KHOLODKEVICH S.V., IVANOV A.V. , KUZNETSOVA T.V. , KURAKIN A.S., TRUSEVICH V.V.
Saint-Petersburg Scientific Research Center for Ecological Safety RAS, Russia, Кaradag Natural Reserve NAS of Ukraine, Ukraine

Nowadays the great attention is paid to development of biomarker approach for marine ecosystems’ health assessment in the oil and gas regions of Arctic shelf.

In particular investigations aimed to reveal and study physiological biomarkers giving principal opportunity to develop on their base automatic systems for on-line control of ecosystems’ health play a special role in this approach.

It is known that all living organisms are characterized by the presence of rhythms in functioning of their systems and organs. In any functional system there coexist rhythms of different frequencies, what, apparently, gives rise to strict hierarchic organization of different processes inside the organism.

When study physiological and behavioral animals’ reactions the great attention is paid to investigation of ultradian rhythms (UR), since they reflect features of main physiological processes, can characterize mechanisms of short-term physiological responses of animal’s organism and occur at different organization levels. In particular, the stability of ultradian cell cycles is essential factor for normal development and functioning of living organism and a lack thereof can lead to severe development abnormalities [1]. The interest to UR is also based on principal possibility to use such characteristics in wide range of problems concerning environmental control [2].

In recent paper [3] there was reported on revealing ultradian rhythms in mantle and valve movements of mussels Mytilus edulis (L.) being kept in aquarium conditions. The authors linked these rhythms to cyclic changes in filtration velocity and feeding behavior. In that laboratory investigations the mussels behavior was studied with help of web-camera and original software for image analysis.

The aim of the present paper was to study peculiarities of UR realization in mussels cardiac activity and valve movements.

Earlier the authors for the first time discovered UR of 10- and 30-min periods in cardiac activity of bivalves [4]. Such rhythms reflect peculiarities of feeding behavior and metabolism of the animals in natural habitat conditions. In the present paper based on laboratory and field studies conducted with help of different bioelectronic methods [5, 6] it is shown that observed in valve movements UR may synchronically appear in cardiac activity in different ways: as in-phase heart rate (HR) changes with constant amplitude of heart contraction (AHC), as anti-phase changes of AHC with constant HR.

Besides, the UR can be observed in cardiac activity without essential changes in valve movements and vice versa. In the authors’ opinion, with sufficient knowledge of UR, as physiological characteristics of functional systems state peculiarities of organisms, UR in mussels cardiac activity and valve movements can become new biomarkers for assessing state and health of marine ecosystems.

References

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Kholodkevich S.V., Ivanov A.V., Kuznetsova T.V., Kurakin A.S., Kornienko E.L., Pan’kov S.L., Khalatov A.N., Ultradian rhythms in cardiac activity of bivalves. // Doklady Akademii Nauk – in press.
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OIL AND GAS OF ARCTIC SHELF 2008