Introducing Slipper Snails

A lot of the research in the Collin Lab focuses on slipper snails (sometimes called slipper limpets or slipper shells).  I like to refer to them as slipper snails because they are more than just a shell; they are really cool and complicated animals. 

The Latin name for the genus of slipper snails is Crepidula.

Slipper snails and their relatives all belong to a single family, the Calyptraeidae.  Future posts will explain the questions we are trying to answer, the methods we employ, and some of the things we have discovered. But for now, here are a few quick facts as an introduction to my favorite snails.

New species are being discovered all the time. At the moment, there are about 200 species of calyptraeids.  That is, there are 200 species that have been officially described and named, and which biologists agree represent distinct species.  But nobody really knows how many species have yet to be discovered.

I described and named Crepidula ustulatulina in 2002.

Slipper snails change sex.  Small young animals first develop as males. As they grow they gradually change to become female.  Once female they cannot change back.  This kind of sex change - from male to female - is known as protandry.  Sex change from female to male, which is seen in a number of fishes is known as protogyny.

Slipper snails do not move around much. They don’t have to because they are filter feeders –in other words they filter particles out of the water for food – so they don’t have to search for food.   They attach themselves to the substrate and hunker down in the face of adversity. 

They often just look like bumps on a rock.

The most important aspect of calyptraeid biology, from the point of view of our research, is that slipper snails display an amazing diversity in how they develop from eggs to adults.  Some species have swimming larvae, some species have large eggs that develop directly into juveniles that look like small adults, in some species the embryos actually eat their siblings as they grow, and in other species the kind of development can change during the life of the mother.

Surrounded by History (Part I)

We work on a small island at the Pacific entrance to the Panama Canal.

It’s not as remote as it sounds.  Isla Naos is one of three small islands in front of Panama City and is the site of the Smithsonian Tropical Research Institute’s (STRI) Naos Laboratories.  In 1912 the islands were connected to Panama City by a  3 km causeway made from rock excavated during the construction of the Panama Canal.  The causeway blocks currents and reduces sedimentation at the entrance of the Canal. And, of course, it means we can drive to work.

The Amador Causeway with Naos, Perico and Flamenco Islands.

It’s not just the large 1914 emblazoned on each end of the building that hints at its history. If you look carefully, among the lab benches and science equipment you can see traces of the building’s story. The third floor has strange metal poles scattered at inconvenient locations through the labs and offices.  These turnbuckles actually act to suspend the floor from the ceiling.

The Collin Lab is officially in STRI’s building 359 

but we call it the “1914 building”.

Turnbuckles hold up the floor.

Our 1914 building was originally a military building.  Gun batteries and later missiles were stationed on the islands to defend the Canal.  In the early days, trains were used to move the small guns from the islands to the mainland. A large space in our 1914 building was originally used to maintain these trains, and used to have tracks running along the floor.  There was a large hoist on an H frame running most of the length and width of what are now the 1^st and 2^nd floors of the lab. The hoist had an electric winch that could lift rail cars from the track and move them to the side for maintenance.  Now, 100 years later, this historic building houses modern scientific equipment.

 The 1914 building circa 1970.

Click here to go to Part II