April 30, 2012
If you read my last blog you will remember that rays give
live birth whereas skates lay egg cases. Well, not too long after I wrote that
blog our skates began to do just that, lay egg cases. Seeing as both of our
skates are female, they had already mated before they arrived on our property. Momma
skates have the ability to store the male's sperm for up to 6 months after
mating!
On February the 14th, the first egg case was found in our
ray tank. We were thrilled to witness at least one stage of reproduction on our
site and had high hopes for the developing babies. In the months that followed,
more and more cases were laid. It was almost like an Easter egg hunt every
morning in search of more cases.
Now we had a good number of cases but what to
do with them? I tried to come up with different ways for us to observe the
growth of the embryos while still inside the egg casing. This was a tricky task
because most would involve back lighting and skate embryos are very sensitive
to warm temperatures and all of our lights put off heat. So I took a risk and
removed a developing embryo from the safety of it protective egg case and
placed it in a glass jar so that it would still be "protected” but visible to
us while it grew.
Two weeks later, I am happy to announce that our embryo
(who we call Mr. Wiggles) is doing great! Growing, wiggling and absorbing it's
yolk sac all before our eyes. In addition to having a growing embryo on
exhibit, our first egg case hatched. Since the case was laid on February 14th we call it Valentine.
Both Mr. Wiggles, the embryo and Valentine, the baby are
sharing a tank in our coastal center. This is a great chance to see stages of
skate development that most people will never experience.
Below is a video of
the skate embryo from two weeks ago and a video of the baby skate, Valentine.
Come by
and check them out!
- Brit
