One or two pairs of anterior nephridia
, in 6/7-8/9, with compact spindle-shaped postseptale (up to 90 [micro]m x 40 [micro]m) tapering into short (35 [micro]m) ectal duct in its posterior end.
In particular, Acidovorax-like symbionts of earthworms colonize the nephridia
(excretory organs) and degrade peptides and amino acids, facilitating the reabsorption of nitrogen by the worms before it is excreted as waste (Schramm a al., 2003).
Benham (1888: 72) reported on a specimen from an unknown type locality, with two pairs of nephridia
per segment and the gizzard in segment 6, and named it Brachydrilus [sp.].
Oblique transverse sections, approximately 5 mm thick and including mantle, gills, gonad, digestive gland, nephridia
, and foot were taken from each specimen.
These cells appear to be the larval mesoderm, which we suspect will form larval muscles such as the dorsal levators, and possibly the larval nephridia
. At the opposite side of the archenteron, the surface of the embryo protrudes just below the mesodermal pockets (Fig.
, in posterior segments two pairs per segment, coiled; the dorsal pair larger and the ventral smaller, this varying between segments, in some the dorsal smaller and the ventral larger.
Remacha-Trivino (2002) found a parallel disorganization and subsequent reorganization of nephridia
and gonads in S.
Based on nephridia
characteristics, Korniushin (1998) suggested that all African Sphaerium spp.
Tissue samples were embedded in Paraplast, and oblique transverse sections, approximately 5-mm thick, were taken from each specimen including mantle, gills, gonad, digestive gland, nephridia
Females with single pair of ciliated ducts (oviducts, nephridia
, or both) opening on ventral surface of segment 11, with external opening only 10 [micro]m in diameter (Fig.
They mature to metaphase of meiosis I in the coelomic fluid, are collected by the nephridia
, and spawned (Daly, 1972).
Antidiuretic and diuretic activities of FMRFamide and GDPFLRFamide respectively have been demonstrated in nephridia
of a leech (Salzet et al., 1994).