Figure 4

Compared skeleton surface textures of thickening deposits (i.e. shingles) in Acropora eurystoma corals cultured for 4.5 days (108 h) in constant light or constant dark conditions.

(a–c) Specimen growing in constant darkness (D) during last 3 ⁸⁶Sr labeling pulses. (d–f) Specimen growing in constant light (L) during last 3 ⁸⁶Sr labeling pulses (see Figs 1 and 4). Although shingles (scale-like thickening deposits) are recognizable in both samples, shingles in specimen growing in constant light (d–f) are more regular and have surface with clearly visible fibers. In contrast, shingles in specimen growing in constant darkness (a–c) are irregular and fibers at their surface are smooth.