Biology Reference
In-Depth Information
SS
ot
ot
ot
ol
ol
ol
S
C
t
t
t
SS
OS
S
Fig. 50.
Changes in the confi guration of ovarian and testicular tissues in hermaphroditic
fi shes. (a) Delimited type:
Pagrus pagrus
, (b) Undelimited type 1:
Hypoplectrus puella
and
(c) Undelimited type 2:
Epinephelus guttatus
. c = connective tissue; ol = ovarian lumen; os =
ovarian sinus; ot = ovarian tissue; s = sperm duct; ss = sperm sinus; t = testicular tissue (from
Sadovy and Shapiro, 1987)
dichromatics (e.g.,
Sparisoma viride
) are present. Among the diandric
species, the newly sex changed Initial Phase (IP) males have a dull body
color like the females (cf Neff, 2003a) but they are then transformed into
brightly colored Terminal Phase (TP) males (e.g.,
Calotomus japonicus
).
The serials change sex more than once in either direction. One or another
pattern of hermaphroditism is not necessarily restricted to a taxonomic
family or genus. For example,
T. cupido
is a monoandric but
T. bifasciatum
a diandric,
Pseudolabrus celidotus
a dichromatic monoandric but
P. sieboldi
a serial (Pandian, 2010). Within a single genus such as
Choerodon,
there are
monoandric, as in
C. transversalis
and diandric, as in
C. albigena
(Nakazona
and Kusen, 1991).
Distribution of gonad types: Hermaphrodites have either an ovotestis
or a gonad. Delimited type of ovotestis consisting of distinct heterologous
zones of testicular and ovarian lobes, which are separated by a connective
wall (Fig. 50) is present among both protogynous species (e.g., many
sparids,
P. pagrus
) and protandrous species (e.g.,
Acanthopagrus schlegeli
).
In these sparids, the ovary is located dorsally and the testis ventrally. The
undelimited type of gonads, are classifi ed into two groups (Sadovy and
Shapiro, 1987). In the undelimited type 1, the ovarian and testicular tissues
come in contact with each other but are never intermixed (e.g.,
Hypoplectrus
puella
) and in the type 2, the ovarian and testicular tissues are intermingled
during the course of sex change (e.g.,
E. guttatus
). Rather a very different
gonad type, not described by Sadovy and Shapiro (1987), has been described
by Takamoto et al. (2003); in the balastid
Suffl amen chrysopterus
the female
to male sex change is accompanied by the diminishing ovarian component,
and enlarging and maturation of the vestigial testies (Fig. 51).
