I am currently doing my final year project about the long-spined sea urchin, Diadema setosum.Am actually looking at the spawning behaviour correlated with tides.I've been collecting samples since last month, each time 6 urchins, 4 times a month. My question is, why are all the urchins i collected are female urchins? I've opened them up and studied them with my supervisor and we really could not figure this out. Any idea???