Skeletal eroding band

[citation needed] When H. corallasia divides, the daughter cells move to the leading edge of the dark band and produce a protective shell called a lorica.

[5][6] H. corallasia is a sessile protozoan that secretes a bottle-like housing called a lorica (Latin for cuirass, flexible body armor[7]), that is anchored to a surface and into which the cells retract when disturbed.

[8] When a mature individual cell division divides, it produces a pair of worm-like larvae that settle on undamaged coral just ahead of the black band.

The discarded loricae of the "parent" H. corallasia cells remain, leaving the distinctive spotted region in the wake of the living black band.

[1] A survey in the Caribbean Sea conducted in 2004 and published in 2006 reported a disease with very similar symptoms, affecting 25 species of coral within 6 families.

Although the authors initially suspected H.corallasia, more detailed examination showed that the culprit was another species that was previously unknown and has not yet been formally named, although it is clearly a member of the same genus, Halofolliculina.