I had a fantastic German teacher in high school who often went to great lengths to teach us vocabulary. I’ll never forget the day he dressed up like a homeless man and pulled plastic vegetables out of the otherwise empty classroom trash can, naming each one as he went. Trust me, I remembered my vegetables after that. One day, our vocabulary word was “überraschen” (to surprise), and he taught us the verb in an extremely clear way. He chose a student from the class and instructed her to go wait in the hallway. Then he chose another student, instructed him to wait inside the classroom, near the door but just around a corner so he could not be seen through the door. He whispered something in the inside student’s ear (at this point, the rest of the class was thoroughly confused), then stood back and gestured for the outside student to come back into the classroom. As she entered the room, the inside student sprang out from his hiding place and made a loud noise. She squealed. The teacher turned to the rest of the class and announced “Er überrascht sie” (he surprises her). We didn’t even need the translation to be clarified. We scribbled in our notes. An Überraschung is a surprise.
|Hydroids living on the Tramper|
Yesterday was a day of surprises, each one better than the next. The main event yesterday was the recovery of a deep-sea vehicle called the Tramper, which is an exceptional technological tool. It looks like an ROV with rollers like a tank, and for the past year, it has been recording microprofiles of oxygen concentrations in the sediment and then rolling itself to a new sampling location once a week. When the Tramper came up, I headed out to the deck with the other scientists to see the vehicle, and there was a surprise waiting for me.
Large pink polyps were living on the Tramper, about 14 of them, each 1 – 3 cm long. I could hardly believe my eyes. The polyps were athecate hydroids, and they actually reminded me of Tubularia, the hydroids that were all over my fouling panels at theWHOI pier this spring and early summer. It’s not the same species but probably the same family. My mind started going crazy with thoughts about athecate hydroids being the first opportunistic colonists on cold-water substrata. The polyps were on the top and front parts of the vehicle, especially on the two satellite antennae, which stood about a meter and a half above the seafloor. The elevation plus the vehicle’s weekly movement must have exposed the polyps to faster current, allowing them to feed efficiently and grow large. I ran into the lab, grabbed my forceps and sampling tubes, and started picking the animals off of the vehicle.
As I scoured the vehicle for polyps, I got another surprise: there was a second species of hydroid on the Tramper! It was difficult to see and I probably wouldn’t have noticed it if I weren’t already looking closely, but there were several colonies of a thecate hydroid on the satellite antennae covers. Thecate hydroids look like the Obelia that were on my fouling panels at the WHOI pier this summer. They have stolons running like roots across the substratum, and the stalks for each polyp stand up from the stolon. There are cup-shaped covers (thecae) around each polyp. This second species reminded me of Stegopoma plicatile, the species that dominated my fouling panels from 200 m in Kongsfjorden, Svalbard in 2015, but I’m not sure it’s quite the same. I’ll probably have to send a sample to a taxonomist to be sure.
|Close-up of one of the large|
pink (athecate) hydroid
polyps from Tramper.
I knew the thecate hydroids would be extremely difficult to get off of the antennae covers, especially intact, so I approached one of the Tramper engineers and asked what was going to be done with the covers now that the vehicle had been recovered. It took me a little bit to clarify that I was talking about the covers, not the antennae or attached battery packs, but eventually the engineer shrugged and said “Nothing.” I asked if the covers would be needed for another deployment. “Yeah, but we can build new,” he answered. I asked if I could have them. He shrugged. “Sure.”
I had my third surprise for the day – I got to take home the very substrate my animals were living on! The engineer even helped me cut the covers in half so they were easier to preserve, and did so without destroying any of the animals. I am extremely grateful for his helpfulness and diligence.
I packed my samples away and felt quite satisfied with my day of surprises. As I headed up to the ship’s bar for another scientist’s birthday party, I had no idea there would be one more before the night was over. Scientists and crew chatted and chilled in the bar, and then to our amazement, the ROV team entered, carrying guitars, a drum set, and speakers. The ROV team is also a band! They set up in a corner of the bar and played several songs – country, rock, some Johnny Cash. I listened and swayed and tapped along. It was a great way to end a successful day.