Some aspects of hepatic and renal excretion in Myxine

Abstract

Little is known concerning excretory patterns in the primitive marine cyclostome Myxine glutinosa (hagfish). There is interest in these patterns in hagfish because these animals have atubular kidneys on the basis of morphologic evidence. We have studied the urinary excretion of inulin, phenol red, Mg++ and Ca++, and the excretion of the last three ions into the bile. The results indicate that the U/P (urine-plasma) ratios for inulin, phenol red, and Mg++ were close to unity and for these substances the kidney may be considered atubular. Both phenol red and Mg++ were concentrated significantly in the bile and, therefore, the bile may be the important excretory pathway in this animal.