. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PERIODICITY TO BARNACLE SETTLEMENT 437 CM E~ -— « c. o O> "O -i § IQOi •£ S2 co « o 03 o o -320 ! *••_ -280 | -240 in o» o> Q o o> 200 May June Date July FIGURE 6. Daily barnacle settling rate (number/3 cnr/h of submersion/day, solid line) at + m MLLW plotted with the daily resultant wind direction (dashed line). Wind direction is the direction from which the wind is blowing. Onshore winds come from around 270°. Settlement data were collected from 9 April to 30 June, 1983, at Dike Rock, Calif
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PERIODICITY TO BARNACLE SETTLEMENT 437 CM E~ -— « c. o O> "O -i § IQOi •£ S2 co « o 03 o o -320 ! *••_ -280 | -240 in o» o> Q o o> 200 May June Date July FIGURE 6. Daily barnacle settling rate (number/3 cnr/h of submersion/day, solid line) at + m MLLW plotted with the daily resultant wind direction (dashed line). Wind direction is the direction from which the wind is blowing. Onshore winds come from around 270°. Settlement data were collected from 9 April to 30 June, 1983, at Dike Rock, California. onshore-transporting internal waves are only formed around the spring tide and I would predict that settlement of organisms transported by these waves would be highest during these periods. For an organism to utilize slicks over internal waves as a mechanism of onshore transport, it is necessary for it to remain at or near the surface. The megalopae of P. crassipes display a set of behaviors—positive phototaxis, negative geotaxis, high baro- and photokinesis, high swimming speed (9 cm/s), and high thigmokinesis (Shanks, 1985a)—which aid them in locating and remaining at the ocean's surface. The be- haviors associated with the planktonic existence of cyprids have not been well studied but the behaviors which have been observed—positive phototaxis (Knight-Jones, 1953; Crisp, 1955; Crisp and Ritz, 1973), fairly high swimming speeds (4 to 5 cm/s, Crisp, 1955), and high barokinesis (Knight-Jones and Morgan, 1966)—are all behaviors which may, as they do for P. crassipes megalopae, aid cyprids in locating and remaining in the surface waters where transport by slicks can occur. In addition, the cyprids of some species are hydrophobic and may remain at the ocean's surface by sticking to the surface film (Knight-Jones, 1953; Crisp, 1955; Connell, 1956). However, actual contact of an organism with the ocean's surface is not necessary for internal-wave mediated
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
