. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SALINITY DETECTION IN LOBSTERS 429. 10 210 410 610 Time (s) 1010 Figure 3. Heart and scaphognathite rates during a drop in salinity for a lobster with lesioned cardioregu- latory nerves. The baseline heart and scaphognathite rates were 63 and 120 bpm, respectively. When the salinity reached 31 ppt. the scaphognathite rate dropped suddenly and continued a pattern of intermittent stops and starts until the salinity increased again. Over the course of the salinity drop, heart rate declined slowly to 53 bpm, a decrease of 16% fr
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SALINITY DETECTION IN LOBSTERS 429. 10 210 410 610 Time (s) 1010 Figure 3. Heart and scaphognathite rates during a drop in salinity for a lobster with lesioned cardioregu- latory nerves. The baseline heart and scaphognathite rates were 63 and 120 bpm, respectively. When the salinity reached 31 ppt. the scaphognathite rate dropped suddenly and continued a pattern of intermittent stops and starts until the salinity increased again. Over the course of the salinity drop, heart rate declined slowly to 53 bpm, a decrease of 16% from baseline, and then slowly increased back to baseline. Similar results with four additional lobsters indicate that cardiac responses to changes in salinity are mediated by the cardioregulatory nerves. (Fig. 2). During bradycardia, the heart rate fell significantly from ± to ± bpm (paired t test, P ) from females ( ± ppt) to males ( ± ppt). The bradycardia response in the 30 animals tested occurred at ± ppt, which represents an average drop of ppt from the ambient salinity. For the lobsters that showed both bradycardia and tachycardia responses, the salinity at which bradycardia occurred was significantly lower than that at which tachycardia occurred (paired t test. P < ). The SDT for bradycardia was also significantly higher (unpaired t test, P < ) for females ( ± ppt) than for males ( ± ppt). Involvement of cardioregulatory nen'es Under control conditions, prior to treatment, there was no significant difference (P = one-way ANOVA) between the baseline heart rates of control (n = 5, ± bpm). experimental (n = 5. ± bpm). and sham-lesioned lobsters (n = 5, ± bpm). After recovery from treatment (4-7 days), the heart rates of both the sham and lesioned groups were elevated in comparison to the control group, but this difference was not statistically signifi
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
