Determination of developmental stages of embryo in the Sea Urchin, Echinometra mathaei



Sea Urchin is one of the most useful tools in
developmental biology studies because this organism has the simplest kind of
developmental stages. We aimed to determine developmental stages and timetable of
Echinometra mathaei embryo (the species of Persian Gulf). The
spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into
the coelomic cavity. After fertilization, embryos were placed in beakers and were
incubated at 29◦C and a salinity of 39
ppt until embryos reached the pluteus stage. The developmental stages of embryos and
the timing of each stage including cleavage, morulae, blastula, gastrula, prism
and pluteus larvae were studied under the microscope. Our results showed that after
30 hours from fertilization time, the embryos developed to pluteus larvae. E.
mathaei had the shorter development time in comparison to the other Sea Urchin
species. Therefore, it may be appropriate as a
model organism in biological researches.