International Journal of Marine Science 2015, Vol.5, No.19, 1-10
9
individual species. Still S.A. Zernov was noted that
the most abundant
M. galloprovincialis
settlement
developed on the rocks in close proximity to
Sevastopol (Zernov, 1913) which domestic waste
water are man-made eutrophicators. As filter feeders
like mussels are the main food of Rapana and many
other muricides, the size and number of the predators
in areas of anthropogenic eutrophication may even be
higher than originally clear waters. In the investigated
bays the lowest average size and weight of
R. venosa
individuals correspond to the purest of them - the
Laspi bay. And the greatest individual maximum
weight of Rapana and the number of the oldest (12
years of age) specimens were marked for the most
polluted Round bay.
Based on the above the change in color of
R. venosa
females gonads not necessarily related to imposex
status and pollutants. Change in color of gonads
R.
venosa
females without a penis on the colors typical
of males can also be attributed to the manifestation of
intersexuality. Supposedly this is the result of changes
in physiological processes caused by external factors.
But it remains unclear exactly which environmental
factors are responsible for the occurrence of such
physiological abnormalities.
Changes in the color spectrum gonads of male
R.
venosa
in some populations probably due to a change
of the food spectrum and reflects some evolutionary
change of the species. Further study of the changes in
the generative and other soft tissues in conjunction
with the ecological and biochemical studies will help
open a bit the “door to the kitchen” of Evolution.
3 Material and Methods
Collection of samples for this study was carried out in
the vicinity of the city of Sevastopol and the southern
coast of Crimea (Laspi bay). Sampling conducted at
depths of 3 - 6 meters in ecologically different habitats:
1- open shallow bay in the city (Round Bay), 2 open
bay on the border of the city limits (Blue bay), 3-
rocky cape Theophane, 4 - open bay in the
recreational area of Crimea (Laspi bay) (Figure 1).
In the Round and Blue bays samplings were made in
June-September 2012 - 2014, at Cape Theophane - in
August and September 2014, in the Bay of Laspi - in
July and August 2014.
The number of individuals examined by area and year
was as follows: Round bay: 2013 - 35 individuals,
2014 - 40 individuals; Blue bay: 2012 -30 individuals,
2013 - 50 individuals, 2014 - 180 individuals; cape
Theophane: 2014 - 25 individuals; Laspi bay: 2014 -
15 individuals. In addition to specialized collections
considered unpublished authors' data for the study of
R. venosa
1990-2010 periods.
After the sampling
R. venosa
individuals subjected to
freezing followed defrost for testing and
photographing in the laboratory. Empirically it has
been found that the color of the mollusks soft parts
after thawing remained unchanged. After freezing and
defrosting the percentage of extracted from the shell
without significant damages soft organs is increased
compared with freshly caught from 10-30% to
60-90% in different populations. Soft body was
extracted by a metal hook that allows getting inside
the shell and tearing columellar muscle at the place of
attachment. This method allows keeping intact the
shell which is necessary to determine the age of
mollusk. Individual age
R. venosa
specimens
determined based on annual spawning marks on the
shell in accordance with the method proposed
Chuhchin V.D. (1961a,b) as represented (Bondarev,
2010). To more accurately determine the age the
specimen shell must be cleaned of various types of
surface growths. The outgrowth from the surface of
the shell removed using a chlorine-containing alkali
(the first stage) then mechanically and hydrochloric
acid (the final stage) to remove any of remains
calcareous encrustations. Age of the investigated
specimens ranged from 2 to 12 years.
Total shell length (SL) was measured using a caliper
(0.1mm) total animal wet weight (W) and whelk wet
tissue weight (TW) were recorded using a digital scale
balance (0.1g). Since soft body mollusk difficult to
measure accurately the Figures in the article are
accompanied by data on total shell length (SL).
Each whelk was classified as male or female by penis
presence/absence respectively and gonad color. Sex
determination in males with reduced penis was performed
under an optical microscope at 40x magnification.
Photographing samples using digital cameras carried
out selectively directly after removing the soft body of
the shell. Abnormal specimens photographed
everything and typical ones in the number necessary
to cover age and color range.
