アコヤガイの外套膜の再生と癒着に関する組織学的観察

抄録

Histological observation was made on the reparative process of the mantle of the pearl oyster after a small portion (circular, about 1cm in diameter) of the mantle was resected in the pallial zone or the central area. Oysters used were of 2 to 3 years of age.
Experiments were done during the months of August to October at water temperature of 25 to 28°C.
The results obtained are as follows:
1. Within 2 to 3 days after operation the cut surface is completely covered by the layer of epithelial cells spread out from the cut edges.
The shell and inner folds are formed on the epithelial layer, about 10 days after operation in case of the pallial zone and 13-17 days in case of the central area. The middle fold appears 13-17 days and 19 days after operation, respectively.
After about 24 days a groove from which a periostracal substance is secreted is formed by the depression of a part of the outer epidermis, though the folds are still small in the whole shape.
Observation as a whole suggest that every portion of the mantle has the capacity of regeneration and that of formation of three kinds of folds and a periostracal groove.
2. Usually within 5 to 7 days after operation regenerating mantle tip spread out from the surrounding cut surface unite with each other.
On the area of union small pearl sacs (seed pearl-sacs) are frequently formed owing to the depression of the outer epidermal layer.