. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 314 RUDOLF S. SCHELTEMA Equatorial Undercurrent a vertical distance between 50 and 100 m depth) one can compute the volume of water in which most of the larvae are to be found (Table V). Assuming the lowest measurable concentration of one larva per tow, and considering the case in which a single veliger occurs in each sample of a trans- oceanic section, one can now roughly calculate the number of larvae that ought to. 101 10 10' FIGURE 14. Intensity of larval settlement of the sea-star Asteria forbcsi (stippled bars) and the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 314 RUDOLF S. SCHELTEMA Equatorial Undercurrent a vertical distance between 50 and 100 m depth) one can compute the volume of water in which most of the larvae are to be found (Table V). Assuming the lowest measurable concentration of one larva per tow, and considering the case in which a single veliger occurs in each sample of a trans- oceanic section, one can now roughly calculate the number of larvae that ought to. 101 10 10' FIGURE 14. Intensity of larval settlement of the sea-star Asteria forbcsi (stippled bars) and the oyster Crassostrca rirginica (solid bars) over a period of twenty-five years. The ordinate gives the percentage of years during which settlement occurred at a density value ( nr) shown on the abscissa. The success of settlement is regarded as being directly related to larval survival and, at least in the species represented here, the median density of settlement is approximately equal to the survival when ps = 2/tt (, when each individual in the population gives rise to one offspring). There are other species where the latter relationship is probably not true, specifically, when the frequency-density curve is skewed (data taken from Loosanoff, 1964, 1966). be present throughout the length of any such current at one instant in time. Thus if the concentration of gastropod veligers is X 10~3/m3, the number of larvae in the North Equatorial Current will be | X 10s km3] • X 10C larvae/knr] := X 1011 or about 460 billion veligers. East-west sections made across the Atlantic in the North Equatorial Current during the months of January and June show that, in. 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 Lab
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
