Further studies on Mouthpart Receptors in decapoda crustacea

Summary In the lobster Homarus gammarus (L.) (=Homarus vulgaris M. Ed.) three bilateral groups of proprioceptors are arranged around the mouth. These strand receptor organs, termed Mouthpart Receptors (MPRs) 1, 2 and 3, were described previously and their physiological responses, mainly to mandibular movements, were characterised (Laverack and Dando, 1968).The receptor organs are described here for Panulirus argus Latr., Nephrops norvegicus L. and Astacus leptodactylus Esch.. Because of the anatomical differences between the receptors in Panulirus and Homarus the physiological work on Panulirus was designed to characterise the responses of the receptor neurones in some detail. The input from the receptors studied was similar to that of the Homarus receptors. In Nephrops and Astacus where the anatomy is similar to that of Homarus we have demonstrated that these receptors form a non-specialised system which responds to many of the movements associated with the act of ingestion of food.It is suggested that with other work now in progress, particularly on the innervation of the mandible (Wales and Laverack, 1970), a reasonably complete summary of the proprioceptive input associated directly with food ingestion is now possible. The relevance of this work to studies on the stomatogastric ganglia is discussed, and finally an attempt is made to compare the crustacean information with that for several insect species where the anatomy of the receptors in the mouth region is known but physiological experiments are much more difficult.This work was supported partly by the Centre National de la Recherche Scientifique (Equipe de Recherche Associée No. 231).This represents contribution No. 487 from the Bermuda Biological Station. Work carried out in Bermuda was supported by the Science Research Council (B/SR/4866).