Nancy:

You may have to look out in the field, as to what kind of algae is associated with this coral. Kindly see link for insight:

https://www.researchgate.net/profile/M_Seabra2/publication/235899036_Algal_contact_as_a_trigger_for_coral_disease/links/02bfe513f1bd556779000000.pdf

Best

Syed

Article Algal contact as a trigger for coral disease

Hi Nancy,

Our local coral disease expert, Marilyn Brandt, believes this is one of two things:

1) An odd, possibly recovering, black band infection. Odd because it appears to be slow moving, and the black band isn't very obvious. So, the coral may be recovering.

2) A possible ciliate infection. Hard to say without getting higher magnification images.

Good luck!

Dan

Hi,

I'd say option 1 of Marilyn Brandt but no recovery. This is recent and rapid death. Most diseases are opportunistic infections of a compromised host. This is likely the result of a combination of factors (high temperatures, algal competition, eutrophication, high microbial loads etc). In the end, it does not really matter which specific pathogens cause it and what specific symptoms it showed.

Cheers,

Maggy

AT first look and with this magnification, I agree with Marilyn assessment. It seems to be BBD rather than a ciliate infection mostly due to the fast tissue mortality (the clean white skeleton is evidence of rapid advancement). Ciliate infections do not kill tissue that fast. The cyanobacteria band however, is thin and loose compared to typical summer-fall BBD infections. This  signs are more typical of the disease when it persist through mild winters and spring temperatures. The band gets thiner. When did you observe these corals.  

As long as my experience in coral disease observation, That look like Black Band Disease infection cause the coral colony be white.  BBD contain the black fibric of bacteria and ciliates eat the soft tissue of polyps.

cheers

Syafyudin Yusuf_ipul

Hello Ernesto Weil, I observed it in August 2015 (Summer), so is it BBD? Thank you! And thank you all  for all your contributions!

Fabiola