. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 428 C. G. DUFORT ET AL. 180 -, 160 - 140 - ^ 120 - S g 100 \ ^ 80- & 60 - 40- 20-. fWi ^ Tachycardia ^; in « v i ; I * i >*. '% Vu; x r35 -30 -25 -20 - 15 - 10 - 5 10 210 410 610 Time (s) 810 0 1010 ex ex ^ s Figure 2. Changes in heart and scaphognathite rates in response to changes in salinity. As in Figure 1, salinity was decreased at a rate of 1-2 ppt/min. Each heart and scaphognathite data point is an average of 10 s of data from a digital ratemeter. while each salinity data point comes from a single refractometer
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 428 C. G. DUFORT ET AL. 180 -, 160 - 140 - ^ 120 - S g 100 \ ^ 80- & 60 - 40- 20-. fWi ^ Tachycardia ^; in « v i ; I * i >*. '% Vu; x r35 -30 -25 -20 - 15 - 10 - 5 10 210 410 610 Time (s) 810 0 1010 ex ex ^ s Figure 2. Changes in heart and scaphognathite rates in response to changes in salinity. As in Figure 1, salinity was decreased at a rate of 1-2 ppt/min. Each heart and scaphognathite data point is an average of 10 s of data from a digital ratemeter. while each salinity data point comes from a single refractometer measurement each min. Initial heart and scaphognathite rates were 35 and 50 bpm. respectively. Tachycardia first occurred at 31 ppt (upward arrow) and was accompanied by an increase in ventilation rate. When the salinity reached a value of 22 ppt. the lobster responded with bradycardia (downward arrow). The bradycardia response was accompa- nied by apnea. Shortly after the salinity began to increase, both heart and scaphognathite rates rebounded to levels well above baseline and then slowly recovered towards baseline over time. with normal seawater flowing through both the branchial chambers and the experimental chamber (tank), overnight. The next day, lobsters were exposed to the following treat- ments. (1) Normal seawater (32 ppt) was perfused through the tank while the salinity in the branchial chambers was gradually reduced. (2) The salinity in the tank was reduced while the branchial chambers were perfused with normal seawater. (3) The salinity in the tank was reduced and no solutions were perfused through the branchial chamber, as in a typical salinity-reduction experiment. Treatment #1 was always carried out last; the other two treatments were ran- domized. Animals were given at least 1 h to recover be- tween treatments. Water from both branchial chambers and the experimental chamber dripped into a reserve tank through PE tubing so that salinity could be sampled each m
Size: 3140px × 796px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
