Lucy Corrander's picture

Large Worm Cast

Observed: 14th March 2013 By: Lucy CorranderLucy Corrander’s reputation in InvertebratesLucy Corrander’s reputation in InvertebratesLucy Corrander’s reputation in Invertebrates
LUCY CORRANDER - WORM CAST - MARCH 14TH 2013 - IMG_3033
Description:

Worm cast. Firm and grey on top of soft, very wet,yellow sand. About two inches across. Sand pile about two inches high and three across.
Any idea what might have created it?

Identifications
Species interactions

No interactions present.

Comments

chrisbrooks's picture

ID comment

I'll start the ball rolling and say it looks like a Blow Lugworm Cast, which consists of an untidy pile of castings (the bottom of which seems to have been effected by water movement in this case). It lives in a "U" shaped tunnel and therefore a few inches away should have been the other end which looks like a hole in the sand. The cast of the Black Lugworm tends to look like a Catherine Wheel.

However I'm not sure if there are other species of worms that leave casts on the beach.

Lucy Corrander's picture

Worm Cast

Thanks for your comment. It sent me off to look at images etc. and you may well be right. And I know there are lugworms in the sand for I have spoken to fishermen digging for them there as bait. What drew my attention to this particular cast though was that it was especially large compared with others on the beach. Also, that the other casts matched the colour of the sand - where this is distinctly grey. Maybe a monster lugworm! I should have photographed one of the smaller casts too - maybe they have been made by a different variety of interesting worm!

Blog - Loose and Leafy - http://looseandleafy.blogspot.com/

gramandy's picture

because of...

....depths that they go down to create their burrows - they very often meet anaerobic mud/sand - which is expelled at the surface by the worm (hence the grey colour). This is distinctive for lugworm.

Lucy Corrander's picture

About the lugworm cast

Thanks for your explanation. I wonder if you might add to it? I'm not clear if the cast is sand consumed and excreted by the worm or whether it's merely pushed, toothpaste-like by water being forced through the burrow or by the worm itself as it pushes its way in.

Blog - Loose and Leafy - http://looseandleafy.blogspot.com/

gramandy's picture

the worm,

pushes the sand through it's body and excretes it :)

Lucy Corrander's picture

Thanks. Assumed so but

Thanks. Assumed so but couldn't find anywhere which says so explicitly. (Getting bogged down in articles about how to dig lugworm for bait.) Does the worm gain nutritional benefit from the sand going through its system? Or does it get its food in other ways?

Blog - Loose and Leafy - http://looseandleafy.blogspot.com/

gramandy's picture

A quote....

for you. 'The worm's burrow, which is often located in anaerobic soils, is ventilated by peristaltic movements of its body. Water is pumped through the burrow from the tail to head end, and it is this movement that softens the sand in the pocket area around the head. The worm eats this softened soil by engulfing it with its large, frilly, expansible proboscis. Defecation is prodigious and occurs on a cycle of 10-30min depending upon season and temperature.'
Hobson 1967 Biol Bull 133: 343; May 1972 Biol Bull 142: 71.

It will eat bacteria, detritic organic material, etc.

Lucy Corrander's picture

Thanks. I think I understand

Thanks. I think I understand better now how the water is pumped into the burrow. What a funny, lonely life it must be to be a lugworm.

Blog - Loose and Leafy - http://looseandleafy.blogspot.com/

gramandy's picture

when...

...you are eaten so regularly by waders (with 3 ft beaks) and dug up by fisherman, wouldn't you like a lonely life? :)