|
|
Ploidy and sexual status of the "Carassius auratus" complex in the waters of the Czech Republic
Lusková, Věra ; Lusk, Stanislav ; Halačka, Karel ; Vetešník, Lukáš ; Papoušek, Ivo
The "Carassius auratus" complex, non-indigenous in the Czech Republic, comprises several forms: C. a. auratus (decorative form), C. a. gibelio (predominant), and C. a. langsdorfii (Japanese form). C. a. gibelio is considered a "non-indigenous invasive species". Around 1975, the form invaded the waters of the Czech Republic from the Danube drainage area. The first invasive individuals were triploid females reproducing gynogenetically. The first males occurred in the Dyje River drainage area after 1990 and began transforming to a mixed type, both the sexual and ploidy status of C. a. gibelio populations changing. At present, the overall percentage representation of males in C. a. gibelio populations varies around 30 %, most of them being diploids, triploids occurring only occasionally. A larger part (60 %) of the females, which still predominate in the population, are triploids, the rest being diploids. Tetraploid individuals of both sexes occur quite singly.
|
|
| |
|
| |
|
|
Several biological characteristic of Carassius auratus
Vetešník, Lukáš ; Lusk, Stanislav ; Spurný, P.
Based on realized research it was found that the present population of Carassius auratus occurred in the lower reach of the river Dyje does not have any significant differences in plastic and meristic characters when compared to the individuals occupying this area 27 years ago. The growth depends on the living conditions of studied individuals. The growth of 2n males was significantly slower comparing to 3n females.
|
|
|
Diploid, triploid and tetraploid silver crucian carp Carassius auratus from the lower reach of Dyje River: the first results of reproductive characteristics and experimental hybridization
Flajšhans, Martin ; Lusková, Věra ; Vetešník, Lukáš ; Halačka, Karel ; Rodina, Marek ; Lusk, Stanislav ; Gela, David
Diploid, triploid and tetraploid males of silver crucian carp, Carassius auratus, produced live motile spermatozoa, capable of fertilization. Flow cytometry for the relative DNA content in male gametes revealed spermatozoa of diploid males to be haploid, those of triploid males to be aneuploid and those of tetraploid male to be aneuploid and/or diploid. Concentration of spermatozoa and the percentage of live spermatozoa showed a tendency to drop with increasing ploidy level and this effect was significant for the tetraploid male compared to those of lower ploidy levels.
|
|
|
The ploidy of Carassius auratus in the Czech Republic in light of the artificial reproduction
Halačka, Karel ; Vetešník, Lukáš ; Flajšhans, M.
State of population of Carassius "gibelio" (the sex ratio and ploidy level) was for a long time observed in the Dyje river floodplain, where it has expanded by natural migration from the Danube river through Morava river in 1975-1976. Results show the time dynamics for both parameters, with increasing proportion of males and increasing proportion of diploids of both sex and the formation diploid-polyploid complex. Diploid, triploid and tetraploid males and females of silver crucian carp, Carassius auratus, as well as males of silver Blicca bjoerkna and Rutilus rutilus, were used in mating. The results show different reaction of females on used sperm even in the same group of ploidy. The existence of some groups of the individuals with a different strategy of reproduction in frame single population could be the explanation.
|
|
|
The influence of ploidy on the complete blood count in silver crucian carp
Vetešník, Lukáš ; Halačka, Karel ; Lusková, Věra ; Lusk, Stanislav
In the sample of 27 specimens of silver crucian carp (Carassius auratus) of different ploidy (5 diploids, 21 triploids and 1 tetraploid), the red component of complete blood count was found. Using the analysis of variance test, highly significantly lower erythrocyte count, insignificantly lower haemoglobin count and haematocrit value were proved. The mean corpuscular volume was increasing significantly with the ploidy increased, and mean corpuscular haemoglobin was increasing highly significantly with the ploidy increased.The tetraploid specimen indicated similar trend depending on the higher ploidy level.
|
guest ::
