Rectal Glands of Marine and Fresh-Water Sharks: Comparative Histology

Science  29 May 1964:
Vol. 144, Issue 3622, pp. 1151-1152
DOI: 10.1126/science.144.3622.1151


The rectal glands of elasmobranchs perform the function of salt-excreting organs. These glands are smaller and show regressive changes in specimens of the bull shark, Carcharhinus leucas found in fresh-water environment, compared with specimens of this and other species from a marine habitat.