. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DISPERSAL AND GENETIC EXCHANGE 307 sufficiently long to account for their trans-Atlantic dispersal over any of the four major routes. The remaining four species, Thais haemastoiiia. I'liilippia. krcbsii, Smaraydia viridis, and Pedicularia sicula seem to have but little opportunity for trans-Atlantic transport either by way of the North Atlantic Drift or the North Equatorial Cur- rent, and only under the most favorable conditions could cross in the South Equa-. 60 FIGURE 12. Geographical distribution of the larvae of Pedicula
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DISPERSAL AND GENETIC EXCHANGE 307 sufficiently long to account for their trans-Atlantic dispersal over any of the four major routes. The remaining four species, Thais haemastoiiia. I'liilippia. krcbsii, Smaraydia viridis, and Pedicularia sicula seem to have but little opportunity for trans-Atlantic transport either by way of the North Atlantic Drift or the North Equatorial Cur- rent, and only under the most favorable conditions could cross in the South Equa-. 60 FIGURE 12. Geographical distribution of the larvae of Pedicularia sicnla Swainson: filled black circles = larvae of Pedicularia sicula; small open circles = stations at which larvae of Pedicularia sicula were not taken. Stippled areas designate geographical regions from which the post-larvae are known (Allen, 1956). The western Atlantic form Pedicularia decussata Gould should probably be regarded as no more than a subspecies of Pedicularia sicula (). Arrows show direction of surface currents. torial Current and the Equatorial Undercurrent. Yet three of the four remaining species under consideration have larvae throughout the entire North Atlantic Drift and two are found also along the North Equatorial Current (see Figs. 9, 10, 11, and 12). The answer to this paradox must be that the duration of pelagic larval devel- opment among these species is longer than estimated. Three possibilities suggest themselves. The first is that the developmental period is much extended under conditions of the open sea. It is known, for example, from observations in the. 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,
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
