Larva of a sea urchin

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The larva of a sea urchin has, like its cousin the brittlestar, a supporting skeleton. With stronger magnification you can see the delicate structure of these. These sea urchin larvae have strong pigmentation.

The larvae of echininoderms all have specific names. These are derived from the taxonomic names of the adults or from their appearance. For example an 'echinopluteus larva' is a larve of a sea urchin (class echinoidae) and an ophiopluteus larva is a larve of a brittle star (order ophiurida) Starfish larva first form a bipinnaria stage. when arms (brachia) appear you call it a brachiolaria stage.

The arms of the starfish larva will help it to attach to a surface where the final metamorphoses takes place.


image Wim van Egmond

size about 0.25 mm.


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