Creature feature: sablefish

Visitors to our Underwater Dome exhibit often ask, “What’s that funny looking gray fish?” Sometimes they’re asking about wolf eels (which aren’t eels, despite their name)—but more often, they’re referring to sablefish.


Despite sometimes being called “black cod” and having some similarities in appearance, sablefish are not a true cod. They’re one of only two members of the Anoplopomatidae family. True cod belong to the family Gadidae.


Name: Sablefish (Anoplopoma fimbria), also known as black cod

Habitat: Typically sandy or muddy seafloor areas deeper than 600 feet (adults)

Range: Throughout the North Pacific

Size: Up to 3 feet long and 55 pounds

Life span: Up to 90+ years*

Diet: Fish, crustaceans and cephalopods

Reproduction: Sablefish are typically reproductively mature at 5–7 years of age. They spawn in winter in deep water. Eggs develop for about two weeks before hatching. At this stage larvae rise toward the surface, where they may be carried long distances by currents (in some cases over 2,000 miles in six to seven years).

The sablefish in our Underwater Dome exhibit came to us from a NOAA research program in 2013. NOAA monitors both sablefish movement and abundance. Movement is tracked via tag and release programs and abundance via longline and trawl surveys. Sablefish have been evaluated by the Seafood Watch program and are currently listed as both a “Best Choice” and a “Good Alternative,” depending on the location and method used to catch them.

*Wait a minute, what? Sablefish can live to be over 90 years old?! It’s true. And how do we know that? Scientists typically use the otolith, or ear bone, to age fish. This structure is part of the acoustico-lateralis system, contributing to hearing and buoyancy in living fish. More of a stone than a bone, the otolith is formed from regular growth and hardening of layers of aragonite, a form of calcium carbonate, in the fish’s skull behind its eyes. Since the growth is regular, it can be counted under a microscope like rings in a tree. Similar to tree rings, the otolith growth can be challenging to interpret, depending on factors like ocean conditions, calcium carbonate availability, and the fish’s overall health. Because of this, additional means of aging fish have been used to predict the otolith’s rate of accuracy, including radio carbon dating. According to one study by NOAA, the otolith was highly accurate in predicting age with only a one percent chance of over-predicting the fish’s age by one or more years—that’s pretty impressive!

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Know your beach-season recap

#8 and final in a series of guest blog posts by Seattle Aquarium beach naturalists Bobby Arispe and Jen Strongin.

It’s been an amazing season on the beach! A few highlights:

pacific red octopus

In early June, Jen had an incredible week—a 17-inch long California sea cucumber, a humpback whale breaching off Golden Gardens beach, bald eagles, moon snails laying eggs, flatfish, sea pens, huge Dungeness crabs, shrimp, sea stars and…lots of octopuses! A grand total of seven were reported from a single day at Lincoln Park beach in West Seattle!

Bobby had his first day as a beach naturalist at Constellation Park where he discovered a gap in the rock, revealing a hidden little world for sea stars and anemones. At the boulder wall he found lots of purple sea stars, and some of the largest anemones he had ever seen.

Crab #2

As June wrapped up, Jen found a new game to play with young beachgoers—“beach detective,” where kids used their senses to determine if the crabs they found on the beach were really dead. A gentle touch to see if they moved; if not, they picked them up and felt how heavy they were. Then, they gave them a good smell. If the crab didn’t smell really stinky, they tried opening the carapace. If it opened easily and looked like the crab below, they knew they had “crab clothes” or, more technically, a molt! This crab had just grown a little bigger and left its old exoskeleton behind.

Bobby loved exploring the beach over the 4th of July weekend. His favorite moment was when a little explorer brought him over to see a fish he found. It was a gunnel, a small fish that can often be mistaken for an eel. This particular gunnel was not moving and they feared it was dead, but it wriggled to life when Bobby lifted it up to take a closer look. The kid was so excited that the fish was ok! He wanted to keep it safe and make sure it made it back under the rock.


One of the coolest finds this summer? A huge squid that washed up on Olympic Sculpture Park beach!

rocks are homes

Beach etiquette tips:

  • Leave things where you find them. Excited about your discovery? Bring a naturalist/teacher to the creature.
  • Touch sea stars gently with one wet finger.
  • Only move rocks that are small enough to be moved with one hand. Carefully return rocks to the exact position you found them in.
  • Carry a small garbage bag to pick up trash.

Thanks to everyone who explored the beach with us this summer—hope to see you next year!

For more information about the Seattle Aquarium’s Beach Naturalist program, visit

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Barney the bubble blower

Visitors to our harbor seal exhibit this month have sometimes been treated to an interesting sight: Barney blowing bubbles in the water. Is he just enjoying the sunshine and goofing around? Nope. The behavior is actually related to the summer breeding season.

During breeding season in the wild, adult male harbor seals display a variety of behaviors in their efforts to attract females: rolling over; splashing the water with their flippers and/or tails; scratching; biting and growling; and—our favorite—blowing bubbles.

barney underwater

Seattle Aquarium Bird & Mammal Biologist Carol Jackson says Barney has been seen making a regular circuit around the harbor seal exhibit, stopping by the north window to blow bubbles, then heading under the ledge to make some noise (growling or roaring).

If it was possible to hear this roaring from outside the exhibit, it would sound a bit like an airplane flying by. Barney’s roommate Q will sometimes add a few of his own bubbles to mix, but Hogan has been staying out of it. He remains on dry land during these displays, sometimes sticking his head underwater to check out the action.

Why isn’t Hogan joining the male posturing? It could be related to his relative youth. Hogan is 3 years old this summer, which could be the start of his sexual maturity—but it could also be a few more years before he’s ready to show off with the big boys.

This activity usually stops the first week in August, so plan a visit to the Aquarium soon to check it out! Plus, check out our daily “Meet Our Marine Mammals” sessions and harbor seal fact sheet to learn more.

And, as long as we’re talking about harbor seals…pupping season in Puget Sound is June through September. If you’re lucky enough to spy a harbor seal pup on a local beach, remember to stay at least 100 yards away and keep pets leashed. Pups often come to shore to rest and regulate their body temperatures—seeing them doesn’t mean they’re sick or injured. Thanks for sharing the shore with our beautiful wild harbor seals!

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Know your beach-this week from the beach

#7 in a series of guest blog posts by Seattle Aquarium beach naturalists Bobby Arispe and Jen Strongin.

The author checking out Graceful Cancer Crabs with the kids

Wouldn’t you like to have a day on the beach with Seattle Aquarium beach naturalists giving you and a few of your closest friends an intimate tour of life in the intertidal zone? Although you can come visit us any time we are out working on our local beaches, we move from group to group, answering questions, making sure we spend time with all of our visitors.

But this year, at the annual Seattle Aquarium Splash! auction, one lucky family bid on and won a special, private tour at Constellation Beach in West Seattle. They got to invite a few friends and have my fellow beach captain, Barbara Owens, and me all to themselves!

We spent two glorious hours together, exploring during the low tide. The highlights of our day were seeing all the different species of anemones and getting to gently feel each one; finding several species of crabs in different habitats and getting to observe them skittering about through the seaweed and rocks; checking out tube worms; using magnifying glasses to look at a teeny, tiny sea urchin up close; and, of course, laying claim to a sand bar island.  :)

Painted anemone row at Constellation Beach

These painted anemones are like our old friends at Constellation Beach. Did you know that they can live for up to 80 years?! We visit them year after year and always stop to say hello.

Barbara and the kids searching the field guide

Barbara and the kids searching the field guide

The large, rocky breakwater at the south end of Constellation Beach is a treasure trove of amazing intertidal life. Barbara and the kids were consulting their field guide, looking to identify one of the many chitons they saw. It turned out to be a very large Hind’s chiton. These animals can grow up to 4″ in length.

Hind's chitonWe got to see one of my favorite crabs, a purple shore crab, as we continued to explore in and around the rocks. They are a common species but I think they are pretty spectacular with their deep purple carapaces and fancy, polka-dotted front claws.

purple shore crabThe next time you visit the beach, if you’re in a sandy area, squat down and look across the sand. You might notice what looks like hundreds of small, transparent tubes sticking up. These are actually the homes of an animal called a bamboo tubeworm. Inside the tube is a segmented worm. The worm scrunches down in the tube to hide during the low tide and emerges once it’s covered back up with water.

bamboo tubeworm Moving over to the smaller rocky, breakwater at Constellation Beach, we saw more beautiful chitons, a mama crab with a clutch of eggs under her belly and the teeniest sea urchin ever. The kids pulled out their magnifying glasses to get a closer look and I, of course, pulled out my camera.  :)

tiny urchin Before saying goodbye, we found one last intertidal gem—a huge, healthy, gorgeous purple sea star, basking in the sea lettuce as the tide was coming back in.

purple sea starThank you so much to the wonderful families who came out with us! We appreciate your generous donation to the Seattle Aquarium and we hope to see you on the beach again soon.

One of the greatest joys of being a beach naturalist is getting to share our curiosity and appreciation of all the natural beauty on the beach with so many people. There is nothing quite like seeing that “aha” moment happen for someone as they learn something new. My favorite encounter at the beach last week was a wonderful family visiting from Texas. They were all excellent beach stewards, especially the grandmother who was carrying a plastic bag with her to clean up trash from the beach. She was picking up what she thought were chunks of rubber but as it turned out, they were moon snail egg collars! We had a great conversation about moon snails—everything from how they lay their eggs to how they drill holes in clams with their radulas. Her eyes sparkled with that “aha” moment and it made my day!

Beach etiquette tip of the week: Carry a small garbage bag to pick up trash.

Here are some more of the highlights of my time on the beach this week from Constellation Beach and Saltwater State Park:

red rock crab eating clamWe happened upon this HUGE red rock crab enjoying a clam for lunch. You might notice that this crab is missing its two larger front claws as well as couple of other smaller ones here and there. In spite of its disability, this crab was making it work! It may have had some gulls to thank for cracking that clam open…

Crabs were the highlight of our day at Constellation for sure. I saw several male crabs, both red rock and Dungeness, moving in and out of the protective beds of eelgrass, carrying females around. I am certainly glad human mating rituals are not the same as our crustacean friends! Females release pheromones that signal to the males they are almost ready to molt. When the male and female connect, he embraces her and carries her around for several days or more, until she sheds her old shell (exoskeleton). Once she has molted and her outer shell is soft, the male can transfer his sperm. In a very gentlemanly fashion, he carries her around for another several days, until her new shell hardens, to ensure she’s safe from predators (and possibly other suitors!).

Polychaete worm in a clam shell

The beach at Saltwater State Park is loaded with all sorts of beautiful shells. I’ve learned that if you look under the empty ones, there’s always something interesting to see! This week I enjoyed watching periwinkle snails moving along an obstacle course made of barnacles; limpets navigating a terrain with tiny orange-striped green anemones; a mossy chiton taking a rest; and this lovely and colorful polychaete worm.

I can’t believe our beach season is almost over! Our last low tide series will be July 31-August 3. Come out and join us—we look forward to exploring with you.


About Jen:

Jen writes:

“I ventured westward from Albany, NY and fell madly in love with our city from the moment I arrived. It was 21 years ago this August when Seattle first charmed me with its lush, forested parks, beautiful beaches, and water and mountain views (when the skies are clear enough) all around.

I spent the first half of my 21 years here immersed in Seattle’s wonderful coffee culture. My husband and I owned and operated Victrola Coffee on Capitol Hill until 2008. We sold our business that year to spend more time with our newborn son and I have been a stay-at-home, homeschooling mama and budding photographer and naturalist ever since! It started with me taking my young son to the beach, gazing into tide pools and wanting to know more about what we were looking at. Soon, I was going to the beach by myself, every low tide I could, and following the Seattle Aquarium beach naturalists around asking questions. :)

I signed up to be an interpretive volunteer at the Seattle Aquarium in 2013, became a beach naturalist volunteer in 2014, and this will be my first year as an official member of the Seattle Aquarium staff as a beach captain. My favorite place to be is on the beach, with my camera, sharing my love and knowledge of our intertidal dwellers with the hope that I will inspire others to love and protect the Salish Sea and the ocean beyond.”


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Our tufted puffins are lovebirds!

puffin bond

We have a new bonded bird pair in our alcid exhibit! Green Band tufted puffin (female), also known as Gertie, and Purple Band tufted puffin (male) have paired up. Both animals hatched here at the Aquarium, two years ago in July 2014. This is the first year they’ve grown breeding plumage: a bill plate plus the species’ distinctive yellow tufts (not pictured here).

(A quick note about birds’ names—or lack thereof—at the Seattle Aquarium: birds can be notoriously difficult to tell apart. So they’re identified primarily by the colored bands on their legs…kind of like the parents of identical twins putting I.D. bracelets on their babies to keep track of who’s who! But referring to an animal as “Purple Band” can feel a little impersonal, so some of the birds end up getting named by staff members—like Green Band becoming Gertie.)

Most alcids form long-term bonds. Courtship involves rubbing bills, strutting and “skypointing” (pointing head and bill up to the sky while keeping wings and tail raised). Males also perform head-jerking displays.

After courtship comes the commitment, and it’s a doozy. In the wild, tufted puffins prefer steep, grassy slopes for their nests. After finding a suitable spot, the pair takes turns to dig a burrow between two and seven feet long. Since they have only their bills and feet to work with, this excavation takes an entire breeding season to complete. The pair doesn’t actually use their finished nest until the following summer—when the female lays a single egg.

After the egg is laid, the pair takes turns incubating it—and, once the chick hatches, the parents share responsibility for its care and feeding. With so much involvement from both parents, the value of this bird bond is very apparent!

Plan a visit to the Seattle Aquarium to see our “lovebirds” in person! In addition to Green Band and Purple Band, other current bonded pairs in the exhibit include: Red Blue Band tufted puffin (male) with Yellow Band tufted puffin (female); Orange Band tufted puffin (male) with Orange Band rhinoceros auklet (female); Yellow Band common murre (male) with Black Band common murre (female); and Green Orange Band rhinoceros auklet (male) with Yellow Band rhinoceros auklet (female).

But be aware: bird relationships, just like those of humans, don’t always work out and as animals mature, social dynamics may shift. Interested in learning more about the birds at the Seattle Aquarium? Check out our animal fact sheets!

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