solenocytes

Solenocytes are specialized excretory or secretory cells found in some invertebrate animals. They are associated with excretory ducts in various protonephridial and metanephridial systems, and their exact appearance and position can vary across taxa.

Structure and location

In many descriptions, solenocytes are elongated cells that line parts of an excretory tubule or connect to a duct lumen. They may possess apical projections such as microvilli or cilia to contact filtrate and facilitate exchange, and they often feature a distinct basal region surrounding the nucleus. Solenocytes can occur as solitary cells or in small clusters within the nephrostome or adjacent ductules that drain waste fluids.

Function

The primary role of solenocytes is tied to excretion and osmoregulation. They participate in filtering body fluids, reabsorbing or secreting ions and solutes as needed, and transporting waste into the excretory duct for elimination. The exact mechanisms and ion specificities can differ among groups, reflecting the diversity of invertebrate excretory biology.

Distribution and terminology

Solenocytes have been described in a range of invertebrate lineages, and the term is used to distinguish these cells from other excretory cell types such as flame cells or nephrocytes. Because homologous structures can vary by lineage, the precise anatomy and function of solenocytes are not uniform across all species.

See also

Flame cell, nephrocyte, nephridium, protonephridium, metanephridium.