Today the Pisaster larvae that Scott and I are following are a week old. Happy birthday, little dudes! Yesterday we did the twice-weekly water change and looked at them. They’re getting big fast since we started feeding them on Saturday when their mouths finally broke through. At this stage they are sort of jellybean-shaped and extremely flexible–they don’t…
Tag: larvae
Questions and answers
I’ve been fielding questions about my recent sea star spawning work from people I’ve shared this blog with, which is a lot of fun! To streamline things and make the info available to anybody who might be following, I decided to put together a very brief FAQ-like post to address the most recent questions. Question: Can you…
Strangeness abounds
Wow, they weren’t kidding about “early developmental asynchrony” in sea stars! This morning I looked at the embryos that I had started almost 24 hours earlier, and noticed two things right off the bat: Thing #1: Within the F1 x M1 (Purple female x Purple male) mating , developmental rates among full siblings were all over…
From zero to cleavage in. . . nine hours
A recent college graduate and fellow marine lab denizen (Scott) and I are collaborating on a project to quantify growth rates in juvenile Pisaster orchraceus stars. This is one of the intertidal species whose populations in the field and in the lab were decimated by the most recent outbreak of sea star wasting syndrome (SSWS)….
Immaculate conception
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…
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…
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…