Freshwater fish pee constantly, to get rid of the water that they're constantly drinking. Saltwater fish barely pee at all, as they don't drink any of the water because if they did, they'd dehydrate.
Fish do indeed produce liquid nitrogenous wastes (goldfish are notorious for turning their water into ammonia cesspools). I'm not sure about gaseous wastes, though. Several fishes do gulp air from the surface and absorb the oxygen through their digestive tract (e.g. corydoras catfish). Whether it passes all the way to the end is, unfortunately, unknown to me.
Re czernobog's comment: Freshwater fish urinate all the time. They need to excrete much of the water they take in in order to maintain the osmotic balance of their cells. Saltwater fish, on the other hand, need to retain water and excrete excess salt.
To go into even more needless detail - yes, fish can smell, which is why they have nostrils. Nostrils originally evolved as sensory organs; it was only after animals made the move onto dry land that they became adapted for use in breathing.
I found the comic hilarious, the comments section educational and entertaining, and the fact that you must have actually thought this through very disturbing.
Concerning your analogy in the last panel - of all things to invite into your home, how did you happen choose vampires? More realistic as a dinner guest than a honey badger, I suppose...
Scott: You seem to (logically) attract a large number of science minded folks with your comic. This is not really a surprise, as your humor is wonderful, very logical, and quite linguistic. As a biology professor myself, I also appreciate your sci-fi interest as expressed in your comic too. By-the-way, the naysayers about "peeing" fish are incorrect as several have pointed out... all fish will eliminate cellular wastes, and in freshwater species in particular, the amount of "pee" eliminated is quite significant.
Fish excrete nitrogenous wastes through their gills, tail kidneys, and skin (but not through pores...they don't have hair... The only "pores" are the openings to the lateral line canal that lets them detect movement of the water). Some bony fish do have a urinary bladder in the caudal coelom. Cartilaginous fish have a cloaca, like terrestrial non- mammals.
They do have gas-generating bacteria in the intestine, so, like land animals, they definitely pass gas.
Whether this applies to fish or not, it definitely applies to sea mammals, so think about that when you're wondering how they keep the water at Marineland so clear.
If you're never wondered how they keep the water at Marineland so clear, you obviously don't overthink things enough.
Wow, some amazing lines. "hearing crazy thoughts probably does less mental damage than thinking them" will go into my "please, oh, please, let me use this some day" list.
Is that a Lost Boys reference? (Inviting a vampire into your home makes you powerless against them, etc.) It's been ~2 decades since I've seen that, so I may be off.
In old folklore, vampires can't cross your threshold without an invitation. It's why vampires have to be charming and seductive; otherwise you wouldn't invite them in. It's also why it's your fault if it drinks your blood -- you were unable to resist temptation, and therefore were a bad christian.
September 2, 2012
Reader Comments (33)
As I understand it, fish only excrete solids, which sink.
Your reasoning is otherwise flawless.
Thank you for this train of thought. I really needed it.
It's not beyond the realm of possibility that you taste a fart either. See: Dorm, College Boys.
Hilarious! One of your best!
Scott, you have outdone yourself once again.
Most fish excrete soluble ammonia. It's reptiles and birds who excrete solid uric acid. Your logic is sound, and disturbing.
Freshwater fish pee constantly, to get rid of the water that they're constantly drinking. Saltwater fish barely pee at all, as they don't drink any of the water because if they did, they'd dehydrate.
SCIENCE
Made my morning!! U got readers back there in israel :)
Yo, Scott, Imma happy for you and all, but panel 2 here is my favorite panel of all time. Of all time.
@Czernobog Fish still have to get rid of ammonia, but they do it via the gills, which I suppose makes it more of a burp.
i saw a fish in our pond fart. bubbles came out of its gills. maybe it was burping?
Fish do indeed produce liquid nitrogenous wastes (goldfish are notorious for turning their water into ammonia cesspools). I'm not sure about gaseous wastes, though. Several fishes do gulp air from the surface and absorb the oxygen through their digestive tract (e.g. corydoras catfish). Whether it passes all the way to the end is, unfortunately, unknown to me.
Don't sharks smell (or taste) blood in the water?
http://www.livescience.com/13346-shark-poop-video.html
GREAT WHITE SHARK DISAGREES, czernobog
Plus, a fish will never know the joy of lighting their farts on fire. There but for the grace of God go we.
Fish don't pee like we do; they have no bladders, but excrete it continuously through their pores, like sweat. I don't know if they fart at all.
Re czernobog's comment: Freshwater fish urinate all the time. They need to excrete much of the water they take in in order to maintain the osmotic balance of their cells. Saltwater fish, on the other hand, need to retain water and excrete excess salt.
To go into even more needless detail - yes, fish can smell, which is why they have nostrils. Nostrils originally evolved as sensory organs; it was only after animals made the move onto dry land that they became adapted for use in breathing.
Love the comic, BTW!
I found the comic hilarious, the comments section educational and entertaining, and the fact that you must have actually thought this through very disturbing.
This is amazing, and you have a sick mind. Well done.
Concerning your analogy in the last panel - of all things to invite into your home, how did you happen choose vampires? More realistic as a dinner guest than a honey badger, I suppose...
Scott: You seem to (logically) attract a large number of science minded folks with your comic. This is not really a surprise, as your humor is wonderful, very logical, and quite linguistic. As a biology professor myself, I also appreciate your sci-fi interest as expressed in your comic too. By-the-way, the naysayers about "peeing" fish are incorrect as several have pointed out... all fish will eliminate cellular wastes, and in freshwater species in particular, the amount of "pee" eliminated is quite significant.
I am using this next time someone asks me what I'm thinking, I'm plagiarizing this BI to hell and back.
Fish excrete nitrogenous wastes through their gills, tail kidneys, and skin (but not through pores...they don't have hair... The only "pores" are the openings to the lateral line canal that lets them detect movement of the water). Some bony fish do have a urinary bladder in the caudal coelom. Cartilaginous fish have a cloaca, like terrestrial non- mammals.
They do have gas-generating bacteria in the intestine, so, like land animals, they definitely pass gas.
Whether this applies to fish or not, it definitely applies to sea mammals, so think about that when you're wondering how they keep the water at Marineland so clear.
If you're never wondered how they keep the water at Marineland so clear, you obviously don't overthink things enough.
Yet another reason I don't eat fish.
Wow, some amazing lines. "hearing crazy thoughts probably does less mental damage than thinking them" will go into my "please, oh, please, let me use this some day" list.
When I read this strip, I immediately thought of one of my favourite songs from my favourite band, the Cat Empire, so, thanks for that!
Hákarl - more than you ever wanted to know about shark urine.
Is that a Lost Boys reference? (Inviting a vampire into your home makes you powerless against them, etc.)
It's been ~2 decades since I've seen that, so I may be off.
I think smells are particulate matter so when you smell it you're also tasting it....
Thanks to everyone who corrected me. It's just the sort of useless factoid I love learning from unexpected sources.
And the shark video was hilarious, even though missy might not approve.
@joseph:
In old folklore, vampires can't cross your threshold without an invitation. It's why vampires have to be charming and seductive; otherwise you wouldn't invite them in. It's also why it's your fault if it drinks your blood -- you were unable to resist temptation, and therefore were a bad christian.
I'm laughing and I don't even know why.