Student papers after the second-year practice - 2008 and something else

Student works after the II year practice - 2009 Student works after the II year practice - 2010 Student works after the II year practice - 2011 Student works after the II year practice - 2012 (Part I) Student works after the II year practice - 2012 (Part II) Student works after the II year practice - 2013 Student works after the II year practice - 2014 Student works after the II year practice - 2015 Student works after the II year practice - 2016 Student works after the II year practice - 2017 STUDY OF THE POSSIBILITY OF DETERMINING FORMS OF GREEN FROGS BY EXTERNAL MORPHOLOGY AND COLORATION MARKS Dedukh D.V., Zarubenko E.S. Kharkiv National University named after V.N. Karazin, Faculty of Biology pl. Svobody 4, Kharkiv, 61077, Ukraine Rana esculenta complex—a group of green frogs consisting of parental species and their hemiclonal hybrids. In the vicinity of the HNU biostation both representatives of one parental species—Rana ridibunda—and various (in particular, both diploid and triploid) hybrids—Rana kl. esculenta (Shabanov et al., 2006)—co‑occur. We collected 73 sexually mature green frogs from the floodplain of the Seversky Donets River. Frogs were caught with a net at night, collecting them from the bank and in stands of emergent aquatic vegetation using a flashlight. After the work was completed, the studied frogs were released at the capture site. Among the examined frogs, 15 individuals possessed “typical” R. ridibunda traits: a straight heel tubercle and absence of a yellow pattern on the thighs. 17 individuals were “typical” R. esculenta: they had a high heel tubercle and a yellow pattern on the thighs. The remaining frogs (n = 41) displayed combinations of traits characteristic of both R. ridibunda and R. esculenta. Discriminant analysis was applied, comparing “atypical” individuals with “typical” R. ridibunda and R. esculenta based on characters used by various authors to differentiate green frog forms. These characters included body‑to‑tibial length ratio, heel‑tubercle‑to‑tibial length ratio, dorsal body colour (dark‑green, green, light‑green), spot shape (smaller than the eye, larger than the eye), spot frequency (more background, equal to background, less background). As a result of the discriminant analysis, the traits of “atypical” frogs formed a scatter cloud within which the traits of “typical” R. ridibunda and R. esculenta were located. This indicates that, using this set of characters, it is impossible to determine the affiliation to a particular form for all frogs from the studied habitat. This work was performed as a student research project within the vertebrate zoology field practice. The authors thank the supervisors, senior lecturer Kravchenko M.A. and associate professor Shabanov D.A., as well as A.A. Atemasov for valuable consultation. Dedukh D.V., Zarubenko E.S. (scientific supervisors – Kravchenko M.A., Shabanov D.A.) Study of the possibility of determining forms of green frogs by external morphology and coloration // “Biology: from molecule to biosphere”. Materials of the III International Conference of Young Scientists. – Kharkiv: SPD FO Mykhailov G.G., 2008. – pp. 364‑365. STUDY OF FLUCTUATING ASYMMETRY OF THE PATTERN IN RANA ESCULENTA COMPLEX Deriashentseva A.A., Diakonova I.V., Mykos I.G. Kharkiv National University named after V.N. Karazin pl. Svobody 4, Kharkiv, 61077, Ukraine e‑mail: bell-iren@mail.ru One of the measures of sustainable development assessment is fluctuating asymmetry (FA) (Gelashvili D.B. et al., 2004). In the Rana esculenta complex interspecific hybridization, clonal inheritance, and natural polyploidy have been recorded (Plötner, 2005; Shabanov et al., 2006). This makes a comparison of two different frog forms from the same habitat interesting with respect to their FA levels. A total of 149 green frogs belonging to the Rana esculenta complex were studied. All individuals were captured in the Seversky Donets River near the HNU biostation (village Haidary, Zmiiv district, Kharkiv region). Based on morphophysiological characteristics, frogs were assigned to one form or another. Of the examined specimens, 116 displayed typical R. ridibunda traits: low and oblique heel tubercle, absence of a yellow pattern on the thighs, dark resonators in males; 24 were assigned to the R. esculenta form based on criteria: high heel tubercle, yellow coloration on the hind limbs, light‑gray resonator coloration in males. Nine individuals could not be confidently assigned to any form, possibly due to polyploidy (morphophysiological traits formed under the influence of several genomes simultaneously). To assess the nature of asymmetry we recorded the following characters: the character of the dorso‑medial stripe (DMS) (symmetrical, slightly asymmetrical, strongly asymmetrical), number of spot‑stripes on the right and left hind limbs from thigh to the end of the tibia, and number of spots along the DMS on the left and right sides. To determine whether these characters could be used as an FA measure, we compared groups by these criteria. It turned out that an FA measure could be the absolute (modulus) value of the difference between the number of spots on the left and right along the DMS, ranging from 0 to 3. The mean FA value for this character (i.e., the difference between the number of spots along the DMS on the right and left) was 0.87 for R. esculenta and 0.67 for R. ridibunda (Student’s t test, p = 0.18). Thus, the difference between hybrids and parental‑form individuals is not statistically reliable (possibly due to insufficient sample size), yet despite the obtained values, a tendency toward greater asymmetry in hybrid individuals was observed. It was found that male Rana esculenta complex individuals exhibit stronger asymmetry, presumably because their development is less tightly regulated compared with females. Therefore, we propose that the number of spots along the DMS can be used to assess FA in various (diploid and triploid) hybrids. This work was carried out within the vertebrate zoology field practice student research project under the supervision of senior lecturer Kravchenko M.A. and associate professor Shabanov D.A. Deriashentseva A.A., Diakonova I.V., Mykos I.G. (scientific supervisors – Kravchenko M.A., Shabanov D.A.) Study of fluctuating asymmetry of the pattern in Rana esculenta complex // “Biology: from molecule to biosphere”. Materials of the III International Conference of Young Scientists. – Kharkiv: SPD FO Mykhailov G.G., 2008. – pp. 365‑366.

STUDY OF FLUCTUATING ASYMMETRY OF THE PATTERN IN RANA ESCULENTA COMPLEX Deriashentseva A.A., Diakonova I.V., Mykos I.G. Kharkiv National University named after V.N. Karazin pl. Svobody 4, Kharkiv, 61077, Ukraine e‑mail: bell-iren@mail.ru One of the measures of sustainable development assessment is fluctuating asymmetry (FA) (Gelashvili D.B. et al., 2004). In the Rana esculenta complex interspecific hybridization, clonal inheritance, and natural polyploidy have been recorded (Plötner, 2005; Shabanov et al., 2006). This makes a comparison of two different frog forms from the same habitat interesting with respect to their FA levels. A total of 149 green frogs belonging to the Rana esculenta complex were studied. All individuals were captured in the Seversky Donets River near the HNU biostation (village Haidary, Zmiiv district, Kharkiv region). Based on morphophysiological characteristics, frogs were assigned to one form or another. Of the examined specimens, 116 displayed typical R. ridibunda traits: low and oblique heel tubercle, absence of a yellow pattern on the thighs, dark resonators in males; 24 were assigned to the R. esculenta form based on criteria: high heel tubercle, yellow coloration on the hind limbs, light‑gray resonator coloration in males. Nine individuals could not be confidently assigned to any form, possibly due to polyploidy (morphophysiological traits formed under the influence of several genomes simultaneously). To assess the nature of asymmetry we recorded the following characters: the character of the dorso‑medial stripe (DMS) (symmetrical, slightly asymmetrical, strongly asymmetrical), number of spot‑stripes on the right and left hind limbs from thigh to the end of the tibia, and number of spots along the DMS on the left and right sides. To determine whether these characters could be used as an FA measure, we compared groups by these criteria. It turned out that an FA measure could be the absolute (modulus) value of the difference between the number of spots on the left and right along the DMS, ranging from 0 to 3. The mean FA value for this character (i.e., the difference between the number of spots along the DMS on the right and left) was 0.87 for R. esculenta and 0.67 for R. ridibunda (Student’s t test, p = 0.18). Thus, the difference between hybrids and parental‑form individuals is not statistically reliable (possibly due to insufficient sample size), yet despite the obtained values, a tendency toward greater asymmetry in hybrid individuals was observed. It was found that male Rana esculenta complex individuals exhibit stronger asymmetry, presumably because their development is less tightly regulated compared with females. Therefore, we propose that the number of spots along the DMS can be used to assess FA in various (diploid and triploid) hybrids. This work was carried out within the vertebrate zoology field practice student research project under the supervision of senior lecturer Kravchenko M.A. and associate professor Shabanov D.A. Deriashentseva A.A., Diakonova I.V., Mykos I.G. (scientific supervisors – Kravchenko M.A., Shabanov D.A.) Study of fluctuating asymmetry of the pattern in Rana esculenta complex // “Biology: from molecule to biosphere”. Materials of the III International Conference of Young Scientists. – Kharkiv: SPD FO Mykhailov G.G., 2008. – pp. 365‑366.

SKELETOCHRONOLOGICAL AGE DETERMINATION OF GREEN FROG REPRESENTATIVES RANA ESCULENTA COMPLEX FROM THE KHARKIV REGION Usova E.E. Kharkiv National University named after V.N. Karazin, Department of Zoology and Animal Ecology, pl. Svobody 4, Kharkiv, 61077, Ukraine e‑mail: e_usova@mail.ru The group of green frogs—Rana esculenta complex—is one of the most interesting animal groups of the Kharkiv region for study. It includes two parental species and various diploid, triploid, and even tetraploid hybrid forms (Plotner, 2005). Co‑existence of hybrids with parental species is maintained by clonal inheritance (transfer of specific genomes by hybrids clonally, without recombination), which is of considerable scientific interest. When diploid and triploid hybrids coexist, the possibility arises to compare their viability. An appropriate method for this is skeletochronological age and growth‑rate determination. We examined 62 green‑frog specimens housed in the Zoological Institute of the Russian Academy of Sciences (St. Petersburg), the HNU Natural History Museum, and the Department of Zoology and Animal Ecology of HNU. Fifty specimens were Rana esculenta (hybrids); 9 were Rana ridibunda and 3 were Rana lessonae. Frog collection in the Kharkiv region took place from 2004 to 2007. Species identity and genome composition in the genotype of most studied individuals were determined by flow DNA cytometry at the Institute of Cytology and Genetics of the RAS (St. Petersburg) by S.N. Lytvynchuk and Yu.M. Rozanov. Some individuals (R. lessonae representatives) were identified morphologically by a suite of characters (Lada, 1995; Shabanov et al., 2006). For age determination, decalcified finger‑phalanx sections were prepared and stained with Ehrlich’s hematoxylin (Romey, 1953). Sections were obtained using a freezing microtome. Age was estimated by counting the number of lines of apposition in the periosteal bone zone, taking possible resorption of initially deposited layers into account. Typically, the first line of apposition is completely resorbed, the second only partially. Age can be calculated by the formula: age = number of fully visible (non‑resorbed) lines of apposition + 2. We established that in the Kharkiv region the age of sexually mature green frogs caught during spawning ranges from 4 to 10 years, with a predominance of 5‑ and 6‑year‑old individuals. Among the studied hybrid specimens a considerable diversity in growth rates was recorded. The oldest individuals are not the largest, and the largest are not the oldest. For example, specimens with body length over 740 mm were 5 years old, whereas 8‑10‑year‑old specimens did not exceed 689 mm in body length. No significant differences in growth rate between diploid and triploid hybrids were registered, which preliminarily indicates normal viability of triploid hybrids. In further studies we plan to increase the number of examined frogs and determine growth dynamics of individual specimens. Studying frogs from a single habitat (the floodplain of the Seversky Donets near the HNU biostation) and comparing growth rates and lifespan of representatives of different forms will allow assessment of their viability and contribution to the reproduction of the hemiclonal population system. The work was performed under the supervision of associate professor of the Department of Zoology and Animal Ecology, PhD Shabanov D.A. The author thanks A.V. Shabanova, A.V. Korshunov, and D.A. Shabanov for assistance. Usova E.E. (scientific supervisor – Shabanov D.A.) Skeletochronological age determination of green‑frog representatives Rana esculenta complex from the Kharkiv region // “Biology: from molecule to biosphere”. Materials of the III International Conference of Young Scientists. – Kharkiv: SPD FO Mykhailov G.G., 2008. – pp. 396‑397.{ "translated_text": "FEATURES OF THE HEAD FOLIDOS STRUCTURE IN QUICK LIZARDS (LACERTA AGILIS) IN THE VICINITY OF THE HNU BIOSTATION\nSadvynychna M. A., Chusova O. A.\nV.N. Karazin Kharkiv National University, Faculty of Biology\npl. Svobody 4, Kharkiv, 61077, Ukraine\nThe determination of folidos (scale) features is widely used in reptile systematics and the analysis of their population structure. This takes into account the number, shape and spatial arrangement of individual head and body scales.\nThe work examines the scale pattern of the frontal part of the head of 16 individuals of the quick lizard (Lacerta agilis) collected in the NPP \"Homolishansky Forests\" (Zmiivskyi district, Kharkiv region) and in the vicinity of the HNU biostation (Zmiivskyi district, Hai-dary village). In describing the head folidos of quick lizards, a summary table of morphological traits of pre-nasal (pn), prefrontal (pl), frontonasal (ln) and other scales, compiled from the results of a study on the geographic variability of quick lizards within the former USSR (Yablokov, Laryna, 1985), was used as a basis.\nDuring the examination of the collected specimens, traits not included in the cited summary were noted. The first of these is a variant of the pre-nasal scale structure, in which a inter-nasal (in) scale inserts relatively deeply between them anteriorly (Fig.1). This condition was observed in 5 of the 16 studied individuals.\n[IMG_1]\nThe second recorded trait, which was not part of the published description scheme, is a variant of the frontonasal scale structure, in which it has the shape of a regular hexagon. The anteriorly and posteriorly directed vertices of this scale connect with the anterior vertices of the prefrontal scales at an angle of approximately 110° (Fig.2). This feature is the most common variant of frontonasal scale structure for the studied sample of lizards and was observed in 15 of the 16 examined individuals.\nFinally, a new variant of prefrontal scale structure was noted, in which they have a rhombic shape and touch only at a single point in their posterior part (Fig.3). This folidos feature was observed in one of the examined individuals.\n\nNo correlation between animal coloration and scale pattern features was registered during the work.\nPresumably, the presence of \"unusual\" morphological folidos traits of the head characterizes the specific features of the lizard sample we considered. In the future, these traits may be used for phylogenetic analysis of quick lizard populations.\nThe work was carried out at the HNU biological station named after V.N. Karazin under the supervision of senior lecturer Kravchenko M.A. and associate professor Shabanov D.A., to whom we express sincere gratitude.\nSadvynychna M. A., Chusova O. A. Features of the head folidos structure in quick lizards (Lacerta agilis) in the vicinity of the HNU biostation // \"Biology: from molecule to biosphere\". Materials of the III International Conference of Young Scientists. - Kharkiv: SPD FO Mykhailov G.G., 2008. - pp. 398-399.\nON THE DEVELOPMENT OF METHODS FOR FORMALIZED ASSESSMENT OF THE REASONABLENESS OF NATURAL OBJECTS PROTECTION\nKravchenko M. A.\nV.N. Karazin Kharkiv National University, Faculty of Biology, Department of Zoology and Animal Ecology\npl. Svobody, 4, Kharkiv, 61077, Ukraine\ne-mail: m_kravchenko@inbox.ru\nIn the context of rapid biosphere changes caused by anthropogenic impacts and possibly other reasons, the problem of selecting natural objects that are priority for protection becomes urgent. In this paper we consider some principles that determine the bases for protecting natural objects (populations, species, biogeocenoses, etc.).\nAn object can be protected either for its utility or for ethical reasons, moral duty. The utility assessment may be its cost, while the ethical assessment may be its value. For example, the concept of rational use of natural resources evaluates potential protection objects in terms of their utility (current or potential) (Marushevskyi, 2008), whereas so‑called \"environmental ethics\" and other anthropocentric concepts primarily consider ethical grounds for nature protection (Ruse, 1992; Boreiko, 2004). In our view, when selecting objects for protection, both their cost and ethical value should be taken into account. The concept guiding such selection must allow at least a qualitative assessment of these parameters.\nEthical grounds for protecting objects are linked to their uniqueness and the possibility of their long‑term existence, potential immortality (Kravchenko, Shabanov, 2006). In line with this, we propose the following method for comparing the grounds for protecting particular objects\n[IMG_2]\nThe very need to protect a given object results from some danger threatening its existence. In the overwhelming majority of cases protection cannot completely eliminate the threat of object loss, but only reduces its probability. Protection effectiveness can be evaluated as the reduction in the probability of object loss due to protective measures.\nThe uniqueness of an object can be assessed by the probability of occurrence of an analogue identical to the given object in the properties significant to us. A measure of potential immortality of an object may be the probable duration of its existence if it persists in the short term (the period for which protection measures are planned).\nThe presented approach combines economic grounds for object protection with a formalized assessment of their ethical value. In addition to two economic assessments (object cost, i.e., possible benefit derived from its existence, and the cost of protection measures), which require economists, the formula uses probabilistic quantities related to the emergence and loss of protected objects. Estimating such probabilities should be the task of specialists studying these systems. It can be based on statistical processing of empirical data describing the fate of similar objects, or on modeling results of the corresponding natural systems.\nThe author thanks associate professor, candidate of biological sciences D.A. Shabanov, under whose guidance this work was performed.\nKravchenko M. A. On the development of methods for formalized assessment of the reasonableness of natural objects protection // \"Biology: from molecule to biosphere\". Materials of the III International Conference of Young Scientists. - Kharkiv: SPD FO Mykhailov G.G., 2008. - pp. 442-443.\nWHAT NEW CAN BE LEARNED ABOUT GREEN FROGS THROUGH SIMULATION MODELING?\n1 Kravchenko M.A., 2 Lutsyk A.A., 1 Shabanov D.A.\nV.N. Karazin Kharkiv National University,\n1 Faculty of Biology, Department of Zoology and Animal Ecology\n2 Mechanical‑Mathematical Faculty, Department of Higher Mathematics and Informatics\ne-mail: 1 m_kravchenko@inbox.ru; d.a.shabanov@gmail.com, 2 aalutsyk@gmail.com\nDescribing the diversity of the living world, we simplify the variety of observable phenomena to a set of typical schemes. Thus, it is commonly assumed that organisms belong to certain species and form populations consisting of individuals of that species. The vast majority of separate‑sex diploid organisms transmit to their offspring genomes that result from recombination of the two genomes each organism received from its parents. However, many exceptions to these schemes exist. One such exception is hybridization producing hemiclonal hybrids that transmit to offspring the genome of one of the two parental species in a pure form. In particular, this hybridization is characteristic of green frogs.\nThe European green frog group includes two parental species: the pool frog, Pelophylax lessonae (Camerano, 1882), and the marsh frog, Pelophylax ridibundus (Pallas, 1771), as well as their hybrids, called edible frogs, Pelophylax esculentus (Linnaeus, 1758). These names follow the latest amphibian systematics revision (Frost et al., 2006 and earlier works). Their more traditional names are Rana lessonae Camerano, 1882; Rana ridibunda Pallas, 1771; and Rana esculenta Linnaeus, 1758. Why does the hybrid form bear a name similar to a species name? Hybrid frogs can persist for long periods without repeated crosses of the parental species and form populations in which they successfully reproduce over many generations.\nWhen describing green frog reproduction, we denote the genome of P. lessonae (comprising 13 chromosomes) by L, and the genome of P. ridibundus (also 13 chromosomes) by R. Hemiclonal inheritance in P. esculentus is expressed by only one of the diploid hybrid frog genomes being transmitted to gametes. Such a genome is called clonal; we propose to indicate this circumstance by placing the symbol of the corresponding genome in parentheses. The second genome in diploid hybrids is eliminated at some stage of gametogenesis. For example, in many habitats of eastern Ukraine P. ridibundus and P. esculentus co‑occur and reproduce. Such and similar assemblages of green frogs should not be called \"populations\" because they consist of animals not belonging to a single species. We propose to call these biosystems hemiclonal population systems – HPS. Individuals of the parental species produce gametes with recombinant genomes of that species, while hybrids produce only gametes with the clonal genome (L). As a result, all offspring from crosses of the parental species and hybrids with the clonal genome of the other species become hybrid: RR × (L)R → (L)R. The clonal genome is thus passed from generation to generation without recombination.\nOften HPS has a much more complex composition. In the vicinity of the HNU biostation (Hai-dary village, Zmiivskyi district, Kharkiv region) there is an HPS comprising frogs RR, (L)R, L(R), (L)(R), LLR, LRR, and among juvenile individuals also LL and LLRR. In tri‑ and tetraploid hybrids, clonal genomes are not placed in parentheses because their gametogenesis is not fully studied; individuals denoted as (L)(R) simultaneously produce gametes carrying pure P. lessonae and P. ridibundus genomes.\nHPS is a relatively new category of biosystems for modern science. The processes sustaining their reproduction remain largely unexplored. To study them we applied simulation modeling using a multi‑agent computer model. One of the authors of this report (A.A. Lutsyk) under the supervision of associate professor M.V. Vladimirova and Prof. G.N. Zholtkevich created the program Batrahometrics, modeling transformations of green frog HPS. With this model one can describe the initial state of an HPS (including the number of individuals of certain forms and ages); specify the rules by which the state of the HPS in year n determines its state in year n+1; and determine the probability distribution of the state the HPS will occupy after a given time.\nAmong the simplifications adopted in building the model are the constancy of the spawning stock size (1000 individuals) and the identity of properties of individuals belonging to a given form (defined by its set of genomes). Depending on the genome set, an individual is characterized by a certain attractiveness to partners, fecundity, survival to sexual maturity and after maturation. At each model step, corresponding to one year, probabilistic pair formation and probabilistic death of existing individuals occur. Tracking the transmission of clonal and recombinant genomes from generation to generation, the Batrahometrics program monitors changes in HPS composition over time.\nFor each separate experiment (modeling transformations of a particular HPS over a certain period) a relatively small number of parameters is taken into account (population size, age and sex composition of frogs of particular forms, and, if necessary, the dynamics of their arrival into the model population system). When modeling changes, the program accounts for changes during each \"year\" (model step) of 16 000 independent parameters linked to individual organisms in the model HPS. The experiment result is a particular sequence of HPS composition transformations, as well as a relatively small set of key parameters describing the achieved state.\nThus, a small number of parameters is used as input and output of the model, while at each step a much larger number is analyzed. This is due to the fact that annual HPS changes contain both deterministic and stochastic components. The carrier of a particular genotype may reproduce and alter the entire population system, or simply die. Tracking the \"fate\" of each individual provides the ability to model the impact of randomness on HPS transformations. Conducting experiments with identical initial conditions many times allows determination of the probability distribution of the final state.\nWhy are such experiments needed? Their main purpose is not to determine the fate of specific HPS, but to test the adequacy of our concepts about such systems. We learn some features of the objects we study and build a system of our representations about them. To build a model, such a system must be formalized (which in itself is a very useful work revealing possible logical inconsistencies in common views). The model is built on the basis of a system of representations of the object and allows comparison of the diversity of objects observed in nature with the diversity of model states observed in the experiment. If the set of states that HPS can transition to in the model differs from the set of states observed in natural objects, the model’s underlying representations need revision. Model‑object correspondence does not prove the correctness of the representation system, but serves as an argument in its favor.\nThe described use of the model demonstrates the possibility of moving from a reductionist, element‑by‑element description of the studied object’s properties to studying its characteristics as a whole (defining the set and probability distribution of development pathways).\nFrom the authors’ perspective, such an approach can also be applied to the study of other biological systems at various levels of organization.\nThe authors thank M.V. Vladimirova and G.N. Zholtkevich for invaluable assistance in formulating the task of this work and its execution.\nKravchenko M.A., Lutsyk A.A., Shabanov D.A. What new can be learned about green frogs through simulation modeling? (Plenary report at the conference opening) // \"Biology: from molecule to biosphere\". Materials of the III International Conference of Young Scientists. - Kharkiv: SPD FO Mykhailov G.G., 2008. - pp. 9-11." }

SKELETOCHRONOLOGICAL AGE DETERMINATION OF GREEN FROG REPRESENTATIVES RANA ESCULENTA COMPLEX FROM THE KHARKIV REGION Usova E.E. Kharkiv National University named after V.N. Karazin, Department of Zoology and Animal Ecology, pl. Svobody 4, Kharkiv, 61077, Ukraine e‑mail: e_usova@mail.ru The group of green frogs—Rana esculenta complex—is one of the most interesting animal groups of the Kharkiv region for study. It includes two parental species and various diploid, triploid, and even tetraploid hybrid forms (Plotner, 2005). Co‑existence of hybrids with parental species is maintained by clonal inheritance (transfer of specific genomes by hybrids clonally, without recombination), which is of considerable scientific interest. When diploid and triploid hybrids coexist, the possibility arises to compare their viability. An appropriate method for this is skeletochronological age and growth‑rate determination. We examined 62 green‑frog specimens housed in the Zoological Institute of the Russian Academy of Sciences (St. Petersburg), the HNU Natural History Museum, and the Department of Zoology and Animal Ecology of HNU. Fifty specimens were Rana esculenta (hybrids); 9 were Rana ridibunda and 3 were Rana lessonae. Frog collection in the Kharkiv region took place from 2004 to 2007. Species identity and genome composition in the genotype of most studied individuals were determined by flow DNA cytometry at the Institute of Cytology and Genetics of the RAS (St. Petersburg) by S.N. Lytvynchuk and Yu.M. Rozanov. Some individuals (R. lessonae representatives) were identified morphologically by a suite of characters (Lada, 1995; Shabanov et al., 2006). For age determination, decalcified finger‑phalanx sections were prepared and stained with Ehrlich’s hematoxylin (Romey, 1953). Sections were obtained using a freezing microtome. Age was estimated by counting the number of lines of apposition in the periosteal bone zone, taking possible resorption of initially deposited layers into account. Typically, the first line of apposition is completely resorbed, the second only partially. Age can be calculated by the formula: age = number of fully visible (non‑resorbed) lines of apposition + 2. We established that in the Kharkiv region the age of sexually mature green frogs caught during spawning ranges from 4 to 10 years, with a predominance of 5‑ and 6‑year‑old individuals. Among the studied hybrid specimens a considerable diversity in growth rates was recorded. The oldest individuals are not the largest, and the largest are not the oldest. For example, specimens with body length over 740 mm were 5 years old, whereas 8‑10‑year‑old specimens did not exceed 689 mm in body length. No significant differences in growth rate between diploid and triploid hybrids were registered, which preliminarily indicates normal viability of triploid hybrids. In further studies we plan to increase the number of examined frogs and determine growth dynamics of individual specimens. Studying frogs from a single habitat (the floodplain of the Seversky Donets near the HNU biostation) and comparing growth rates and lifespan of representatives of different forms will allow assessment of their viability and contribution to the reproduction of the hemiclonal population system. The work was performed under the supervision of associate professor of the Department of Zoology and Animal Ecology, PhD Shabanov D.A. The author thanks A.V. Shabanova, A.V. Korshunov, and D.A. Shabanov for assistance. Usova E.E. (scientific supervisor – Shabanov D.A.) Skeletochronological age determination of green‑frog representatives Rana esculenta complex from the Kharkiv region // “Biology: from molecule to biosphere”. Materials of the III International Conference of Young Scientists. – Kharkiv: SPD FO Mykhailov G.G., 2008. – pp. 396‑397.{ "translated_text": "FEATURES OF THE HEAD FOLIDOS STRUCTURE IN QUICK LIZARDS (LACERTA AGILIS) IN THE VICINITY OF THE HNU BIOSTATION\nSadvynychna M. A., Chusova O. A.\nV.N. Karazin Kharkiv National University, Faculty of Biology\npl. Svobody 4, Kharkiv, 61077, Ukraine\nThe determination of folidos (scale) features is widely used in reptile systematics and the analysis of their population structure. This takes into account the number, shape and spatial arrangement of individual head and body scales.\nThe work examines the scale pattern of the frontal part of the head of 16 individuals of the quick lizard (Lacerta agilis) collected in the NPP \"Homolishansky Forests\" (Zmiivskyi district, Kharkiv region) and in the vicinity of the HNU biostation (Zmiivskyi district, Hai-dary village). In describing the head folidos of quick lizards, a summary table of morphological traits of pre-nasal (pn), prefrontal (pl), frontonasal (ln) and other scales, compiled from the results of a study on the geographic variability of quick lizards within the former USSR (Yablokov, Laryna, 1985), was used as a basis.\nDuring the examination of the collected specimens, traits not included in the cited summary were noted. The first of these is a variant of the pre-nasal scale structure, in which a inter-nasal (in) scale inserts relatively deeply between them anteriorly (Fig.1). This condition was observed in 5 of the 16 studied individuals.\n[IMG_1]\nThe second recorded trait, which was not part of the published description scheme, is a variant of the frontonasal scale structure, in which it has the shape of a regular hexagon. The anteriorly and posteriorly directed vertices of this scale connect with the anterior vertices of the prefrontal scales at an angle of approximately 110° (Fig.2). This feature is the most common variant of frontonasal scale structure for the studied sample of lizards and was observed in 15 of the 16 examined individuals.\nFinally, a new variant of prefrontal scale structure was noted, in which they have a rhombic shape and touch only at a single point in their posterior part (Fig.3). This folidos feature was observed in one of the examined individuals.\n\nNo correlation between animal coloration and scale pattern features was registered during the work.\nPresumably, the presence of \"unusual\" morphological folidos traits of the head characterizes the specific features of the lizard sample we considered. In the future, these traits may be used for phylogenetic analysis of quick lizard populations.\nThe work was carried out at the HNU biological station named after V.N. Karazin under the supervision of senior lecturer Kravchenko M.A. and associate professor Shabanov D.A., to whom we express sincere gratitude.\nSadvynychna M. A., Chusova O. A. Features of the head folidos structure in quick lizards (Lacerta agilis) in the vicinity of the HNU biostation // \"Biology: from molecule to biosphere\". Materials of the III International Conference of Young Scientists. - Kharkiv: SPD FO Mykhailov G.G., 2008. - pp. 398-399.\nON THE DEVELOPMENT OF METHODS FOR FORMALIZED ASSESSMENT OF THE REASONABLENESS OF NATURAL OBJECTS PROTECTION\nKravchenko M. A.\nV.N. Karazin Kharkiv National University, Faculty of Biology, Department of Zoology and Animal Ecology\npl. Svobody, 4, Kharkiv, 61077, Ukraine\ne-mail: m_kravchenko@inbox.ru\nIn the context of rapid biosphere changes caused by anthropogenic impacts and possibly other reasons, the problem of selecting natural objects that are priority for protection becomes urgent. In this paper we consider some principles that determine the bases for protecting natural objects (populations, species, biogeocenoses, etc.).\nAn object can be protected either for its utility or for ethical reasons, moral duty. The utility assessment may be its cost, while the ethical assessment may be its value. For example, the concept of rational use of natural resources evaluates potential protection objects in terms of their utility (current or potential) (Marushevskyi, 2008), whereas so‑called \"environmental ethics\" and other anthropocentric concepts primarily consider ethical grounds for nature protection (Ruse, 1992; Boreiko, 2004). In our view, when selecting objects for protection, both their cost and ethical value should be taken into account. The concept guiding such selection must allow at least a qualitative assessment of these parameters.\nEthical grounds for protecting objects are linked to their uniqueness and the possibility of their long‑term existence, potential immortality (Kravchenko, Shabanov, 2006). In line with this, we propose the following method for comparing the grounds for protecting particular objects\n[IMG_2]\nThe very need to protect a given object results from some danger threatening its existence. In the overwhelming majority of cases protection cannot completely eliminate the threat of object loss, but only reduces its probability. Protection effectiveness can be evaluated as the reduction in the probability of object loss due to protective measures.\nThe uniqueness of an object can be assessed by the probability of occurrence of an analogue identical to the given object in the properties significant to us. A measure of potential immortality of an object may be the probable duration of its existence if it persists in the short term (the period for which protection measures are planned).\nThe presented approach combines economic grounds for object protection with a formalized assessment of their ethical value. In addition to two economic assessments (object cost, i.e., possible benefit derived from its existence, and the cost of protection measures), which require economists, the formula uses probabilistic quantities related to the emergence and loss of protected objects. Estimating such probabilities should be the task of specialists studying these systems. It can be based on statistical processing of empirical data describing the fate of similar objects, or on modeling results of the corresponding natural systems.\nThe author thanks associate professor, candidate of biological sciences D.A. Shabanov, under whose guidance this work was performed.\nKravchenko M. A. On the development of methods for formalized assessment of the reasonableness of natural objects protection // \"Biology: from molecule to biosphere\". Materials of the III International Conference of Young Scientists. - Kharkiv: SPD FO Mykhailov G.G., 2008. - pp. 442-443.\nWHAT NEW CAN BE LEARNED ABOUT GREEN FROGS THROUGH SIMULATION MODELING?\n1 Kravchenko M.A., 2 Lutsyk A.A., 1 Shabanov D.A.\nV.N. Karazin Kharkiv National University,\n1 Faculty of Biology, Department of Zoology and Animal Ecology\n2 Mechanical‑Mathematical Faculty, Department of Higher Mathematics and Informatics\ne-mail: 1 m_kravchenko@inbox.ru; d.a.shabanov@gmail.com, 2 aalutsyk@gmail.com\nDescribing the diversity of the living world, we simplify the variety of observable phenomena to a set of typical schemes. Thus, it is commonly assumed that organisms belong to certain species and form populations consisting of individuals of that species. The vast majority of separate‑sex diploid organisms transmit to their offspring genomes that result from recombination of the two genomes each organism received from its parents. However, many exceptions to these schemes exist. One such exception is hybridization producing hemiclonal hybrids that transmit to offspring the genome of one of the two parental species in a pure form. In particular, this hybridization is characteristic of green frogs.\nThe European green frog group includes two parental species: the pool frog, Pelophylax lessonae (Camerano, 1882), and the marsh frog, Pelophylax ridibundus (Pallas, 1771), as well as their hybrids, called edible frogs, Pelophylax esculentus (Linnaeus, 1758). These names follow the latest amphibian systematics revision (Frost et al., 2006 and earlier works). Their more traditional names are Rana lessonae Camerano, 1882; Rana ridibunda Pallas, 1771; and Rana esculenta Linnaeus, 1758. Why does the hybrid form bear a name similar to a species name? Hybrid frogs can persist for long periods without repeated crosses of the parental species and form populations in which they successfully reproduce over many generations.\nWhen describing green frog reproduction, we denote the genome of P. lessonae (comprising 13 chromosomes) by L, and the genome of P. ridibundus (also 13 chromosomes) by R. Hemiclonal inheritance in P. esculentus is expressed by only one of the diploid hybrid frog genomes being transmitted to gametes. Such a genome is called clonal; we propose to indicate this circumstance by placing the symbol of the corresponding genome in parentheses. The second genome in diploid hybrids is eliminated at some stage of gametogenesis. For example, in many habitats of eastern Ukraine P. ridibundus and P. esculentus co‑occur and reproduce. Such and similar assemblages of green frogs should not be called \"populations\" because they consist of animals not belonging to a single species. We propose to call these biosystems hemiclonal population systems – HPS. Individuals of the parental species produce gametes with recombinant genomes of that species, while hybrids produce only gametes with the clonal genome (L). As a result, all offspring from crosses of the parental species and hybrids with the clonal genome of the other species become hybrid: RR × (L)R → (L)R. The clonal genome is thus passed from generation to generation without recombination.\nOften HPS has a much more complex composition. In the vicinity of the HNU biostation (Hai-dary village, Zmiivskyi district, Kharkiv region) there is an HPS comprising frogs RR, (L)R, L(R), (L)(R), LLR, LRR, and among juvenile individuals also LL and LLRR. In tri‑ and tetraploid hybrids, clonal genomes are not placed in parentheses because their gametogenesis is not fully studied; individuals denoted as (L)(R) simultaneously produce gametes carrying pure P. lessonae and P. ridibundus genomes.\nHPS is a relatively new category of biosystems for modern science. The processes sustaining their reproduction remain largely unexplored. To study them we applied simulation modeling using a multi‑agent computer model. One of the authors of this report (A.A. Lutsyk) under the supervision of associate professor M.V. Vladimirova and Prof. G.N. Zholtkevich created the program Batrahometrics, modeling transformations of green frog HPS. With this model one can describe the initial state of an HPS (including the number of individuals of certain forms and ages); specify the rules by which the state of the HPS in year n determines its state in year n+1; and determine the probability distribution of the state the HPS will occupy after a given time.\nAmong the simplifications adopted in building the model are the constancy of the spawning stock size (1000 individuals) and the identity of properties of individuals belonging to a given form (defined by its set of genomes). Depending on the genome set, an individual is characterized by a certain attractiveness to partners, fecundity, survival to sexual maturity and after maturation. At each model step, corresponding to one year, probabilistic pair formation and probabilistic death of existing individuals occur. Tracking the transmission of clonal and recombinant genomes from generation to generation, the Batrahometrics program monitors changes in HPS composition over time.\nFor each separate experiment (modeling transformations of a particular HPS over a certain period) a relatively small number of parameters is taken into account (population size, age and sex composition of frogs of particular forms, and, if necessary, the dynamics of their arrival into the model population system). When modeling changes, the program accounts for changes during each \"year\" (model step) of 16 000 independent parameters linked to individual organisms in the model HPS. The experiment result is a particular sequence of HPS composition transformations, as well as a relatively small set of key parameters describing the achieved state.\nThus, a small number of parameters is used as input and output of the model, while at each step a much larger number is analyzed. This is due to the fact that annual HPS changes contain both deterministic and stochastic components. The carrier of a particular genotype may reproduce and alter the entire population system, or simply die. Tracking the \"fate\" of each individual provides the ability to model the impact of randomness on HPS transformations. Conducting experiments with identical initial conditions many times allows determination of the probability distribution of the final state.\nWhy are such experiments needed? Their main purpose is not to determine the fate of specific HPS, but to test the adequacy of our concepts about such systems. We learn some features of the objects we study and build a system of our representations about them. To build a model, such a system must be formalized (which in itself is a very useful work revealing possible logical inconsistencies in common views). The model is built on the basis of a system of representations of the object and allows comparison of the diversity of objects observed in nature with the diversity of model states observed in the experiment. If the set of states that HPS can transition to in the model differs from the set of states observed in natural objects, the model’s underlying representations need revision. Model‑object correspondence does not prove the correctness of the representation system, but serves as an argument in its favor.\nThe described use of the model demonstrates the possibility of moving from a reductionist, element‑by‑element description of the studied object’s properties to studying its characteristics as a whole (defining the set and probability distribution of development pathways).\nFrom the authors’ perspective, such an approach can also be applied to the study of other biological systems at various levels of organization.\nThe authors thank M.V. Vladimirova and G.N. Zholtkevich for invaluable assistance in formulating the task of this work and its execution.\nKravchenko M.A., Lutsyk A.A., Shabanov D.A. What new can be learned about green frogs through simulation modeling? (Plenary report at the conference opening) // \"Biology: from molecule to biosphere\". Materials of the III International Conference of Young Scientists. - Kharkiv: SPD FO Mykhailov G.G., 2008. - pp. 9-11." }