Problem situations in the protection of amphibians (hybridization, minimal viable population, etc.)

     In issues related to the protection and monitoring of objects from the Red Book of Ukraine there is a number of nuances which require a special study. This work does not claim to offer their comprehensive consideration yet only marks several of them to any extent related to the problem of the protection and monitoring of certain representatives of the Amphibious Class, as well as development of their cadastres. In the first place it should be pointed out that the main object which caused the creation and maintenance of the Red Book of Ukraine is a species (and partially a population). At the same time, special research of the recent years shows that the decision about the taxonomic rank and level of differences (individual populations, subspecies, species) often depends on the type of the concept of species the author adheres to (Pisanets, 2001, 2002).

      On the other hand, there is clear proof (Dubois, 1998), that the species is not the only evolutionary and taxonomic unit, and among lower vertebrates this role is also played by the clepton (among reptiles — clonon). Such evolutionary and taxonomic units are characterized by specific features and sharp distinctions from the species. In Ukraine, the clepton is represented by the edible frog Rana kl. esculenta Linnaeus, 1758. Thus, when organizing monitoring of animals subject to protection, their populations can be represented by such evolutionary and taxonomic units as a species (subspecies) or a clepton (in reptiles — by a clonon). Another problem associated with the protection and monitoring of the Red Book species is conditioned by hybridization. Currently, it can be considered proven that the species as a separate evolutionary and taxonomic unit is not always a(n) (absolutely) closed genetic system, and in a whole number of cases in natural populations there is natural interbreeding between representatives of various species.

      Broad hybridization between red-bellied and yellow-bellied toads, found hybrids between green and running toads, crested and Danube tritons, as well as between common and Carpathian tritons can serve as an example of hybridization between various animal species from the Red Book. In all similar cases the main problem is presented by the lack of the possibility to refer unconditionally such hybrid species and populations to a concrete taxon due to their satiation with alien genes originating from parents with various systematic positions and, as a result, difficulty with labeling of the protective status of such hybrids. Until these issues are finally resolved we propose to consider animals with gene complexes and coming from parents from the Red Book of Ukraine as such which are also covered by Law of Ukraine “On the Red Book of Ukraine”.

      The problem related to the number of species in a minimally viable population and the smallest (the lowest number of species in a) genetic population (Evens and others, 1989; Mezhzherin and others, 1997, Mezhzherin and others, 1999, etc.) takes a special place in the range of issues related to protection of animate nature objects. In this case the point is that when forming any approaches to the protection of concrete groups of organisms (in this case — representatives of any taxons of amphibians) one should know the minimal population which in natural environment allows its representatives to exist during a certain (often unlimitedly long) period of time. Such a number usually depends on demographic (age of reproductive maturity, sex and age structure, prolificacy, death-rate, reproduction period, etc.) and genetic parameters (genetic diversity, often related to the degree of heterozygosis). First attempts of such calculations from the point of view of the level of heterozygosis of individual populations of domestic amphibians already exist (Mezhzherin and others, 1997). According to such calculations, for example, the size of an elementary population should contain 400–450 agile frogs, 300 spotted salamanders, 100 Alpine tritons, 30 Carpathian tritons. More detailed information on genetic and demographic parameters is supplied in species reviews.