Sunday, March 29, 2009

like sesame seeds in a sandbox

Field season has not yet truly begun here in New England (we're still anxiously awaiting budburst!), but I have been spending some time in the field, investigating barnacle recruitment in Narragansett Bay. Here, the intertidal barnacle Semibalanus balanoides reproduces in the fall and broods its larvae until the winter. Larvae are released in January and develop in the water column for about a month and begin to settle in February and March. They settle as cyprids, a larval stage that looks an awful lot like a sesame seed (see photos). In the cyprid stage, the barnacles decide where on the shore to settle and attach, based on chemical cues from adult barnacles and surface texture. This is a critical moment in a barnacle's life - after metamorphosis, it will be stuck in the same place for the rest of its sessile adult life.

Click here for full size photos.

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