a larva from a Polychaeta

Images made through a microscope. All subject types.

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Franz Neidl
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Joined: Wed Jan 14, 2009 11:59 am
Location: Italy

a larva from a Polychaeta

Post by Franz Neidl »

This is a planctonic larva from the Sabellidae (fan worms or feather duster worms) maybe Sabellaria alveolata (?). The lenght of the animal is 500 µm.

I would be happy to know what are the yellow spots (symbiotic algae?).

First picture: Obj. 10x, DIC.
Second picture: Obj. 20x, DIC.




Posts: 354
Joined: Sat Sep 29, 2007 10:53 am
Location: England

Post by BJ »

hello Franz,

just a quick posting,

the yellow orange patches are made of of oil filled cells - of the worm itself. The pigment is a carotenoid pigment (ie of the carotene family - probably a xanthophyll) dissolved in the oil. In adult sabellids the pigment is often some form of astaxanthin (the pigment in salmon, lobsters etc).

I guess the function may be to help the larva orientate itself in relation to light ( in the ocean, brightest direction = "up").

here is a paper on sabellid larval development:


I am enjoying all your posts..thank you !
kind regards

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