. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 356 KANDULA PAMPAPATHI RAO time and degree to the tidal levels in the locality from where they have been col- lected (Fig. 1). The pattern holds good even when several individuals are grouped together and their activity as a whole is measured. The rhythm is inde- pendent of temperature over the whole range measured, from 9 to 20° C. (as has been found by Brown, Bennett and Sandeen, 1953, in the fiddler crab) and persists for over four weeks in the laboratory in continuous darkness or continuous light, or the normal day and n
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 356 KANDULA PAMPAPATHI RAO time and degree to the tidal levels in the locality from where they have been col- lected (Fig. 1). The pattern holds good even when several individuals are grouped together and their activity as a whole is measured. The rhythm is inde- pendent of temperature over the whole range measured, from 9 to 20° C. (as has been found by Brown, Bennett and Sandeen, 1953, in the fiddler crab) and persists for over four weeks in the laboratory in continuous darkness or continuous light, or the normal day and night environment. No indications of a diurnal rhythm in the rate of water propulsion were noticed. Similar results were obtained regardless of the height inter-tidally from which animals were collected and even with mussels obtained from a sub-tidal population at a depth of about 30 ft. off the shore (Fig. 2). 0>. "*" 3 M— 1 0) •o 1=0,1 \ / \ xx '^.-S \ / \»..^x '"N i _^ B 24 6 12 Apr. 18 24 20 6 12 Apr. 18 21 24 Hrs FIGURE 4. Record of rate of water propulsion in M. edulis from Barnstable Harbor on Cape Cod, kept in darkness at 9° C. at Los Angeles, California. Dotted line indicates the tidal cycle at Los Angeles. Mytilus edulis Samples of M. edulis collected from the same locality and treated similarly showed a tidal rhythmicity in their rate of water propulsion. What is more remark- able, mussels collected from the underside of floats showed a pattern of activity which was quite parallel to that exhibited by mussels collected from the pilings nearby (Fig. 3). M. edulis collected at Barnstable Harbor on Cape Cod and studied at Los Angeles, California—nearly 3000 miles west—showed a rhythm in their rate of water propulsion which was out of phase with the local tidal cycle by about 6% hrs. (Fig. 4), and this difference persisted for over four weeks in the laboratory. Of the mussels obtained from Cape Cod, one dozen were kept in a small wire cage and
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
