Acropora ID mini-class

Hi Howard:

Some I cannot determine from your photos, some may not be able to be dtermined, and some are all yours to determine. Did you post a photo of the whole colonY.. I must be missing it, if so.

So, here'show I would answer based on what i can see from your corals (you should be able to do much better with it than me)

1. around single axial around more than one axial
2. can't tell (need to see whole colony)
3. can't tell (need to see whole colony)
4. can't tell (need to see whole colony)
5. axial dominated
6. can't tell from photo but appear to be different
7. can't tell
8. appears to be broken costate
9. can't tell
10. one size or graded
11. appears to be developed?
12. I'd probably call them nariform, but varied
13. oval to rounded
14. many
15. all yours
16. small to medium
17. all yours
18. terete
19. need to see whole colony, and may not be possible to determine unless mature
20. don't touch
21. can't tell
22. porous
23. can't tell

JB:

Look at the diagram on p. 54. That one has three synapticular rings. Synapticulae are the plates and rods and layers between the walls and rings can form from them...and sometimes they don't. So, you can see in that photo that there are three layers outside the axial wall, and all three form rings.
 
Thanks for taking the time, Eric. A few more questions:
  1. Is character 5, Branch diameter axial or radial dominated, a good character to go by? Or could an axial-dominated branch in the tank be 50/50 in other circumstances?
  2. Is character 20, radial crowding, a good character to go by? Does "radials don't touch" mean that non-axials absolutely never touch?
  3. Is branch thickness a good indicator? Could a tank branch be much smaller than a wild branch?
    [/list=1]
    For my piece, judging the branch to be axial dominated and that the radials don't touch eliminates almost the entire list. You'd think this would be a good thing, but those specie that remain have poor correlation with the rest of the character states of the piece, especially branch thickness.

    This is the last time I intend to bug you on this thread. I've got no special affection for Acroporas, and my interested:having to think hard character state is starting to be a fractional number. Anyway, I now have a vague notion about what such a thing as "coenosteum" is, which I think has it's own worth, even if I can't tell my Acropora from a ham sandwich.
 
After a crazy amount of time looking at my branch, the Wallace book and this thread, here is what I've come up with.

Here is another picture of my coral from the first page.

When I first bought the coral
DSCN3117.jpg


Now
DSCN4178.jpg


Growth Form
caespitose-corymbose

axials
Septa: six primary. No secondary.
Septal lenght: mostly equal
Cycles of septal: One cycle
Septal height: not exsert
septal dentition: forms comb rows (not 100% on this as it's hard to see)
Paliform structures: absent

Radials
One type of radial corallite
Radial corallites are 'appressed'.
Radial corallite opening is dimidiate.
Radial corallite shape is nariform.
Nariform with elongate (looks oval shape) openings (picture I on p 56)
No septa in radials, Larger radials that look as if they will form axials, have 4 radials.

Coenosteum
Coenosteum between radials is costate or broken costate.
Top edges of the costae contain spinnules that are shark-like.
Costate with spinule development. Closest to picture E on p 57

Grouping
Acropora latistella also thought maybe nasuta.
 
1.branch formation: 0
2.branching orders: 1
3.colony outline: 0
4.Predominant outline: 5
5.Branch diameter: 0
6.Coenosteum: 0
7.Radial coralite coenosteum: 0
8.Between radials coenosteum: 0
9.Spinule shape: 6
10.Radial corallite sizes: 0
11.Radial corallite inner wall: 1 ?
12.Radial corallite shape: 0
13.Radial corallite openings: 1
14.Axial/radial ratio: 1
15.Axial coralite outer diameter: 2
16.Radial coralites: 3
17.Branch thickness: 2
18.Branch taper: 1
19.Max branch length: 2
20.Radial crowding: 0
21.Axial corallite syn rings: 0
22.Skeletal porosity: 0
23.Radial cor syn rings: 0

<b>click for larger image</b>
<a href="http://www.cnidarianreef.com/images/misc/acro01_DSCN4305.JPG" target="_blank"><img src="http://www.cnidarianreef.com/images/misc/acro01_DSCN4305_sm.JPG" border="0" alt=""></a> <a href="http://www.cnidarianreef.com/images/misc/acro01_DSCN4314.JPG" target="_blank"><img src="http://www.cnidarianreef.com/images/misc/acro01_DSCN4314_sm.JPG" border="0" alt=""></a>

<a href="http://www.cnidarianreef.com/images/misc/acro01_DSCN4315.JPG" target="_blank"><img src="http://www.cnidarianreef.com/images/misc/acro01_DSCN4315_sm.JPG" border="0" alt=""></a> <a href="http://www.cnidarianreef.com/images/misc/DSCN4322.jpg" target="_blank"><img src="http://www.cnidarianreef.com/images/misc/DSCN4322_sm.jpg" border="0" alt=""></a>

Narrowing it down to the corals in the latistella and nasuta groups

species/score

latistella/13
subulata/10
nana/10
aculeus/12

nasuta/8
cerealis/10
valida/10
secale/7
lutkeni/7
kimbeensis/10

So based on score I am closest to latistella but looking at the Wallace skeletal pictures, I feel it looks to be closest to cerealis.
 
Kind of off topic, but is there any way to do something like this with montis, or is there too much variation within a species to be able to ID them by the skeleton? I just thought it might be interesting to see how many people's "caps" are really caps.
 
I thought I would finish to species to catch up (after a long break) in case this starts up again:

First, after re-evaluating, I concluded my group was nasuta:

Some of the species characteristics were identical for all the species in the group and some I could not ID in my acro with any degree of certainty (the synapticicular rings). Lucky for me these rings were identical in all the species except for one which I was able to eliminate due to other characters. I'll use JB NY's abbreviations for consistency (hope you don't mind)

1.branch formation: 0
2.branching orders: 1
3.colony outline: All species identical (mine is frag so can't tell)
4.Predominant outline: All species identical (mine is frag so can't tell)
5.Branch diameter: 1
6.Coenosteum: 0
7.Radial corallite coenosteum: 1
8.Between radials coenosteum: 1
9.Spinule shape: 5,6
10.Radial corallite sizes: 0
11.Radial corallite inner wall: 0
12.Radial corallite shape: 0, 4
13.Radial corallite openings: 0
14.Axial/radial ratio: 1
15.Axial corallite outer diameter: 2
16.Radial corallites: 2
17.Branch thickness: 1
18.Branch taper: 2
19.Max branch length: all identical (mine is frag)
20.Radial crowding: 1
21.Axial corallite syn rings: can't tell
22.Skeletal porosity: 1
23.Radial corallite syn rings: can't tell


So counts are (number of matching characters out of 18:

A. nasuta: 14
A. cerealis: 16
A. valida: 15
A. arabensis: eliminated due to geography
A. secale: 13
A. lutkeni: 12
A. kimbeensis: 13



So A.cerealis wins by score and a closer look at the two species. One major difference between A. valida and A. cerealis was that the latter has rather uniform reticulate structure adjacent to the radials and between the radials. In addition, the skeletal characteristics more closely match that in Corals of the World. My sample does not exhibit any of the tubular radials with unique bulge and round opening seen in A. valida. The description that the radials begin appressed and flare out more as they reach the axial corallite also matches my coral. One character that matches A. valida is branch thickness, but my thickness at 10 mm is near the intersection of the characters for the two species. As a result, I am fairly confident mine is A. cerealis.

David
 
good job, David. I have had a lot of requests to pick this back up. If there is a demand, we can do it all again and get some more practice. Maybe you guys can help me on some corals I am currently working on as new species or rage extensions from a recent trip to Easter Islands...at least one Letastrea and at least one Psammacora....its been fun, and we are now working on writing up a revision of the scleractinia of Easter Island.
 
Thanks Eric,


I am in for doing it again whether it is Acropora or another genus. Sorry for the late reply, I am moving into a new house and got a puppy..talk about busy. But that should be over with after this week anyways.

David
 
Let's try an easier one....I'll post a date when I have some time to devote to it....maybe a faviid or something with bigger polyps.
 
rotflmao. absolutely. In fact, that might be the best to start with. Although, I see single polyps of Lobophyllia being sold as Cynarina or Scolymia, and Scolymia is often confused with the monotypic Cynarina. But...maybe Nemenzophyllia? ehhehehehe
 
I think, seriously, that we should do Acanthastrea. I think the timing is perfect right now...and also for Blastomussa. They are large, have disitnct features, and will be so opportune insofar as people actually paying such sums for corals that are almost assuredly misidentified.

Want to make a go of it? I have a potential donor, and have one bleached colony in my collection of Acanthastrea, and several Blastomussa.
 
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