Shell-fish industries . accom-modation of the attached byssus. This bundle of threadsis cast off at will from its proximal end, and newthreads are formed when needed. From time to timeattachment occurs during the greater part of the scallopslife, though infrequently in full-grown individuals. It should be observed that the habit of very earlybyssus attachment seems to have a direct bearing on thedistribution of scallops, for it accounts for the fact thatthey are so frequently found in grass-covered in the early summer great numbers appear at-tached to the blades of eel-grass wi
Shell-fish industries . accom-modation of the attached byssus. This bundle of threadsis cast off at will from its proximal end, and newthreads are formed when needed. From time to timeattachment occurs during the greater part of the scallopslife, though infrequently in full-grown individuals. It should be observed that the habit of very earlybyssus attachment seems to have a direct bearing on thedistribution of scallops, for it accounts for the fact thatthey are so frequently found in grass-covered in the early summer great numbers appear at-tached to the blades of eel-grass with which they mayhave come in contact while swimming, and to which theyhave fastened, as to the glass of the aquarium. The longblades of this plant, rooted in the bottom, seem to be both The Scallops 343 detrimental and useful to the scallops, detrimental be-cause their mass checks the food-bearing currents, anduseful because they undoubtedly offer great protectionby preventing the washing away of these light bodies in. Fig. 67.—Pecten one-half inch in diameter, a in, adductormuscle; b, byssus; c, eye on mantle edge; /, foot; g, gill; It,heart; /, shell ligament; m, mantle; in f, mantle fold; p,striated inner surfaces of the palps. Storms. Pectens that have had only scanty protectionof this kind are often thrown up by waves to die onbeaches. This probably is the explanation of the factthat the best scalloping grounds are on eel-grass coveredbottoms. They also attach in deeper water, though insmaller numbers, to stones, shells, and other after they have passed the embryonic stage, they 344 Our Food MoUusks may reach the grass blades above the bottom, for theystiU continue to swim from time to time by the padclHngmotion of the foot, and then by the shell, and duringthese short journeys they may attach on striking anysolid body. They may perhaps also attain a lodgmentabove the bottom by creeping up the grass blades, andthis is a function of the foot not yet described
Size: 1674px × 1493px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1910
