Title: Studies on the Movement of the Japanese Hard Clam, Meretrix meretrix lusoria (RöDING)-I
Abstract: As has been previously reported by some students, Meretrix meretrtx tusoria has the peculiar habit of moving by means of string-like mucous excreted from the posterior region of the clam. This method of locomotion was found to be common during late spring and autumn. In the course of their histological studies, the present writers discovered conspicuous mucous tissue in this posterior region, which they believe may be correlated with this peculiar method of locomotion. This mucous tissue lies between the root of the siphons and the black line extending along the posterior palliat margins on the inner wall of the mantle surrounding the siphons, as shown in Fig. 1 & 4. For fixation of this tissue, Susa and Gilson solutions gave good results, while Bouin's solution caused great swelling followed by rupture. This mucous tissue was stained with Mucicarmine and Haematoxylin. The mucous cells were very tall, reaching a length of 0.35mm in clams 30mm in length (Fig. 2). Similar mucous tissue was not found in other clams such as Venerupis semidecussata (Fig. 3), Dosinia japonica, Mactra sulcataria and Mactra veneri formis which do not have this mucous-string method of locomotion.