Mitochondria in Obliquely Striated Muscles of the Horsehair Worm Gordionus alpestris (Nematomorpha, Gordioidea) with Structural Organization Typical of Cells with Energy-Intensive Processes

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V. B. Vays¹, I. M. Vangeli¹, C. M. Eldarov¹, B. D. Efeykin², and L. E. Bakeeva^1,a,b*

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia

²Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 119071 Moscow, Russia

^* To whom correspondence should be addressed.

Received July 11, 2018; Revised September 5, 2018; Accepted September 5, 2018

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The ultrastructure of mitochondria in the flattened circomyarian fibers of the horsehair worm Gordionus alpestris (Nemathelminthes) was examined. In contrast to the previously published data, we showed these mitochondria to be giant elongated organelles that densely fill the central cytoplasmic space of the ribbon-like muscle fibers. No fundamental differences were found in the ultrastructure of the muscle tissue mitochondria in actively moving free-living and parasitic G. alpestris worms. The functional significance of the observed ultrastructural organization of mitochondria is discussed in connection with the necessity for an extended mitochondrial membrane system for a uniform supply of active muscle tissue with energy.

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KEY WORDS: mitochondria, obliquely striated muscle, ultrastructure

DOI: 10.1134/S0006297919010073

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