International Journal of Marine Science 2015, Vol.5, No.19, 1-10
2
Figure 1 Sampling areas: 1 – Round bay, 2 – Blue bay, 3 – Theothan cap, 4 – Laspi bay
Figure 2
R. venosa
soft body with base color of gonad: M –
male with dark orange gonad, F – female with yellow gonad;
gon – gonad, dg – digestive gland, p – penis
The first detailed description of the rapa-whelk gonads
with the sex differences in color indication, gonads’
internal structure and stages of development of germ
cells was performed by V.D. Chuhchin on the
samplings from the Sevastopol bay of the Black Sea
(Chuhchin, 1961a). He also showed that
R. venosa
(misnamed
Rapana bezoar
L.) reaches sexual maturity
at the age of 2+ years (Chuhchin, 1961a, b). At any
time of year the rapa-whelk ovaries contain significant
amounts of mature eggs. Changes only the volume of
the gonads and the number of young oocytes; gonad
never completely released from eggs. In mature
females ovary is yellow and presented in the form of a
dense compact mass, its thickness reaches 3-6mm
(Chuhchin, 1961a, 1970, 1984).
With regard to female gonads color there are no
discrepancies between other researchers who have
studied the
R. venosa
in different areas also. In the
Uruguayan coastal zone of Rio de la Plata females
was determined by the presence of gonophores and
yellow gonads (Lanfrankoni et al., 2009). In the
south-eastern Black Sea of
Turkey the color of the
females’ gonad specified as yellowish (Saglam and
Duzgunes, 2014). In the western part of the Black Sea
off the coast of Romania (Agigea littoral) the females
(with no penis) had yellow gonads (Micu et al
.
, 2009).
Rapa whelk female gonads in Chesapeake Bay were
completely yellow in color with special indication for
“no penis” females (Mann et al., 2006). That
qualification “no penis” is because of besides true
females in Chesapeake Bay and in the Romanian
Black Sea Agigea littoral area as well there were
imposex females registered.
R. venosa
imposex females in Chesapeake Bay had
penis lengths ranging from 1.9mm to 25mm and
gonads that were either completely yellow or a mix of
