A histomorphological comparison of the urinary systems in the serranid fishes, Roccus sexatilis and Roccus americanus
The urinary systems of the striped bass,Roccus saxatilis (N=13), and white perch,R. americanus (N=12), were studied to determine if they supported the monogeneric classification and to examine the osmoregulatory structure that may enable the species to survive in environments of different salinities. The gross anatomy of the urinary systems of the two species showed a number of similarities, e.g. the general mesonephric form and size, ureteral position and length, and the renal venous system. The head kidney, a hemopoietic organ, was larger inR. saxatilis than inR. americanus. Histological comparisons were made of H and E serial sections of the posterior part of the kidneys, and of the ureter, from threeR. saxatilis and fourR. americanus; included were the entire kidneys of two 2-year-old males of each species. The kidney of a young specimen of each species was also studied. The glomeruli inR. americanus (59.7 ?) were found to, be larger than those inR. saxatilis (47.7 ?); in a previsize. The number of goblet cells in the anterior part of the ureter was treater inR. saxatilis (approx. 20:1) and may be correlated with glomerular size. A distal tubular segment, usually, present in freshwater fishes, was absent in both species; probably a reflection of their marine origin. As the differences in the urinary systems were explained on the basis of phenotypic responses to the environment, they, and the number of similarities, were considered to support a monogeneric classification.
- 1 - sciences appliquees, technologies et medecines
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- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Aquatic Science
- 1 - Physical Sciences ; 2 - Chemistry ; 3 - General Chemistry
- 1 - Physical Sciences ; 2 - Chemical Engineering ; 3 - Catalysis