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Vol. 20 (2017 year), No. 2, DOI: 10.21443/1560-9278-2017-20-2
Pakhomov M. V., Ishkulov D. G., Zaytsev A. A.
The influence of the optical characteristics of the environment on colour vision of earless seals
The results of studying the influence of optical characteristics of sea water on the ability of earless seals to differentiate tablets of blue and red colours have been presented. The experiment involved four specimens of gray seals (Halichoerus grypus, Fabricius, 1791), five species of harp seals (Pagophilus groenlandicus, Erxleben, 1777), and two ringed seals (Pusa hispida, Schreber, 1775). The seals have been trained to choose from a pair of plates the plate of blue colour and to mark it by touching. The experiments have been conducted on air (control study) to produce the sensitivity curve in the air without affecting transparency and colour depth and on 2 m underwater. It has been found that at the illumination above 50 lux in all model animals the proportion of correct answers corresponds to the control one and is 89 ± 3.6 % for gray seals, 74.8 ± 6.2 % for harp seals, 71 ± 5.7 % for ringed seals. When light level is reduced the proportion of correct answers decreases and becomes equal to the random selection at 15 lux for gray seals, 20 lux for harp seals and 25 lux for ringed seals. It has been shown that at the depth of 2 m with illumination below 50 lux the average number of errors for the experience slightly increases from 1.2 to gray seals, harp seals at – 0.6, in ringed seals – 1.8. It has been found that the transparency and colour of water have little impact on the ability of model animals to differentiate blue and red tablets at the given depths. Only the light level has the main influence on colour perception of model animals under water.
(in English, стр.7, fig. 6, tables. 0, ref 12, Adobe PDF, Adobe PDF 0 Kb)
Vol. 21 (2018 year), No. 2, DOI: 10.21443/1560-9278-2018-21-2
Zaytsev A. A., Yakovlev A. P., Zavoloka P. A.
Changes in activity of harp seal (Pagophilus groenlandicus) in the spring – summer period in conditions of aviary keeping
The results of research on changes in active forms of behavior of two representatives of harp seal (Pagophilus groenlandicus Erxleben, 1777) in the spring - summer period in conditions of aviary keeping by analyzing its quantitative characteristics have been presented. Material for this paper was gathered within a series of observations on Murmansk Marine Biological Institute's aquacomplex in Polyarny, 2011. Method of "recording individual behavioral manifestations" was used as the main method of observation. The following characteristics have been used as parameters for assessing animal behavior: the mean duration of apnea, the mean duration of animal being on surface, the number of surfacing per minute, the percentage of being underwater and on the surface from the total budget of time, the percentage of being on platform and resting in water from total budget of time. A comparison has been made between the behavior parameters of each animal, and the individual characteristics of their behavior have been described. The gathered data have allowed us to consider possibility of influence of some environmental factors on behavior of harp seals. The impact assessment has been carried out based on the values of the following factors: temperature of water, temperature of air, wind speed, atmospheric pressure level. The statistical analysis has not revealed any significant dependencies between animals' behavior changes and such factors as atmospheric pressure. The Spearman rank correlation coefficient has shown the presence of feedback between the surfacing rate and the water temperature for both animals, and also a positive connection between the mean duration of apnea and water temperature for one animal and the air temperature for other.
(in English, стр.8, fig. 3, tables. 7, ref 10, adobe PDF, adobe PDF 0 Kb)
Vol. 22 (2019 year), No. 2, DOI: 10.21443/1560-9278-2019-22-2
Yakovlev A. P., Zaytsev A. A., Ishkulov D. G., Grigoriev V. F.
The influence of low-frequency electromagnetic field on the operability of gray seals
Gray seals are widely used in biotechnical systems for various purposes. In the study of the effect of an artificial electromagnetic field (EMF) with 8 Hz frequency on the performance of gray seals, the method of conditioned reflexes has been used (one of the most informative for experimentally studying the functional state of the higher divisions of the Central nervous system). Two adult female grey seal have been used in the experiment; two series of experiments have been conducted for each individual gray seal. The first series of experiments has been conducted in the conditions of natural (background) geomagnetic field. During the second series of experiments, individuals of gray seals have been affected by an artificial electromagnetic field throughout the training. The criterion for assessing the effect of EMF on the operability of animals is the implementation of skills due to their behavior. During the study, the following parameters of instrumental reflexes have been monitored: the average retention time of the target pointer (the Target command); average target search time (the Search command); total time spent on training; the number of mistakes made by the seal per workout. It has been shown that experimental animals are characterized by similar properties of higher nervous activity. Experiments without exposure to an electromagnetic field have shown comparable values of the target index hold time, target search, and the number of errors made. When conducting training with the effects of artificial low-frequency electromagnetic field, the animals were more excited, made more errors when executing commands; the target pointer hold time was significantly reduced, and the target search time increased by one and a half times. Thus, when exposing gray seals in the artificial electromagnetic field with the frequency of 8 Hz, an annoying, alarming effect of this field has been observed manifesting itself in a decrease in the effectiveness of instrumental conditioned reflexes that means reducing the operability of gray seals.
(in Russian, стр.9, fig. 3, tables. 2, ref 26, Adobe PDF, Adobe PDF 0 Kb)
Vol. 26 (2023 year), No. 2, DOI: 10.21443/1560-9278-2023-26-2
Pakhomov M. V., Zaytsev A. A., Litvinov Yu. V., Troshichev A. R.
Application of tonal audiometry methods to assess the hearing of grey seals in air and water environments
Anthropogenic noise load on the traditional habitats of marine mammals continues to increase due to the active development of the Arctic zone. The study of the hearing of Arctic seals is of great importance for the development of measures to reduce the impact of technogenic noise. During the study, a group of ten grey seals of different ages and genders has been trained to press a special key when demonstrating a pure tone sound with a frequency from the standard and extended set of frequencies recommended for pure tone audiometry. The experiments have been carried out by placing the key and the sound source in air and water (at a depth of 2 m) environment. The main indicator is the reaction time of the seal to the demonstrated stimulus. For each seal, individual audiograms for hearing in air and in water have been compiled using 32 frequencies. An analysis of the data obtained has shown that the reaction time can serve as an individual indicator in the study of the hearing of grey seals reflecting their age characteristics. According to the response time to sounds with different tone frequencies it is possible to establish biologically significant and indifferent frequencies for grey seals.
(in Russian, стр.10, fig. 2, tables. 0, ref 29, AdobePDF, AdobePDF 0 Kb)