Tuesday, October 29, 2013

5 Worms that will give you the creeps! Happy Halloween!

The "worm" body plan is a successful one. A head. Bilateral symmetry. Long body. That makes a lot of sense. The head takes the lead and you've got a long, slender body which facilitates success for moving through crevices and such. This has been thought by some to be the body plan for the very first metazoan predators (although not all with the body plan are predators).

Land Planarian
Image by Divaholic
There's versatility in feeding and life modes... and the body plan is observed in multiple PHYLA (major grouping) of animals (e.g., annelids, flatworms, etc) and even in other groups which don't primarily have a "worm" like body plan (e.g., aplacophorans in molluscs, sea cucumbers in echinoderms, snakes in vertebrates).

Curiously, there's something ABOUT animals with this body shape that seems to freak people out.

Is it the body shape? Something left over from our "metazoan" brain from a LONG time ago?

People hate snakes. They always use 'mealworms" (actually beetle larvae) on monster and horror films and TV (totally harmless btw).   Heck, earthworms are HARMLESS (at least to people) and you can still totally squick most people out by dangling one in front of them!
monster worm ball
Image by Mely-o
So what if we looked at worms that are actually PREDATORS? That feed on prey in really graphic ways??

Its Halloween week! Here's FIVE disturbing predatory worms! 

Imagining ANY of these as human sized or above would be cause for alarm!

1. Bobbit Worm-Raptorial Predator!

Bobbit Worm
Lets start with an easy one.  By this point, a LOT of people know about Bobbit Worms. I've written about them before.

Short version: Tropical, shallow-water predators.  Up to 6 or more FEET long. They lie in wait and pounce on prey with their spring-loaded jaws. They feed on fish and other vertebrates!
Bobbit worm stretch
Image by MerMate
There's plenty of video... but here's a nice one...

So, I know 46 year old men who STILL get freaked out by Bobbit Worms. Even after all the reassurances and graphic photo evidence PLUS the knowledge that they will never go SCUBA diving in the tropical Pacific!!

Wanna see WORSE than the Bobbit worm?? Let's GO!

2. Ribbon Worms-Long distance Death!
Worms dining on a fish head

Ribbon worms, also known as Nemerteans, are an obscure phylum of worms that are similar in appearance to flatworms (below) BUT one of the big differences is that Ribbon Worms possess a CRAZY long proboscis!

Basically the proboscis is an extended feeding structure used for a FAST grab which in some cases, extends easily 100% of the worms body LENGTH! 

Ribbon worms really need to be seen to be appreciated. So here's some video!

A terrestrial species....

But not all nemerteans are small, cryptic beasts. Some species, such as the Antarctic Parborlasia are HUGE. I wrote about them in this post about Weird Antarctic Invertebrates. They are upwards of THREE FEET LONG. And are about as wide around as a garden hose!
Worm snarl
Image by Icy_Sea_Slugs
and they EAT everything. In both the picture above and the one near the top, there's a dead fish under all those worms!

Ribbon worms are CRAZY abundant and are almost certainly important to the ecosystems they inhabit but they're often difficult to find...

3. Marine Flatworms! Eating from the inside out
Image from this website on introduced Netherlands invertebrates
Feeding in this worm, is to put it mildly, HORRIFIC.  The marine Euplana gracilis is a flatworm that consumes its prey by LITERALLY sucking out its guts, while the prey is still ALIVE! 
I'll let the video's author comment:
In this video, Euplana attacks a shrimp-like amphipod by wrapping around its back and completely immobilizing it. Sticking its tube-like pharynx through a segment of the amphipod, the flatworm then consumes and digests its internals--a process that takes about half an hour. Once finished, it abandons the empty carcass and goes into a resting period until its next meal. On the outside, an amphipod that's been eaten doesn't look that different from a normal amphipod...except for the fact that it's, well, dead.
Videographer: Dean Janiak (Smithsonian Environmental Research Center Benthic Ecologist)

4. LAND Flatworms! Eat em' while they're alive!
Flatworms that live on the land are seen uncommonly but they're there. And they are mean, vicious predators. I wouldn't have known or even thought to think that, but here we go...

Here is Bipalium, a widely known genus of terrestrial flatworm. Originally from Asia, they've since been introduced all over the world. In their natural habitat, they have these really gorgeous, bright colors....
Land planarian (Bipalium sp.)
image by pbertner
Bipalium feeds on earthworms, so much so that they will inspire an immediate escape response whenever they are put in contact with one (see the video below).

Ever see an earthworm literally JUMP in sheer terror? Watch this...

Here's the feeding dance blow by blow...  The worm's head approaches the worm and applies digestive enzymes. It physically begins digesting its prey WHILE THE PREY IS ALIVE...
Planarian Dissolves Its Earthworm Meal
Image by Amuderick
It digests its meal as a dissolved earthworm milkshake...
Image by Cornell Fungi
BUT its not just the one to one predation which is a concern. TOO many of these predatory land flatworms can actually affect the large-scale ECOLOGY of a region if they devour all the earthworms!

As summarized nicely in the video. No earthworms?  No aeration of the soil. No crops.
Flatworms: An Invasive Flatworm Hunts Earthworms from Shape of Life on Vimeo.

giant amazon leech
Image by uezane
There's marine leeches, terrestrial leeches and of course, freshwater leeches such as the Giant Amazon Leech pictured above! It reaches a length of frakking 18 inches long!!  and feed on mammals that happen to stop by to drink...

While many leeches do the blood sucking thing- others are purely predatory, feeding on earthworms and other comparably sized animals.  Here is a pretty amazing pic of a leech eating a tiny toad! 

Here's some marine leeches!   One from Lembeh, Indonesia.
marine Leech - Lembeh
Image by Christian Loader
and another from Singapore
Unidentified animal: fish leech?
Image by Ria Tan and Wild Singapore! 
Honorable Mention to Whale Worms!
When I say "whale worms" No, I don't mean, yet another post about Osedax, I mean worms that live IN the INTESTINES OF WHALES! (and other cetaceans)
thanks to Miriam for letting me borrow her pic to the Tokyo Tapeworm Museum & fr providing scale
As a tantalizing and horrifying tip, the tapeworm that parasitizes a whale's intestine has SIX sets of reproductive organs and is over 30 METERS (90 FEET) LONG! 

But that's for another day....

Wednesday, October 23, 2013

Paris! The city of lights? Or the city of the Octopus?

October 26, 2013. UPDATED with more! 

PARIS! I've just arrived and hard at work with my colleagues at the Museum national d'Histoire naturelle!  But this week has been crazy. Wi-fi down, taking care of last minute projects and so forth on top of travel and jet lag.

So this week the blog is about a curious set of street art I've seen. OCTOPUSES all around Paris! 

These are often painted or posted surreptitiously around Paris in strange corners and rarely travelled nooks around the city. Based on the arm length and overall appearance they appear to most closely resemble the "dumbo" octopus -something like Grimpateuthis or Opisthoteuthis but I'm pretty sure the artist has mainly taken the image from his own imagination...
                           dumbo octopus

This one actually bears a striking resemblance

They all have the same basic shape but vary by character....  The following I have seen...

These I found on Flickr and elsewhere...  
Gzup_8449 rue du Temple Paris 03
image by meuh1246
The old Japanese superhero Spectreman! 
Gzup_3585 passage Lisa Paris 11
Image by meuh1246
Cyclops from the X-Men
Gzup_5111 rue Vavin Paris 06
Image by meuh 1246
King cyclopopod! 
Gzup_8666 rue Jean-Marie Jego Paris 13

and extra bonus! GIANT CEPHALOPOD mounted on a Paris building wall!

Some Halloween fun next week!

Monday, October 14, 2013

Why We Should be Concerned About a Mass Starfish Die-Off and/or Disease! Plus Updates and New Links!

Image by Jon Martin
UPDATE: You can upload new pics of starfish wasting disease to this website (iNaturalist). Help track its progression!

Since I originally reported on the big Pycnopodia starfish die off in British Columbia, I've gone on to invoke Starfish Wasting disease which has led to much discussion and reporting of the issue all along the west coast of North America, including concerns invoking the die off of the east coast starfish Asterias, which is closely related.
Meeting of the seastars
Image by Jeff Goddard
New developments since I last wrote:

The disease (?) occurrence in British Columbia seems to be reported now from several places:
Whytecliff Park (video here),
Kelvin Grove (video here),
Howe Sound (account at Aquablog) ,
Croker Island, Sechelt Inlet and ... (I will continue to update).(thanks to Jon Martin, Neil McDaniel and others for their pics and records)

Could Wasting disease also be headed for Washington? (via KUOW.org)

The number of taxa seems to be broadening but is most acutely observed in Pycnopodia. But other accounts in BC waters have been seen in Mediaster, Dermasterias, and Solaster.
image by Jon Martin
Other places starfish wasting disease is observed (e.g., California) it seems to be more focused on asteriids, such as Pisaster. An excellent summary of what the disease in California looks like can be found HERE.

Why Should We care? 
With all the media picking up the story and carrying it around to multiple outlets, at some point someone will get beyond the "weird news" twist that has been put on the articles and ask "So What?" Here are 5 reasons I think understanding why this die-off MUST be studied.

1. An Endemic Starfish Fauna.  
     A few years ago I wrote about the phylogenetic (aka the family tree) of forcipulate starfishes. The blog I wrote about it was here (w/paper cited within)

Basically, one of the important facts was that all of the asteriid starfishes in this area, including Pycnopodia (the sunflower starfish), Pisaster (the ochre star), Evasterias, Leptasterias, etc. on the Pacific coast of North America are ENDEMIC TO THE COAST.

That means, you could see a starfish which resembles Pycnopodia in Australia or Mexico and it will have LESS relationship to Pycnopodia than Pycnopodia has to Pisaster!

Bottom line: You won't find these starfish species anywhere else in the world. These animals are an important part of the marine ecology of the Pacific coast of North America.

2. Aesthetic & Cultural History
Ed Ricketts, 1937
Image by sjonnie van der kist
“What do they find to study?” Hazel continued. “They’re just starfish. There’s millions of ’em around. I could get you a million of ’em.”
“They’re complicated and interesting animals,” Doc said a little defensively.
The starfish on the west coast of North America have become iconic. Pisaster ochraceus, aka the Ochre Star is THE model for the Keystone Species in Ecology.  The starfish of the west coast were in John Steinbeck's famous novel Cannery Row as part of the rich career of Ed "Doc" Ricketts:
What if there weren't a million of em any more?  More on this below under #5-ecological impacts. These are animals which have become part of our culture. Conservation of these species is important.

Montastraea Cavernosa With Active Black Band Infection
Image by CIOERT
3. We don't know what causes it. At the moment, there are a bunch of ideas. Bacteria. Virus. Some
kind of microbe?  But as we see in Coral bleaching diseases, microbes are present.
They might be the cause OR they might be the RESULT of some shift in their surroundings? such as temperature or overall water quality. Sea stars DO have a natural microbial fauna (here) What if that fauna/flora goes bad because of changes in some greater part of their environment?

If this isn't a communicable disease per se but is instead more of a series of symptoms related to poor or changing environmental factors, which activates/corrupts/modifies that fauna, THAT could be a concern which leads us to our next point...

4. Canary in a Coal Mine- Global Warming? I think the thing that always concerns me about this whole thing is whether this whole phenomena-the die offs in British Columbia, the wasting disease observations in California and elsewhere - are all tied to a particular environmental change. I have written about echinoderms as the "canary in the coal mine" animals before..but for specific environments such as Antarctica. What if something is happening and this is an early warning that we aren't picking up on?

The original paper by Amanda Bates (here) observed that wasting disease seemed to be most acute when it was warmer.  What happens if Starfish Wasting Disease takes on the scale of the various coral wasting diseases?  Vigilance and data are an ongoing concern....

5. Widespread Ecological Impact. Here's the million dollar issue.. What happens if diseases change abundance or remove these species from their habitats? WHAT HAPPENS? What COULD happen?
Sea Stars
Image by Phil Williamson
Sunflower Star at Rest
Image by Daniel Johnson
The thing is, that BOTH of these species occupy important ecological positions. As mentioned earlier, Pisaster is a keystone species. The presence or absence of a keystone species in an ecosystem can dramatically change the interactions of that ecosystem. 

For example, Ochre stars (Pisaster ochraceus) removed from the intertidal would likely result in a significant overgrowth of mussels and other invertebrates which ochre stars typically feed upon. Mussels might come to dominate an ecosystem and prevent other animals from inhabiting that area. There could be a cascade of other consequences of course...

Similarly, Pycnopodia is a dominant predator of MANY other invertebrates species, sea urchins, abalone, snails, clams, etc.

But MORE than that there could be an unpredictable cascade resulting from fluctuating populations of any of these taxa. An increase in sea urchins, resulting from an absent predatory starfish, for example might result in additional sea urchin "barrens" (as I've described here)

What is perhaps most concerning is how MANY starfish species seem to be affected. Many of their ecological roles are poorly understood but are likely to be important. The effect on the ecosystem is likely to be significant. 

Thanks to many discussions at Science Online Oceans this past weekend for discussions that inspired this post! 

Monday, October 7, 2013

Some Stunning & Swimming Feather Star (Crinoid) Pics!

Crab on Crinoid
Image by Raymond Dy
Crinoids are always that weird member of the Echinodermata that seems to get out from under the "weird animals" category.. maybe because they can be so ethereal and frankly, just so damn photogenic!

So, this week: Some Feather Star Fascination! Some Charismatic Crinoids!  Here's some neat "best of" links about crinoids:
  1. The Crinoid Life Cycle: How Feather Stars (comatulid crinoids) show their relationship to stalked crinoids!(here)
  2. Urchins Attack! And Why Feather Stars Swim (here
More Swimming!
2013 Shetland 093 301 Fetlar crinoid
Image by tdpriest
Feather star
Image by Jules Nene
031_adj_DSC0536 swimming crinoid
Image by Erwin Poliakoff
Flying feather star
Image by Raymond Dy
Not only was this one caught swimming-but there's a crab holdin' on! Yowee!
Crab on Crinoid
Image by Raymond Dy
and of course this video that is just about as soothing as anything you will watch an echinoderm do..

A crazy Splash of crinoid color!
Image by Sea Dog Diver
A colorful but more muted color crinoid combo!
Image by Rene Cazalens
This one seems to be "standing" on its arms. Unusual behavior!?
Standing Crinoid
Image by Troy_Williams
A fantastic one called "Crinoid Corona"
crinoid corona
Another one by Troy_Williams
This one is called "Honshu crinoid sunburst." Nice. 
Hoshu crinoid sunburst
and yet another by Troy_Williams
A nice shot showing crinoid and associated fish..
7-27 zanpa boat crinoid and fish
Image by Troy_Williams
Wow! An unusual shot by Simon Marsh
A nicely posed Antarctic Promachocrinus kerguelenensis (maybe)
Image by Icy_Sea_Slugs