International Journal of Marine Science 2015, Vol.5, No.19, 1-10
4
At any time of the year the male vas deferens is filled
with matured sperm and in testis germ cells are found
in all stages of development. In the two-year male
gonads are yellow or yellow-orange and testis of
mature males have light or dark orange color
(Chuhchin, 1961a, 1970, 1984). In the late 1990s -
early 2000s the color of the
R. venosa
males gonads in
the Black Sea match this description (Figure 2)
according to our unpublished observations.
Rapana venosa
male gonads in Chesapeake Bay were
bright orange-red (Mann et al., 2006), reddish-brown
in the Uruguayan coastal zone of Rio de la Plata
(Lanfrankoni et al., 2009), and red-brown gonads from
Romanian Agigea coast (Micu
et al.
, 2009) that is also
close to basic description of specimen from
Sevastopol Bay (Chuhchin, 1961a, 1970, 1984). Quite
different is brownish for males’ color of the gonad of
Rapana venosa
from the south-eastern Black Sea of
Turkey (Saglam and Duzgunes, 2014).
In 2012
R. venosa
male with gonad dark brown almost
black in color (Figure 6 L) was found. Further investigation
Figure 6
R. venosa
males’ soft bodies of Round (A-C, L) and
Laspi (D-K) bays 2014 sampling with indication of individual
age and the shell length: A – 3 years, 43.1mm, B – 4, years
58.2mm, C – 4 years, 57.5mm, D – 5 years, 61.5mm, E – 6
years, 46.5mm, F – 6 years, 59.2mm, G – years 6, 66.0mm, H –
6 years, 46.5mm, I – 7 years, 53.5mm, J – 8 years, 70.1mm, K
– 8 years, 50.4mm, L – 10 years, 52.1mm
showed that the dark brown “abnormal” color actually
was normal for males older than 6 years of the studied
populations in 2012-2014 bays (Figs 6F-L, 8K, L, M)
and does not occur in younger individuals. Very dark
brown to black-brown gonads are characteristic
specimens older than 8-10 years (Figures 6K, L; 8Q,
R, S). Young adult males age 2+ - 3-4 years gonads
much lighter, they are painted in cream and beige or
light brown tone (Figures 6A, B; 8F, G).
Enhancing the intensity of brown color gonads with
advancing age is a trend for the majority of the
Crimean
R. venosa
populations at the present stage of
the species development (Figures 6, 8). Moreover, it
was found that the previously typical males’ gonads
orange color began seldom met after 2012 for the
local populations inhabiting on the sandy bottom
where the main nutrition object is bivalve
Chamelea
gallina
(L., 1758).
The population, which still prevail
R. venosa
males
with red and orange colors and shades of gonads
(Figure 7) inhabits the rocky surface Cape Theophane
where Rapana feeds mainly on bivalves
Mytilus
galloprovincialis
Lam., 1819 and
Mytilaster lineatus
(Gmelin, 1791).
Figure 7
R. venosa
males’ soft bodies of cap Theothan 2014
sampling with indication of individual age and the shell length:
A – 3 year, 48.2mm, B – 3 years, 54.0mm, C – 8 years, 66.8mm
Orange-red part of the spectrum is present in the color
of the Rapana gonads from sandy bays as an impurity
to brown, creating a sufficiently large variety of
shades (Figure 8). It is possible to trace the two color
lines in the color of the gonads, characterized by the
presence and amount of impurities to the basic brown
of red and orange hues (Figure 8). It is possible that
such a pattern characteristic of Blue Bay population as
a result of interaction with the located nearby Cape
