Answer: When it’s a snail! Yes, there are snails that secrete and live in white calcareous tubes that look very similar to those of serpulid polychaete worms. Here, see for yourself: The worms secrete calcareous tubes that snake over whatever surface they’re attached to. When the worm is relaxed, it extends its delicate pinnate feeding…
Marine invertebrates
A naturalist goes in the field
This morning I took a small group of Seymour Center volunteers on a tidepooling trip to Point Piños (see red arrow in the photo below). Point Piños is a very interesting site. It marks the boundary between Monterey Bay to the right (east) of the point and the mighty Pacific Ocean to the left (west). As…
Timing is everything
This morning I went here (see arrow): See how it’s covered in water? I took this picture at about 13:00, probably right at high tide. And of course when I was out there this morning at 06:00, it was low tide. It wasn’t the greatest of low tides but it allowed me to see what…
Graduation Day
Today was a big day for me. I got to graduate some of my baby urchins from glass slides onto coralline rocks. They were growing very quickly on the slides, chowing down on scum faster than I can grow it, so now it’s time for the biggest ones to really put their Aristotle’s lanterns to…
Hitting the wall
We humans use the term “hitting the wall” when we find ourselves in situations in which progress is elusive despite extreme effort. For endurance athletes or anyone doing any serious physical training it can mean not being able to break one’s personal best time for a race, or not being able to continue getting measurably…
Eating, pooping, and turning over
My baby urchins have become scum-eating machines! They are 88 days old now and I am beginning to wonder if I can generate scum fast enough to keep up with them. I did a head count this morning and have three bowls, each of which holds a population of ~100 urchins, and a bowl that…
Symmetries II
Most of the animals that we are familiar with (think of any pets you’ve ever had) have bilateral symmetry: they have a head end and a tail end, a left and a right, and a top and a bottom. In scientific terms that translates to the anterior-posterior, left-right, and dorsal-ventral axes. Also, most bilateral animals…
Symmetries I
As a long-time student of invertebrate zoology I have for most of my life appreciated the immense variety and ingenuity of animal body plans. And one of the things I’ve always found the most intriguing is the pentaradial symmetry of echinoderms. I remember thinking, the first time I encountered a live echinoderm (probably a star at the…
And. . . we have mouths!
Finally! At long last I have evidence that my juvenile urchins have mouths and are feeding. A week ago I put a batch of seven teensy urchins onto a scuzzy glass slide and have been watching them daily ever since. And yesterday, just as I was beginning to worry that they’d never be able to…
Old skills
When I was in graduate school I found myself drawn to the “old-fashioned” skills of classical zoology: observation of and experiments with living animals. I had, and still have, very little interest in the new-fangled high-tech methods of studying animals, and part of me strongly resents having to homogenize an animal to know what its…