The ploidy and genetic structure of hybrid population of water frogs Pelophylax esculentus complex (Amphibia, Ranidae) of Ukraine fauna

The complex study, including allozyme variability and cytometry of hybrid populations of green frogs Pelophylax esculentus (L., 1758) complex has confirmed that the only region of Ukraine where allodip loid are encountered frequently is the Severski Donets basin (9% of all hybrids). In other areas, only two poly ploidy hybrids (0.9%) and one probably autopolyploid individual of each parental species have been regis tered. According to allozyme specters, all three polyploidy hybrids from the Severski Donets basin were males and belonged to biotype P. esculentus (=lessonae) – 2 ridibundus, and their population in this region has halved during the past decade

Evidences of Multicomponent Structure of the Migratory Stock and Morphological Distinctions of Shads from the Genus Alosa (Clupeaformes, Alosiinae) of the Sea of Azov

Migratory stocks of shads passing through the Kerch strait during their seasonal migrations consist of three groups of specimens, that can be identified based on the number of gill rakers on the first arch. These are so called Kerch shad A. maeotica (50.2 %), Pontic shad A. immaculata (48.7 %) and Caspian shad A. caspia (1.1 %). This ratio of species in the region remains stable for the last 60 years. Populations of Kerch and Pontic shads have similar age structure and sex ratio with a shift toward females 52–54 %. Specimens of A. maeotica have greater linear size and weight than those of A. immacuta, that indicates higher growth rate of the former. Analysis of 26 body measurements shows definite differences between these shads in their absolute features, there are also some differences in the proportions of the head. Nevertheless, degree and reproducibility of interspecific differences during various periods of time, do not allow for the reliable discrimination of specimens of these species assumed by some researchers.Миграционные стада пузанковых сельдей, проходящие в период сезонных миграций через Керченский пролив, состоят из особей трёх групп, которые можно идентифицировать по числу жаберных тычинок на 1-й дуге. Это так называемая керченская сельдь, A.?maeotica (50,2 %), черноморско-азовская сельдь, A. immaculata (48,7 %), и пузанок, A. сaspia (1,1 %). Такое соотношение между этими видами в регионе остаётся стабильным на протяжении последних 60 лет. Популяции керченской и черноморско-азовской сельдей имеют одинаковую возрастную структуру и соотношение полов, при котором самки составляют 52–54 %. Особи A. maeotica отличаются от A. immaculata большими линейными размерами и массой, что свидетельствует о более высоком темпе их роста. Использование 26 промеров тела показывает определённые различия между этими сельдями по абсолютным признакам, также отмечаются некоторые различия и в пропорциях головы. Тем не менее масштаб и низкая воспроизводимость межвидовых различий в разные периоды не позволяют надежно дискриминировать особей этих предполагаемых некоторыми исследователями видов

Inheritance of parental genomes by a hybrid form Rana “esculenta” (Amphibia, Ranidae)

In this study, quantitative analysis of paternal genome inheritance by a hybrid form Rana “esculenta” (= Rana esculenta L., 1758 × Rana ridibunda Pall., 1881) (Amphibia, Ranidae) was examined. The hybrid form examined was characterized by a polymodal mode of inheritance (genome of any of the parental species can be inherited). The absence of correlation between the proportion of normal gametes and either sex or ploidity of the producer was demonstrated. The gametes produced could be both haploid and diploid (hybrid or homozygous). The mechanism of alloploid reproduction is discussed

Karyotypes and Morphological Variability of Crayfish Pontastacus leptodactylus and P. angulosus (Malacostraca, Decapoda)

The existence on the territory of Ukraine of two sympatric widespread species definitely different by their chromosome number was proved based on the meiotic chromosome preparations. Besides the nominal species Pontastacus leptodactylus (Dana, 1852) with modal haploid chromosome number n = 93 we prove the existence of P.?angulosus (Rathke, 1837) with n = 88.На основании анализа мейотических хромосомных препаратов доказано существование в Украине двух симпатрических широко распространённых видов, которые чётко отличаются по числу хромосом. Кроме номинативного длиннопалого рака, Pontastacus leptodactylus (Dana, 1852), с модальным числом хромосом в гаплоидном наборе на уровне n = 93 доказано присутствие и угластого рака, P. angulosus (Rathke, 1837), с модальным значением n = 88

Генетична диференціація річкових раків із водойм басейну р. Прип'ять

Based on the research of allozymes variability, the presence of three species of freshwater crayfish in the reservoirs of the Pripyat basin: A. astacus, A. angulosus and A. leptodactylus has been proved. It is established that the species A. astacus is genetically substantially more differentiated from narrow-clawed crayfish than A. angulosus and A. leptodactylus among themselves. This can be regard as evidence of the subfamily or possibly the generic level of differentiation of this crayfishes. The presence of clear allozymes differences between the sympatric species of narrow-clawed crayfish A. leptodactylus and A. angulosus proves their reproductive isolation and species autonomy. For the first time were analyzed the geographical distribution, abundance and biotopes dependence of species of crayfish in the Pripyat basin and neighboring territories of Ukraine. It has been established that angular crayfish more adapted to modern environmental conditions.На основі проведених досліджень алозимної мінливості доведено наявність у водоймах басейну річки Прип’ять трьох видів річкових раків: A. astacus, A. angulosus та A. leptodactylus. Установлено, що вид A. astacus генетично більш диференційований від довгопалих раків, ніж A. angulosus й A. leptodactylus між собою

Absorbing hybridization of cobitis taenia and sabanejewia aurata (Cypriniformes, Cobitidae) in water reservoirs of northern Ukraine connected with diploid-polyploid complex formation

Absorbing Hybridization of Cobitis taenia and Sabanejewia aurata (Cypriniformes, Cobitidae) in Water Reservoirs of Northern Ukraine Connected with Diploid-Polyploid Complex Formation. Mezhzherin, S. V., Pukhtayevych, P. P., Tsyba, А. А. — In the rivers of the Northern Ukraine by meams of karyological and allozyme analysys obtained extensive natural hybridization between Cobitis taenia and Sabanejewia aurata, initially leading to the formation of diploid hybrids. Besides that certain water bodies are predominantly populated by triploids of the C. taenia — C. tanaitica — S. aurata biotypes. Since the share of this kind of hybrid biotypes signifi cantly exceeds the number of individuals of S. aurata, it is concluded that the hybridization of a common and eurybiontic C. taenia with rarer stenobiontic S. aurata, is of absorbing character

Evolutionary transition-transversion bias by the example of the cytb gene of palearctic Muridae (Rodentia) and Vespertilionidae (Chiroptera)

A comparative analysis of the features of the transition-transversion bias of the nucleotide sequence of the cytb gene in microbats (Vespertilionidae, Chiroptera) and mice (Muridae, Rodentia) shows both general regularities and certain family-level features. A common feature of the two families is the fact of the sharp predominance of transitions over transversions at the early stages of the evolutionary process, followed by the equalization of the ts/tv-displacement at the species and genus levels of divergences, as well as the fact that the increase in the frequency of transitions in phyletic lineages is gradual, and the transition is intermittent. At the same time, the levels of spontaneous mutations and evolutionary drift, as well as the rate of ts/tv drift compensation, are specific to families. These circumstances do not make it possible to obtain comparable estimates of divergence in different phyla and cause insurmountable difficulties in creating a universal formula for molecular clocks.Порівняльний аналіз особливостей транзитивно-трансверсивного зсуву нуклеотидної послідовності гена cуtb гладконосих (Vespertilionidae, Chiroptera) і мишачих (Muridae, Rodentia) показує як загальні закономірності, так і певні особливості родинного рівня. Загальними для двох родин є факт різкого переважання переходів над трансверсіями на ранніх етапах еволюційного процесу з наступним вирівнюванням ts/tv-зміщення на видовому та родовому рівнях дивергенцій, а також та обставина, що зростання частоти транзицій у філетичних рядах носить поступовий характер, а транзицій — стрибкоподібний. При цьому рівень спонтанного мутування та еволюційного зсуву, а також швидкість компенсації ts/tv зсуву є специфічними для родин. Ці обставини не дають можливості отримати порівнянні оцінки дивергенції в різних філумах і спричиняють непереборні труднощі для створення універсальної формули молекулярних годин

Genetic evidence challenges the native status of a threatened freshwater fish (Carassius carassius) in England.

A fundamental consideration for the conservation of a species is the extent of its native range, that is, regions naturally colonized. However, both natural processes and human-mediated introductions can drive species distribution shifts. Ruling out the human-mediated introduction of a species into a given region is vital for its conservation, but remains a significant challenge in most cases. The crucian carp Carassius carassius (L.) is a threatened freshwater fish thought to be native to much of Europe. However, its native status in England is based only on anecdotal evidence. Here, we devise an approach that can be used to empirically test the native status of English fauna. We use this approach, along with 13 microsatellite loci, population structure analyses, and Approximate Bayesian Computation (ABC), to test hypotheses for the origins of C. carassius in England. Contrary to the current consensus, we find strong support for the human-mediated introduction of C. carassius into England during the 15th century. This result stimulates an interesting and timely debate surrounding motivations for the conservation of species. We discuss this topic, and the potential for continued conservation of C. carassius in England, despite its non-native origins