Coral is an Animal

[TaNuki]

Science is an ever changing thing. That is what makes it science. There will always be innovation, and new light that shines on every topic imaginable. One of the most interesting parts of science, is how often opinions and classifications are reworked. Lets look first at something like red wine. For the longest time it was said to do great things for your body when it was consumed in moderation on a daily basis. Years later, that "Fact" has been proven untrue. Next, let's look at our favorite dwarf planet, PLUTO. I think we all know the story behind that classification which resulted in an 8 planet solar system.

My question/ theory, is regarding the classification of coral. I am not closed minded on the topic, but would really like to see a good discussion with all of us playing devil's advocate to our own ideas so that we can more thoroughly study the classification of coral in the animal kingdom.

My research shows that coral is classified as an animal because:

• Coral has a mouth used to collect food
• Coral has a digestive system
• Reef-building corals contain algal cells that photosynthesize and produce some sugars and other chemicals, but ALL reef building corals need additional sources of nutrition, and most are actively predatory and MUST be fed.
• Most coral lack symbiotic algae and are incapable of photosynthesis
• Corals contain muscles, nerves, digestive and reproductive tissues, and capable of sensing and rapidly responding to their environment.

I am sure there are a few other things that classify coral as animals as well, but are they classified as animals because they are closer to animal classification than plant classification?

To me, comparing to either family only drives me to believe that coral should be a family of its own, here is why:

• What other animals in the animal kingdom are stationary?
• What animal has potentially thousands if not millions of mouths attached to one skeleton?
• Are Venus Fly Traps animals since they catch food and absorb it? What about other carnivorous plants?
• What controls a coral's nervous system? Why is damage done to one part of a coral not felt on the opposing end of that same animal?
• What animal is most similar to a coral and in what ways?
• A jelly Fish, a Coral, and a Jellyfish are all related
• I am sure there are a lot more questions, but in the animal kingdom, are there other animals that have loosely related characteristics that define them as animals?

While most corals do require some sort of "meat" in their diet, very few can survive without sunlight. The digestion system is not enough to sustain life. Much like a lichen, we decided that it must be a sort of hybrid organism. With such an intertwined symbiotic relationship, it is nearly impossible to classify any coral into flora or fauna.

I think that there will be a day when science creates a family specific to coral, but I am VERY interested to hear your take on coral family classification. I am sure there are many of you who know a lot more about it than I do. I would like to hear from some of your biology buffs who can really help me get how coral is clearly defined as an animal.

I guess in thinking about the 5 kingdoms, animalia, plantae, fungi, protista, and monera, why was fungi given its own kingdom and not adjusted to fit an existing kingdom?

Should be interesting, thanks for joining the conversation!

 

[Palting]

Waaay too cerebral for me, man. My simple minds says, Coral are fauna, in symbiosis with Zooxanthellae, a flora. Zooxanthellae are a wide array of flora (algae) of the Genus Symbiodinium, and the animals that are symbiotic with algae in this genus are considered Zooxanthellate. So coral are zooxanthellate animals. Done deal.

My head hurts .

 

[TaNuki]

See and that is how they explain it everywhere, and I can see the point, but I still feel like the just did a checklist of characteristics and said they are the closest to fauna, so fauna it is.

 

[jlnielsen13]

Very interesting questions and ones my students ask all the time in biology...

A few quick facts:

There are actually 6 kingdoms now with Monera being split into archaebacteria and eubacteria.

Coral does have its own family, in fact many families:

kingdom is animalia
Phylum is Cnidaria (means having specialized cells for catching prey)
Class is Anthozolia (reproduce by budding)
Order
Family
Genus
Species

From Order on it depends on the species of coral.

Cnidaria also has the jelly fish in its Phylum. So corals and jellies share a common kingdom and phylum

The reason I tell students is in the coral's cells. Although they house symbiotic algae, coral cells are more animal like in nature and divide and reproduce more like animal cells.

Thanks,
JIM

 

[KafudaFish]

If you are interested in cladistics and taxonomy you should go to a used book store and look for college level invertebrate zoology textbooks or head to a college library. Maybe you could contact an invert. zoo. professor and ask to borrow books as well.

Also look up development as one of your missing links as to why corals are animals and not plants.

 

[disc1]

If that troubles you then this should blow your mind. Tunicates... they are in the phylum chordata among the animals.

 

[TaNuki]

Thanks for the great responses. Would any of you be surprised to ever see a 7th family created for coral one day, maybe in 100 years? I guess I would be surprised to see anything 100 years from now, I would be one old dude.

 

[TaNuki]

If that troubles you then this should blow your mind. Tunicates... they are in the phylum chordata among the animals.

Actually another great example of something to blow the mind.

 

[Flame_Angel]

Wait, this is new thinking? I've always considered coral animals. I thought the thinking of corals as being other than animals died out in the 1800's.

 

[TaNuki]

Wait, this is new thinking? I've always considered coral animals. I thought the thinking of corals as being other than animals died out in the 1800's.

No, I am not trying to prove that they are plant or animal, I am saying that they should belong to a kingdom of their own because really they dont have that much in common with the rest of the animal kingdom. I also listed some key questions that have brought me to this thinking. I am just curious to see how die hard everyone is in their thinking that these are exclusive to the animal kingdom.

 

[coral_addict]

In addition, taxonomically I believe the sponges (Porifera) are also sedentary And yet they too, are animals. It is an interesting discussion. Also, not all coral are sedentary. The anemone is actually a part of cnidaria, as are jellyfish. Fungia and certain dendrophyllia species actually can move slightly, as can anemones and motile jellyfish (I say motile because certain jellyfish or stages of jellyfish are in fact sessile). Finally, clams, like the tridacna clams, are in a different phylum than both sponges and corals, although the name escapes me, and they can not really move either.

 

[jcolletteiii]

What other animals in the animal kingdom are stationary?

Sponges, barnacles, sea pens, many, many mollusks, most crinoids - many, many more. All of these have a larval stage - including corals. Barnacles are particularly interesting - becasue they are attached by their heads, they can't just go off and have sex, and they don't broadcast their gametes. Solution? VERY, very, very long penises - many times the length of their own bodies.

What animal has potentially thousands if not millions of mouths attached to one skeleton?

Extinct - graptolines; exant - sponges again. Although they have no 'mouth', they are colonial, multicellular animals that have cells capable of phagocytosis - certain cell types can directly absorb foods and digest them; siphonophores - colonial jellies.

Are Venus Fly Traps animals since they catch food and absorb it? What about other carnivorous plants?

Don't know all that much about plants, other than we'd be screwed without 'em and that I like to eat 'em, but I do recall that plants have a cell bounded by rigid cell walls - quite different from animal cells. Easy to classify in that case.

What controls a coral's nervous system? Why is damage done to one part of a coral not felt on the opposing end of that same animal?

There are many animals with limited pain receptors. Were I a r-selected species, I'd want to have limited pain receptors as well - getting eaten alive probably hurts pretty badly. Mole rats have no reaction to many painful stimuli - they're even vertebrates. What controls any nervous system? Electrochemical impulses travelling over a nerve network. Back to sponges - they have NO nervous system - talk about weird. You can put a sponge in a blender, pour it out into some seawater, and it will reassemble itself.

What animal is most similar to a coral and in what ways?

Jellies. They're not fish, I hate when people say jellyfish. Pet peeve of mine. Also, anemones, hydras, etc.

A jelly Fish, a Coral, and a Jellyfish are all related

Yes.

I am sure there are a lot more questions, but in the animal kingdom, are there other animals that have loosely related characteristics that define them as animals?

I'm not sure what you mean. To be classified as an animal, an organism has to possess certain key characters. If it does, good - it's an animal; if it doesn't, it's in one of the other kingdoms.

 

[jcolletteiii]

Thanks for the great responses. Would any of you be surprised to ever see a 7th family created for coral one day, maybe in 100 years? I guess I would be surprised to see anything 100 years from now, I would be one old dude.

You mean 7th kingdom? I would not be surprised to see a 7th kingdom in 100 years - we have to classify the weird stuff we are going to find in the oceans below the ice on Titan! For corals? Not unless we dramatically change the characters that make an animal an animal.