Morphology of excretory organs in branchiobdella pentodonta (Clitellata, Branchiobdellida)

Abstract

The nephridium of Branchiobdella pentodonta is composed of a richly ciliated nephrostome, a lacunar capsule whose cells are phagocytic, a long nephridial tubule and excretory canal both concerned with reabsorption, and a dorsally placed nephridial pore.In contrast to the nephridia of previously studied species of Oligochaeta and Hirudinea the nephridia of Branchiobdella are characterized by having only two pairs of nephridia: an anterior in the second, third and fourth segments of the trunk and a posterior in the eighth and ninth segments. Another characteristic of Branchiobdella pentodonta is that the excretory orgen has no vascular supply and therefore waste matter is excreted solely from the coelomic fluid. © 1983 Taylor & FrancisGroup, LLC.