According to my notes at the lab, the last time I spawned urchins was December of 2016, making it four years ago. It has always been something I enjoyed doing, but I didn’t have a reason to until now. When the coronavirus pandemic began almost a year ago now, access to all facilities at the…
Tag: sea urchins
Metamorphosis
It has been a few weeks since I posted about my most recent batches of urchin larvae. Some strange things have been happening, and I’m not yet sure what to make of them. It would be great if animals cooperated and did what I expect; somehow that never seems to be the case. The upshot…
The hybrids are winning!
Although at this stage it’s a close race. Two and a half weeks ago I spawned sea urchins in the lab, setting up several purple urchin crosses with the hope of re-doing the feeding experiment that I lost this past summer when I was on the DL (that’s Disabled List, for those of you who don’t…
Fine distinctions
Sea urchins have long been among my favorite animals. From a purely aesthetic perspective I love them for their spiky exterior that hides a soft squishy interior. I also admire their uncanny and exasperating knack for getting into trouble despite the absence of a brain or centralized nervous system. Have you ever been outsmarted by…
Progress report
My most recent batch of sea urchin larvae continues to do well, having gotten through the dreaded Day 24. I haven’t written about them lately because they’re not doing very differently from the group that I followed last winter/spring. However, I’ve been taking photos of the larvae twice a week and it seems a shame to…
Some ins and outs of raising larvae
Today my most recent batches of urchin larvae are six days old. Yesterday being Monday, I changed their water and looked at them under the scopes. I was pleased to be able to split each batch into two jars, as the larvae have already grown quite a bit; I now have a total of four jars to take…
Boy meets girl, urchin style
Having obtained decent-ish amounts of gametes from sea urchins, the next step is to get eggs and sperm together. The first thing I did was examine the spawned eggs to make sure they were round and all the same size. Lumpy eggs or a variety of sizes of eggs indicates that they are probably not…
Playing matchmaker
We are finally heading into the time of the year that our local intertidal sea urchin, Strongylocentrotus purpuratus, spawns. Usually I would wait until December or January to try to spawn urchins in the lab, but next week my students will be dissecting urchins in lab and I thought I might as well evaluate gonad development…
You are what you eat, part the fourth
The juvenile sea urchins I’ve been raising this year are now nine months old. Back in June I put them on three different macroalgal diets and have been measuring their test diameters monthly. I do the measuring in the first week of every month, and today was the day for November. Over the past few weeks I…
You are what you eat, part the second
Two months ago now I gave my juvenile sea urchins a job. It’s the kind of job they’re perfectly suited for: eating algae. I measured them all and randomly divvied them up into three food treatments. One group remains on the pink coralline alga they’d all been eating once they graduated from a diet of scum,…