. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. GROWTH AXD VARIATION IN DAPHNIA MAGNA 87 Table I brings out an interesting relation. The mean size for each group during the instar when eggs first appear in the brood chamber varies from mm. to millimeters. Apparently Daphnia magna must attain a certain size before becoming sexually mature. Singh-. TII /nsTar 6 /O /4 Fin. 4. Growth curves of a group of animals reared on unmodified manure- soil medium. These had five pre-adult instars (7 individuals). T—total length; C—carapace length; H—height. The arrow indicates
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. GROWTH AXD VARIATION IN DAPHNIA MAGNA 87 Table I brings out an interesting relation. The mean size for each group during the instar when eggs first appear in the brood chamber varies from mm. to millimeters. Apparently Daphnia magna must attain a certain size before becoming sexually mature. Singh-. TII /nsTar 6 /O /4 Fin. 4. Growth curves of a group of animals reared on unmodified manure- soil medium. These had five pre-adult instars (7 individuals). T—total length; C—carapace length; H—height. The arrow indicates the first adult instar. Pruthi (1925, etc.) found that metamorphosis of mealworms took place only after the larvae were full-grown. Rammner (1930^) has found that eggs were produced after the fourth instar in Daplinia inagna. After observation on well over a thousand individually reared females, the writer has never observed less than five. L. A. Brown has observed five pre-adult instars for this TABLE II Number of Individuals Primiparous During the Sixth to Ninth Instar Clone Sixth Instar Seventh Instar Eighth Instar Ninth Instar oo B. 4 10 4 9 0 C 8 3 1 0 1 D 7 4 0 0 0 E. 9 1 1 0 0 F. 6 11 7 0 0 G * 10 4 4 0 1 =c Those living beyond the 10th instar without bearing eggs. * Clone secured from Dr. A. M. 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
