled from Chang et al., 1997)
species represent only a simple membrane (Fig. 54). The wall has not yet
attracted electronmicroscopic studies (cf Lacerda et al., 2006, Fig. 41). It
remains to be seen whether the former ovarian wall comprises of PGCs/
SSCs and/or germ cells supporting somatic cells, from which cells of the
spermatogonia arise. This information is a base for further experiments like
the transplantation of PGCs/SSCs/OSCs.
