Showing posts with label shrimp. Show all posts
Showing posts with label shrimp. Show all posts

Tuesday, October 1, 2013

Crabs & Shrimps that Live in Sea Cucumber Anuses!

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Image by Yellowbeetlebug
Crab IMG_1357-2
Image by Jasdivr
One of the things I find fascinating about sea cucumbers is that they're basically a section of intestine, including the mouth and the anus which has evolved to live on its own. We sometimes think of animals by their most prominent features.. jaws in sharks, eyes in insects...

But Sea cucumbers are basically a big living gut! and have developed many unusual ways of living with this body plan..
Sea Cucumber
Image by WhiteBeachDivers
It should not be so unusual that the openings to this "living gut" are especially important. The mouth of course, we see used in feeding but in sea cucumbers, of particular significance seems to be the importance of that second, most prominent opening.. the ANUS!
Another Sea Cucumber Anus
Awesome image by PacificKlaus
This is of course, where inorganic sediment is defecated after the animal has eaten and removed the organic material that fuels its diet...

But SO many other biological functions in sea cucumbers are now being observed in sea cucumbers..

This account for example about how sea cucumbers can FEED through their ANUS. and of course, the simple fact is that sea cucumbers use the anal opening in order to process water over their internal "gills"...

OPEN
Open
Image by Pacific Klaus
and shut! 
Closed
Another fantastic image by Pacific Klaus
And by the way.. Pacific Klaus has assembled an AWESOME photo gallery of echinoderm anuses on Flickr here. 

But of course, sea cucumbers can host several commensal animals. That is, animals which live, in or around the animal as a habitat but which bring neither harm nor advantage to the host sea cucumber..

The most striking example is the "fish-in-sea cucumber-anus" Pearl Fish. Go here to see this. 
or there's video of course...


and just because I can, lets not forget: Anal Teeth!
Sea Cucumber Anus
Image by PacificKlaus
Awhile back I wrote about flatworms living in sea cucumbers and sea urchins..
But another evocative animal living in sea cucumber anuses?  These little crabs!
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Image by Yellowbeetlebug
Many of these have been called Lissocarcinus throughout the internet.. but I'm not sure how dependable those names are. They appear to be scavengers taking advantage of any leftover food ..

Is the anal habitation a matter of opportunity? Regular behavior? Species specific?

But clearly, they do seem to make the most out of uh... living in the shadow of greatness...
Sea Cucumber Crab - Where the Sun don't Shine from liquidguru on Vimeo.

Another
DSC_0353
Image by Martin "El Grande" Sequerah
Interestingly, there are also photo accounts of these shrimps living around sea cucumber anuses.. perhaps to take advantage of other organic material?
IMG_2336
Image by Eric Francis
Here are more shrimp+crab anal assemblages...
Lembeh Strait
Image by Swaflyboy
Incidental occurrence? or preference?
shrimp on sea cucumber 2
Image by ScubaSchnauzer
This shrimp seems to have found itself completely embedded in sea cucumber anus!
Imperator Shrimp - Periclimenes Imperator stuck in the anus of a Sea Cucumber
Image by Prillfish
Many questions-what do the crabs and shrimps get out of this? Are they species specific? Is this really a region specific habitat? Or do they just use the whole animal as a house with the anus as a door?

Tuesday, February 21, 2012

What can the Internet do for Biodiversity? Let's study COMMENSALS!! Some biology can't be studied from samples!

Hostess with the Mostest
(photo by MerMate)
The Internet is amazing!

But often one gets the impression that a lot of people haven't quite realized the potential for discovery.
What can something as simple as humble as a photostream or video channel do for science?

Especially for something like exploring biodiversity? For looking at the many different kinds of animals -some that have yet to be discovered?

What makes the Internet so potentially important is YOU. Everyone out there. A nearly infinite amount of eyes, cameras, videos, talent, and interest.

What does that mean? That means that some people have the good (nay excellent!) graces to take pictures (and/or videos) of moments and/or species in places that many scientists just aren't or can't be. I believe the buzzword is "crowd sourcing".

Sources like Flickr and YouTube thus become great treasure troves of potential discoveries.  Moments and relationships caught of the live animals doing their thing!

So, today I thought I would use some videos and images to demonstrate some commensal relationships between sea stars/starfish) that most people don't often see because they are best seen in the wild when the animals are left to their own devices.

........But then, some incredible individual took a picture or video of it!

And in conjunction with a little bit of narrative (on my part) there is another layer of appreciation of these images as more than just aesthetically pleasing-but a representation of something in nature that everyone can enjoy. GO!

1. Fish Living commensally among the oreasterid Protoreaster nodosus


This video was exciting! I'd never heard of fish living in and around asteroids and have yet to discover prior accounts.

Was this unique or does it happen all the time? Are fish juveniles tied to sea stars? Is this important to their life cycle?

Note also the tiny little brittle stars living on the spines! Probably Ophiactis savignyi-a species of ophiuroid that may literally live everywhere!
Cool star 2 (photo by Mermate)

2. The benthic ctenophore Coeloplana living on the surface of Echinaster luzonicus
Benthic ctenophores on Echniaster  luzonicus (Coeloplana astericola)
(photo by Arne Kuilman)

So, what are these?

Ctenophores are usually found swimming in the water column like this (intro to the group in the video)

But some of the really WEIRD ones live on tropical bottoms and look like this.. (note the feeding tentacles emerging out of the two top "lobes")

But some of these benthic ctenophores are these worm-like forms and they actually live ON sea stars, such as this Echinaster luzonicusBenthic combjelly on Luzon seastar  (Coeloplana astericola)
(photo by Arne Kuilman via Flickr)
I don't know if they are necessarily rare..but people don't see them often. They can be difficult to see and who thinks to look for what is basically a bottom-living jellyfish??

On top of all this- the benthic ctenophores themselves almost never preserve well. So scientists have relativelly little data on them. When I learned about these in Invertebrate Zoology way back when, there was only a footnote about these critters.



If we were lucky-we MIGHT see one in our lifetime. Now-everyone can!
Parasitic flatworms Hostess with the Mostest
(photo by "MerMate" on Flickr)
Here's one close up..

Sea Star (Starfish) Rider
(photo by Mark Atwell via Flickr)

3. This looks like a polychaete and/or a flatworm living on another specimen of what looks like Echinaster luzonicus (Taiwan? or the Philippines?)
2010_0703_100935
(photo by Star Tsai via Flickr)

4. And finally,the shrimp Periclimenes that lives in and around various big tropical sea stars.

They're all called P. soror in the pictures but there seem to be so many-I'm not entirely sure its the same species.. But here's a bunch...

This one living on the ophidiasterid Linckia laevigata in Komodo, IndonesiaSoror Shrimp on Blue Starfish (photo by Fiona Ayerst)
this one on the Crown of Thorns-Acanthaster planci..4113 Commensal shrimp on crown-of- thorns

(photo by Diver Ken)
Periclimenes soror on Acanthaster ellisii
(photo by Olin Feuerbacher)
This one looks like a shrimp living in/around the uncommon oreasterid Halityle regularis
Pin Cushion Star and Periclemenes Shrimp
(photo by Shaun-in-Munich)
On/around the mouth of a "cushion star" so..Culcita?Shrimp On Cushion
(photo by pummkin)
In and around Echinaster luzonicus (oreasterids aren't the only ones with shrimp!)Who's the star?

(photo by MerMate)

If you had collected any of these shrimp without the asteroid (or vice versa) it would have been difficult to make the animal-animal association. What function do the shrimp serve? What do they get out of it? Protection?

These images may seem just like holiday snaps-but to some scientist-they may demonstrate some new species/behavior/relationship!

So, if you're in some exotic part of the world and have some weird, neat picture that you've never seen before let a biologist who knows a thing or two-take a look! You never do know...

And uh... for those with more...mercantile motivation, scientists don't do it for the money (and mostly don't have a lot to give away).

Tuesday, August 24, 2010

Shrimps ♥ Sea Urchins!! Videos showing tropical crustacean-urchin LOVE!

I'm not sure why..but for some reason there's a TON of awesome sexy shrimp-sea urchin commensal love videos floatin' round the Internets this week!!

Go Forth and be amazed!!

A shrimp that the videographer-the awesome Morphologic Studios identifies as Gnathophylloides mineri on the Caribbean "sea egg" Tripneustes ventricosus...


Morphologic studios shot this amazing footage of a "pea crab" (Dissodactylus primitivus)(length=7.0 mm!) on the heart urchin Meoma ventricosus!


A tiny shrimp on what looks like a fire urchin..


Here's a little guy in what looks like a diadematid urchin..with just some stunning video..


What looks like the same species...of shrimp/urchin...


I'm guessing this is a decorator crab that has added a fire urchin (Astropyga?) as it makes a break for it across an open plain...


Oddly enough here's another person with video of the SAME thing...