Oblique, transverse, 5-mm-thick sections, containing gills, digestive gland, mantle, nephridia
, gonad, and foot were taken from each clam.
We will describe the morphological and molecular development of mesoderm in these species, and the differentiation of two important mesodermal cell types: nephridia
Comparative morphology and evolution of the nephridia
Oblique transverse sections, approximately 5 mm thick, including mantle, gills, gonad, digestive gland, nephridia
and foot were taken from each specimen.
Excretory system meroic; small number of nephridia
, very difficult to find.
1-3 pairs of anteclitellar nephridia
observed in 7/8-9/10 (or none, in some individuals); postclitellar ones beginning in 13/14 or 14/15; compact postseptale of variable shape and with short duct arising posteriorly.
On the paired nephridia
of Prosobranchs, the homologies of the only remaining nephridium of most Prosobranchs, and the relations of the nephridia
to the gonad and genital duct.
The gut was then freed from surrounding blood vessels and nephridia
with a flamed forceps and separated into three sections: foregut, mid gut and hindgut.
An unexpected and surprising result was the finding of coccidia in the gills of Ensis macha, because these Apicomplexan protozoa are usually located in nephridia
or digestive glands in mollusks.
Micro-PIXE studies of Cd distribution in the nephridia
of the earthworm Eisenia fetida (Oligochaeta).
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.
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.