I was casually checking the numbers for the Echinoblog over a July 4th weekend in 2009 and on the day just before a 3 day weekend I found there was a HUGE spike of hits (>600 in one day!) simultaneously and inexplicably searching for something that I narrowed down to a massive international search for the term "sea pig".
(This image from the Galathea 3 expedition site)Reasons were offered: A new Facebook quiz app. A video on Youtube. Who knows?
But if the PUBLIC wants to know what a SEA PIG is and I KNOW??? Then Frak it!! Its my duty to society to tell it WHAT a sea pig is!!! Who am I to deny the public's interest in sea pigs??
So, let's get to it!
What is a Sea Pig??
The "sea pig" is the common name (i.e. non-scientific name) for a species of sea cucumber (in the class Holothuroidea) that lives in the deepest abyssal depths of the world's oceans.
Specifically sea pigs belong to the genus Scotoplanes, a genus of deep-sea sea cucumber which currently includes four species. Sometimes other genera of deep-sea sea-cucumbers are called "sea pigs", but historically, THIS is the one most people mean. Its not entirely clear if those four species are all distinct, but THAT is a discussion for another day...
The name Scotoplanes has been around for a LONG time. The genus was discovered and described by H. Theel in 1882 as part of the famous HMS Challenger expedition reports. Sea pigs are ELASIOPODID sea cucumbers, an order of sea cucumbers whose members are prominent in the deep-sea.
They are often characterized by having these little legs that come off the bottom surface such as what you see here (legs on side, mouth pointing outwards)
(This image from the Galathea 3 expedition site)Because waters in the Southern Ocean (Antarctica) are so cold, sea pigs can be found in shallower waters around the South Pole. Pictured here is one collected during the recent expedition operated by the New Zealanders and held by NIWA scientist (and friend of the Echinoblog) Sadie Mills:
(Photo credit: Richard O'Driscoll, NZ IPY-CAML)Scotoplanes live in the ABYSS. That's not just a little deep..that's the DEEPEST part of the ocean on the flat oceanic plains. Its not unusual for sea pigs to be collected from over 6000 meters!!! How deep is that? That's about 3.7 miles DOWN (by contrast the Grand Canyon at its deepest point is only about 1.1 miles deep). Some can be found shallower..but they live across a wide bathymetric range.
Scotoplanes don't just occur individually either. Collections and observations of these animals show that they often number in the hundreds. Early trawling records have recorded some 300-600 specimens per trawl!!!
What do they do down there??
Very little is known about Scotoplanes general biology, but we do know a thing or two about their nutriton.
Like a lot of other deep-sea sea cucumbers, Sea pigs are what's called deposit or detrital feeders. That is, they feed on the fine nutritious scum and goo that falls to the bottom of the seafloor from the top of the ocean. They feed on them with the ring of tentacles that surrounds the mouth...
(This image from the Galathea 3 expedition site)
BUT contrary to some accounts that these are "slug like" or coarse dirt worms, deep-sea cukes like Scotoplanes have evolved this feeding mode into a finely honed adaptation!!
For instance, this study by Robert Miller et al. (2000) studied several deep-sea cuke species from the North Pacific, including Scotoplanes globosa using isotope tracers.
S. globosa (and other species in the region) ingests only VERY fresh (and presumably very rich) food-rich sediments. This species (and others like it) feed on a thin veneer of food that had settled out of the water column the last 100 days. So they actually eat FRESH food.
(This image from the Galathea 3 expedition site)BUT contrary to some accounts that these are "slug like" or coarse dirt worms, deep-sea cukes like Scotoplanes have evolved this feeding mode into a finely honed adaptation!!
For instance, this study by Robert Miller et al. (2000) studied several deep-sea cuke species from the North Pacific, including Scotoplanes globosa using isotope tracers.
S. globosa (and other species in the region) ingests only VERY fresh (and presumably very rich) food-rich sediments. This species (and others like it) feed on a thin veneer of food that had settled out of the water column the last 100 days. So they actually eat FRESH food.
(from Gage & Tyler 1991)1. According to Dave Pawson, Smithsonian Curator of Echinoderms (and an expert in deep-sea sea cucumbers) you can also often see this species all oriented in a particular direction (such as above) facing into the current, where they are presumably rooting around, searching for better and fresher goo to eat
2. According to this study summarized by the Monterey Bay Aquarium Research Institue and performed by marine biologist Henry Ruhl, the food that these beasts eat (which as a reminder- live at THOUSANDS of METERS depth) ARE directly influenced by what comes down from the SURFACE of the ocean!! Yes, what happens at the SURFACE affects animals that live THREE MILES down!!!
There is apparently a direct correlation between some species and rich food that falls to the ocean fall following certain oceanographic phenomenon such as El Nino.
So, for example, the population numbers of S. globosa boomed after the rich nutritional particles descended folowing the 1997-1999 El Nino and La Nina periods. Ruhl also found other relationships between abundance and size (summarized here).
Scotoplanes have parasites!!!
a. Small snails (genus Stilapex) that work their way into the body wall and suck on their juices!! So, what's weirder then sea pigs??? SEA PIG SNAIL PARASITES!!!!
a. Small snails (genus Stilapex) that work their way into the body wall and suck on their juices!! So, what's weirder then sea pigs??? SEA PIG SNAIL PARASITES!!!!
(from the New Zealand R/V Tangaroa weekly log, photo cred-Stefano Schiaparelli, NZ IPY-CAML) b. Crustacean parasites!! Good Grief!! It gets even worse then that!! Tiny tanaid crustaceans will also BORE little holes into the sea pig body wall and feed on the internal organs!!! Yikes!
They have become SO iconic that A Japanese toy company (Agatsuma) makes small toys (about 1 inch long) of them!!!
Whew!! So, any OTHER questions about sea pigs????
104 comments:
Can people actually buy sea pigs? and where are the toys of them sold? also, can they survive in a tank as pets?
Nope. These animals live in thousands of meters of water. The temperature and pressure can't be duplicated at the surface without huge expense.
and even if you could, collecting them usually involves ships and/or submarines, which is why the only people who have ever seen them are usually marine biologists and oceanographers!
btw...the toys show up on ebay or are sold in Japan..
Wow. Wait, wait. I mean, "WWOOOWWWEEEEE!" That was so cool! I have known of them for a long time (probably as long as you have) but didn't know anything about their lifestyle.
Parasitic snails?? Hooray! Go, snails!
These guys remind me of naked mole rats or star-nosed moles. Convergent evolution strikes again!
Also, I don't know if food that clocks in at under 100 days old can be considered "FRESH". . . just my two cents. :)
Thanks for the intro -- absolutely fascinating!
Jennifer Frazer
theartfulamoeba.com
well...it IS marine detrital snow. 100 days is definitely fresh food when you consider how long it takes to sink 3.3 miles!
Ohh I see. Thank you. So they absolutely cannot survive on surface?
Somehow, I found your blog searching for information on cyclocystoids, and have stayed for the obvious reasons.
Wow, thanks for the info.
And to answer your question at the beginning: I guess the huge interest in Sea Pigs was spawned by a Facebook app called "What terrifying creature are you?" in which Sea Pigs was one of the results.
What's the best way to cook them?
i was gonna say... do seapigs taste like pork... or cucumber... or both?!
if you've ever had sea cucumber-that might be the best way to estimate flavor. But its unlikely that 99% of people will get a chance to ever try "sea pig" given that most times its scientists who will be collecting them.
No, "hello there," any creatures living under such an immense pressure could not survive in our "world". It would be like humans trying to live in the deep sea without the protection of a machine or some sort of futuristic pressure protection suit. Any deep sea creatures brought to the surface die instantly.
Also, I thought your info on the sea pig was great! :D
Do they have any predators or prey?
They probably do. Possibly fish or sea stars. But I don't think its ever been really been documented. Ecology in the Abyssal zone is difficult..
I found out about Sea Pigs because of the Wii game "Endless Ocean" and thought they were made up! Thanks for posting such great information about them - the photos are great!
Search the Echinoblog for Scotoplanes or "sea pig" and you should get a few other posts as well. There was a nice slow- mo video of a sea pig I posted awhile a month ago or so.
I was introduced to sea pigs two days ago at during a visit to the Smithsonian Museum of Natural History, and they have been creeping me out ever since then. They are fascinating. And creepy. Thanks for all the great info. Fascinating stuff!
Well, the Smithsonian is near and dear to my heart! I'm always glad to hear that people are learning about sea pigs there! thanks!
Awesome! Any idea how far they can roam? And if they form social groups or herds of some kind?
I don't believe that anyone's ever determined how far they roam or if they form social groups. Often times, their numbers are interpreted as a constraint on where they settle as larvae and food availability..since good deep-sea food is often difficult to locate.
Very informative. But may I ask if Scotoplanes have genders. How do they reproduce? Also another blog mentioned that they enjoy the rich ooze surrounding decaying whale remains. Is it known which organisms are primarily responsible for breaking down whale tissue into nutrients that Scotoplanes can use?
Raymond-Maurice,
My understanding is that sea pigs have two sexes (most if not all sea cucumbers do-but I will check).
In general, sea cucumbers reproduce externally. That is the males and females secrete their gonads into the water. The sperm and the eggs then find one another-probably using some kind of chemoreception facilitated by behavior (i.e, the dense aggeregations), fertilize and then settle out. Probably based on some optimal environmental cue based on substrate, food or some other essential need.
As a generality, Scotoplanes would consume freshly deposited nutrients wherever they occurred. I don't know exactly which blog you are referring to.. but presumably such a site would be a good place for sea pigs to incidentally find food (i.e., because they are drawn to nutrients in the sediment or in the water)..but-to my knowledge-is not one of the primary or even a significant player in a "whale ecology" type system. It may feed on surrounding detritus and/or nutrients in the surrounding sediment..but my understanding is that sea pigs consume relatively fine material..and as far as I know-don't eat flesh or particles of meat off bone.
hope that helps!
This is really cool! I'm doing a science project on some of the weirdest creatures on Earth, and the sea pig is defidently one of them. I got here from the Animal Planet website.
dont' forget this post about pearlfish
http://echinoblog.blogspot.com/2010/05/when-fish-live-in-your-cloaca-how-anal.html
or this one about giant brittle stars that capture fish.
http://echinoblog.blogspot.com/2008/11/giant-green-brittle-stars-of-death-when.html
and don't forget Gorgonocephalus
http://echinoblog.blogspot.com/2010/01/gorgonocephalus-because-weird-is-what.html
OMG! I am doing a science report. This site has really hepled me. Thank you.
By the way, this creature is cool yet scary.
Hey there, i am doing an assignment for school and decided to do some research on sea pigs. Would i be able to use your information for my work? This included both pictures and text. Please email me for confirmation at ethan.murray93@hotmail.com,
thanks.
you can use the blog (as long as its cited) but there are several scientific references linked within the blog that will likely be of more use.
you don't say which level of school-but so long as you don't plagarize my work using it as a resource is fine.
hey there
what about the sea pigs over grazing and forest management in the ocean and the limiting factor and carrying capacity of it as well. Do you know anything about that?
I LOVE SEA PIGS SO MUCH I HAVE BEEN OBSESSED WITH THEM FOR 2 YEARS!!!
I LOVE SEA PIGS!!!!!!!!!!!!!!!!!!!!
i was wondering what did sea pigs evolve from?
FANTASTIC website by the way!
What did sea pigs evolve from? hmm... good question..
Of course, they are sea cucumbers but I'm not sure where in the grand scheme of sea cucumber evolution they fit...
I'll have a look...
Do you know how big they are?
They don't really get very large. One of the photos shows one being held in the hand of a scientist. That's about typical (about 4 to 6 inches) (about 10 to 15 cm).
I now love sea pigs so very much!etattod
I think that you should also post about the pistol shrimp, they seem pretty amazing themselves...
Thanks for the info and the nice blog. I am nowhere near an ocean but I am just interested in sea pigs. I think they are cute. I wish I can have one as an aquarium pet
Thanks for this excellent explanation.
I'm curious about the differences in the illustrations of the sea pigs. The pictures of them on the ocean floor show thinner sea pigs with longer legs. Those in the air are rounder with short legs.
Are these two varieties of sea pig, or is this what happens when the sea pressure is taken away?
The difference in appearance is probably attributable to a few things
1. The deep-sea vs. the Antarctic pix are of different species and so, yes, the legs and proportions do differ between them.
2. Most sea cucumbers will swell with water when stressed and to me that seems like the most likely explanation here. Its possible that gas is responsible for the swelling in the out-of-water pictures but I don't believe there is a place for the gas to build up other than the intestine-as there are no gas bladders to become swollen as there would be in fish.
Hi! Sorry, I don't have blogger account, so I'm anonymous. Do you think it's not plausible for them to get bigger than 4 inches? Like calamari get huge.
When it dies, does the body stay on the bottom of the ocean?
I've seen something gross that looked exactly like a sea pig, but dark coloured and big, on the tide line in Vancouver, Canada. It smelled really bad too. I thought it was probably elk/ cow carcass (or some other mammal) that was missing head and legs, but the skin looked smooth and shiny. It looked really gross! You couldn't tell what it was, but it looked like something!
Even if they do get big and can get to the surface, it seems unlikely for them to surface on Vancouver beach, as there is Vancouver island that separates open ocean from Vancouver.
Sea pigs and their relatives generally don't get very large for several reasons-most likely having to do with metabolism and a multitude of other factors. Some sea cucumbers in tropical habitats can get very big up to 1-2 feet long but most deep-sea sea cucumbers are in the 4 to 9 inch range depending on species and where they live. Where food is more abundant some species may thrive. Some Antarctic species for example can get to be almost 8 to 9 inches long.
That said, what goes on for sea cucumber is different than what goes on for cephalopods. Giant squids (Architeuthis dux) are a separate species and indeed a separate family than other squids and a different evolutionary history has likely been at play. This includes the fact that squids are predatory swimmers, live in a different habitat (the midwater versus the bottoms) and so on. "Giant" is also relative...but there are no known sea cucumbers that reach greater than about 2 feet long and those tend to occur in tropical reef type habitats.
When sea cucumbers die, they pretty much disintegrate immediately and are either devoured by scavengers or are buried. Its unlikely that anything from this depth (2000 m or so) would reach the surface. If you saw anything at the surface that was a dead sea cucumber it was probably a local species and not a deep-water sea pig.
hope that helps.
Thank you for the explanation!
I'm obsessed with these sea pigs now. :)) Round ones look so cute.
Do we know how old this species is? It looks pretty prehistoric and if a ceolocanth can survive to this day and age, I wouldn't be surprised about the geneology of this strangely facinating creature.
Well, one has to keep all of these things in context. The coelacanth is considered a "living fossil" because its outward appearance closely resembles that of fossil taxa but, actually a great MANY modern animal species are descendants of those which are very old. The lineages of nearly all echinoderms dates back to the Paleozoic.
Sea pigs are elasiopod sea cucumbers, a group which, I believe have a fossil record from the Mesozoic but I don't know if there are complete body fossils-only remains.
The specific evolutionary history of this specific *species* and its ancestor could be quite young but part of an older lineage. But even that is relative. Some species may be less than 20,000 years old but others may be more on the scale of 1 to 3 million which is still considered quite young compared to others.
I have been meaning to publish a little more on the evolutionary history of this or possibly other sea cucumbers so we shall see. There is not as much known about its history as we would like especially given its relationship to the deep-sea.
...and by publish I mean on the blog. Sadly, I don't work on sea cucumbers myself. :-)
Hi I really loved this and I think it's really great of you to make a blog about something that not most people talk about. I get soooo annoyed when people talk about the more common animals. Anyway, I'm doing a project on Sea Pigs at school and one of the questions is," What adjustments are needed to survive in the environment?" I've looked all over the internet and found nothing. Do you think you could help?? If you could, that would be soooooo nice of you!!
Glad you liked it. I published this blog post shortly afterwards that is relevant.. http://echinoblog.blogspot.com/2009/08/why-sea-pigs-and-other-deep-sea-animals.html
Usually echinoderms will not develop a centralised nervous system due to their pentaradial symmetry and their ability to move in any direction equally. However, these animals have not only developed a secondary bilateral symmetry, but also a direction of movement, so I'd like to know if there are any hints of nervous centralisation in Scotoplanes, especially considering they have legs.
@onechordbassist That is an excellent question. The nervous system of deep-sea sea-cucumbers such as a sea pig are poorly known but if they are typical for sea cucumbers (and there is no immediate reason to suspect that they are not dramatically different) the nervous system forms a ring around the oral opening which is connected to nerve fibers running down the length of the body.
Sea cucumbers have a secondary bilateral symmetry imposed over their pentameral symmetry that is associated with their movement through sediment. It is centralized around the front end in the aforementioned nerve ring but there are no known enlarged ganglia or nervous centralizations that I am aware of, but there's a lot of information about these animals which remains unknown or poorly understood.
do sea pigs go through life stages?
The life cycle of sea pigs is poorly understood but all sea cucumbers undergo some change from larvae to juvenile and then growth to adult. Every new or poorly understood species has the potential for some new life cycle or other undiscovered fact about their reproductive cycle so we shall see...
BTW -- Another great source for deep sea items, toys and plushes is ETSY.com. There are a couple cool artists that make deep sea sculptures, knitted critters, stained glass, stoneware, and christmas tree ornaments! Our favorite artist there has made plush deep sea anglerfish and monkfish for us. Next on the horizon: Lasiognathus, Prince Axel's Wonderfish (Thaumatichthys Axeli)...and SEA PIG. I can't think of any better bed time buddies for confirmed nerds. :)
What is a sea pigs support structure, respiration, circulation, excretion, response, and how does it reproduce
To answer your question:
support structure, respiration, circulation, excretion:-Water.
response to what?
they reproduce, presumably by external fertilization. Eggs and sperm in the water=larvae. the larvae settle. boom. there ya' go.
How do sea pigs breath?
Most sea cucumbers have respiratory organs that are connected to the intestine. However, deep-sea cucumbers such as sea pigs lack these organs and can exchange gases across the body surface. They absorb oxygen across the feet and other surfaces on their body.
I'm afraid my English is a bit rusty...
I just stumbled upon this article in search of echinoderms.
I read about sea pigs before, but this was by far the most extensive article about these animals. Because of this excitation of my curiosity I am going to make some additional inquiries about them. I just wanted to thank you for this motivating article.
how do sea pigs adapt to the depth of the ocean?
The question "How do sea pigs adapt to the depths of the ocean" might be better re-stated as "How have sea pigs changed relative to their (presumably) shallow-water ancestors?" In other words how have their body forms been modified by the environment over time.
Deep-sea sea cucumbers such as sea pigs have much larger tube feet which have become modified into the walking "legs" and there are several differences in the physiology of the animals relative to depth and probably to temperature. Many deep-sea species also do not eviscerate (eject their guts as a defense).
At the moment, I don't really have access to the research literature due to the govt. shutdown but I hope that gives you at least some idea..
thanks for ansewering my question, just another one how has their bodys adapt to the temperature of the deep ocean?
does sea pigs are safe to eat ?
I would avoid eating sea pigs
Hello thanks so much for the information about sea pigs. My little boy (4) was fascinated after seeing this episode of octonauts http://www.youtube.com/watch?v=WlFvg5N_XTY&sns=em. Maybe this was the reason for the sudden influx of sea pig queries?
The episode suggests they eat rotting food (kelp) as opposed to what your blog says about a preference for fresher food. Thanks again!
Skymouse,
*laugh* OH WOW! thank you! While you are correct that sea pigs enjoy fresh food, dead kelp does make up part of that as it falls to the sea floor. It all kind of relative.
what do they eat
I like the article very much, ChrisM!
Such weird and interesting creatures.
Do you have suggestions for other resources or blogs of your own to check out and learn more about strange and unique creatures of the sea?
I also read your article on sea cucumbers and their... erm... 'live in guests'.
to quote
"AND as a personal bit of good advice? Don't look up the term "Anal Teeth" on Google Image without the safeties on! It can be....traumatic..." Classic!
Thanks for the post, hope you still visit this board from time to time!
--
Andrew M
What are their lifespan?
Unknown.
Hi I have been searching for a soft toy sea pig for over 2 years now. As my little girl (now 4) fell in love with them after seeing them on the 'Octonauts'. It is right at the top of her Christmas list to Santa. I have tried to communicate with the museum in Tokyo but I am unable too.I have asked friends and family if they know anyone in Tokyo or Japan that could help me but again a blank. Do you know if there is anywhere I can get hold of one of these soft toys for her. Any help will be greatly appreciated. Thanks Nathalie from uk
I would go to ebay and search for either "sea pig" or "plush sea pig" depending on which ever one you wish...
good luck!
Thanks for the help unfortunately I have exhausted that. I did find one in Tokyo but it won't ship to the UK. Thanks again Nathalie
Please reply soon!
How do sea pigs protect themselves?
Love this!
Unfortunately not much is known regarding their defensive abilities. But at the depths at which they occur, its unclear if they have many predators...
How do sea pigs breathe? Thank you for all the help!
probably by diffusing gases across their body surface or perhaps while water enters their digestive tract
lock:)
hi any tips to do it
what makes them unusual to be in phylum echinodermata
they are sea cucumbers and have all the features. This information can be found on Wikipedia and any text book.
What type of circulatory system does a sea pig have - open or closed? Why does that type of circulatory system work for sea pigs?
Since sea pigs are sea cucumbers, their circulatory systems are based on a water vascular system which utilize sea water directly taken in from their surroundings.
Describe, in detail, the sea pigs digestive system - compare the structures to a human system. Explain the differences and similarities.
how do they breathe???
probably by absorption of gases across their body wall
nice
Nice bit of information. Thanks
How come nothing but eat them?
*nothing but parasites*
Its possible that these have plenty of predators but we have very little information on their ecology
They are funny and funny looking.
Hi Chris, I got curious about sea pigs after they were featured on an episode of blue planet II (although I had seen zefrank's true facts about the sea pig previously).
At one point Attenborough mentions that sea pigs must withstand pressures exceeding 30 tons. Is this actually true, or does the open circulatory system mean that sea pigs don't really have to worry about the extreme pressure? Do they have any adaptions that other sea cucumbers don't have to be able to survive in these environments? Thanks!
Yes. Sea pigs and ALL deep-sea animals live at great depth, 1000 to 5000 meters..and the pressures down there, to organisms which live at the surface ARE tremendous. But that's the thing.. all of those organisms/animals have evolved IN THOSE SETTINGS and as such, don't worry about it. They WOULD and HAVE suffered stresses from being brought up to the surface. See
the OTHER post on sea pigs about why they can't be pets:
https://echinoblog.blogspot.com/2009/08/why-sea-pigs-scotoplanes-and-other-deep.html
But yes.. there are likely a whole suite of adaptations that function in these species to permit them to survive at this depth.. RELATIVE to a shallow-water sea cucumber. good question!
I had never heard of these until watching ‘Octonauts’ with my son. I got curious and found this. This is far better than the Wiki page so thank you! The mysteries of the ocean never cease to amaze me!
these things are crazy awesome. im doing a report for school and for some reason i randomly searched sea pig, im glad i did. i have a weird question though. how are these thingys born?
do they have gender or whatever?
Yes. Most likely they have external fertilization.. the eggs and sperm meet in the water, fertilize and then settle out into small sea cucumbers.. but our knowledge of their growth is poorly known.
never mind, i read previous comments and found my answer
oh thank you chrisM!
What are the ancestors of the sea pig?
Good question.. I'm not sure that is well understood.
How fast can they run?
They don't move very quickly by our standards. We're probably talking on the scale of cm per HOUR for these animals. Very low metabolism among other things...
I found your site doing some research about these creatures. I would love to contact you or use this information if you allow it.
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