. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. t 55 t SR Figure 11. Time of day of larval release by females carrying an exchanged cluster and by females from which the cluster had been removed. Records were made in the laboratory under 24-h LD cycle, but under no tidal influence. Solid diagonal lines connect the times of high water (//III in the field. D: larval release on the first night of embryo exchange. A: larval release on the second night after embryo exchange. •: larval release occurs more than three nights after the embryo exchange, . and AT connect the time
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. t 55 t SR Figure 11. Time of day of larval release by females carrying an exchanged cluster and by females from which the cluster had been removed. Records were made in the laboratory under 24-h LD cycle, but under no tidal influence. Solid diagonal lines connect the times of high water (//III in the field. D: larval release on the first night of embryo exchange. A: larval release on the second night after embryo exchange. •: larval release occurs more than three nights after the embryo exchange, . and AT connect the times of sunset and sunnse, respectively. the female must produce some unknown stimulus that enhances synchronous hatching. Females of S. haematocheir release their larvae with vigorous abdominal movements. This same behavior is observed in other terrestrial crabs (Saigusa, 1981). In species that release their larvae under the water, the release is effected by the pumping behavior of the ab- domen (DeCoursey, 1979; Forward ct ai. 1982: Saigusa, 1992a). Forward and Lohmann (1983) suggested that this behavior enhances hatching synchrony. In contrast. hatching in terrestrial species occurs prior to larval re- lease. Clearly, larval release behavior itself does not en- hance the hatching synchrony in female-attached em- bryos. One possible mechanism is that the female kneads the egg-clusters several times around the time of night high tide. In addition to such physical stimuli, the hatching of a few embryos might release a substance like the hatching enzyme suggested by De Vries and Forward (1991), and thus stimulate the hatching of the remaining 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 rep
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
