Tuesday, January 29, 2013

Echinoderm Tube Feet Don't Suck! They Stick!

Side B
Image taken by Barry Fackler




20040128_4 Podia of starfish, Asterias rubens (Sweden)
Image by "ratexla"/Josefine Stenudo


The common N. Atlantic sea star Asterias rubens
Common Starfish,Filey Brigg,North Yorkshire.
Image by Juncea
and the European urchin Paracentrotus lividus...
Paracentrotus Lividus
Photo by Marco Cortesi



1. Observing the tube feet directly!



Figure  1 from Hennebert, Santos and Flammang, 2012

2. Measuring the Attachment Strength of the tube feet

fr. Fig. 3A in Hennebert et al. 2013

B. Measure strength and tenacity on a porous bottom







Tuesday, January 22, 2013

Time Lapse Starfish Videos!

So, between travel, being sick, yesterday's massive Inauguration Day festivities and playing catchup, this week has been crazy!

So here are some neat starfish time lapse videos to keep you informed and entertained!

The awesome video of the tropical shallow-water "chocolate chip star" Protoreaster nodosus, foraging for organic particles and other food on the sea bottom.
Stars of the Sea from Karin Brussaard on Vimeo.

The foraging behavior of the predatory Chilean/Patagonian cold/temperate water Cosmasterias lurida (Stichasteridae)

Some classic videos from the Shape of Life series showing behavioral complexity. Read this article frorm awhile back to see what's going on...
Echinoderms: Sea Star Time-lapse: Eating Dead Fish from Shape of Life on Vimeo.
Echinoderms: Sea Star Time-lapse: Don Wobber's Film from Shape of Life on Vimeo.

Here's a nice HD time lapse of a tiny aquarium asterinid starfish. Note stomach extended and the places where the algae is absent from the glass.
A day in the life of a starfish from Rate My Funeral on Vimeo.

An unusual video that shows what happens when you drop a bunch of Patiriella (bat stars) and let them run free! Starfish show up at about 1:19 (its mostly set up prior to that)

Here's a nice little vid showing Archaster typicus (different from Astropecten-you can tell between the two  by going here to see the differences)  in an aquarium burying itself into gravel

By comparison here is a species of Astropecten from Singapore doing its thing!

The giant Pacific sunflower star (Pycnopodia helianthoides) is fast enough that you can see it moving without time-lapse. What happens when you speed it up a bit? 

Hopefully next will be all caught up and I'll be back to posting more!

Tuesday, January 15, 2013

A Galaxy Class of Gorgonocephalus! A Basket Star Bonanza! (A Star Trek Connection?)

Image by Viktor Lyagushkin. Gorogonocephalus from the White Sea 
Basket stars are a very unusual kind of brittle star (note that they are NOT proper starfish) which have long, branching arms which they extend into the water in order to feed. Tiny little hooks on the arms are used to capture food which eventually makes its way back to the mouth.

Basket stars occur in tropical and cold-water habitats and I have written about their feeding biology here.

Here's a nice video that shows their feeding posture in the wild

and a nice time lapse video of feeding from the Seattle Aquarium

There are currently 10 species of Gorgonocephalus recognized and they seem to occur widely...(here to go to the World Ophiuroidea Database listing)

Here are some gorgeous Gorgonocephalus sp. (which occurs mainly in cold-water settings) images to kick off 2013!! Enjoy!

Some gorgeous shots of G. arcticus from the White Sea by Alexander Semenov

Gorgonocephalus arcticus.jpg
Gorgona's head
Gorgonocephalus arcticus
Gorgonocephalus arcticus.jpg

G. eucnemis from echeng (the "rose star" is the solasterid sea star Crossaster papposus) in Alaska.
Basket star (Gorgonocephalus eucnemis) and rose star, Alaska

Gorgonocephalus from Norway, 928 meters! Arms are tucked away...Image by SERPENT Project!
Basket star (Gorgonocephalus)
Several more on a ridge, using their arms to feed. Also Norway, 928 meters. Image by SERPENT Project.
Basket stars (Gorgonocephalus)

More G. eucnemis from Alaska.. Images by jrixundewater
basketstar branches 0027
Close up of the arms..
Alaskan Basket Star 0022

An unusually pale, "bushy" individual from British Columbia. Image by Ed Bierman
basket star

Here's a really nice one of G. eucnemis. by "northwest diver"
Basket star
Gorgonocephalus fr. Newfoundland. Image by Derek Keats
Basket star
Newfoundland Image by Derek Keats

Hmmm... y'know, it never occurred to me before but Gorgonocephalus DOES bear a striking resemblance to a certain CRYSTALLINE ENTITY from the 24th Century...

Wednesday, January 9, 2013

5 Unusual Invertebrates that People Eat! (it takes an Invert Zoo Class to know what some of them are!)

Okay you invertebrate zoologists out there!! How many phyla can YOU recognize on the plates above???   By the end of this blog you WILL know! (and maybe, you will hate me for telling you)

Everyone seems to have a "Weirdest foods" list out there-but here at Echinoblog we offer you only the STRANGEST sampling of bizarre marine invertebrates cuisine! forget insects, snails or shrimp!

Some of the edible (?) metazoans below are usually only noticed by marine biologists, zoologists and the well-studied biologist!

What better application of knowing the strangest of marine invertebrate phyla can there be than to recognize it on your plate? Its scientific name disguised by colorful cultural argot  or perhaps in a different language?

1. SEA SQUIRTS! (Halocynthia sp. possibly H. roretzi). The Korean name for sea squirts as food is: meongge (although there are several more)
Sea squirts are a kind of tunicate, which are in turn members of the phylum Chordata (the group humans and other vertebrates belong to) and when alive they look like this:
Japan sea animal, Sea Squirts (Class Ascidiacea)
As it turns out, sea squirts are eaten all over the world, including Japan (called hoya and maboya) and Korea (meongge, and in a stew called agujim). They also eat sea squirts in France, Italy, Greece, and Chile .
Images of sea squirts eaten in Korea. Image by scbrianchan
Eating Sea Squirt
image by scbrianchan
A video showing preparation. Sea squirts are filter feeders and processing water through their body is a primary function. Thus, drainage seems to be an important feature...

when cooked and prepared it looks like this
sea squirt
image by seoxcookie
or this..
멍게 - sea squirt
Image by toughkidcst
sometimes served with oysters...
Seoul 2009 - Oysters and Sea Squirts - Seoul Izakaya
Image by Food Fetishist
UPDATE February, 2014. I've actually tried hoya in Tokyo! The raw stuff! Its got a very...sour, almost soapy taste. Not for everyone.. but I'm told that its an acquired taste. Folks who grew up with it, LOVE it...

2. ECHIURAN WORMS! aka "fat inkeeper worm" aka "penis fish" aka gaebul (genus Urechis)
Most people have never heard of this phylum of worms. Commonly known as "spoon worms"

One of the best studied examples is Urechis caupo, occurring on the North pacific coast -living in muddy burrows which serve as homes for many other commensals, including tiny shrimps and fishes.
fat innkeeper worm (urechis caupo)
Image by Peter_r

But in Korea, a related species, Urechis unicintus is collected and eaten!
Apparently it is cut up into segments and served while twitching....
In other cuisines, it is cooked and stir fired..

the picture above? gaebul and mongae aka Echiuran and Sea squirt!!

and uh yeah, there's a belief that eating these imbues men with more virility. That seems unlikely....

Brachiopods are one of the oldest animals observed in the geological record, going as far back as 500 million years. In some cases-they appear relatively unchanged appearing very much as they do as fossils.

and now we eat them.

This gives you an idea of what they look like alive..living in a muddy habitat
亞氏海豆芽 Lingula adamsi Dall
Image by Changhua Coast Conservation Action
There are two shells that fit over the animal on the top and bottom. Bivalves and other clams are fundamentally different in that their shells are oriented on the body left-right. 

In one group, known as the "inarticulate" brachiopods, there is a big fleshy structure called the "peduncle" which emerges from the shell

Biologist Richard Fortey noted that they tasted like "straw' (quote is here).

Here is an image of brachiopods as sold in a food market in Makassar.
Brachiopods (Lingula sp) sold as food on a market in Makassar
Image by Arthur Anker
Here is another from a Thai market.
Lingulids, Thai market
Image by Peter Roopnarine
In Indonesia this dish is called Probolinggo TEBALAN. The blog linked here suggests that Lingula  tastes "sweet and spicy" whereas others I've seen suggest that it is served with a tasty curry.
Huh. Brachiopod curry. NOT something I was expecting to write today!

4. STALKED BARNACLES! Barnacles. Those well-known shelled crustaceans that live on docks and use their "legs" to filter feed out of the water like this:
These of course are what's known as "goose" or "goose-necked" barnacles because of the long, prominent stalk attached to the body sitting on top.

Yes. People eat them! I've seen them in Paris and Belgium.
Percebes [Goose Neck Barnacles]
Imge by RobertoGrego
In some places, barnacles are quite expensive...
Barnacle Prices 99€/kg ($65/lb)
Image by erikamussen

Other "unstalked" barnacles are also eaten! 
barnacles have faces!
Image by charclam
In the Azores and Portugal, these are called cracas!  Basically, these are boiled "acorn" barnacles. 
Cracas bico (barnacles)
Image by Bellyglad
5. SEA STARS! (family Asteriidae- species: Asterias amurensis)
So, first let me distinguish between the "starfish for show" pictures that one sees around like this versus apparently real accounts of people who eat the gonads of starfish as seen in the video below..
didn't know you could eat starfish
Image by Robin G. Ewsing
Honestly, eating sea stars baffles me. And I  recommend against it (as here) and here but obviously, people really eat these.  On the plus side, Asterias amurensis (the species shown below) is a problematic invasive in Australia (as I wrote here)
so maybe there is a silver lining to this?