Heart and scaphognathite activity in the shore crab Carcinus maenas (L.)

Abstract

Simultaneous recordings of the activity of the heart and both scaphognathites of Carcinus maenas (L.) were investigated during a wide repertoire of normal activities. The scope of activity for the heart and scaphognathites could usefully be subdivided into three smaller ranges or levels which, although arbitrary, were recognizable on the basis of frequency and arrhythmic phenomena. Alterations of heart and scaphognathite activity induced by a variety of laboratory treatments were investigated in order to evaluate and aid the interpretation of such data for comparative purposes. Providing the recent manipulative history of the animal is known, the behaviours of heart and scaphognathites have been shown to be predictable and useful as sensitive sources of comparative data. The observed behaviour of the heart and scaphognathites has been discussed in terms of their nervous control systems and of their implications in a variable system of blood circulation and gill ventilation.