Spring has sprung

And that means the first sighting of mollusc eggs on the beach!

Last weekend was a beautiful early morning spring tide -- and in this case, a spring tide in spring. It was rough getting up that early on a Saturday, but as always it was worth it. The tide was a -0.9, meaning it was 0.9 feet below the average low water mark. I was able to get out to parts of my collection site that I have never seen before, and on top of that the early morning sunlight was perfect for seeing animals.

You can tell it is spring because the barnacles are settling.

Newly settled barnacle cyprids (the small brown dots on the rocks) from Semibalanus balanoides. Older barnacles are larger and white.

The cyprids are the last larval stage of barnacles, and they are probably worth their own blog post. They walk around on the rocks looking for a good place to settle and metamorphose, and then they attach permanently. The newly settled barnacles are always extremely abundant at this time of year, and pretty much every hard substrate in the area is dotted with brown. It's impossible to walk in the intertidal without crushing thousands of them. 

You can also tell it is spring because some of the snails have started laying eggs:

A sand collar, the egg mass of the moon snail. The eggs are hiding in there somewhere, in that beautiful structure made of sand grains.

 

Newly laid egg capsules of the dogwhelk Nucella sitting on a rock.

Spring also means that the snails can be seen out moving around, especially in the early morning before it gets too hot.

An Ilyanassa obsoleta moving around. The thing sticking out of the front of its shell is its siphon, which it uses to sniff the water looking for food. Pretty soon these guys will start mating and their eggs will be all over everything.

A whelk (Busycon) poking out of its shell. You are looking at its foot, and the horny plate on the bottom (with concentric rings) is the operculum, used to close up the shell and protect the soft parts of the animal from predation or desiccation. The shell has been fouled by some Crepidula fornicata on the left and a small bivalve on the right. And yes, I do wear rubber gloves to collect when the water is still so cold.

 The Crepidula that I collected and brought back to my lab were brooding newly laid egg masses, so in a couple of weeks it should be time to collect ready-to-hatch larvae for experiments. 

Happy spring!