Pallial sinus
The pallial sinus is a notch or inward bend on the inside of a bivalve shell, along the pallial line. It marks where the siphons (the tubes clams use to feed and breathe) extend in siphonate species. This area often appears as a shiny line on the inner shell.
This page was last edited on 2 February 2026, at 15:30 (CET).