Wyville Thomson Ridge Survey WTR0924S (Blog #3): Wyville’s Weird Wonders
By Kate Wade & Rosie Clewett (Night Shift)
Find out about some of the organisms the offshore survey team found on their visit to Wyville Thomson Ridge, in their third blog post.
So far, you have heard about the geography of Wyville Thomson Ridge SAC, and the survey methods we are using this year. This blog post will have a particular focus on the 'weird' organisms we have found so far at the site – the ones which you may not have seen before.
Sea spiders, or pycnogonids (see Image 1), are found in oceans all over the world – though there are only 38 species found in the North-East Atlantic, where we are. Collosendeis proboscidea was also was also found on a previous JNCC survey to the Faroe-Shetland Sponge Belt MPA in 2021 (see blog post). Not much is known about the biology or feeding habits of these spiders, so there is lots to be found out!
Image 1: Sea spiders (pycnogonids)
(photo © JNCC and Scottish Government's Marine Directorate).
The sea cucumber, Parastichopus tremulus (see Image 2), can grow up to 50 cm in length! It has hundreds of small feet, called 'podia', on its belly which allow it to crawl at a sluggish pace, breathing through their anal sphincter with structures commonly known as 'respiratory trees' or 'butt-lungs'.
Image 2: Sea cucumber (Parastichopus tremulus)
(photo © JNCC and Scottish Government's Marine Directorate).
Cidaris cidaris, or pencil urchin (see Image 3), are named after their thick, pencil-shaped spines, which protect them from being eaten by predators. These spines can be twice as long as the diameter of their body.
Image 3: Pencil urchin (Cidaris cidaris)
(photo © JNCC and Scottish Government's Marine Directorate).
Finally, we have our spoon worm (see image 4). They live in burrows in soft sediment and can extend their proboscis (like a tongue) up to ten times its contracted length. The worm moves its proboscis around the sea floor secreting mucus to trap detritus to feed on.
Image 4: An 'anchor-shaped' spoon worm
(photo © JNCC and Scottish Government's Marine Directorate).
Even in the depths of Wyville Thomson Ridge, there is evidence of marine litter. As you can see below in Image 5, these were found around 800 metres deep on the seafloor.
Image 5. Marine litter from Wyville Thomson Ridge
(photos © JNCC and Scottish Government's Marine Directorate).
The survey team have now returned to shore, but you can catch up on their earlier blog posts: