. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. GLYCERA RED CELL VOLUME REGULATION 631 pernatant to cyanmethemoglobin (Eilers, 1967) and measuring absorbance spec- trophotometrically at 540 nm. The red coelomocyte pellet was then hemolysed in distilled water, and samples analyzed for amino acid and hemoglobin concentra- tions. All amino acid values presented are corrected for the small amount of hemolysis which occurred in both high and low osmotic concentration media. Statistically significant salinity-dependent changes in amino acid efflux were identified by a paired /
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. GLYCERA RED CELL VOLUME REGULATION 631 pernatant to cyanmethemoglobin (Eilers, 1967) and measuring absorbance spec- trophotometrically at 540 nm. The red coelomocyte pellet was then hemolysed in distilled water, and samples analyzed for amino acid and hemoglobin concentra- tions. All amino acid values presented are corrected for the small amount of hemolysis which occurred in both high and low osmotic concentration media. Statistically significant salinity-dependent changes in amino acid efflux were identified by a paired / test (Steel and Torrie, 1960). RESULTS Coelomic fluid osmotic concentration and body wall tissue water The osmotic concentration of G. dibranchiata coelomic fluid varies directly with the osmotic concentration of the acclimation media over the range of salinities tested (Fig. 1). Although the slope of the regression line describing this rela- tionship (TTCF — 1-005 (TTMED) + mosm where CF = coelomic fluid and MED = medium) is not significantly different from (P>), the coelomic fluid is not isosmotic with the environment. Rather, the osmotic concentration is sig- nificantly higher (P<) than the environment at every point, averaging 8 mosm hyperosmotic to the acclimation medium. Body-wall-tissue water, as a percent of wet weight, varied by over the range of acclimation salinities tested (Table I). Body wall and coelomocyte intraccllular free amino acids The intracellular FAA pool of both body wall and coelomocytes decreased significantly (P < ) with lowered external salinity (Figs. 2, 3). Both the 1000 900 800 ~- 700 O 600 O E 500 400- 300-. 200 300 4OO 500 600 7OO 800 (mOsm/ Kq H20)Q FIGURE 1. Osmotic concentration of Glyccra dibranchiata coelomic fluid from worms acclimated to 1001, 697, 463, 374, and 230 mosm/Kg H,O ASW. The points represent the mean osmotic concentration measured from five animals at each salinity. The lower limit of the 9
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
