Babbacombe, Devon: Compass jellyfish

22nd July 2013

Summer holidays are here and Bo and Anna have arrived in England. This means, crab catching time. Their talents have extended this year, to hunting jellyfish.

 

Jellyfish have roamed the seas for at least 500-million years, possibly 700-million or more, making them the oldest multi-organ animal. A group of jellyfish is called a swarm, or a bloom; which is rather lovely.

Ours was a Compass jellyfish - Chrysaora hysoscella: Chrysaora is derived from chrysaor in Greek mythology, the son of Poseidon and the god of lightening.  Hysoscella is from the two Greek words: isos, meaning 'alike' and scelis, meaning 'ribbon'. 

Chrysaor was the result of the ill-fated mating of Medusa and Poseidon. He was born from the blood droplets from Medusa's head when it was cut off by Perseus and oh look here, some fitting Pre-Raphaelite art by Edward Burne-Jones!

The Birth of Pegasus & Chrysaor from the Blood of Medusa

Little is known of Chrysaor other then he was considered a stout hearted warrior. His name means Golden Sword and his appearance is unknown but given his family, it is likely to have been unusual. Some say he was possibly a giant.

Perseus and Chrysaor (c1876-1885) 

Compass jellyfish appear in coastal waters all round the British Isles, they are most prevalent off the south and west coasts of England and Wales and although we discovered relatively early on that they are a non-stinging species, it didn't prevent a mild feeling of terror as we waded through them on our way out to sea to swim.

They have a saucer-shaped bell, with 32-semi circular lobes around the fringe, each one with a brown spot. On the upper surface of the bell,16-brown V-shaped marks radiate outwards from a dark central spot. The mouth, the only opening to the exterior, is located on the centre of the underside of the bell, and is surrounded by 4-arms. There are also 24-tentacles around the edge of the bell, grouped in threes.

Compass jellyfish change sex: first they are male, followed after by female. The medusae live mainly off other medusae, comb jellyfish and arrow worms.

While looking into the subject matter of jellyfish, I came across these beautiful pictures called 'Haeckel's medusae' from a magnificent series of botanical artwork Haeckel produced, called 'Art forms in Nature'.

Ernst Haeckel (1834 - 1919) was a German zoologist, biologist, and philosopher who was born in Prussia. He studied medicine and was a lecturer then professor of zoology. He undertook several scientific expeditions the the Mediterranean, Canary Islands, the Red Sea, Ceylon and Java and discovered many new species of lower marine animals. 

Haeckel's zoological works included descriptions of these some 4000-new species, mainly radiolarians, medusae, and sponges. He was immediately converted to Darwinism upon reading On the Origin of Species, and although a slightly ropey and fraudulent past was recorded, he was the first German advocate of organic evolution.