Fireworms seem to be a regular sight at the Blue Heron Bridge – both during the day and on night dives. I’ve seen Bearded Fireworms before (and I’m sure I’ll share photos of them soon) but this was my first time seeing Blackline Fireworms (Chloeia viridis). They just seem to be a bit more fancy… I guess that might be why another name for them is Ornate Fireworm.
These are not nudibranchs – though they do have gills on the outside of their bodies like nudis – they are more closely related to things like Feather Duster and Christmas Tree worms. The tufts along their sides are both their gills (usually the reddish parts) and bristles which can break off and cause severe irritation (I assume much like fiberglass). They tend to be scavengers. I’m not sure if they are able to hybridize with the Bearded Fireworms, but the second photo certainly looks somewhat like a cross between the two.