#echinoderms
Star of the Abyss
The abyssal brittle star (Ophiocten hastatum) gets its name from its choice of habitat: the abyssal plain, a vast, flat expanse of seabed located over 4,000 meters beneath the surface.
Despite the sinister appearance of its mouth, this deep sea echinoderm feeds only on organic particulate matter and marine detritus. Yum!
It is an opportunist, with life history traits that include an early age of maturity, and the capacity to produce large quantities of tiny, easily-dispersed eggs. This survival strategy allows it to quickly multiply during times of plentiful food—a rare occurrence in the barren blackness of the deep.
Image source: Museum Victoria
Reference:Gage et al.2004.
Post link
A Star Is Born
Much like their echinoderm cousins, the sea urchins, sea stars (such as this Luidia sarsi) possess a variety of larval forms that can look quite different from their adult forms.
One of these forms is the bipinnaria larva—the elongated, transparent, tentacled thing you see in the first image. As the bipinnaria floats with the plankton, feeding and growing, a juvenile sea star begins to develop at its oral end, looking vaguely star-shaped, but not quite there yet.
The juvenile L. sarsi soon outgrows its larval form (which it absorbs), and sets out to begin life as a young star. *tear*
Image sources: BBC Brasil and Interesting Animal Facts
Reference: Domanski. 1984.
Post link
BURNT HOT DOG SEA CUCUMBER
(Holothuria edulis)
Stender, K. “Holothuria edulis”
Kaneohe Bay, Oahu, Hawaii
A species’ name often originates from an animal’s appearance. It’s certainly no different with the burnt hot dog sea cucumber, but come on. Joking aside, Holothuria edulis can be eaten (the Latin ‘edulis’, meaning edible), but I’m afraid we can’t guarantee the flavour. You’d probably be safer sticking to traditional hot dogs.
Post link
Brisingid starfish, brittle stars and chrinoids on an old barrel
A large brisingid starfish is accompanied by numerous brittle stars and chrinoids on a discarded barrel on the seafloor offshore Olympic National Park at 2315 m depth.
- Photo taken by ROPOS, which is operated by the Canadian Scientific Submersible Facility./ Ocean Networks Canada flickr
Post link
