Storm strandings -- Part 2

Okay, last night I mentioned there were quite a few different types of gelatinous zooplankton washed up on the beach.  Although these "gelatinous bits" can all seem similar at first, the closer you look, the easier it is to tell the different species apart.  It's often helpful to compare side-by-side photos, so here's a parade of plankton for the record:

 

 

Pyrosome (Pyrosoma atlanticum) — see "Fire bodies" from 8 December 2014

 

 

 

 

A salp, possibly Iasis zonaria — see "Wide mouth and ribbon-like muscles" from 29 March 2013

 

 

The swimming bell of a siphonophore, Chelophyes appendiculata — see "Swimming bells" from 3 April 2013

 

 

Part of a heteropod, Carinaria japonica — see "Carinaria -- Part 2" from 7 December 2014

 

 

 

The pseudoconch (false shell) of the pteropod Corolla spectabilis — see "Gelatinous thimble" from 11 August 2012

 

 

Hard to tell at first, but this is a different pteropod, Cliopsis krohni — see "Angel on the sand" from 13 March 2013

This last species can be tricky to identify.  It really does just look like a round blob on the sand.  But note the darker line running through the middle (that's the digestive tract) -- it's a hint that this is more than just a piece of a jellyfish.  These pteropods are delicate (used to being submerged in offshore waters), so they get beat up when they are tumbled in the surf zone and deposited on the sand.  But if you put them in a little bit of water, sometimes their heads (with tentacles) are revealed, as are their "wings" — the foot of a mollusc modified into swimming appendages.  Here's a short video clip so you can see the wings in action.  [If you can't see the video player in the e-mail, click here to see the video.]