Abstrakt
Surfaces of microscopic organisms are often adorned with various patterns whose putative functions are largely unexplored. In this study, we tested the hypothesis that the formation of parallel-arranged ribs im-proves the mechanical resistance of microscopic silica scales.
Computer models of scales were constructed for chrysophyte species Mallomonas striata and Synura petersenii, varying the ribs number and orientation. The finite element method was used to evaluate the model static parameters.
Our results showed a large difference in the function of ribs depending on the species studied. In S. petersenii, the ribs play a key role in scale stability by fixing the longitudinal tubular structure (the median keel) to the basal plate.
Although a larger number of ribs increases the scale strength, in extant species the number of ribs is usually optimised to save silicate. In M. stri-ata, on the other hand, ribs have a negligible effect on overall scale stability.
Moreover, vertically arranged ribs that most stabilize the scales are very rarely produced in nature. This suggests that these ribs have a function other than improving the mechanical resistance of the scales.