By: Dany Burgess, Angela Eagleston & Diana Olegre, Environmental Assessment Program
|Doto columbiana, the British Columbian Doto|
Another Northwest slug?
|D. columbiana - profile of whole |
preserved specimen stained pink
Excuse me? My “antennae” are called rhinophores!The antenna-like structures on the nudibranchs’ heads are called rhinophores. These are a type of chemo-sensory structure, allowing nudibranchs to sense the world around them. The word “rhinophore” comes from the Greek word “rhino,” meaning nose, which is appropriate since they function as an organ of “smell.”
However, while humans smell scents in the air with their noses, nudibranchs “smell” or detect scents that are dissolved in the sea water around them to find food. The rhinophores’ worm-like appearance makes them an easy target for predators, so they can be quickly retracted into a trumpet-shaped rhinophore sheath for protection.
You are what you eat
|D. columbiana on a colony of the hydroid Aglaophenia|
The British Columbian Doto is quite drab by comparison. D. columbiana eats hydroids from the genus Aglaophenia. Hydroids are colonies of tinier critters called “polyps” that are related to jellyfish. An Aglaophenia colony looks like a brown fern frond or feather plume, and these neutral colors are incorporated into D. columbiana’s body to help camouflage it from predators.
D. columbiana conveniently lives on what it eats as well, laying its eggs on the underside of the hydroid’s branches. When the eggs hatch, the young larvae have shells which disappear as the nudibranchs become adults.
D. columbiana, like many soft-bodied critters, does not preserve well. The colors can be lost and the shape can become distorted. Benthic taxonomists, the scientists who identify these small marine critters, have to look closely at features like the cerata and rhinophores to determine which critter they have collected.
Eyes Under Puget Sound Critter of the MonthOur benthic taxonomists, Dany and Angela, share their discoveries by bringing us a Benthic Critter of the Month. Dany and Angela are scientists who work for the Marine Sediment Monitoring program. These posts will give you a peek into the life of Puget Sound’s least-known inhabitants.
In each issue we will highlight one of the Sound’s many fascinating invertebrates. We’ll share details on identification, habitat, life history and the role this critter plays in their sediment community. Can't get enough benthos? See photos from our Eyes Under Puget Sound collection on Flickr. Look for the Critter of the Month every month on our blog.