spiral valve


Also found in: Encyclopedia, Wikipedia.

spiral valve

References in periodicals archive ?
Meristic measurements include vertebral counts, spiral valve turns and upper and lower tooth counts.
This indicates that these cololites are not from taxa that contained a spiral valve, and are thus not attributed to sharks or rays.
The fish also has a long spiral valve in its intestine, which slows the passage of food and enables it to be more completely digested.