The feeding mechanism and structure of the gut ofOwenia fusiformisdelle Chiaje

Abstract

Oweniamay feed either by ciliary means or by swallowing sand and detritus. The gut consists of three main parts, a fore-gut or stomach which is secretory, a non-secretory mid-gut region which is absorptive, and a hind-gut which is non-secretory, non-absorptive and serves to elaborate and store the faecal pellets. The mid-gut contains coproporphyrin III and also phaeophorbide-6, to which the green colour is due. The green pigment in the epidermis is also phaeophorbide-ft, but phaeophorbide-a is apparently absent from the body.