scientificillustration

cjohnstonbioart:

Sea Star Locomotion

Selections from the storyboard for an upcoming animation project. I am depicting the anatomy and movements involved in sea star locomotion.

Sea stars achieve movement through a simple hydraulics system, known as the water vascular system. The sea star draws water in through the madroporite, a filter and siphon located on the top of its body. The water travels through a series of ducts, called canals, to the tube feet that sprout from the underside of the sea stars’ arms.

The tube feet extend and retract via water pressure as the bulbous top part, the ampulla, contracts and relaxes. Muscles located in the podium, the ‘trunk-like’ part of the tube foot, move the tube foot from side to side to aid in walking. The sucker at the bottom of the tube foot uses a glandular secretion to stick to substrate on the ocean floor (or the glass of an aquarium).

The  sea cucumber, Oneirophanta mutabilis, is found on the seafloor at depths ranging from 1,800 - 6,000 m (over 19,000 ft). 
It was first described by the Swedish zoologist Hjalmar Théel in 1879, being one of the many deep sea animals discovered during the Challenger expedition of 1872–1876. The scientists on the Challenger expedition would probably be in awe to see an image like this of this species in its habitat. Modern taxonomists have split the species into two sub-species that are very difficult to distinguished from images alone. Thanks to submersibles like MBARI’s ROVs, we have beautiful images of many deep-sea animals that were originally described based on trawled specimens that were often damaged during collection.
(via: Monterey Bay Aquarium Research Institute)

The sea cucumber, Oneirophanta mutabilis, is found on the seafloor at depths ranging from 1,800 - 6,000 m (over 19,000 ft).

It was first described by the Swedish zoologist Hjalmar Théel in 1879, being one of the many deep sea animals discovered during the Challenger expedition of 1872–1876. The scientists on the Challenger expedition would probably be in awe to see an image like this of this species in its habitat. Modern taxonomists have split the species into two sub-species that are very difficult to distinguished from images alone. Thanks to submersibles like MBARI’s ROVs, we have beautiful images of many deep-sea animals that were originally described based on trawled specimens that were often damaged during collection.

(via: Monterey Bay Aquarium Research Institute)

NOAA Office of Ocean Exploration and Research
Pretty awesome sea star photo captured during NOAA Ship Okeanos Explorer’s 2010 expedition to the Coral Triangle region near Indonesian.  The Coral Triangle is thought to be one of the most diverse and biologically complex marine ecosystems in the world. Although much of the region’s diversity is known, most still remains unknown and undocumented. Without increasing our knowledge of what actually exists within the Coral Triangle, we can’t adequately manage, protect, and conserve this unique ecosystem. Learn more: NOAA Ocean Explorer

Pretty awesome sea star photo captured during NOAA Ship Okeanos Explorer’s 2010 expedition to the Coral Triangle region near Indonesian.

The Coral Triangle is thought to be one of the most diverse and biologically complex marine ecosystems in the world. Although much of the region’s diversity is known, most still remains unknown and undocumented. Without increasing our knowledge of what actually exists within the Coral Triangle, we can’t adequately manage, protect, and conserve this unique ecosystem.

Learn more: NOAA Ocean Explorer

Why You Should Care That Sea Cucumbers Are Going Extinct

by Jason G. Goldman

Sea cucumbers are in trouble. Everyone knows about the problems that elephants and rhinos face due to poaching, that dolphins face due to drive hunts, and that sharks face when overzealous governments try to convince their constituents that they’re helping them avoid shark attacks. Sea cucumbers may not be as charismatic as their megafaunal counterparts, but they actually provide an important service for reef ecosystems.

They help to keep the sand in reef lagoons and seagrass beds fresh by turning them over, and by feeding on the dead organic matter that’s mixed in with the sand, the nutrients they excrete can re-enter the biological web by algae and coral. Without the sea cucumbers, that sort of nutrient recycling could not occur. It’s also thought that sea cucumbers help to protect reefs from damage due to ocean acidification. Feeding on reef sand appears to increase the alkalinity of the surrounding seawater.

The problem, according to a study conducted by Steven Purcell and Beth Polidoro, is that sea cucumbers are considered a luxury snack. As they explain at The Conversation, dried-out versions of the tropical species retail between $10 and $600 per kilogram in Hong Kong and on mainland China. There’s actually one species that is sold for $3000 per kilo, dried. Sea cucumbers are thought of as “culinary delicacies,” and often adorn the buffets of festival meals and are served at formal dinners…

(read more: animals.io9)

Brisingids 
… are an order of deep-sea seastars that have between six and 20 long, thin arms surrounding a small disc with a large mouth. Brisingids are suspension feeders, meaning they filter water current through their arms that are upheld in the water. It is not uncommon to observe large aggregations of brisingids in deep-sea habitats, such as cliffs and rock formations, where water current is optimal for feeding. 
This image was captured by ROV Doc Ricketts on a seamount off the coast of Oregon.
(via: Monterey Bay Aquarium Research Institute)

Brisingids

… are an order of deep-sea seastars that have between six and 20 long, thin arms surrounding a small disc with a large mouth. Brisingids are suspension feeders, meaning they filter water current through their arms that are upheld in the water. It is not uncommon to observe large aggregations of brisingids in deep-sea habitats, such as cliffs and rock formations, where water current is optimal for feeding.

This image was captured by ROV Doc Ricketts on a seamount off the coast of Oregon.

(via: Monterey Bay Aquarium Research Institute)

libutron
libutron:

Cushion Sea Star | ©MacChristiansen
A bunch of Cushion Sea Star (also named Carpet Sea Star or Eight-armed Sea Star) from New South Wales, Australia.
These sea stars belong to Patiriella calcar species (Echinodermata - Asteroidea - Valvatida - Asterinidae), a moderately large seastar with clear-cut, short, tapering, pointed arms.
Patiriella calcar normally has eight arms, but sometimes 7 and 9 armed individuals are found. The color on top is extremely varied and often beautiful.

libutron:

Cushion Sea Star | ©MacChristiansen

A bunch of Cushion Sea Star (also named Carpet Sea Star or Eight-armed Sea Star) from New South Wales, Australia.

These sea stars belong to Patiriella calcar species (Echinodermata - Asteroidea - Valvatida - Asterinidae), a moderately large seastar with clear-cut, short, tapering, pointed arms.

Patiriella calcar normally has eight arms, but sometimes 7 and 9 armed individuals are found. The color on top is extremely varied and often beautiful.

Absurd Creature of the Week:  The Pearlfish
This Fish Swims Up a Sea Cucumber’s Butt and Eats Its Gonads
by Matt Simon
(You’re a Sea Cucumber…) You’re breathing through your anus, by the way, and when you take a breath, the pearlfish strikes — squirming up your butt, making itself comfortable in your respiratory organ, and eating your gonads. Or, they’ll go up in pairs and have sex in your body cavity. And that’s when you realize that you must have been a really awful human being in a past life. Like, the type of person who talks on their phone in a movie theater kind of awful.

Such pearlfishes come in a range of species, and don’t necessarily limit themselves to invading sea cucumbers. They’ll also work their way into sea stars, and are so named because they’ve been found dead inside oysters, completely coated in mother-of-pearl. Beautiful, really, though I reckon the pearlfish would beg to differ.

This behavior is the strange product of a housing crisis. You see, shelter is in short supply on many seafloors, particularly those that lack reefs. And there are few better shelters than sea cucumbers, little mobile homes that pearlfishes will enter pretty much as they please, leaving to hunt and returning for protection. If they can’t return to the same one, no worries at all. There’s plenty of decent housing squirming around the seafloor — if you’re willing to live in a sea cucumber’s bum…
(read more: Wired Science)
images: Daniel Bay and Oceans IQ

Absurd Creature of the Week:  The Pearlfish

This Fish Swims Up a Sea Cucumber’s Butt and Eats Its Gonads

by Matt Simon

(You’re a Sea Cucumber…) You’re breathing through your anus, by the way, and when you take a breath, the pearlfish strikes — squirming up your butt, making itself comfortable in your respiratory organ, and eating your gonads. Or, they’ll go up in pairs and have sex in your body cavity. And that’s when you realize that you must have been a really awful human being in a past life. Like, the type of person who talks on their phone in a movie theater kind of awful.

Such pearlfishes come in a range of species, and don’t necessarily limit themselves to invading sea cucumbers. They’ll also work their way into sea stars, and are so named because they’ve been found dead inside oysters, completely coated in mother-of-pearl. Beautiful, really, though I reckon the pearlfish would beg to differ.

This behavior is the strange product of a housing crisis. You see, shelter is in short supply on many seafloors, particularly those that lack reefs. And there are few better shelters than sea cucumbers, little mobile homes that pearlfishes will enter pretty much as they please, leaving to hunt and returning for protection. If they can’t return to the same one, no worries at all. There’s plenty of decent housing squirming around the seafloor — if you’re willing to live in a sea cucumber’s bum…

(read more: Wired Science)

images: Daniel Bay and Oceans IQ

Songs for Unusual Creatures: The Sea Pig

Who loves the Kronos Quartet? Who loves a sea pig? Now’s your chance to see them BOTH in one video. A dream come true!
But, wait, what in the world is a sea pig? Linda Kuhnz at the Monterey Bay Aquarium Research Institute is here to tell you all about it …

If you have any questions, leave them in the comments. And subscribe to the channel for new animals and songs every other week. (It’s free!)

Host: Michael Hearst
Producer: Joe Beshenkovsky & Michael Hearst

In association with PBS Digital Studios

For more about Songs for Unusual Creatures, including a book and CD:
http://www.unusualcreatures.com

alex-does-science

marine-science:

Scientists discover that starfish eyes really can see things, at least a little…

So, starfish actually have eyes - they are located on each of their arms—but up until now we didn’t know if they could actually see out of them!! Exciting new research has indicated that the eyes of sea stars can actually vaguely see images. These images are thought to help prevent them from moving too far from their home. 

"These new findings are an important breakthrough in our understanding of how sea stars perceive the world" - Christopher Mah (researcher at the Smithsonian’s National Museum of Natural History in Washington, D.C.) 

"After decades of wondering what starfish use their eyes for, scientists see some light"

A majority of sea stars have eyes on the ends of their arms. They are difficult to see and even if you do find them, you may not know that they are eyes. The starfish in the top image is an Indo-Pacific species called the blue star (Linckia laevigata). The image below (image two) is an up-close of one arm. There is a small groove along the bottom-side, which has many little tubular “feet”. The seastar uses these to move about. At the end is where the eye sits, just near the top of the groove (white arrow). 

Pretty amazing!

Photo credits: 

Image 1 - Blue starfish, Linckia laevigata, at Myrmidon Reef, Great Barrier Reef 

Image 2: Close up of star fish foot, white arrow points towards the end of the groove where the eye is located 

Info gathered from National Geographic 

Sea Cucumbers Are Animals, Not Vegetables…
Found only in salt water, more than a thousand species of sea cucumbers exist around the world. These squishy invertebrates are echinoderms, making them distant relatives to starfish and urchins. Unlike starfish or sea urchins, the bodies of sea cucumbers are covered with soft, leathery skin instead of hard spines.
If you ever encounter a sea cuke and he feels threatened, you could be in for a surprise. Some sea cucumbers shoot sticky threads at their enemies, entangling and confusing predators. Others can violently contract their muscles and shoot some of their internal organs out of their rear ends. The missing body parts are quickly regenerated…
(read more: NOAA National Ocean Service)
photo: NOAA

Sea Cucumbers Are Animals, Not Vegetables…

Found only in salt water, more than a thousand species of sea cucumbers exist around the world. These squishy invertebrates are echinoderms, making them distant relatives to starfish and urchins. Unlike starfish or sea urchins, the bodies of sea cucumbers are covered with soft, leathery skin instead of hard spines.

If you ever encounter a sea cuke and he feels threatened, you could be in for a surprise. Some sea cucumbers shoot sticky threads at their enemies, entangling and confusing predators. Others can violently contract their muscles and shoot some of their internal organs out of their rear ends. The missing body parts are quickly regenerated…

(read more: NOAA National Ocean Service)

photo: NOAA

Urchin ID - Maui, HI:
Creature ID please :) Found these little purple things clinging to the rocks on a beach in Maui. Picture was taken November 2013.
Paxon:
This is the Helmit Urchin aka Shingle Urchin (Colobocentrotus atratus), found on wave swept rocky shorelines around the Indo-Pacific. :)
http://echinoblog.blogspot.com/2008/04/holding-on-in-rough-world.html
http://en.wikipedia.org/wiki/Shingle_urchin

Urchin ID - Maui, HI:

Creature ID please :) Found these little purple things clinging to the rocks on a beach in Maui. Picture was taken November 2013.

Paxon:

This is the Helmit Urchin aka Shingle Urchin (Colobocentrotus atratus), found on wave swept rocky shorelines around the Indo-Pacific. :)

http://echinoblog.blogspot.com/2008/04/holding-on-in-rough-world.html

http://en.wikipedia.org/wiki/Shingle_urchin