Okay internet, we've got to talk. Yes, the ocean is incredibly vast and minimally explored. There are many creatures out there that people have never heard of, and I'm really excited that you want to share the ones you just discovered with humanity. But friend, most other people have also watched Planet Earth. You can't go around publishing listicles of the animals from the deep sea episode and call it "Top 10 Ocean Creatures You've Never Heard of!" or some such thing. We've all heard of blobfish; flapjack octopuses inspired a character in Finding Nemo; and literally everyone knows about Mola mola. So for those of you who are tired of the same list getting republished on 30 different blogs with slightly different descriptions Depth and Taxa Presents our first ever listicle:
Top FiveOcean Creatures You've Actually Never Heard of!
Or:
Top Five Ocean Creatures That Aren't Horrifying, Just Well Adapted to Their Environmental Conditions.
Seven-Arm Octopus (Haliphron atlanticus)
Courtesy: H.J.T Hoving and S.H.D. Haddock via Scientific Reports
Okay wait, wait, wait; seven-arm, octo-pus; that literally makes no sense. Why isn't it a septapus? To understand we need a refresher on our old friends, the Argonauts.
If you've been following Depth and Taxa for a while you might remember our profile on the specialized octopuses called argonauts. You can check out that post (which is a personal favorite of the D&T team) here. Argonauts and their close relatives are different from more familiar octopuses because they live in open water, rather than on the bottom; and because males are waaay smaller than females. In the case of seven-arm octopuses, females are six times longer than males! The enormity of the open sea and the males' small size mean that the odds of two seven-arm octopuses running into one another are pretty low. So in order to ensure the continuation of the species males have to be sure they mate successfully on the first try. To that end, males actually tear off a specialized reproductive arm called a hectocotylus (pronounced: hek-toh-kot-uh-luss) and embed it into the body of the female. Since seven-arm males only get to use their hectocotylus once they keep it well protected inside a "thick, gelatinous" sack near their right eye. Because that arm is tucked out of sight, it looks like male seven-arm octopuses really only have seven arms.
Eulachon (Thaleichthys pacificus)
Courtesy: James Crippen via Wikimedia Commons
Yeah, it's a bait fish; but take a second to think about how many bait fish species you can name. Maybe herring, anchovy, sardine, and...... anything else? Also called forage fish; small fish like eulachon (pronounced: yoo-la-kon) are the only reason we have bigger, more charismatic animals in the ocean. Tuna, sharks, salmon, humpback whales, dolphins, seals, sea lions, pretty much anything larger than one foot wouldn't exist without forage fish like eulachon. Just because something is common, doesn't mean it's not important or interesting. In fact, forage fish are probably waaaaaay more important to the overall ecology of the ocean than many of the creatures we get really stoked about.
Eulachon in particular are really awesome. Like tiny salmon, eulachon are born in freshwater and migrate out to the ocean where they spend 2-3 years growing rich off the abundance of the open sea. And boy they get rich, eulachon have a higher body fat percentage than almost any other fish species. Eighteen to twenty percent of a eulachon's wet weight is oil! They're so greasy that if you dry a eulachon you can actually set it on fire; leading to their other common name: candlefish.
In case the plug-in doesn't work on your device:
https://www.youtube.com/watch?v=wEMQujyzHQA
The people processing the eulachon in the above video are members the Nisga'a first nation. Nisga'a territory is the watershed of the Nass river near the Alaska panhandle's southern border with British Columbia. Because eulachon come back to their home rivers to spawn in late winter when other food sources are scarce they can tide-over a family until the abundance of spring. Eulachon are so important that one of their names in Nisga'a means "savior fish". Not bad for a type of smelt.
Yeah, it's a bait fish; but take a second to think about how many bait fish species you can name. Maybe herring, anchovy, sardine, and...... anything else? Also called forage fish; small fish like eulachon (pronounced: yoo-la-kon) are the only reason we have bigger, more charismatic animals in the ocean. Tuna, sharks, salmon, humpback whales, dolphins, seals, sea lions, pretty much anything larger than one foot wouldn't exist without forage fish like eulachon. Just because something is common, doesn't mean it's not important or interesting. In fact, forage fish are probably waaaaaay more important to the overall ecology of the ocean than many of the creatures we get really stoked about.
Eulachon in particular are really awesome. Like tiny salmon, eulachon are born in freshwater and migrate out to the ocean where they spend 2-3 years growing rich off the abundance of the open sea. And boy they get rich, eulachon have a higher body fat percentage than almost any other fish species. Eighteen to twenty percent of a eulachon's wet weight is oil! They're so greasy that if you dry a eulachon you can actually set it on fire; leading to their other common name: candlefish.
https://www.youtube.com/watch?v=wEMQujyzHQA
The people processing the eulachon in the above video are members the Nisga'a first nation. Nisga'a territory is the watershed of the Nass river near the Alaska panhandle's southern border with British Columbia. Because eulachon come back to their home rivers to spawn in late winter when other food sources are scarce they can tide-over a family until the abundance of spring. Eulachon are so important that one of their names in Nisga'a means "savior fish". Not bad for a type of smelt.
Brachiopods (phylum Brachiopoda)
Courtesy: Peter Grobe via Flickr
"Alright wait a minute, that's literally just a clam. You can't pull one over on me. I've been to Ivar's." Well they look a lot like clams, but aside from both having two shells, brachiopods (pronounced: brak-ee-oh-pods) and clams are completely different.
Even the shells of clams and brachiopods aren't the same. The shells of a clam are oriented left and right of its body, while a brachiopod's shells are above and below. It can be a little hard to visualize without pictures so we'll use some anatomical standards to help us: Pokemon.
Shellder has shells oriented like a brachiopod.
Cloyster has shells oriented like a clam.
Of course we all know it's what's on the inside that counts. Once inside a brachiopod the difference from clams is pretty apparent. Fully two-thirds of a brachipod's body is taken up by a feeding structure called a lophophore (pronounced: lo-fo-for). The lophophore has spiral or u-shaped coils that are unique to each species. These structures funnel free-floating plants and animals into the brachiopod's mouth using little cellular hairs that beat back and forth.
Brachiopods have been around for a long time and at one point there were at least twelve-thousand different species! That number makes a little more sense when you remember that brachipod is a phylum, which is one of the least specific ways to group organisms. For example: humans are part of the "chordate" phylum which is everything on earth with a spinal chord. That's a bewildering number of animals. Even understanding that they're a big group, it's astonishing to realize that brachiopods were once so abundant that make up the majority of all fossils!
There are only about 450 modern species of brachiopods, but they're pretty common in cold seas around the world. Very few animals eat them, even though they have thin shells, probably because brachiopods don't pack a lot of nutritional punch once you get them open. So the next time you feel lame for being unassuming and quiet; remember that brachiopods literally took over the world for millions of years by being mundane.
"Alright wait a minute, that's literally just a clam. You can't pull one over on me. I've been to Ivar's." Well they look a lot like clams, but aside from both having two shells, brachiopods (pronounced: brak-ee-oh-pods) and clams are completely different.
Even the shells of clams and brachiopods aren't the same. The shells of a clam are oriented left and right of its body, while a brachiopod's shells are above and below. It can be a little hard to visualize without pictures so we'll use some anatomical standards to help us: Pokemon.
Cloyster has shells oriented like a clam.
Of course we all know it's what's on the inside that counts. Once inside a brachiopod the difference from clams is pretty apparent. Fully two-thirds of a brachipod's body is taken up by a feeding structure called a lophophore (pronounced: lo-fo-for). The lophophore has spiral or u-shaped coils that are unique to each species. These structures funnel free-floating plants and animals into the brachiopod's mouth using little cellular hairs that beat back and forth.
Brachiopods have been around for a long time and at one point there were at least twelve-thousand different species! That number makes a little more sense when you remember that brachipod is a phylum, which is one of the least specific ways to group organisms. For example: humans are part of the "chordate" phylum which is everything on earth with a spinal chord. That's a bewildering number of animals. Even understanding that they're a big group, it's astonishing to realize that brachiopods were once so abundant that make up the majority of all fossils!
There are only about 450 modern species of brachiopods, but they're pretty common in cold seas around the world. Very few animals eat them, even though they have thin shells, probably because brachiopods don't pack a lot of nutritional punch once you get them open. So the next time you feel lame for being unassuming and quiet; remember that brachiopods literally took over the world for millions of years by being mundane.
Pink Ghost Shrimp (Neotrypaea californiensis)
The larger pincher is called the "master claw", which is also
a kickass name for a metal band.
Courtesy: Ken-ichi Ueda via Flickr
a kickass name for a metal band.
Courtesy: Ken-ichi Ueda via Flickr
Pink ghost shrimp are just one of many species of shrimps that burrow into sand and mud in the intertidal zone. Although you probably haven't seen the actual shrimp there's a decent chance you've seen one of their burrows. These shrimps' extensive burrow systems have multiple entrances that allow water to flow through when the tide is in. You can easily find the entrances because the of the mounds of darker colored sand around the hole. The material from underground is usually dark gray or black because the low oxygen conditions within the muck stain the sand. Areas with low oxygen may sound like a terrible place to live, but pink ghost shrimp can survive for six days in those conditions! And if the oxygen gets too low ghost shrimp can be seen standing at the entrance to their burrows flushing in new water using the swimmerettes on their tail.
Ghost shrimp aren't just cool because they can survive without the chemical that literally makes complex life possible; they're also a major consumer of extra nutrients that get into estuaries. So much so that ghost shrimp might actually be the key to minimizing the damage human organic waste (fertilizers and more) does on the ocean.
Even if you're not into crustaceans there's a good reason to love ghost shrimp.
"Whale, hello there!"
Courtesy: Linda Tanner via Flickr
Ghost shrimp are the main source of food for gray whales as they travel back and forth from Mexico to Alaska every year. The whales dive down, suck up giant chunks of mud, and filter out the shrimp with their sturdy baleen. At low tide in Puget Sound near the mouths of rivers you can actually go and stand in pits dug by gray whales foraging for ghost shrimp. Who would have thought you would have a goop dwelling shrimp to thank for your Facebook profile picture of you in San Ignacio with the baby gray whale.
Ghost shrimp aren't just cool because they can survive without the chemical that literally makes complex life possible; they're also a major consumer of extra nutrients that get into estuaries. So much so that ghost shrimp might actually be the key to minimizing the damage human organic waste (fertilizers and more) does on the ocean.
Even if you're not into crustaceans there's a good reason to love ghost shrimp.
Courtesy: Linda Tanner via Flickr
Ghost shrimp are the main source of food for gray whales as they travel back and forth from Mexico to Alaska every year. The whales dive down, suck up giant chunks of mud, and filter out the shrimp with their sturdy baleen. At low tide in Puget Sound near the mouths of rivers you can actually go and stand in pits dug by gray whales foraging for ghost shrimp. Who would have thought you would have a goop dwelling shrimp to thank for your Facebook profile picture of you in San Ignacio with the baby gray whale.
First off, leather limpets are one of those rare molluscks that are freaking adorable. Seriously they're so tiny and they have goofy little faces!
Courtesy alex_bairstow via iNaturalist
Confusingly, leather limpets are not limpets at all. True limpets have a tent or volcano like shell on their back that they can raise and lower to protect themselves. Leather limpets have no shell to speak of, just a tough coating of tissue on their back. These little dudes also don't have gills to breathe in the water, they have a lung!
Leather limpets avoid drowning by trapping a bubble of air in an opening above their butt. The opening is kind of like your nostrils and windpipe, so they're basically holding their breath while underwater. Land slugs have a system like this too. If you've ever looked closely at a slug you'll see a hole on what you can think of as their right shoulder. Pictures here.
Instead of hiding when the tide is low and crawling about when it comes back in; leather limpets' lung allows them to do the opposite. By moving around when the tide is out, leather limpets guarantee their predators will be firmly ensconced between rocks or in the sand. In case predators like sea stars do come calling while a leather limpet is hiding at high tide they have an effective defense. The little bumps on the leather limpet's side side secrete a fluid that repels sea stars and probably crabs.
Courtesy: paul_norwood via iNaturalist
So there you have it. Five ocean creatures you've probably never heard of. To be honest this list could have been thousands of animals long. The ocean makes up 99% of the habitable space on earth! It's deep, vast, and at the same time contains millions of tiny microhabitats. But there's one thing I hope you take away from this post. Look back at all the animals listed. How many of them are super rare? How many are a deep sea species that's only been seen a few times? And how many live in the waters or shore just down the road? Only one of these creatures isn't found in the intertidal zone. So what I hope everyone understands is that our planet, and even our immediate neighborhood, is incredibly rich. That you don't have to have access to high technology and millions in funding to explore and discover incredible things.
So get out there! Walk the beach. Poke around in the sand and mud. Lift rocks; peer on their undersides. And share your discoveries with us in the comments!
P.S. If you like this style of short, digestible information we do a similar segment called: "Wow Cool! of the Week" on our Facebook page every Wednesday. Check us out, and if you like what you see give us a like and a follow @depthandtaxa.
https://www.facebook.com/depthandtaxa/?ref=br_rs
References:
Cowles, David, "Onchidella borealis", Invertebrates of the Salish Sea (Online), Walla Walla University, 2007
Accessed via:
https://inverts.wallawalla.edu/Mollusca/Gastropoda/Gymnomorpha/Order_Onchidiacea/Onchidella_borealis.html
Cowles, David, "Neotrypaea californiensis", Invertebrates of the Salish Sea (Online), Walla Walla University, 2007
Accessed via:
https://inverts.wallawalla.edu/Arthropoda/Crustacea/Malacostraca/Eumalacostraca/Eucarida/Decapoda/Thalassinidea/Neotrypaea_californiensis.html
DeWitt, T H., "Response of Ghost Shrimp (Neotrypaea californiensis) Bioturbation to Organic Matter Enrichment of Estuarine Intertidal Sediments", Presented at 27th Annual Meeting of Pacific Estuarine Research Society, Port Townsend, WA, May 17-18, 2004
Accessed via: https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryID=81528
MacKinnon, J.B. "'Salvation Fish' That Sustained Native People Now Needs Saving", National Geographic Online, July 7th 2015
Accessed via:
https://news.nationalgeographic.com/2015/07/150707-salvation-fish-canada-first-nations-animals-conservation-world/
Pruitt, Casey & Donaghue, Cindy, "Ghost Shrimp and Gray Whale Feeding: North Puget Sound, Washington", Washington State Department of Natural Resources Report, October 28th 2016
Accessed via: https://www.dnr.wa.gov/publications/aqr_aamt_shrimp_whale_study_2015.pdf
Cowles, David, "Onchidella borealis", Invertebrates of the Salish Sea (Online), Walla Walla University, 2007
Accessed via:
https://inverts.wallawalla.edu/Mollusca/Gastropoda/Gymnomorpha/Order_Onchidiacea/Onchidella_borealis.html
Cowles, David, "Neotrypaea californiensis", Invertebrates of the Salish Sea (Online), Walla Walla University, 2007
Accessed via:
https://inverts.wallawalla.edu/Arthropoda/Crustacea/Malacostraca/Eumalacostraca/Eucarida/Decapoda/Thalassinidea/Neotrypaea_californiensis.html
DeWitt, T H., "Response of Ghost Shrimp (Neotrypaea californiensis) Bioturbation to Organic Matter Enrichment of Estuarine Intertidal Sediments", Presented at 27th Annual Meeting of Pacific Estuarine Research Society, Port Townsend, WA, May 17-18, 2004
Accessed via: https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryID=81528
MacKinnon, J.B. "'Salvation Fish' That Sustained Native People Now Needs Saving", National Geographic Online, July 7th 2015
Accessed via:
https://news.nationalgeographic.com/2015/07/150707-salvation-fish-canada-first-nations-animals-conservation-world/
Pruitt, Casey & Donaghue, Cindy, "Ghost Shrimp and Gray Whale Feeding: North Puget Sound, Washington", Washington State Department of Natural Resources Report, October 28th 2016
Accessed via: https://www.dnr.wa.gov/publications/aqr_aamt_shrimp_whale_study_2015.pdf
National Marine Fisheries Service, West Coast Region, "Endangered Species Act Recovery Plan for the Southern Distinct Population Segment of Eulachon (Thaleicthys pacificus)", 2017
Accessed via:
http://www.westcoast.fisheries.noaa.gov/publications/protected_species/other/eulachon/final_eulachon_recovery_plan_09-06-2017-accessible.pdf
Wright, J. 2014. "Brachiopoda" (On-line), Animal Diversity Web, May 21, 2018
Accessed via: http://animaldiversity.org/accounts/Brachiopoda/
Wright, J. 2014. "Brachiopoda" (On-line), Animal Diversity Web, May 21, 2018
Accessed via: http://animaldiversity.org/accounts/Brachiopoda/
Young, Richard E., "Haliphron atlanticus", Tree of Life Web Project, 2016
Accessed via: http://tolweb.org/Haliphron_atlanticus/20200
