. Bulletin of the United States Fish Commission. Fisheries -- United States; Fish-culture -- United States. 67 Figs. 67 and 68.—A young mussel on: to three days after leaving the fish, in outward form like the original glochidium but internally (tAt is. inside the shell) showing organs developed. Drawn with a camera lucida. X 140. 67.—Ventral view with valves apart, from specimens stained and cleared. 68.—Side view; a narrow growth of the new definitive shell may be seen bordering the glochidial shell. This species belongs to the bradytictic group called winter breeders. The glochidia are prod
. Bulletin of the United States Fish Commission. Fisheries -- United States; Fish-culture -- United States. 67 Figs. 67 and 68.—A young mussel on: to three days after leaving the fish, in outward form like the original glochidium but internally (tAt is. inside the shell) showing organs developed. Drawn with a camera lucida. X 140. 67.—Ventral view with valves apart, from specimens stained and cleared. 68.—Side view; a narrow growth of the new definitive shell may be seen bordering the glochidial shell. This species belongs to the bradytictic group called winter breeders. The glochidia are produced in the late summer or fall and are carried through the winter in the dis- tended marsupial gills (see fig. 62) of the female. The glochidia (fig. 64) are favorable for infection, because their comparatively large size makes it easy to follow the progress of infection (fig. 65) and subsequent shedding. Unfortunately, the number of glochidia produced is relatively small. The gravid mussels for this experiment were obtained in Lake Pepin, Minn., about May 15, 1914, and shipped to Fairport, Iowa, by express. On May 21 ripe glochidia were taken from three of the live mussels for the experiment. Some dozen different species of fish were infected and of these, six proved susceptible and carried the young mussels through their metamorphosis. Before the young mussels began to be shed eight infected largemouth black bass were placed in basket No. 2 of the floating crate. Some very rough weather followed, tossing the crate about in such a way as to make. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States Fish Commission. Washington, The Commission, Govt. Print. Off
Size: 1422px × 1757px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1900, bookcollectionbiodiversity, bookdecade1920
