Ernst Haeckel’s Nudibranchia Plate-43

Ernst Haeckel’s *Kunstformen der Natur* ("Art Forms of Nature") is a masterpiece of 19th-century scientific illustration and natural artistry and few pages capture the surreal beauty of the ocean quite like Tafel 43: Nudibranchia. This iconic plate showcases a vibrant parade of sea slugs, or nudibranchs — flamboyant marine gastropods famed for their delicate, flower-like shapes and mesmerizing colors.

Meet the Nudibranchs

Below is a guide to some of the species depicted in this plate, along with a few delightful facts for fellow ocean nerds:

1. Hermaea bifida (Montagu, 1815); Hermaea refers to Hermes, the swift messenger god. Bifida refers to the sensory organs on it's head being 'bifed' or split into two withe the front pair much longer than the back pair. Found near in coastal areas of the North Atlantic Ocean and the Caribbean Sea. it feeds on red algae and has been reported to have a distinctive smell, similar to Geranium plants and sulphuric acid.
   
2. Facelina auriculata coronata (O. F. Müller, 1776);  Sometimes known by the common name Slender Facelina or Slim Aesop. Auriculata means ear-lobe but it's unclear which feature made Müller use that name. This species seems confined to the European Coast.
   
   
3. Dendronotus frondosus (Ascanius, 1774); The Genus name means Tree Backed and the Species name means Bushy or leafy Backed so it seems that Ascanius was taken with the bountiful cerata which can be seen in Haeckel's illustration to be larger and more branched than most. The Bushy-backed nudibranch is also known as The Christmas Tree Sea Slug.
   
   
4. Okenia elegans (Leuckart, 1828); The the yellow skirt or Venus Sea Slug is a fan favorite for our Nudibranch Bikini Bottoms; this species dazzles with slender, elegant appendages. The Genus name honors Prof. Dr. Ludwig Gilbert Lorenz Oken, a German natural philosopher who published a Natural History Textbook.
   
   
5. Doto coronata (Gmelin, 1791); Doto was a Sea Nymph in Greek Mythology. The Crowned Sea Nymph is believed to only by found off the Dutch Coast. While it was previously thought to be more widely distributed, many of those specimens from around the North Atlantic have now been reclassified into no less than 9 other Doto Species.
   
   
6. Tritonia hombergii (Cuvier, 1803); Named for Triton, the son of Poseidon in Greek Mythology and Wilhelm Homberg, a 17th-18th century German-Dutch-French chemist. This is the largest of the British nudibranchs, with a maximum recorded body length of 200mm. The color varies from white to pinkish-brown. 
   
   
7. Ancula gibbosa (Risso, 1818);  A beautiful, translucent nudibranch with striking white and yellow lines; this one inspired our minimalist Nudibranch Bikini Bottom.
   

Why Haeckel Loved Nudibranchs

Haeckel’s fascination with nudibranchs stemmed from their ethereal forms and almost alien colors — he saw them as living art shaped by evolution. His intricate drawings, like this Tafel 43, helped bridge the gap between science and aesthetic beauty, making sea slugs beloved even by those who never snorkel or dive.

Fun fact: Nudibranchs have no shells and many species borrow toxins from the creatures they eat — turning them into walking chemical fortresses!

Wear a Little Haeckel History

Want to carry Haeckel’s magical nudibranchs beyond your bookshelf? We’ve turned select sea slugs from this very illustration into elegant swimwear and apparel:

• Nudibranch One-Pices Swimsuit
• Nudibranch Bikini Top
• Nudibranch Baby Tee

Every piece is made from recycled materials and designed to celebrate the timeless weirdness of these underwater jewels.

Dive Deeper

Want more ocean nerdery? Check out our Shared Artist Bio Page for a full dive into Haeckel’s life, his pioneering science, and the stories behind our other vintage marine designs.

Sources: Original artwork from Kunstformen der Natur (1904); species names and trivia cross-referenced with modern marine biology records.