Preparation of Sea Urchin Specimens
Sperm and eggs (Gametes) were collected from adult sea
urchins (Paracentrotus lividus) inhabiting the Adriatic Sea at
Limski kanal, Croatia. Fertilization, using 0.5 M KCl injection
to induce spawning of gametes, was carried out in natural
seawater filtered through a 0.22 µm membrane filter. For
AgNP-exposed samples (in contrast to the control), about 2 h
after fertilization, AgNPs were added to the sea urchin larvae
at a concentration of 0.3 mg/L. In both cases, the larvae were
collected at 51 h after fertilization by fixing with 100%
ethanol. The samples were washed with DI water several
times before any measurements