サルボウとカリガネエガイの足糸の解剖學的構造

Abstract

The byssus gland of Anadara subcrenata is a single thread with a somewhat dilated end (Fig. 1) and composed of 10-30 single long compressed tubules at the root. The tubules are nearly in parallel with each other (Fig. 2) and arranged radially in U-shape in cross section (Fig. 3) and do not anastomose one another at the proximal ends and their distal ends are gathered together into an opening at the conical process (Fig. 2, C) which is located in the byssus pit (P). When the adult of Anadara, measuring 30-40mm in length, is placed in the aquarium, it casts away the byssus and attaches itself to the substratum with a newly formed byssus. The new byssus is secreted from conical process which reaches at first the substratum to fix the end fo byssus over there and then contracts into the byssus pit in stretching the byssus substance so as to from a thick thread. The byssus of Barbatia obtusoides is thick lamellar in shape (Fig. 5) and is secreted from the numerous deep long glandular grooves, running parallel in longitudinal direction of foot (Fig. 6), anastomosing sometimes at the proximal ends. The glandular grooves are gathered together in one groove on each side and united into one on the byssus ridge (C). The byssus of Barbatia is so much well developed as it may withstand a heavy beach-comber in the cleft of rock between tide marks.