. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. \\,. FIGURE 4. One column contraction pulse (CCP) occurring with a number of tentacle contraction pulses (TCP's) recorded from one gastrozooid. One electrode is attached to each tentacle and a third attached to the column. Symbols are: Filled squares, TCP of tentacle 1; filled circles, TCP of tentacle 2; open circles and squares, TCP recorded from passive tentacle; open triangles, TCP recorded from the gastrozooid; and filled triangles, CCP of the gastro- zooid. The horizontal bar represents 5 sec and the vertical bar 1 mV.
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. \\,. FIGURE 4. One column contraction pulse (CCP) occurring with a number of tentacle contraction pulses (TCP's) recorded from one gastrozooid. One electrode is attached to each tentacle and a third attached to the column. Symbols are: Filled squares, TCP of tentacle 1; filled circles, TCP of tentacle 2; open circles and squares, TCP recorded from passive tentacle; open triangles, TCP recorded from the gastrozooid; and filled triangles, CCP of the gastro- zooid. The horizontal bar represents 5 sec and the vertical bar 1 mV. from the column of a gastrozooid appears as a negative-going potential with a small positive overshoot (Fig. 4). Conduction velocities of TCP's range from cm/sec in the tentacles to 3 cm/sec on the abaxial surface of the gastrozooid measured from individuals partially relaxed, with the tentacles as long as the column (all at 15° C conducted in a distal direction). Column contraction pulses (CCP's}. Column contraction pulses can only be recorded from the column of the gastrozooid. If they are conducted up into the tentacles the amplitude of these pulses must he less than 5 Each CCP corre- sponds to a contraction of the column longitudinal muscles with fibrils on the abaxial side shortening more than those on the axial side of the column. The fre- quency of TCP's is always less than that of CCP's. CCP's can either appear alone or with TCP firing of both tentacles. Conduction velocities of CCP's have not been measured since it is difficult to stimulate CCP's electrically without generating other pulse types, and not enough spontaneous CCP's were recorded to give a statistically reliable value. Figure 4 shows a column con- traction pulse appearing in a burst of TCP activity. Colonial pulses (CP's}. Colonial pulses can be recorded by suction electrodes attached to any part of the external surface of the colony (the medusa just prior to release shows no electrical connectiv
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
