An asteroid makes its appearance

This is a placeholder post, mostly. It's been a busy week. The spring tides just ended, and I took advantage of them to drive north and collect for a project or three. I have lots of pictures to show off, and a couple of topics rolling around in my head for a future post. But this little guy is just too cute not to share. It's the first echinoderm on the blog! (If echinoderms are your favorite phylum, check out The Echinoblog. If you have a favorite phylum, you're probably an invertebrate biologist, even if you don't know it yet.)

A small sea star, found in Massachusetts. It's in the class Asteroidea in the phylum Echinodermata, a.k.a. an asteroid, hence the title of the post. Photo credit A. Cahill.

Summer comes in like a lion

Here in the U.S. it is Memorial Day weekend, which is the Unofficial Start of Summer. Mostly that means barbeques and parties and beer and swimming. This year, in my part of the U.S., it meant cold rain yesterday and cold wind today.

It's continued to be a cold spring through the last few months, which means that the animals are behind where they usually are at this point on the calendar. But the last week or so we had a rash of warmer weather, and I was hopeful that I would be able to collect fully incubated Crepidula eggs to set up the first of my summer's experiment with newly hatched larvae.

I went out on this morning's spring tide to a lower water level even than last time, previously the lowest I had ever seen the beach. This happens sometimes on windy days -- the wind pushes the water even farther away from the shore. And boy, was it windy. There were whitecaps on the water, which is not something I usually see in the summer, and it was so cold that I was bundled up just as much as when I go out in October (note the rubber gloves in the photo below).

An egg mass of a whelk. All but the last compartment or two had already hatched, and I could see miniature snails ready to come out of the last ones. I very much wanted to take them back to the lab to watch them grow, but they are predatory and I don't want them eating my experiments when they get bigger. Photo credit A. Cahill.

My site this morning. If I share enough of these you might start to get the feel for the tidal heights at this place too. See this post for a comparison of the jetty on a neap tide. Photo credit A. Cahill.

Crepidula fornicata bed, normally subtidal at this part of the site. Pretty high densities for this area. Photo credit A. Cahill.

 As you can see from the third photo, the Crepidula were very abundant and very easy to get to. I had a sudden flash to my childhood trips to the strawberry farm at a similar time of year, elsewhere in the country. It really was as easy today as just bending over and picking them up.

And when I got back to the lab, I was thrilled to find this:

Crepidula fornicata egg masses and larvae. The yellow ones on the left are recently laid eggs and embryos with lots of yolk. The brownish-grey blobs on the right are ready-to-hatch egg masses whose larvae have used up all of their yolk. The little dots that look like snow are the larvae themselves. Photo credit A. Cahill.

 I spent the rest of my day setting up larval cultures for my experiments. Happy summer!