hi.
I apologize to those that still want to comment or vote, but since some of you are impatient about the answer, I will anounce it right now.
ANSWER:
Abyssal gland of
Tridacna crocea (bivalve in the poll)
FACT:
Abyssal gland of Tri. clams are used to anchor themselves to the substrate, usually rock. Sometimes, a clam may "let go" of the abyssal gland during growth or in period of stress. The clam may not attach itself to substrate once this happens, and often reported for the case of
T. deresa. However, many large derasa can still attached to substrate.
There are misconception that a missing abyssal gland for smaller clams, such as
T. crocea or
T. maxima usually means that the clam is in ill health, but many time, the clam will do well for many years as reported by some hobbyists.. This misconception probably is due to other related injury when the gland is ripped off the clam forcefully in an efford to remove the clam.
However, because large amount of energy is needed to regenerate the abyssal gland (high protein content), when a clam is stressed by other factor, a missing gland will compromise it chance to recovery.
In the pic, the gland is several years old. As a clam is growing, it add new threads to one end of the gland. This growth pattern give the gland a conic shape. The earlier threads are stained by dead tissue and dirt, while the newer threads are white in color. A few bubble algae were
glued onto the thread since they grow near the substrate, making the gland the appearance of a nudibranch. This red-herring is not intended when the photo was taken.
The clam from which the gland is taken from is doing well, and is currently attached to another substrate within 4 days.
No vertabrate is harmed for this thread. :wink:
