Yesterday I learned about the weirdest undersea creatures ever: siphonophores. I first saw them mentioned in this New Yorker interview with a giant squid hunter. Check this shit out: "whether siphonophores are single individuals or colonies of well-integrated polymorphic hydroid and medusoid individuals is a matter of debate among specialists." No one can decide whether they are colony organisms made up of very well-coordinated creatures or individuals with strangely differentiated body parts! They're like those snakey things in Anvil of Stars, man! They can be over 100 feet long! They're often bioluminescent! Read and marvel:
All siphonophores are predators and typically spread a veil of nematocyst-laden tentacles for capturing unsuspecting prey. Some of the "individuals" along the length of the stem provide tentacles for defense (dactylozooids) and food capture. Depending on the type of siphonophore, others may function as swimming bells (nectophores), aid flotation (pneumatophore), provide additional defense (bracts), digest prey (gastrozooids), or serve for reproductive functions (gonozooids). The central stem to which all these units are attached is hollow. The gastrovascular cavity passes throughout the stem, and extends into the float (if present), swimming bells, tentacles, bracts, gastrozooids and gonozooids.
How fricking weird is that? The big ones live deep in the sea, so that often all that is seen closer to the ocean surface is broken up bits of siphonophore chains. This happens off the coast of South Carolina in the summer, and we call it "hot jelly". You are liable to get stung, not by a whole jellyfish, but by little stinging segments of jelly. Now I learn that "hot jelly" is really siphonophore dactylozooids gone astray!
And their reproductive method is also bizarre: the (apparently hermaphroditic) gonozooids do their egg fertilizing thang, and the fertilized eggs develop into larvae, and then into one of the main structures, like the diving bell. Then the rest of the specialised sub-units form by budding!? WTF?
The most famous siphonophore is the Portuguese Man o' War. I have been stung by one (or rather, by one of its dactylozooids) before and boy howdy was that painful. I got a fever and everything, and my right leg looked as if a poisonous whip had curled around it several times, leaving a track of pinhead blisters embedded in the swollen flesh. In time these faded to white dots, and so for a while the whole thing seemed worth it because I had the coolest scar ever. Sadly, it too faded after a year or so.
Anyway, let's all give a hand to my new favorite order of gelatinous zooplankton: siphonophorae.