Actually… elaborate disguises or moonlight dances are not necessary. If you’d like to become a beach naturalist, opportunities begin around the Puget Sound over the next few weeks. Scroll below for more information.
As for a moonlit nuptial dance, we need to chat with a sea nymph (Nereis sp.). Sea nymphs are large (some very creepily so!) worms that stretch out of their burrows and use inordinately fierce looking jaws to grab a nibble of algae or maybe a soft invertebrate. However, when the moon and tides and light are right, they have a different priority.
Kind of like a werewolf, their bodies change with the coming of the full moon. The once burrow-dwelling omnivore becomes an actively swimming, gutless baby-making machine called an epitoke. On full moons in the winter and summer, the males epitokes will vigorously swim from their holes and rise into the water column, shedding sperm as they go. Once the females sense the males in the water, they follow closely spewing eggs. The sperm and eggs are often released through ruptures in the body wall (ouch!). The close proximity of eggs and sperm help ensure many of the eggs will become fertilized, but mom and dad contribute to the next link in the food chain.
Ricketts’ words painted a fabulous image of the experience of
coming across giant sea nymph worms in their nuptial fervor:
” Specimens may be nearly a meter long, and are broad in proportion — a likely source of sea-serpent yarns. To the night collector, already a bit jumpy because of weird noises, phosphorescent animals, and the ominous swish of surf, the appearance of one of these heteronereids swimming vigorously at the surface of the water must seem like the final attack of delirium tremens.” (Between Pacific Tides, 1939). … I had to look up delirium tremens… shudder!
In early March, just after the full moon, a volunteer brought the epitoke remains pictured here to a beach exploration and said they were all over her beach. Thanks for sharing!
During that same time on the beach, we got a closer look at another really cool worm…
Beach Scrap Castle
When you’re on a Puget Sound beach that’s not entirely dominated by gravel and cobble, you’re likely to encounter worm tubes sticking out of the sand. The tubes represent several of the nearly 1000 species of marine worms in our region. Particularly common in the lower intertidal is the jointed three-section tube worm. Unwieldy common name aside, it can be abundant enough to look like mini forest of leafless bamboo in the sand.
The tube of the ornate tube worm (Diopatra ornata) is well decorated by bits of plant, shell debris and algae and may be overlooked even when abundant. The tube is not as sturdy as some and may lay on the beach when the tide is out. Under the sand, the tube is much narrower, doesn’t have any decoration and feels like tough parchment. It can also extend a foot deep into the sand, giving the worm a safe place to retreat. As complex as the tube may be, the worm can abandon it and build a new on if need arises.
Ornate tube worms are thought to be scavengers but eat a lot of algae. In The diet of worms: A study of Polycheate feeding guilds (actually a really cool paper to cruise through), Fauchald and Jumars described the various things this tube worm has been observed eating, but clarified that it’s apparently not picky, “feeding experiments have shown that it will accept any plant or animal material, dead or alive, fresh or rotten (R.R. Emerson, pers. comm.).” Yum.
The image to the left is also from The diet of worms. When the tide’s out, you don’t get to see this kind of activity, but it’s fun to imagine a bunch of these worms bickering over who gets the best bit of the kelp.
Finally, if you’re lucky enough to get a look at the beast inside the tube, you get to see that the tube isn’t the only ornate character in its life story. The five black-tipped feelers on the front of it’s head are purported to have smelling abilities though I couldn’t find any more detail on that.
The gills extend for scores of segments behind the head and look like skinny red Christmas trees with branches spiraling up toward the tip. The worm my have more than 100 segments beyond that.
Segments are apparently disposable since the worm can pinch off segments from its hind end, presumably to give a predator something to nibble on while the important bits head off to build a new tube.
Beach Naturalist Opportunities
If you’re in the Kitsap area, join me, other volunteers and guest experts at the Poulsbo Marine Science Center on Thursday evenings this spring. The Kitsap Beach Naturalist training starts March 28th and will include classes on the oceanography, invertebrates, seaweed and the nearshore environment’s form and function. You can print and fill out the form to the right or register online.
Similar opportunities are available all over the Puget Sound area.
- The Seattle Aquarium’s training program is full for this year, but you can visit their website and get on a list for next year.
- If you in the Olympia area, the South Sound Estuary Association’s training begins April 19th.
- Beach naturalist elements are also part of the WSU Beach Watcher trainings in Island and Jefferson counties. For other training opportunities, check with your county WSU extension office.
If you don’t necessarily want to be part of a training and volunteer program, check with any of the groups above for naturalist led beach exploration opportunities. Hope to see you in a classroom or on the beach!
Jeff Adams is a Washington Sea Grant Marine Water Quality Specialist, affiliated with the University of Washington’s College of the Environment, and based in Bremerton. You can follow his Sea Life blog, SalishSeaLife tweets, FaceBook and video posts, send email to firstname.lastname@example.org or call at 360-337-4619.