J. M. Gosline, J. D. Steeves, A. D. Harman and M. E. DeMont. (1983).
Patterns of circular and radial mantle muscle activity in respiration and
jetting of the squid Loligo opalescens. J. Exp. Biol. 104, 97-109.
1. By simultaneously recording the electromyographic (EMG) activity of squid
mantle muscles, changes in mantle cavity pressure and changes in mantle
diameter, we have been able to distinguish the pattern of radial muscle
activity from circular muscle activity, and in so doing were able to
determine the functional role of these muscle groups in motor
2. Three distinguishable phases of activity appear during escape jets:
(i), hyper-inflation brought about by the contraction of the radial muscles;
(ii), the jet powered by the contraction of circular muscles; and (iii),
refilling powered largely by the elastic recoil of the mantle wall, but
with a small contribution from the radial muscles.
3. Two distinctly different patterns of muscular activity were seen in
respiratory movements. One pattern (pattern I) is powered by the radial
muscles alone, while the other (pattern II) is powered by the circular
muscles alone. In both modes of respiration, the muscles are apparently
antagonized by tissue elasticity.
4. Thus, the storage of elastic energy in the connective tissue
fibre-lattice of the mantle wall plays a very important role in both modes
of squid movement.
Edwin DeMont, Associate Professor
Biology Department, St. Francis Xavier University
P.O. Box 5000, Antigonish, Nova Scotia, B2G 2W5 Canada
Voice 902-867-5116 FAX 902-867-2389
January 18, 1997