Coastal Gastropod Reproduction: an Animated Cartoon

Dr. Tom Carefoot, a retired faculty member of the University of British Columbia, made an animated cartoon about reproductive strategies of two types of coastal gastropods. This is just one of the features of his amazing website, A Snail's Odyssey. Enjoy!

Dr. Carefoot also shares a short history of the word dogwhelk. I have always wondered why the word "dog" is part of the name of this type of gastropod. Here is his commentary:

The word “whelk” has appeared in many different forms over the ages and has an obscure origin. The Oxford English Dictionary notes that the “unetymological” spelling of wh-elk (as opposed to such earlier names as “wiloc”, “wyloc”, “wylke”, and “welke”) commenced in the 15th C. The term “dog” whelk is used commonly in Britain and elsewhere in reference to Nucella spp., for no obvious reason that would relate to a snail. However, as we also have “dog shark”, “dog rose”, “dog violet”, and “dog wood”, perhaps it refers to something that is common or familiar, like our 4-legged companions.

Field experiment finished!

After 40 weeks, my field experiment examining how dogwhelk predation affects mussel bed communities is finished! I collected the experimental mussel beds and cleaned up the equipment in the beginning of August.

Before:

During:

   

This is a video of the tide washing over my experimental cages.

    


After:

   

After August, low tides are during the night, which is why I decided to end it then. It's a very good thing I did, because two weeks later during the next spring tide, this washed up!

This is a spotter boat—one that locates schools of squid at night so other fishermen can catch them—that has run aground on the reef.

It was about 100 ft. away from where my experiment was and probably would have ruined the whole thing, which would have been a HUGE loss for me; I honestly might not have been able to graduate this year if my experiment was still out there when this happened.

Over the course of a few days, the waves tore up the boat and left it in pieces. A salvage crew eventually came down and lifted up the pieces with a crane.

Now that that's all cleaned up and done, I have started measuring the mussel samples and I'm eager to get results!

Field experiment observations

I'm about to wrap up my field experiment finally! Now that lots of mussels are drilled and empty, thanks to my dogwhelks, I've noticed many lined shore crabs that like to live inside them. I'm not sure if this will be a real result or if it's just a fun observation, but either way, it's cute.

We also found many of these gelatinous, salp-looking creatures in my cages this week. I don't know what they are, but they look really weird!

Pachygrapsus crab hiding in an empty mussel shell. I suspect larger empty mussels 

support more Pachygrapsus. Could this be an interesting result of my experiment?

Unknown gelatinous creature or substance found in my experimental mussel beds.

Field experiment interview

Here I explain some of the details of my field experiment in the mussel beds. Huge thanks to Laura Shields, a former Science Communications student at UCSC for putting this together.

Real, live, squirming dogwhelk proboscides

This time in the lab I found several dogwhelks eating a mussel they had killed just a day or two ago. Since the mussel was gaped open, you can see the dogwhelks' proboscises (or proboscides, which apparently is also the plural of proboscis) nosing around for mussel tissue. There's a point in the video where you can see all three proboscides together. The video is mostly at 20 x speed, but at the end I put in some 1 x speed so you can see how fast they actually move.

Check it out! The proboscis action is in the bottom right corner of the video. Each proboscis is a beige trunk-looking thing with a pink tip. Look for them moving inside the open mussel. The GoPro is not exactly in focus, but you can still see each proboscis fairly well.

I am starting to realize that perhaps the best way to get a dogwhelk to feed is to make it jealous; once one dogwhelk is drilling, others tend to join it. There was another healthy mussel in the tank with these dogwhelks and they ignored it and all fought over the same meal! How strange. Granted the other healthy mussel was glued to a hydrophone, but I have no reason to believe that would deter the snails.

Speaking of hydrophones, mine has been picking up lots of really loud static. I have checked the connections and moved things around and nothing seems to make it better or worse. It will randomly go quiet sometimes, but today it was very static-y for hours. If you have any recording experience and think you can help out, please let me know! The only thing I can think of now is maybe being in seawater continuously for several days is having a negative effect on it.

Interesting dogwhelk behavior in lab

The other day I was working with dogwhelks in the lab and I noticed one of them was stuck hanging from the top of the cage by a byssal thread. Apparently, a mussel had attached a thread to it and when I turned the cage on its side, the dogwhelk was dangling by it. The poor thing was clearly trying to grab something to get unstuck, but there wasn't much for it to hold onto. I wanted to see if it could get itself out of its unfortunate situation, so I set up my GoPro and started filming!

I soon noticed another dogwhelk crawling up the side of the tank and heading directly toward the top where the dangling dogwhelk was attached. It then proceeded to push on the threads, causing the dangling whelk to bounce! Was this dogwhelk trying to free the dangling one? Here is the 8x speed footage!

I waited a long time for the scene to progress, but the helper dogwhelk didn't break the byssal thread and eventually crawled away. The dangling one wasn't able to grab anything on its own, so I pushed it over to the side of the tank where it held onto the wall, started crawling, and eventually broke the thread and freed itself. 

My first time recording drilling?

In my continued effort to record dogwhelk rasping, I think I finally got a dogwhelk to drill a mussel glued to my hydrophone! Previously, the dogwhelks drilled all the other mussels in the tank, but not the only mussel that we wanted them to drill.

We've captured this process using time-lapse photography, and here are a couple pictures: one with the lights on during the daytime and one with them off and a red light on at night.

Here's what you're seeing: The cord is connected to the hydrophone, which is a black puck-like object. The hydrophone is on top of a black mussel, and the dogwhelk is the grey-white thing on the mussel. This is easier to see in the not-red photo. There is also a smaller mussel just to the right of the larger mussel with the dogwhelk on it. The smaller mussel is only there because it was attached to the large one and I didn't want to disturb it by pulling it apart.  Finally, there is a thermometer in there with them, and the tank itself is in a cooler.

We have yet to go through the audio files to see what we can hear, but at least this time we know the snail was drilling in a quiet room, so the odds are in our favor to hear some rasps!