TY - JOUR
T1 - Effects of environmental dilution on body fluid regulation in the yellow stingray, Urolophus jamaicensis
AU - Sulikowski, James A.
AU - Maginniss, Leigh A.
N1 - Funding Information:
We thank Dr Richard Spieler and his graduate students at Nova Southeastern University Oceanographic Center for the use of lab materials, animal holding facilities, equipment and help in collection of the stingrays in South Florida. Thanks are further extended to Dr Frederick Prete for assisting with statistical analysis of the data and to Mark Gonka for his expertise with salt water aquaria and animal maintenance at DePaul University. This project was supported, in part, by LA&S and URC grants from DePaul University.
PY - 2001
Y1 - 2001
N2 - Adult yellow stingrays (Urolophus jamaicensis), collected off the southeast Florida coast, were maintained in filtered and re-circulated synthetic sea water (33‰) for 5-13 days at 30°C. Animals exposed to 82%, 74% and 66% SW in gradual steps exhibited rapid and significant weight gains followed by recovery to pre-dilution levels in 2-6 days. Acclimated animals at each salinity [100% (N = 12), 82% (7), 74% (4) and 66% SW (3)] were anesthetized (MS222) and bled from the caudal vein. In 100% SW, stingray plasma was slightly hypo-osmotic to the external medium. Plasma osmolality decreased with stepwise dilutions, but became increasingly hyperosmotic to the bathing media. Plasma [Na] and [Cl] each decreased by approximately 13%, 23% and 16%, respectively, in 82%, 74% and 66% SW. Plasma [urea] decreased by 21%, 25% and 59%, respectively. Changes in plasma [K] and [Ca] were minor. Mean corpuscular [Hb] measurements suggest that stingray red cells swelled less at each dilution than predicted for a passive erythrocyte osmometer. RBC [K] decreased by 12%, 36% and 29%, respectively, in 82%, 74% and 66% SW. Quantitatively, the other measured electrolytes (Cl, Na and Ca) changed by lesser amounts. Results suggest that for mild and moderate dilutions (82% and 74% SW), yellow stingrays release both ions and urea from intracellular and extracellular compartments. With further dilution (66% SW), the elasmobranchs retain electrolytes at the expense of urea.
AB - Adult yellow stingrays (Urolophus jamaicensis), collected off the southeast Florida coast, were maintained in filtered and re-circulated synthetic sea water (33‰) for 5-13 days at 30°C. Animals exposed to 82%, 74% and 66% SW in gradual steps exhibited rapid and significant weight gains followed by recovery to pre-dilution levels in 2-6 days. Acclimated animals at each salinity [100% (N = 12), 82% (7), 74% (4) and 66% SW (3)] were anesthetized (MS222) and bled from the caudal vein. In 100% SW, stingray plasma was slightly hypo-osmotic to the external medium. Plasma osmolality decreased with stepwise dilutions, but became increasingly hyperosmotic to the bathing media. Plasma [Na] and [Cl] each decreased by approximately 13%, 23% and 16%, respectively, in 82%, 74% and 66% SW. Plasma [urea] decreased by 21%, 25% and 59%, respectively. Changes in plasma [K] and [Ca] were minor. Mean corpuscular [Hb] measurements suggest that stingray red cells swelled less at each dilution than predicted for a passive erythrocyte osmometer. RBC [K] decreased by 12%, 36% and 29%, respectively, in 82%, 74% and 66% SW. Quantitatively, the other measured electrolytes (Cl, Na and Ca) changed by lesser amounts. Results suggest that for mild and moderate dilutions (82% and 74% SW), yellow stingrays release both ions and urea from intracellular and extracellular compartments. With further dilution (66% SW), the elasmobranchs retain electrolytes at the expense of urea.
KW - Body fluid regulation
KW - Elasmobranch
KW - Erythrocyte
KW - Extracellular solute concentration
KW - Hematocrit
KW - Hemoglobin
KW - Intracellular solute concentration
KW - Osmoregulation
KW - Urea
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U2 - 10.1016/S1095-6433(00)00304-4
DO - 10.1016/S1095-6433(00)00304-4
M3 - Article
C2 - 11223383
AN - SCOPUS:0035109586
SN - 1095-6433
VL - 128
SP - 223
EP - 232
JO - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
JF - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
IS - 2
ER -