#Dogwalking miscellany

A blue, #beachcombing edition.

#Hydrozoans and #Gastropods

The first image is the beautiful radial skeleton of the Blue Button, or Porpita porpita, a colony organism (when alive), made up of cooperating hydroids. It drifts in the surface waters, using its stinging tentacles to capture small copepods, but will also hunt crabs and fish.
Next is the bluebottle, Physalia utricula, well known on Australian beaches. It's also a colony organism with stinging tentacles.
The next two are mollusks, one with and one without a shell, both preying on the former pair.
The first is the beautiful violet sea snail, Janthina janthina, a free-floating mollusk that uses a raft of bubbles to keep it on the surface where it preys on hydrozoa. (unlike the others, this was taken back home with my D700, not the iPhone3GS).
The second is the spectacular nudibranch Glaucus atlanticus, Sea swallow or Sea dragon. This predator cunningly saves and stores the nematocysts, or stinging barbs, from its prey and uses them to defend itself, so picking one up with bare hands can result in a stings just as painful as a bluebottle.
Unfortunately this last picture is very poor quality, being made in a hurry with an iPhone 3GS, and with the animal out of the water so that its branching arms are collapsed.
#beachcombing
#photography #beach #macro #animals #iphoneography #iphone3gs #nikon