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Solutions today for reefs tomorrow



Invertebrate Predation: Check for the presence of corallivores at the lesion margin or the base of the colony.

Hermodice fireworms (F)

Engulf entire branches and protuberances on the colony; uniform and complete removal of tissue from branch tips or projections; smooth, uniform margin between skeleton and live tissue; no evidence of tissue sloughing. Feed mostly at night.

Coralliophila snails (A-E)

Feed in groups (2-70+) at the edge or base of a coral consuming tissue directly under their shell footprint, creating a scalloped pattern. Tissue loss initiating at base or perimeter of coral. The feeding scar progressively radiates out in a linear or annular pattern, but it may extend in an irregular path across the coral. Tissue loss is concentrated on upper surfaces of branches (B) Lesion margin may be irregular, serpiginous, serrated or undulating (A) ; no sloughing of tissue at the interface of exposed skeleton like in WBD, WP and WPD.


Fish Predation: Fish may be seen biting coral; fresh lesions stream mucus. Absence of tissue and skeleton.

Parrotfish predation

  1. Spot biting (M-P): Focal and multifocal scrapes and pairs of bite marks, each <2 cm elongate, concentric or irregular in shape; acute lesions and recovering lesions (P) may occur together.
  2. Focused biting (Q-T): loss of larger areas of tissue and skeleton to depths of 1-2 cm; removal of entire knobs, projections, branch tips (R), and edges of plates; focal, multifocal, coalescing and linear lesions 2-50 cm diameter; lesions expand from the perimeter across exposed surfaces (S); tissue in depressions/ bases often undamaged (Q).

Damselfish predation

  1. Lesions on Acropora are circular to irregular (<2 cm in diameter) and may occur over the entire branch; accelerated calcification may result in chimney-like structures (G-H). Lesions may also become larger, resembling white patch disease; no skeletal damage but corallites often broken
  2. S. planifrons bite on the projecting ridges of brain corals (J-L) removing tissue from one or more ridges. As ridges are colonized by algae, fish bite new areas causing the lesion to radiate out in a linear or annular manner. This condition is also called Ridge Mortality. On faviids, fish bite individual round corallites which will appear white, often with a tuft of filamentous algae (I).