Sivash gulf of the Sea of Azov it has been started in autumn and winter, 2010–2011,
that in periodically desalinated by the rice checks waters close to Mysovoye and
Chaykino villages all the studied round gobies Neogobius melanostomus were free
of Kudoa nova, and in sand goby N. fluviatilis this parasite species was found only
once (Yurakhno and Gorchanok 2011). In summer 2011–2012 we observed in the
Black Sea estuary zone of Dnieper river and in Bug and Wisla rivers an absence of
myxosporeans in parasite fauna of round goby N. melanostomus, racer goby
N. gymnotrachelus, sand goby N. fluviatilis and western tubenose goby
Proterorhinus semilunaris. K. nova was met only once in round goby caught near
Ochakov, where we observed periodic approach of the sea waters to the firth
(Kvach et al. 2014). This may testify to the fact that in the zones of considerable
inflow of fresh waters either possible intermediate hosts of the given myxosporeans
species are absent or extremely low water salinity is destructive for its spores. To
reveal survival of myxosporeans Kudoa nova spores when kept in different salinity
waters in summer 2014 we fulfilled an experiment (Yurakhno 2015).
29.2 Material and Methods
On June 19, 2014 fresh fish (25 specimens of round goby, general length
12,7–24,0 cm), caught in the Sea of Azov near Zolotoye village and strewed with
ice was transported from Kerch to Sevastopol. On June 20 the first parasitologic
analysis of sample has been conducted. 48% of 15,5–24,0 cm gobies appeared to be
infected; from their muscle tissue K. nova cysts of 0,25–0,70 mm  1,0–4,0 mm
size have been isolated. By 30 cysts of the given parasite were put into Petri dishes
(60 ml water volume) with sea water (from bay near institute, salinity 17,6‰) and
fresh water (from source of Maximova dacha, 0,22‰ salinity), filtered through
double layer of the filtering paper; then dishes were put into refrigerator (with water
temperature of +16
C). The remaining muscle tissue from 12 infected fishes was
placed into closed crystallizers (water volume 1,5 l), filled with salt and fresh water,
and then placed to the window-sill in a deep niche behind the window (with water
temperature at the day time in shadow +18
C). To struggle with fungi and bacteria
we added to water antibiotics with doses of 1 g of penicilline and 1 g of
streptomycine for 1 l of water (Zavyalov 2007; Adroher et al. 2004 etc). Percentage
of anomalous spores was counted, as a rule, from observations of more than
200–300 spores in fresh water smears.
29.3 Results
At the beginning of experiment the share of anomalous (deformed) K. nova spores
made 2%.
496
V. Yurakhno
that in periodically desalinated by the rice checks waters close to Mysovoye and
Chaykino villages all the studied round gobies Neogobius melanostomus were free
of Kudoa nova, and in sand goby N. fluviatilis this parasite species was found only
once (Yurakhno and Gorchanok 2011). In summer 2011–2012 we observed in the
Black Sea estuary zone of Dnieper river and in Bug and Wisla rivers an absence of
myxosporeans in parasite fauna of round goby N. melanostomus, racer goby
N. gymnotrachelus, sand goby N. fluviatilis and western tubenose goby
Proterorhinus semilunaris. K. nova was met only once in round goby caught near
Ochakov, where we observed periodic approach of the sea waters to the firth
(Kvach et al. 2014). This may testify to the fact that in the zones of considerable
inflow of fresh waters either possible intermediate hosts of the given myxosporeans
species are absent or extremely low water salinity is destructive for its spores. To
reveal survival of myxosporeans Kudoa nova spores when kept in different salinity
waters in summer 2014 we fulfilled an experiment (Yurakhno 2015).
29.2 Material and Methods
On June 19, 2014 fresh fish (25 specimens of round goby, general length
12,7–24,0 cm), caught in the Sea of Azov near Zolotoye village and strewed with
ice was transported from Kerch to Sevastopol. On June 20 the first parasitologic
analysis of sample has been conducted. 48% of 15,5–24,0 cm gobies appeared to be
infected; from their muscle tissue K. nova cysts of 0,25–0,70 mm  1,0–4,0 mm
size have been isolated. By 30 cysts of the given parasite were put into Petri dishes
(60 ml water volume) with sea water (from bay near institute, salinity 17,6‰) and
fresh water (from source of Maximova dacha, 0,22‰ salinity), filtered through
double layer of the filtering paper; then dishes were put into refrigerator (with water
temperature of +16
C). The remaining muscle tissue from 12 infected fishes was
placed into closed crystallizers (water volume 1,5 l), filled with salt and fresh water,
and then placed to the window-sill in a deep niche behind the window (with water
temperature at the day time in shadow +18
C). To struggle with fungi and bacteria
we added to water antibiotics with doses of 1 g of penicilline and 1 g of
streptomycine for 1 l of water (Zavyalov 2007; Adroher et al. 2004 etc). Percentage
of anomalous spores was counted, as a rule, from observations of more than
200–300 spores in fresh water smears.
29.3 Results
At the beginning of experiment the share of anomalous (deformed) K. nova spores
made 2%.
496
V. Yurakhno