Last night the moon was new, meaning that we are now in spring tides. The spring tides occur during the new and full phases of the moon and result in the largest swings between high and low tides; in the weeks between the full and new moons we have neap tides, during which the height difference between…
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…
A phobia that I don’t have, and a tiny phurry phriend
This morning I was teaching lab when three of my students in the back corner called me over to where they were working. “We have a problem,” one of them declared. Since they were making posters I assumed that the problem had to do with format or content or something related to the scientific papers…
A reason to hope
About two and a half months ago, the ongoing disaster of sea star wasting syndrome raised its ugly head again when one of my bat stars (Patiria miniata) developed lesions on its aboral surface. Here’s what it looked like then: and here’s a close-up of the lesion, taken the following day: See how the lesion…
Happy to get stumped
You may have heard that earlier this month the California Department of Fish and Wildlife postponed the scheduled opening of the commercial Dungeness crab season. Gasps of dismay were heard all over the state from Californians whose Thanksgiving traditions include cracked crab, as well as from the folks who make a living fishing for them. The…
A visit to Doc’s lab
A few weeks ago I made a pilgrimage to the Great Tidepool in Pacific Grove, where Ed Ricketts did much of his collecting in the 1920-40s. Ricketts is a legend among students of the intertidal here in California, but he is known to a much wider audience as the inspiration for the character Doc in John…
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…