Biology Reference
In-Depth Information
Table 4.
Ontogenetic pathways of sex differentiation in monandric protogynic and protandric
hermaphrodites
Species/References
Reported observations
Protogynics : Serranidae
Cromileptes altivelis
Liu and Sadovy de Mitcheson (2009)
Undifferentiated gonadal primordium develops
an ovarian lumen. Meiotic oocytes are then
formed. Differentiate into functional ovary and
testis. A bisexual phase is missing
Sparidae
Pagrus major
Matsuyama et al. (1988)
Juvenile bisexuality
. Gonad with ovarian
lumen. Testis and ovary arise from bisexual
gonad. Delimited gonad. Sex ratio 1♀ : 1♂.
Transitional 13-33%
Gobiidae
Tigrigobius multifasciatum
Cole (2008)
Commences with ovary. Differentiates into
transient expression of bisexual gonad. Testis
and ovary are differentiated from the bisexual
gonad
Labridae
Labroides dimidiatus
Kobayashi (1999)
Early gonadogenesis. Differentiation into
intersex gonad. Some of them differentiate into
testes, while others into ovaries
Parapercidae
Parapercis snyderi
Kobayashi et al. (1993)
Early undifferentiated gonad become
intersexual. All of them differentiate into ovaries.
Secondary males arise from females
Protandrics : Sparidae
Diplodus sargus
(Coetzee, 1986)
D. vulgaris
(Pajuelo et al. 2006)
Males and females are seen to arise from special
types of protandric juvenile hermaphrodites
Sarpa salpa
Joubert (1981)
Juvenile hermaphroditism
. All mature males
retain the vestigial juvenile ovarian tissue
is prolonged for 5.5 years, when the bisexual gonad sexually matures and
differentiates into male and female bronze bream.
Type 3.
Rudimentary hermaphroditism
is observed among the gonochores
of Serranidae, a family known for simultaneous and sequential
hermaphroditism. In this type, all of them commence as rudimentary
hermaphrodites; some directly differentiate into females (Fig. 3), while
from the remaining both males and females arise.
Mycteroperca rosacea
is a
good example (Table 3).
Type 4.
Juvenile hermaphroditism
is a well known type as documented in
Danio rerio
. In this type, all gonads fi rst develop into ovary with oocytes
and ovarian cavity (Fig. 3). Later, the oocytes are degenerated by apoptosis
in half of them and the degenerated gonad in the presumptive males
differentiate into normal testes. The transformation from the ovary to
