A 'Ghost Shark' Swims into our Imaginations
The Monterey Bay Aquarium Research Institute fascinated the world when it released a video of an unusual species of "ghost shark" in its natural, deep-sea habitat off our own Central Coast—the first time the species has ever been seen alive. These recently published observations also established a range extension for the species into the Northern Hemisphere.
Commonly called the pointy-nosed blue chimaera, Hydrolagus trolli was first described—from a dead fish caught in a trawl net—in 2002 living in deep waters around the Southwest Pacific. But during remotely operated vehicle (ROV) surveys off Central California, MBARI researchers noticed what appeared to be the same species.
To verify the identity of this species, MBARI's video lab enlisted the help of taxonomic experts with expertise in chimaeras and, eventually, collaborated on a paper about the pointy-nosed blue chimaera living in our local waters. MBARI also released a video describing their findings and showed it swimming in the deep sea, curious about the ROV following it, and looking a little like Frankenstein's monster. The story and video went viral.
MBARI Senior Research Technician Lonny Lundsten studied this chimaera on video, and is one of the authors of that paper. We recently interviewed Lonny about the "ghost shark," and why exploring the deep sea is so amazing.
What's your job at MBARI?
I'm a senior research technician in MBARI's video lab and my primary job is to analyze all the video that's recorded by the ROVs. There are four video analysts in the lab and we spend about 70 percent of our time analyzing video—we try to identify items from different biology, geology and equipment deployments observed by the ROVs. Currently there are about 25,000 hours of deep sea video in MBARI's library, and we're almost up to date in analyzing all of this video. MBARI has designed a database system that allows us to log and track all the different things we've seen, and it contains over 5 million objects so far—our observations include identifying different marine species, geological features, scientific equipment, and even trash. We essentially try to identify everything that the ROV sees to the best of our abilities. We're also managing the conversion to a digital recording system for the ROV camera systems; we write science publications; go out to sea quite a bit; and write copy for, narrate, and edit videos on MBARI’s YouTube channel. We wear a lot of hats, but it makes our work exciting, fun, and variable.
You've worked at MBARI for 15 years. What is your most interesting memory?
Probably the best experiences were the first few times I went out to sea on long expeditions aboard the Western Flyer. Other highlights include manned submarine dives in the South Pacific, expeditions to the Gulf of California, Mexico, and, last summer, when I went to the Beaufort Sea in the Canadian Arctic Ocean. Anytime I see something like Hydrolagus trolli, or any other species that nobody has ever seen before, that's always a highlight for me. Exploring new locations and seeing something that nobody's ever seen before—those are really the best days 'in the office.' I also enjoyed discovering and describing a new species of soft coral from the Northeast Pacific that we named in honor of Julie Packard (Gersemia juliepackardae).
This species of "ghost shark" hasn't been seen before in the Northern Hemisphere. Why do you think this one was?
There are other ghost sharks that have been seen in the Northeast Pacific; we just hadn't seen this species here before. The deep sea is such a vast habitat. MBARI has been conducting deep sea research for 30 years and we've really only seen about 1 percent of the seafloor in and around Monterey Bay—and this is probably the most well-studied deep-sea habitat on the planet! As we've expanded further afield we're seeing more and more unusual things, including new species and new habitats. We're now regularly going to places like the Gulf of California, the Pacific Northwest, and far offshore California—and we're exploring habitats where nobody's been before so the odds of seeing something new or unusual are greatly increased.
How many of these "ghost sharks" did you encounter—was it just the one?
We've observed six of these ghost sharks—we've even seen them in Monterey Canyon. We originally saw one at Davidson's Seamount, which is an underwater mountain about 90 miles southwest of Monterey, but as we've explored more locations we've even seen them elsewhere.
What's the difference between a shark and a chimaera?
Chimaeras diverged from sharks about 400 million years ago, and the primary difference is that the chimaera has a bony tooth plate instead of the rows of teeth that sharks have. The bony tooth plate is more like a bird's beak. The upper jaw on the chimaera is also fused to the skull, unlike sharks where the upper jaw is loosely attached, giving sharks much greater flexibility in their bite.
What's most exciting to you about this animal?
It's this very large, charismatic animal, about a meter long, and something no human has ever seen alive before. It's fantastic to be able to watch its acrobatic swimming in its deep-sea habitat.
The "ghost shark" has some rather unusual body parts. How do you explain these odd (to us) adaptations?
The oddest body part is one of the male's copulatory organs, which is located on its head—it's thought to be used for grasping and holding a female during copulation. That's the one thing people talk about that's so bizarre with chimaeras. But, again, bony tooth plates; a long, slender, pointed tail; large eyes; large pectoral fins—those also make it a little odd in appearance.
Why does this chimaera look stitched together?
The visible lines on its head and sides are an extension of the lateral line canal system, which allow fishes to sense vibrations or movement in the water and, most likely, help this animal find prey.
What's unusual about the behavior of Hydrolagus trolli?
Ghost sharks are usually found over soft, sedimented seafloor, but we've always found the pointy-nosed blue chimaeras in rocky habitat. As far as chimaeras go, it's an unusual observation. Besides that, we didn't see anything else really unusual except maybe the fact that they swam as they did—they didn't seem to be scared by the ROV—and seemed almost curious as to what the robot submarine was.
This animal was filmed by MBARI both before and after the original description of Hydrolagus trolli was published in 2002. How did you realize that the species you had been seeing all those years was Hydrolagus trolli?
We had a sense of what the animal we were seeing was, but didn't know for sure, so we brought in some experts to verify its identity. The lead author on the most recent paper, which I contributed to, spent several months analyzing video and writing up her observations. Our paper also describes this species' existence in the North Pacific—a range extension—and we added some behavioral and habitat information, which is valuable observational data.
What's the process to identify a new or rare species?
We try to get good footage of it, try to collect it if we can, and then we'll consult with experts at MBARI or look further afield for experts in that particular group. With chimaeras and sharks and rays in general, there are experts at Moss Landing Marine Laboratories, so we contacted them for help in identifying this animal. I specialize in corals and sponges, so I can usually do those identifications myself. For other animals, we might have to consult with experts in the taxa that we're interested in.
But then there's the process of describing the species wherein you consult all your information sources, and if you determine it's a new species you have to formally describe it. You describe its morphology, you may do a genetic analysis, you describe what's known of its habitat, geographic and depth ranges, and behavior. You must also review the scientific literature to better understand the other species that have been described. You then have to develop an argument for why your new species is different from all previously described species. Finally, you write up all that information and submit it to a journal for peer review. It takes a while.
How does MBARI's video lab help you and other biologists identify new or rare species, and especially their behavior?
MBARI is using state-of-the-art technology to push into the deep sea, down to 4,000 meters. This is an environment that is largely unexplored and certainly hasn't been filmed using high-definition video cameras. We use specialized lighting systems and HD cameras that can resolve details down to about a millimeter in size. This allows us to capture organism details and behavior, which we were unable to achieve in the past. We're able to see how these animals live in their own environment, we can see variations in color, we can observe animal behavior, and we can see what the habitat looks like where they're found.
You can imagine 100 years ago how people were sampling the deep sea—dragging a net through the water column or along the sea floor, basically taking a big scoop of whatever was there. Then they dumped that big scoop on the deck of the ship and started sorting. In many cases scientists had fragments of animals, animals that had been damaged or destroyed, with colors that no longer represented how they appear in life. In the past, deep sea animals were occasionally described based on small fragments of an entire animal. And they had no idea of exactly where the specimens came from or what their habitat looked like.
Now we see these animals in their own environment, we can see their habitat, their abundance, and the other organisms that live near them. We make stunning video observations and then we can carefully collect them so they are undamaged—that's something deep sea biologists couldn't do in the past.
HD camera resolution is amazing.
It really is, and it's only getting better. Camera technology is changing constantly—they're already manufacturing 4K cameras, which is more than twice the resolution we have now, so it's just a matter of time before we develop these cameras for deep sea use. And we're putting cameras on lots of different devices now. In addition to ROVs, we have cameras mounted on benthic rovers, stationary camera platforms, and AUVs (autonomous underwater vehicles). MBARI has recently developed an AUV to go out and record transects in the midwater with high-definition, 2K video—this is a technological development that we could not accomplish in the past, and it gives us a new way to sample this vast, unexplored habitat.
What do you like best about deep-sea exploration?
The coolest thing is that I get a sense of what it must have felt like for early explorers in human history to go places nobody's ever been and to see things that nobody's ever seen before. It's truly exciting and rewards me with a feeling of awe and wonder for the natural world. There was this anglerfish a while back, and we saw six of them at Taney Seamount and one at Davidson Seamount, and nobody had ever seen those alive. They were described from one specimen collected in the 1870s and no one had ever seen it alive in its natural habitat. No one knew what it was like aside from this one dead fish that was trawled up from the deep back then. For me that's exciting! Even though it's a species that was previously described, having the opportunity to see something nobody's ever seen before is awesome. It gives you the chills.
What animal or thing—real or imagined—would you like to see in the deep sea?
Honestly, on a personal level, I've done what I had hoped to do—I had always hoped to see new species and I hoped to describe one—so those dreams happened for me. But it's still exciting each time I explore a new location or see a new animal or witness a new process that no one has ever seen before. It's always exciting to see new things, to continue exploring. I'm pretty lucky—I don't think a lot of people get to have their dreams come true like I have.
Anything imaginary you’d like to see down there?
The things I see are so remarkable and startling that I don't need to imagine what might be in the deep sea. Carnivorous sponges are my current specialty—I'm describing three new species right now and have described four or five in the past. They are such a bizarre animal—their body plan is different from the description of the phyla. That's a real animal that is amazing and utterly surprising!
Table of Contents
- Director's Note
- Building a World-Class Animal Care Center
- Summer at the Aquarium
- What's New: Come Explore the Incredible Lives of Seabirds, and We Celebrate a Makana-versary
- Online Exclusive: A 'Ghost Shark' Swims into our Imaginations
- Thanks: Creating a Legacy for the Ocean, and Business Partnerships