ABSTRACT
The effect of tensile mechanical stress on the calcification pattern of isolated test plates of the echinoid Tripneustes gratilla elatensis was examined, using a radioisotope. Interambulacral plates, stretched in the horizontal direction (adradial-interradial) calcified at higher rates than the vertically stretched, or non-stretched plates. The ratio between the calcification rates at the upper and lower sutural margins and those of the horizontally directed (v/h ratio) was also affected in the treated plates: Plates stretched at the horizontal direction showed lower v/h ratios than the vertically stretched or the non-stretched. These results suggest that in situ the test plates are subject to mechanical stresses – tension along the longitudinal sutures and compression at the horizontal sutures.
