SUBJECT: A chain of salps (probably Pegea confoederata) floating midwater
LOCATION: Aegina island, Saronikos Gulf, Greece.
 
These are actually pelagic tunicates that move with the help of rhythmic contractions of the circular muscles of their body walls. As water is pumped through their body, they filter it, capturing the most abundant food source of the well lit pelagic zone during springtime: phytoplankton! 
Encounters like this one reminds me of how different and special life in the sea is, with every pelagic submergence feeling like an exploration trip in our planet's liquid space.