determination system in sterlet sturgeon is female heterogamety (ZW). In this sex
determination system, both females and males produced and population and descendant of
sterlet sturgeon could recover.
Discussion
Sturgeons with female heterogametic sex determination system (ZW) could be recovered
using induction of gynogenesis, namely by presence a female only, both female
and male can
be produced (Saber et al., 2014). For induction of gynogenesis, it is sufficient using UV-
irradiated heterlogous sperm and inseminated with normal egg of threatened species. Then
diploidization carried out using retention of the second polar body. Such a methodology in a
species with female heterogamety would produce both females and males simultaneously,
making population recovery possible; for example, inducing gynogenesis in eggs from
endangered species such as Japanese sturgeon (Sakhalin)
Acipenser mikadoi using UV-
irradiated sperm of the bester (Omoto et al. 2005). Irradiated Siberian sturgeon’s sperm could
be used as a heterologous sperm for gynogenesis induction in other sturgeon species. Also,
inducing diploid gynogenesis of endangered sturgeon populations in which their males cannot
be recovered could be reproduced with genetically inactivated donor sperm from other
sturgeon species, and this method would save them from extinction.
Acknowledgements
The authors thank the personnel and staff of the Propagation & Culture
Department of the
International Sturgeon Research Institute.
References
Gessner J, J., Freyhof, and M., Kottelat, (2010),
Acipenser ruthenus – The IUCN Red List of Threatened
Species. Version 2014.2.
www.iucnredlist.org
.
Omoto N., Maebayashi M., Adachi S., Arai K. and Yamauchi K. Sex ratios of triploids and gynogenetic
diploids induced in the hybrid sturgeon, the bester (
Huso huso female×
Acipenser ruthenus
male) // Aquaculture,
s,
Elsevier, 2005, 245(1-4), p. 39-47.
Saber M. H., Noveiri S. B., Pourkazemi M., Yazdani M., Ghoroghi A., Bahmani M., Pourdehghani M.,
Chakmehdouz F., Yarmohammadi M. and Nowruzfashkhami M. Induction of meiotic
gynogenesis in
ship sturgeon Acipenser nudiventris using UV-irradiated heterologous sperm //
Journal of applied genetics, Springer, 2014,
55(2), p. 223-229.
Urbányi B., Horváth Á. and Kovács B. Successful hybridization of Acipenser species using cryopreserved
sperm // Aquaculture International, Springer, 2004, 12(1), p. 47-56.
16
ADAPTATION OF DIATOMS (IN CLONIAL CULTURE) TO THE CHANGE OFTHE
IONIC COMPOSITION OF THE MEDIUM
S.K. Jafarova, Sh. J. Mukhtarova
Institute of Botany, ANAS, Badamdar highway 40, AZ 1004 Baku, Azerbaijan
Key words: diatoms, clone culture, salinity, growth rate, ionic composition.
Introduction
Salinity is an important mediumal factor in the marine medium [
Kinne, 1964; Оdum, 1975
].
Salinity of water as an mediumal factor can be considered in two aspects: osmotic and ionic.
For the growth and development of algae is no less important than the total salinity, has the
ionic composition
of water, the ionic ratio. The significance of this factor was recognized long
ago [
Provasoli et al., 1954
,
Droop, 1958
]. So, V.N. Beklemishev and V.P. Baskin [
Beklemishev et al.,
1933
] noted that the nature of the ionic relationships is, in some cases, a decisive mediumal
factor. But researchers working mainly with algae from the saline seas, naturally, did not give
him due attention either in experiments or in the treatment of the spread of algae in nature. It
was not possible for experimentalistsExperiments dealing with the same species dealing with
theof desalinated Black (average salinity -17‰) and Caspian (12‰) seas, to ignore this factor.
In these brackish-water seas, not only dilution of fresh sea
water takes place, but also a
qualitative change of the salt composition: the ionic ratios vary greatly with respect to oceanic
waters. In each of these seas, the salt composition of water has its own peculiar features and,
accordingly, other ionic relationships.
Materials and methods
The objects of research were four clonal cultures of marine diatoms isolated from
phytoplankton of the Caspian and Black Seas at points with a salinity of 12 and 17‰,
respectively. These Caspian clones are
Thalassionema nitzschioides (Grun.) Hust.,
Coscinodiscus granii Gough and the Black Sea
Ditylum brightwellii (West) Grun., and
S. granii.
The method of research and the scheme for setting up experiments (I and 11 series) are
covered in our publication. For the first time, a serious study of this factor, called rapic was
used by the Romanian researcher E. Pora [Pora
, 1961; 1969
]. L.A. Lanskaya [Lanskaya
, 1969
] also
noted that "some algae reproduce more intensively in the water of that pond from which they
are isolated".
The salinity of the medium prepared on the White Sea water was calculated according
to the formula of M. Knudsey [Harvey
, 1948
]. In calculating the salinity for medium prepared
on
Caspian water, the chlorine coefficient A.A. Lebedintsev was used [Zenkevich
, 1963
]. When
preparing medium using the Black Sea water, salinity calculations were made using the
formula taken from the work of Nikitin et al. [Blinov
, 1962
]. In the described series of
experiments "(III series) we attempted to cultivate Black Sea and Caspian clones ion water with
an ionic composition which is characteristic of a typical marine, for which the White Sea water
was used, which is close to the oceanic one in chemical composition
to the oceanic one
[
Воронков, 1939
]. In some experiments of the third series of. T the number of saline points was
reduced due to a shortage of the White Sea water.
Results
A number of researchers [
Proshkin - Lavrenko
, 1963;
,
Williams, 1964;
,
Braarud
, 1965
]
based on the study of diatoms both in experiment and in natural conditions, suggests that
marine euryhaline species are capable of the formation in the nature of local populations of
phytoplankton that are characterized by different salinity. However, there are experimental
studies that contradict this assumption. Thus, E. Paasche [
Paasche, 1975
] studied two clones
Skeletonem costatum (Grev.) Cl., isolated from the Baltic Sea (6‰) and Osloford (20‰), found
17