1. FIRST starfish from a Hydrothermal Vent Habitat!!
UPDATE: New Video!
Why? Hard to say, exactly but it probably has to do with the fact that most echinoderms can't process toxins very well. Their "body fluid" is basically sea water. This is probably why there are no freshwater or land echinoderms.
These starfish aren't "primary" vent fauna, such as big vent worms or clams that can manufacture food out directly of toxic sulfide.. These exist at the edge of the community feeding on the animals that ARE part of the primary vent community. BUT that said, they are pretty important (see below)
this handy chart from THIS paper by Leigh Marsh et al. in PLOS One! shows this relationship...
So, we have a weird, deep-sea habitat with weird inhabitants. What does the starfish look like??
The skeleton is pretty reduced. A fairly soft and fleshy body wall.
An analysis of the molecules from these two species showed that they were in fact, closely related to one another!!
The truth is that there were not a lot of external characteristics that could have been used to have done the same analysis.
AND molecules also revealed that these two species were part of a lineage or clade SEPARATE from other known species!
4. Unusual and yet related to something familiar...
So, a lot of this might seem kind of alien to everyone, so here's a little something that I think everyone can relate to..
It turns out that these two starfish species are members of the Forcipulatacea, which is the larger group of starfishes to which familiar, intertidal species belong! Read this account of their unusual evolutionary tree!
5. Named for some deep-sea biologists!
So... WHAT TO NAME THEM?? As a taxonomist, one of my super powers is that I can honor a person, place or thing by converting their name into Latin, thus immortalizing them into the history of science!
As a matter of good practice, its considered more informative to use descriptive terms, but ultimately species names are at the discretion of the author.
The Antarctic species had been discovered by the British Antarctic Survey and these expeditions had heavily involved Dr. Paul Tyler from the Southampton Oceanographic Centre and so it was decided that the Antarctic species would be named Paulasterias tyleri!
Which basically translate's to "Paul Tyler's starfish" (kind of)...
Dr. Tyler is a HUGE name in deep-sea biology, having co-written one of the most important books in deep-sea research in addition to hundreds of articles on deep-sea ecology and invertebrates!
Professor Tyler was recently been made a Member of the Most Excellent Order of the British Empire (MBE)!!(here)
The North Pacific species was discovered under the auspice of my colleague and friend Craig Mcclain over at Deep-Sea News!
And so, I deemed that this second species would be named for him! honoring him was critical!
Otherwise would these species have EVER been discovered if it were not for him???
Craig has written a GREAT post on Paulasterias mcclaini over at Deep-Sea News here.
MORE QUESTIONS!..This discovery is only the START of many MORE questions!
- How does this species tolerate even a little bit of the toxic sulfide in the water?
- Do these have defenses given that they are basically little six to eight-rayed fleshy, water bags?
- How do they capture and eat a hoff crab??
- What is the relevance of this group to the diversification and evolution of forcipulate sea star?
- How do members of this family become so widely distributed??
- How many more of these are out there somewhere??
- IS this 6-rayed Atlantic starfish seen by the Okeanos Explorer the same thing???
My special thanks to Katrin Linse, Jon Copley (@expeditionlog), Leigh Marsh, Dave Foltz, Alex Rodgers, Dave Clague, Craig Mcclain, Lonny Lundsten and Linda Kuhnz!