MOVEMENT ACTIVITY OF ROUND GOBY (NEOGOBIUS MELANOSTOMUS PALLAS, 1814) UNDER THE INFLUENCE OF GEOMAGNETIC FIELDS

Abstract

Introduction. Behavioral traits of fish are an important manifestation of their response to external stimuli. Locomotor activity reflects the influence of specific factors on fish behavior and the role they play in their lives. Among the least studied factors are fluctuations in the geomagnetic field and their impact on the locomotor activity of the round goby Neogobius melanostomus Pallas, 1814. Aim. The aim of this study was to investigate the influence of fluctuations in the geomagnetic field on the locomotor activity of the commercially important speciesof benthic ichthyofauna, the round goby Neogobius melanostomus Pallas, 1814, in the Black Sea. Methods. The ichthyological material was collected in the coastal waters of the Odesa Bay, ranging from Cape Northern Odesa to Cape Velikyi Fontan, during a scientific research survey conducted by the I.I. Mechnikov Odesa National University (ONU). Laboratory investigations were conducted in the aquarium room of the Aquatic Biology and General Ecology Department of the I.I. Mechnikov Odesa National University. Hourly changes in fish locomotor activity were recorded and analyzed as a result of the study. During the specified observation period, periods of increased geomagnetic activity were identified and compared to periods when this activity was within normal range. An original methodology called “Computer Vision Method” was employed for processing the visual data and tracking of the laboratory animals. Results. The maximum values of geomagnetic activity during the observation period, classified as a first intensity magnetic storm of class G1, were observed on February 3, 2022, from 6 to 12 hours, and on February 4 and 10, 2022, from 15 to 21 hours. When comparing the levels of fish locomotor activity during these time intervals with their activity during the time intervals on days with minimal geomagnetic activity (February 8, 9, and 15, 2022), a decrease in locomotor activity of individuals during magnetic storms of 27% to 42% can be observed. Conclusion. The fluctuations in locomotor activity of the round goby during increased geomagnetic activity up to the level of magnetic storms indicate the ability of this species to perceive magnetic fields and respond to changes in its properties. Specifically, when the Kp-index values corresponded to a first intensity geomagnetic storm (G1), a decrease in fish locomotor activity was observed compared to the activity during the same time intervals on days with minimal geomagnetic activity.