A Snail with a "Bubble Raft" - Observation of the Week, 7/16/18

Our Observation of the Week is this Violet Sea Snail, seen in Brazil by @deboas!

Ben Phalan (deboas) is currently residing in the Brazil, where he is a visiting professor at the Federal University of Bahia, but he’s taken quite a route to get there. Originally from rural Ireland, Ben says “I’ve been a naturalist for as long as I can remember...I was free to spend the entire day out exploring woods, fields, ponds and a large garden. My parents were very supportive, and were unfazed when I filled my bedroom with fungi, ferns, jars housing tadpoles and caterpillars, old skulls, discarded fragments of birds’ eggshells, and whatever else captured my interest.”

While his interests covered nearly all taxa, Ben says he “found it most satisfying when I could put a name to what I had found...and I think I ended up focusing most on birds because of the satisfaction of being able to identify them to species level.” He joined what is now BirdWatch Ireland and eventually learned to band birds, even venturing to Bird Island off of South Georgia to band albatrosses. Ben thanks his many mentors over the years, including John Marsh, the late Oscar Merne, and Alyn Walsh.

Switching gears to study “the effects of agricultural expansion and intensification on biodiversity in Ghana, West Africa” for his PhD, Ben has travelled to West Africa several times, “recently to lead an expedition in search of the enigmatic Liberian Greenbul (a species that was described in the early 1980s, but which – partly thanks to blood samples I collected in Liberia – we now know was never a valid species).”

And after stints in Cambridge, England and Corvallis, Oregon, Ben has found himself in Salvador, Brazil, where he says “the incredible biodiversity of the Brazilian Atlantic Forest and Caatinga is sure to keep me occupied for years!” And that biodiversity includes, of course pelagic snails that might wash up on the beach:

I was walking with my wife and dog along a beach in Salvador and started to notice beautiful little blue sea snails (Janthina) washed up along the tideline. I’d left my smartphone at home for safety, but luckily my wife had hers and I was able to document a few of the snails. I had heard about these ocean wanderers, but this was the first time I was lucky enough to see one...There were also some small Portuguese Men o’ War washed up, which is one of the prey species of Janthina, and some shells which I took to be from a gastropod. In fact, the shells were from a deep-water, bioluminescing squid-like creature called Spirula, which is the only member of its Order.

Look closely at Ben’s snail photos and you will notice a mass of bubblies by the shell’s opening - this is its “bubble raft,” which the animal uses to stay afloat in the open ocean. It “collects” the bubbles in transparent layers of chiton and, as Ben notes, “incredibly, for a species that spends its life on the open sea, the adults can’t swim. If they get detached from their bubble raft, they’ll sink and die.” The snails do feed on hydrozoans like the Portuguese Man o’ War and By-the-wind Sailor and like many other marine life are countershaded - one side of the shell is dark purple, the other whitish.

“The feeling of contributing to something bigger is the main thing that attracted me to [iNaturalist],” says Ben (above, checking out some large fungi in Oregon). “I like being able to learn more about the species I encounter, and it makes me especially happy to know that my observations become part of GBIF and can be used by researchers worldwide.” He’s also begun adding old observations from his time in Africa and admits “I spend probably more time than I should adding identifications. I tend to focus on birds in Brazil, but occasionally dabble in other taxa and regions as well. It’s especially satisfying to find and correct misidentifications. I have definitely learned a lot through doing this.”

- by Tony Iwane. Photo of Ben Phalan by Luciana Leite.

- You can find Ben’s publications here. 

- You want to watch a Janthina snail make a bubble raft, right?

- Ben still manages BioBlitz projects in Corvallis, Oregon from Brazil, like this one! 

Posted on 17 de julho de 2018, 01:43 AM by tiwane