caa a22 4500 469082496 CHVBK 20180323132954.0 cr unu---uuuuu 170328e19920301xx s 000 0 eng 10.1007/BF00319380 doi (NATIONALLICENCE)springer-10.1007/BF00319380 Structural organization of two fast, rhythmically active crustacean muscles [Elektronische Daten] [Darrell Stokes, Robert Josephson] Summary: The organization of the flagellum abductor muscle and of a scaphognathite levator muscle of the green crab, Carcinus maenas, has been compared quantitatively using light and electron microscopy. These muscles are rhythmically active at relatively high frequencies and for long durations. Fibers of both muscles are interconnected to form fascicles of 50 or more fibers within which there is cytoplasmic continuity. A single muscle is made up of 8-12 fascicles. Individual fibers consist of a peripheral rind of densely packed mitochondria, a thick region of glycogen granules, and myofibrils arranged into scattered central islands. Less than half the volume-density of these muscles is contractile material, the balance being largely mitochondria and glycogen. The fibers within a muscle are structurally similar. They have short sarcomeres (about 2 μm), thin to thick filament ratios of about 3:1, and junctions between the sarcoplasmic reticulum and the transverse tubules at the M line. Sarcoplasmic reticulum occupies about 10% of the myofibrillar volume-density. A well developed sarcoplasmic reticulum appears to underlie the capacities of these two muscles for high frequency contraction; extensive mitochondria and glycogen stores should confer fatigue resistance under both aerobic and anaerobic conditions. Springer-Verlag, 1992 Crustacean muscle nationallicence Ultrastructure nationallicence Dye coupling nationallicence Flagellum nationallicence Scaphognathite nationallicence Fascicles nationallicence Mitochondria nationallicence Carcinus maenas (Crustacea) nationallicence Stokes Darrell Department of Biology, Emory University, 30322, Atlanta, GA, USA aut Josephson Robert Department of Psychobiology, University of California Irvine, 92717, Irvine, CA, USA aut Cell and Tissue Research Springer-Verlag 267/3(1992-03-01), 571-582 0302-766X 267:3<571 1992 267 441 https://doi.org/10.1007/BF00319380 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00319380 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Stokes Darrell Department of Biology, Emory University, 30322, Atlanta, GA, USA aut NATIONALLICENCE 700 1- Josephson Robert Department of Psychobiology, University of California Irvine, 92717, Irvine, CA, USA aut NATIONALLICENCE 773 0- Cell and Tissue Research Springer-Verlag 267/3(1992-03-01), 571-582 0302-766X 267:3<571 1992 267 441 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer