[Coral-List] white Diadema

[Martin Moe]

Dear list,
Remember that thread a while back on white Diadema? I
thought this might be interest. On my Diadema rearing run with the spawn of May
6, 09 many thousands of larvae made it through metamorphosis and into the early
juvenile stage. Settlement occurred on many different types of substrates but
good survival through the early juvenile stage (the first 8 to 10 days after
settlement) only occurred on one type of substrate so survival into the stable
juvenile stage was limited. Once the feeding juvenile developed mortality was very minimal but only 75 individuals made it through this developmental bottleneck.
(I think that with the current rearing run I have a better handle on that
problem.) Now at day 183 from spawn and 139 from settlement, most of the
juveniles are in the 3 cm test diameter range and at about the age when the
banded spines are developing solid color. Most of the juveniles are in the
process of changing the coloration of the spines from banded to a solid dark
color. However, one individual at this point is developing all white spines
rather then the dark purple coloration. The brood stock of 18 individuals,
taken from the reefs offshore of the Upper Keys and maintained now for over 3 years, includes two males with a few sort of muddy
white spines and the coloration of these individuals has not changed over the
time of captivity. The other individuals, both male and female, have all dark spines. For what it’s worth…
 
Martin Moe