Squid mantle muscle

Abstract

The mantles of the small squid Alloteuthis, the larger Loligo, and the cuttlefish Sepia contain an elaborate framework of connective tissue fibres running in different planes. Some of these fibres are apparently elastic. The circular muscle fibres which provide the power stroke in mantle contraction are of two types. Inner and outer mantle zones consist of well-vascularized mitochondria-rich fibres, whereas the central zone contains only mitochondria-poor fibres with a sparse vascular bed. Nerve terminals on the two fibre types are similar. The radial fibres opposing the circular fibres are of the same type as the central fibres, at least in the mid-region of the mantle. It is suggested that the central fibres are involved in escape jetting contractions, and that the fibres of the inner and outer zones are used during rhythmical respiratory contractions.

A hedgehog homolog is involved in muscle formation and organization of Sepia officinalis (mollusca) mantle

“…At the time of hatching (stage 30), all the rounded myocytes were completely differentiated as circular fibres that were subdivided in regular fields by thin radial muscle fibres (Fig. 2P), similar to that previously described in adult animals by Bone et al (1981) and as shown in the colour-coded cartoon (Fig. 1).…”

“…The circularly disposed fibres, providing the power stroke contraction to expel water from the mantle cavity, are in turn divided into two types: oxidative mitochondria-rich fibres, localized in the outer zones of mantle, and mitochondria-poor fibres placed in the central region of mantle. Radial fibres, which are antagonist of the central circular fibres, are mitochondria-poor fibres as well (Bone et al, 1981;Budelmann et al, 1997). Even though the muscular mantle in adult cephalopods has been largely described, neither the increase in size of this muscular district nor the final spatial organization that it achieves during development have been comprehensively described.…”

Treatise Online, no. 17, Part M, Chapter 3: Anatomy of Recent forms

“…Changes in the dimension of the muscle fibers transmit the force of muscular contraction into movement and muscular antagonism (kier, 1988). The major muscles of Loligo pealei have been described by williaMS (1909) and of Sepia officinalis by toMPSett (1939); those involved in locomotion and jet propulsion by ward and wainwright (1972) and Bone, PulSford, and ChuBB (1981); those of the arms and tentacles and their suckers by guérin (1908), kier (1982, 1985), kier and SMith (1990); of the mantle by wellS (1988); and of the fins by kier (1989). An overview of the muscular system was given by Mangold and Bidder (1989) and that of the ultrastructure by BudelMann, SChiPP, and von Boletzky (1997).…”

“…The mantle is attached to the visceral mass by a pair of ligaments that arise near the middle of the visceral mass and extend over the edge of the gladius to the mantle (williaMS, 1909). The large and (Ward & Wainwright, 1972); 2, disposition of connective tissue fibers in mantle of Alloteuthis; skin at bottom of figure; bv, blood vessels; cc, connective tissue fibers; ch, chromatophore; ifz, inner fiber zone; nb, nerve bundle; ns, nerves to skin; ofz, outer fiber zone; ot, outer tunic (Bone, Pulsford, & Chubb, 1981).…”

“…27). The partitions of radial fibers also contain connective tissue fibrils (Bone, PulSford, & ChuBB, 1981). The inner and outer surfaces are covered by layers of collagen, called the tunics (goSline & deMont, 1985), and there is a complex network of connective tissue fibers (Bone, PulSford, & ChuBB, 1981) (Fig.…”