Tag Archives: eggs

Worm your way into being a Beach Naturalist

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.

Giant sea nymphs (Nereis sp.). Photo: Jeff Adams
Giant sea nymphs (Nereis sp.). Photo: Jeff Adams

Explosive Love

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.

Sea nymph (Nereis sp.) epitoke/body-turned-egg-case. Photo: Jeff Adams
Epitoke remains with eggs oozing out the body wall. Photo: Jeff Adams

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

Above ground portion of 12"+ tube of an ornate tube worm (Diopatra ornata). Photo: Jeff Adams
Above ground portion of 12″+ tube of an ornate tube worm (Diopatra ornata). Photo: Jeff Adams

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.

A diagram from the 1979 paper "The diet of worms: A study of Polycheate feeding guilds" by Fauchald and Jumars.
A diagram from the 1979 paper “The diet of worms: A study of Polycheate feeding guilds” by Fauchald and Jumars.

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.

Above ground portion of 12"+ tube of an ornate tube worm (Diopatra ornata). Photo: Jeff Adams
Head end and first 80 or so segments of an ornate tube worm. Photo: Jeff Adams

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

Screen shot 2013-03-19 at 9.18.56 AMIf 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.

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 jaws@uw.edu or call at 360-337-4619.




Terrific tides, crab opener, and croaker care

Students and families at Scenic Beach State Park. Photo: Jeff Adams

Terrific tides
This morning was the first in a great set of minus tides.

  • 6/29, -0.4 at 7:43AM
  • 6/30, -1.6 at 8:36AM
  • 7/1, -2.5 at 9:27AM
  • 7/2, -3.1 at 10:16AM
  • 7/3, -3.4 at 11:03AM
  • 7/4, -3.2 at 11:50AM
  • 7/5, -2.7 at 12:35PM
  • 7/6, -1.7 at 1:20PM
  • 7/7, -0.5 at 2:04PM

Remember that these are predictions for Seattle and can vary depending on geography and weather. Should get you in the ballpark though. Kitsap Beach Naturalists will be on several beaches at different times over the next week if you can take advantage of the great critter stories they have to share.

Eagles know where to find midshipmen. The medium to large rocks such as those in this image often harbor midshipman during the summer. Poulsbo waterfront. Photo: Jeff Adams

When you head out to explore the beaches, keep a few things in mind to protect and respect those who call the beach home.

  • tread lightly and walk more than run (you stay safer and see more cool stuff when you’re walking anyway),
  • look around the edges of eelgrass and kelp beds instead of tramping through them,
  • explore mostly under rocks that are smaller than your head and return them to the way you found them,
  • refill any holes you dig, and
  • remember, shellfish license or not, it’s illegal to take most living sea creatures off the beach, including  shore crabs, hermit crabs, sea stars, sand dollars, snails, etc.
Midshipman eggs with the front half of daddy midshipman cryptically visible to the lower left of the eggs. Fort Ward. Photo: Jeff Adams

Midshipman (croakers)
In the big rock category, if you do turn over a large rock this time of year, you may find male plainfin midshipman (Porichthys notatus) guarding pea-sized yellow eggs that are attached to the underside of the rock. It’s a really cool thing to see, but over-handling of the fish and awkward replacement of a heavy rock may be tough on the fish and it’s progeny. If you do get a good look at one, maybe stick to the “rocks smaller than your head” rule and leave the rest of the large rocks be.

These amazing deeper water fish have light producing spots called photophores under their head to attract prey, and some seriously sharp teeth with which to munch them. Each late spring/summer, they rise up to the intertidal to stake out nests under large solid objects and make grunting noises to attract the ladies (the reason they’re sometimes called croakers).

Midshipman, nibbled on and left to dry. Poulsbo waterfront. Photo: Jeff Adams

Plainfin midshipman are important predators, but also fall prey to seals and sea lions and can be a very important part of eagles’ diet. It’s not unusual to find the bodies of eviscerated midshipman far from the shoreline, delivered there by an eagle or crow. They are also sometimes abundant bycatch in commercial shrimp trawls.

Crab season
For those of you who have been drooling for dungeness since Christmas… The recreational crab season opens this Sunday, July 1st, for much of Puget Sound and lasts until September 3rd. Blain/Bellingham/San Juans are the exceptions with a slightly later start and close to the season. You can only crab Thursdays, Fridays, Saturdays, Sundays and Mondays. I guess Tuesday and Wednesday is the crab weekend.

The large hard substrate that midshipman find isn't always limited to rocks. Silverdale Waterfront Park. Photo: Jeff Adams

You’re still measuring between where the outermost points meet the carapace. In Puget Sound, you’re looking for up to 5 male Dungeness that measure at least 6.25″, and up to 6 red rock crabs of either sex that are at least 5″. Make sure their shells are hard and that you record your Dungeness. For crab sexing, you can check out an earlier post, and for lots of great information including gear and regulations, see WDFW’s excellent recreational crab site.

Enjoy the holiday week and the excellent tides, and our intertidal treasures!

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 jaws@uw.edu or call at 360-337-4619.