10 June 2011

A mysterious tube at low tide

Back in April when we were in Florida, I spent several hours one afternoon at a tidal mudflat near the Honeymoon Island outside of Tampa. The tide was out and it was a good time to collect data on the intertidal snail Batillaria minima.

At the edge of the receding water outside the range of Batillaria minima, which lives quite close to the high tide mark, I saw a tube sticking vertically out of the mud.

I suspect it was the case of a polychaete worm. The worm itself was probably deep inside in a water-filled chamber waiting for the water to return. Either that or it was a drinking straw stuck in the mud. In the next picture my finger provides a scale.


Adorably Dead said...

Note to self: if you see something that looks like a drinking straw stuck in sand, don't pull it up because it might be a worm...and definitely do not drink from it.

xoggoth said...

Looks plastic to me. BTW, do hermit crabs ever use bottle tops etc instead of shells?

Anonymous said...

Most hermit crabs will not willingly use anything but a gastropod shell. Their bodies have evolved to fit one and to grasp one. Usually there is not a shortage of gastropod shells, and they are very resourceful about finding one that it is the right size and right shape for them (they have to get larger ones as they grow of course).

But when they can't find something suitable they will improvise. I have seen a juvenile Caribbean land hermit crab that was wearing one of those tiny individual jam jars that you get at a fancy hotel. And I have seen images and videos of land hermit crabs wearing various other man-made items such as the broken neck and lid of a bottle, long plastic bottle top, and so on. Do a google search for... hermit crab in bottle.

Susan J. Hewitt

JK said...

The tube looks like that of a fan worm's. I've seen them quite often while scuba diving at night in Indo-Pacific reefs.

Anonymous said...

Yeah, it's the tube of a feather duster worm or fan worm, family Sabellidae; like Aydin says, a marine polychaete. I think it's the tube of a Chaetopterus species, a parchment tube worm.

Susan J. Hewitt