Echinoderms come in countless shapes and sizes, but there are a few unique features that unite the 6,500 living species. Many adults of this phylum have 5-way radial symmetry; a pattern most prominent in the shape of the starfish. In addition, they have skeletons made up of interlocking calcium carbonate plates and spines called ossicles. This provides rigidity for their complex structures, making up the protective shell of urchins, or the column-like spine of crinoids. These skeletons are also the reason why fossils for echinoderms are so widespread and well-preserved, with some crinoid fossils being as old as 500 million years. Perhaps the most peculiar creatures of this phylum are the holothurians. Sea cucumbers, with their retractable feeding tentacles and tube feet around the mouth which they use to forage in the sea floor mud.

00:00 - An Introduction to Echinoderms
01:27 - The Structure of Echinoderms
02:01 - Ossicles Explained
02:35 - Holothurians Explained (Sea Cucumbers)
02:53 - The Swimming Sea Cucumber
04:21 - The Sea Pig of the Abyss
05:11 - The Role of Holothurians - Filter Feeding
05:28 - The Role of Holothurians - Bioturbation
05:49 - The Role of Holothurians - Symbiosis
05:55 - Symbiosis: Emperor Shrimps & Sea Cucumbers
06:10 - Symbiosis: Pearlfish & Sea Cucumbers
06:29 - Defensive Adaptations of Holothurians
07:10 - Starfish Explained
07:37 - The Crown-of-thorns Starfish
08:13 - The Consequences of Ecosystem Instability
08:24 - The Role of Sea Urchins - Maintaining Balance
08:59 - Brittle Stars Explained
09:30 - Basket Stars Explained
10:14 - Conclusion: The Importance of Echinoderms

DEEP SEA HUB: naturalworldfacts.com/deep-sea-hub/

Footage used is from various YouTube sources, the BBC, Jonathan Bird's Blue World, MBARI, OceanX, NatGeo, the Ocean Exploration Institute and the Schmidt Ocean Institute, as well as other sources.

Music Used:

Relics by Ben Prunty (from the game Subnautica Below Zero)
Seductress by Francis Preve

Dark Walk by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0/
Source: incompetech.com/music/royalty-free/index.html?isrc…
Artist: incompetech.com/

Lone Harvest by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 licence. creativecommons.org/licenses/by/4.0/
Source: incompetech.com/music/royalty-free/index.html?isrc…
Artist: incompetech.com/

Crystal Caves by Ben Prunty

#deepsea #wildlife #nature #documentary #ocean #marinebiology #science #biology

Resources:
oceanexplorer.noaa.gov/okeanos/explorations/ex1811…
oceanconservancy.org/blog/2019/07/03/everything-ne…