. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EFFECTOR CONTROL IN RENILLA LARVAE 511 Larval development The early cleavages and larval development of Rcnilla kollikcri are similar to that described by Wilson (1883) for Rcnilla rcnifonnis. The intial cleavages are extremely irregular and variable. Seldom can 2-, 4-, or 8-cell stages be recognized. The first detectable cleavages (Rcnilla kollikcri') occur 20 min to 3 hr after spawn- ing, at which time embryos of 8 to approximately 64 cells are observed (Fig. 3). Prior to this stage the embryos are very irregular in shape
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EFFECTOR CONTROL IN RENILLA LARVAE 511 Larval development The early cleavages and larval development of Rcnilla kollikcri are similar to that described by Wilson (1883) for Rcnilla rcnifonnis. The intial cleavages are extremely irregular and variable. Seldom can 2-, 4-, or 8-cell stages be recognized. The first detectable cleavages (Rcnilla kollikcri') occur 20 min to 3 hr after spawn- ing, at which time embryos of 8 to approximately 64 cells are observed (Fig. 3). Prior to this stage the embryos are very irregular in shape (Fig. 2). Early development progressed more rapidly at 25° C than at lower tempera- tures tested. Cooler temperatures, down to 6° C, retarded development without apparent harmful effects. A timetable for the development of Renilla kollikeri (25° C) is shown in Table I, and all further mention of age will refer to this table and temperature. Just prior to cleavage, neutral buoyancy is lost, and the embryos settle to the bottom of the aquarium. No ciliary activity is apparent. Subsequent cell divisions give rise to stereoblastulae. Endoderm formation is followed by gradual disappear- ance of the central, yolky cells. Swimming planulae are formed 38 hr after spawn- ing (Figs. 4, 5). The planulae are barrel-shaped and swim at the air-water inter-. 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
