I’ve shown you how sea urchin eggs are fertilized in the lab, and you’ve watched the fertilization membrane develop in real-time. One day a few years ago, my colleague, Betsy, and I set up shop to spawn urchins. We do this just about every year because it is super fun and we both enjoy watching…
Category: Marine invertebrates
Let there be life!
One of the all-around coolest things I do with my students is spawn sea urchins to show them fertilization. We can actually watch fertilization occur under the microscope. And since the early stages of development are the same in sea urchins and humans the students get to see how their own lives started–not in dishes…
Easy come, easy go
As I suspected, the little Dendronotus veligers didn’t last very long. On Wednesday the very last survivors had kicked the proverbial bucket. All that was left in the jar was some debris and scum from leftover food. They lasted nine days post-hatching, which is about the norm for me when I’ve tried to raise nudibranch…
The problem with shells
The Dendronotus veligers are still alive. I’ve been running into the same difficulties I’ve always had when trying to rear nudibranch larvae: hydrophobic shells that tend to get stuck in the surface tension of the water. Larvae that are trapped at the surface can neither swim nor feed. We can pretty easily rear sea urchin…
The veligers are on their way!
Today a lot of my Dendronotus eggs had hatched on their own, swimming through the water as bona fide veliger larvae. Nudibranch larval culture has officially started! These bad boys are much more spherical now–whew!— which makes me think that pointy-shell thing I saw last week was an artifact of their premature hatching. Now they…
Veligers!
The marine gastropods and bivalves go through a larval stage called a veliger. This larva gets its name from the ciliated structure, called a velum, that the animal uses for swimming. Veligers have shells–1 for gastropods and 2 for bivalves–and can withdraw the velum into the shell. Even gastropods that lack shells as adults, such…
Slugs and sex
What better way to start a new blog than to talk about sex? This morning at the Seymour Center I noticed a blob of what looked like nudibranch eggs on the wall of one of the tanks. Looking around for the likely culprit I saw three big nudibranchs on the tank. Ooh, cool! This is…