Wednesday, March 15, 2017

My Cousin Sal

My Cousin Sal

Here’s a lovely photo of my cousin Sal.  Actually Sal is your cousin, too. 

Sal is the cousin of every human, because Sal, like us, is a chordate, with the very beginnings of a backbone.  Sal’s a salp (hence the name), which is a kind of tunicate, also called sea squirts.  Tunicates in their very early stages have a tiny backbone and look like a tadpole.  (So do humans at that stage.)  Sal might seem more like a jelly fish or a sea slug, but Sal’s branch in the tree of life is very near ours, the chordates.

Hi, Cuz!

As I got to know Sal (we have tunicates at the Aquarium) I found I liked Sal a lot.  My kind of cousin – simple yet very complex, liberated from old fashioned categories, and trying to make the world a better place. 

In Sal there is neither male or female; Sal’s a sequential hermaphrodite, beginning as female then becoming male.  But Sal’s even more complex than that.  As Sal develops, there are stages when Sal is one solitary individual.  But then s/he transforms into what biologists call a “colony,” one organism made up of many many interconnected, mutually dependent organisms, divided into different tasks, unable to live without each other. 

So Sal is made up of many different members, but is also one body.  Some of the individual parts do the feeding, some the breathing (pulsing water through each unit for oxygen), some the motion (together propelling the whole colony.)  If all were the eating parts, where would be the motion?  (This photo shows both the one and the many.)

While Sal lives in the deep sea Sal does not curse the darkness, but rather brings its own light into the darkness.  Sal bioluminesces, creating its own light.  Indeed Sal’s a particular kind of salp called a pyrosome, which means literally “fire body.”  Sal can light up the deep dark ocean for 50 feet.  19th century scientist Thomas Huxley and many other sailors have seen Sal on an ocean night.   "I have just watched the moon set in all her glory, and looked at those lesser moons, the beautiful Pyrosoma, shining like white-hot cylinders in the water."

We often insist on giving living things a restricting label, forcing them into separate categories – male/female, vertebrate/invertebrate, individual/group, dark/light.  Sal won’t let us.  S/he is all of that, both, everything.  And more.  Thanks, Cousin Sal, for transcending our limiting labels.  Thanks also for your deep beauty.

Photo by Nick Hobgood of a pyrosome off East Timor. 

We have salps in Monterey Bay also.  Visit our Blue Theology Mission Station for a family reunion with your tunicate cousins. May 9 a special Blue Theology Day for clergy and religious educators with a sustainable seafood lunch included.  Still some summer openings here for youth groups and adult pilgrimages.

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