At the conclusion of the study, all sea urchins were
dissected to determine wet gonad, gut and test indices
(body parts (g) / whole animal weight (g) × 100)
(Table 1). One gonad section from each animal in the
initial sample and from each treatment was prepared for
histological analysis. Each gonad sample was preserved
in neutral buffered formalin to determine the reproductive
state. According to Byrne (1990), five phases are
recognised: (1) recovering stage with small previtellongenic
oocytes or primary spermatocytes, (2) growingิ stage with many large nutritive phagocytes, (3) mature
stage with no or few nutritive phagocytes around
oocytes or spermatozoa, (4) partly spawned stage containing
few nutritive phagocytes and loosely packed
gametes, and (5) spent stage with gonads without
gametes. Testes and ovaries were not distinguished for
purposes of this study.