Structural colour in Asparagopsis taxiformis (Bonnemaisoniales, Rhodophyta) and its possible role in communicative functions

作者：Hiroshi Kawai, T. Motomura · 发表于：European journal of phycology · 年份：2025 · DOI：10.1080/09670262.2025.2483980 · 被引用次数：3

ABSTRACT Many organisms, especially animals and land plants, are known to use structural colouration, i.e. colour produced by an object’s microstructure rather than by pigments, for communicative functions such as mating, camouflage and aposematic (warning off predators) purposes combined with toxic or distasteful substances. Some macroalgae show structural colours, typically produced by three mechanisms: (1) multilayered structure of the thallus surface, (2) arrays of microfibrils or (3) iridescent/refractile bodies within the cell. Suggested functions include the optimization of photosynthesis by reducing stresses of strong ambient light, especially in species that grow in the intertidal zone, although some subtidal species also show structural colour. Regarding other possible functions of structural colour, some macroalgae accumulate toxic materials such as secondary metabolites and highly acidic substances as defensive systems against herbivorous animals, yet few studies have linked herbivore defence with structural colouration as a possible communicative function. Here we report that refractile bodies in the red alga Asparagopsis taxiformis, which contain anti-herbivory substances such as bromides, also have optical effects causing a whitish appearance of the thallus. This masks the more typical reddish colour of the species, thereby functioning as camouflage from herbivorous animals that seek food by visual cues. Furthermore, the opal-like structure of the refractile bo...